AS 1418.1—2002 (Incorporating Amendment No. 1)
AS 1418.1—2002
Australian Standard™ Cranes, hoists and winches
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
Part 1: General requirements
This Australian Standard was prepared by Committee ME-005, Cranes, General. It was approved on behalf of the Council of Standards Australia on 15 February 2002. This Standard was published on 20 June 2002.
The following are represented on Committee ME-005: Association of Consulting Engineers Australia Australian Elevator Association Australian Industry Group Australian Institute for Non-destructive Testing Bureau of Steel Manufacturers of Australia Crane Industry Council of Australia Department of Administrative and Information Services (SA) Department of Industrial Relations (Qld) Department of Infrastructure, Energy and Resources (Tas) Department of Labour New Zealand Institution of Engineers Australia State Chamber of Commerce University of New South Wales Victorian WorkCover Authority WorkCover New South Wales WorkSafe Western Australia
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This Standard was issued in draft form for comment as DR 00321.
AS 1418.1—2002 (Incorporating Amendment No. 1)
Australian Standard™ Cranes, hoists and winches Part 1: General requirements
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
Originated as part of AS CB2—1938. Previous edition 1994. Fourth edition 2002. Reissued incorporating Amendment No.1 (November 2004)
COPYRIGHT © Standards Australia International All rights are reserved. No part of this work may be reproduced or copied in any form or by any means, electronic or mechanical, including photocopying, without the written permission of the publisher. Published by Standards Australia International Ltd GPO Box 5420, Sydney, NSW 2001, Australia ISBN 0 7337 4372 2
AS 1418.1—2002
2
PREFACE This Standard was prepared by the Standards Australia Committee ME-005, Cranes, to supersede AS 1418.1—1994, SAA Crane Code, Part 1: General requirements. This Standard incorporates Amendment No. 1 ( November 2004 ). The changes required by the Amendment are indicated in the text by a marginal bar and amendment number against the clause, note, table, figure or part thereof affected. The objective of this Standard is to provide uniform requirements within Australia for the design and construction of cranes and similar lifting appliances. Requirements that apply to more than one type of crane are included in Part 1: General requirements. Any requirements that apply to only one type of crane should only appear in the specific part for that crane and not in Part 1. Some requirements have been deleted from this Standard and are being moved to their applicable Part. The term ‘shall’ is used to indicate those requirements that have to be met for compliance with the objectives and intent of this Standard. The Commonwealth, State and Territory governments may choose to incorporate this Australian Standard into their laws and regulations. The exact manner of incorporation will determine whether the whole document is incorporated or whether specific sections or provisions of the Australian Standard are incorporated. The manner of incorporation will determine which of the Standard’s requirements (‘shall’ statements) have been made a legal requirement in a jurisdiction. As a general principle, where an Australian Standard is incorporated by a regulation, the legal status of the Standard’s requirements and recommendations is made clear by the incorporation of provisions of the regulation. Thus, the requirements (‘shall’ statements) in an Australian Standard are not mandatory for legal purposes unless incorporated specifically by an Act or regulation. Readers will need to refer to their jurisdiction’s law to determine which parts of the Australian Standard (if any) have been incorporated and the manner of incorporation. This Standard deviates from ISO 11660.1 in regard to access requirements for safety reasons.
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This revision includes the following changes: (a)
The maximum temperature of touchable surfaces is now 55°C.
(b)
The term ‘safe working load’ has been changed to ‘rated capacity’ and other uses of the word ‘safe’ have been avoided due to the legal significance placed on the word.
(c)
Reference to approval by the relevant authority has been removed to reflect the current regulatory environment.
(d)
Tear-out/tear-off forces for cranes equipped with magnets or grabs have to be taken into consideration.
(e)
There is a new method of calculating the hoisting factor (φ 2), which is taken from DIN 15018.
(f)
Out-of-service wind loads are now considered additional loads instead of special loads.
(g)
Transport loads have to be taken into consideration where the crane is transported during its life.
(h)
The design of monorail beams has been moved to a new Part 18: Runways and monorails.
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AS 1418.1—2002
(i)
The factor of safety against drifting during operation has changed to 1.5.
(j)
The design life of mechanisms may be less than 10 years provided this is documented.
(k)
In determining the group classification of mechanisms, an adjustment to an equivalent number of running hours is allowed after the load spectrum factor has been set.
(l)
Requirements for gearing have been expanded.
(m)
Requirements for hoisting, travel, and traverse motion brakes have been expanded.
(n)
A minimum worn wheel flange thickness has been defined.
(o)
Hookbolts used for rail fastening are required to be ductile.
(p)
Detachable parts are required to be designed for safe assembly and disassembly.
(q)
The attachment of hooks directly attached to structural members is required to be designed such that no bending moment is experienced by the hook shank.
(r)
Some requirements for counterweights have been added.
(s)
Requirements for controllers have been revised.
(t)
Requirements for limit switches have been revised.
(u)
Motor protection requirements have been revised.
(v)
Mention is made of electromagnetic compatibility (EMC) and phase sequence protection.
(w)
Extra requirements for cranes with lifting magnets have been added.
(x)
Emergency egress requirements have been revised.
(y)
Requirements for installation of cranes in hazardous areas have been revised to interface with recently revised applicable Standards.
(z)
Requirements for operators and maintenance manuals have been added.
Questions concerning the meaning, the application, or effect of any part of this Standard, may be referred to the Standards Australia Committee on Cranes. The authority of the Committee is limited to matters of interpretations and it will not adjudicate in disputes.
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Statements expressed in mandatory terms in notes to tables and figures are deemed to be requirements of this Standard. The terms ‘normative’ and ‘informative’ have been used in this Standard to define the application of the appendix to which they apply. A ‘normative’ appendix is an integral part of a Standard, whereas an ‘informative’ appendix is only for information and guidance.
AS 1418.1—2002
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CONTENTS Page FOREWORD.............................................................................................................................. 8 SECTION 1 SCOPE AND GENERAL 1.1 NEW DESIGNS, INNOVATIONS AND DESIGN METHODS ................................. 9 1.2 REFERENCED DOCUMENTS .................................................................................. 9 1.3 DEFINITIONS ............................................................................................................ 9 1.4 NOTATION .............................................................................................................. 10 1.5 CONTACT SURFACE TEMPERATURE................................................................. 10 SECTION 2 CLASSIFICATION OF CRANES 2.1 SCOPE OF SECTION ............................................................................................... 11 2.2 GENERAL ................................................................................................................ 11 2.3 GROUP CLASSIFICATION ..................................................................................... 12 SECTION 3 MATERIALS FOR CRANES 3.1 SCOPE OF SECTION ............................................................................................... 15 3.2 MATERIAL SPECIFICATIONS............................................................................... 15
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SECTION 4 CRANE LOADS 4.1 SCOPE OF SECTION ............................................................................................... 16 4.2 REFERENCE TO OTHER PARTS OF THIS STANDARD...................................... 16 4.3 DETERMINATION OF CRANE LOADS ................................................................ 16 4.4 CATEGORIZATION OF CRANE LOADS............................................................... 16 4.5 PRINCIPAL LOADS................................................................................................. 17 4.6 ADDITIONAL LOADS ............................................................................................ 25 4.7 SPECIAL LOADS..................................................................................................... 28 4.8 PRINCIPLES FOR DETERMINATION OF CRANE LOAD COMBINATIONS..... 30 SECTION 5 DESIGN OF CRANE STRUCTURE 5.1 GENERAL ................................................................................................................ 33 5.2 BASIS OF DESIGN .................................................................................................. 33 5.3 DESIGN OBJECTIVE............................................................................................... 35 5.4 METHOD OF DESIGN............................................................................................. 35 5.5 FATIGUE STRENGTH............................................................................................. 35 5.6 DESIGN FOR SERVICEABILITY DEFLECTION AND VIBRATION .................. 36 SECTION 6 STABILITY 6.1 SCOPE OF SECTION ............................................................................................... 37 6.2 OVERTURNING....................................................................................................... 37 6.3 STABILITY DURING ERECTION AND MAINTENANCE ................................... 37 6.4 SAFETY AGAINST DRIFTING............................................................................... 37 SECTION 7 CRANE MECHANISMS 7.1 GENERAL ................................................................................................................ 39 7.2 MECHANISMS......................................................................................................... 39 7.3 BASIS OF DESIGN .................................................................................................. 39 7.4 MECHANISM LOADINGS ...................................................................................... 42 7.5 PRINCIPAL LOADS................................................................................................. 43 7.6 ADDITIONAL LOADS ............................................................................................ 45
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7.7 7.8 7.9 7.10 7.11 7.12 7.13 7.14 7.15 7.16 7.17 7.18 7.19 7.20 7.21 7.22 7.23 7.24
AS 1418.1—2002
Page SPECIAL LOADS..................................................................................................... 45 CATEGORIZATION OF FREQUENCY OF MECHANISM LOAD COMBINATIONS..................................................................................................... 46 PRINCIPLES FOR DETERMINING MECHANISM LOAD COMBINATIONS ..... 46 MECHANICAL COMPONENTS ............................................................................. 51 DRIVING MEDIA .................................................................................................... 53 BRAKING................................................................................................................. 53 MOTION LIMITS, INDICATORS AND WARNING DEVICES ............................. 57 ROPES AND REEVED SYSTEMS .......................................................................... 58 GUYS, OTHER FIXED-ROPE SYSTEMS, AND STATIONARY ROPES ............... 58 REEVED SYSTEMS................................................................................................. 59 SHEAVES ................................................................................................................. 62 DRUM AND SHEAVE DIAMETERS ...................................................................... 62 DRUMS..................................................................................................................... 63 WHEEL AND RAIL SYSTEMS ............................................................................... 66 GUIDES FOR MOVING PARTS.............................................................................. 83 DETACHABLE PARTS............................................................................................ 83 DIRECTLY FITTED HOOKS................................................................................... 83 COUNTERWEIGHTS............................................................................................... 83
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SECTION 8 ELECTRICAL EQUIPMENT AND CONTROLS 8.1 SCOPE OF SECTION ............................................................................................... 84 8.2 MATERIALS AND EQUIPMENT............................................................................ 84 8.3 INFORMATION RELEVANT TO DESIGN OF ELECTRICAL SYSTEM.............. 84 8.4 MOTORS .................................................................................................................. 85 8.5 MOTOR CONTROL ................................................................................................. 85 8.6 CONTACTORS......................................................................................................... 86 8.7 CONTROLLERS (see also Section 11) ..................................................................... 87 8.8 LIMIT SWITCHES (see also Clause 7.13) ................................................................ 93 8.9 CONTROL CIRCUITS.............................................................................................. 95 8.10 ELECTRICAL ISOLATION ..................................................................................... 96 8.11 ELECTRICAL PROTECTION................................................................................ 101 8.12 HIGH-VOLTAGE SUPPLY TO CRANES ............................................................. 104 8.13 CRANES WITH MAGNET ATTACHMENTS....................................................... 104 8.14 WIRING AND CONDUCTORS ............................................................................. 108 8.15 ACCESSIBILITY.................................................................................................... 111 8.16 ELECTRICAL EQUIPMENT MARKING AND INSTALLATION DIAGRAMS.. 111 SECTION 9 HYDRAULIC EQUIPMENT AND CONTROLS 9.1 SCOPE OF SECTION ............................................................................................. 112 9.2 MATERIALS .......................................................................................................... 112 9.3 BASIS OF DESIGN ................................................................................................ 112 9.4 CIRCUIT DIAGRAM ............................................................................................. 113 9.5 COMPONENTS ...................................................................................................... 113 9.6 INSTALLATION .................................................................................................... 115 9.7 TESTING ................................................................................................................ 115 9.8 MARKING .............................................................................................................. 115 9.9 INSPECTION AND MAINTENANCE ................................................................... 115 SECTION 10 PNEUMATIC EQUIPMENT AND CONTROLS 10.1 SCOPE OF SECTION ............................................................................................. 116 10.2 MATERIALS .......................................................................................................... 116 10.3 BASIS OF DESIGN ................................................................................................ 116 10.4 CIRCUIT DIAGRAM ............................................................................................. 117
AS 1418.1—2002
10.5 10.6 10.7 10.8 10.9
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Page COMPONENTS ...................................................................................................... 117 INSTALLATION .................................................................................................... 118 TESTING ................................................................................................................ 118 MARKING .............................................................................................................. 118 INSPECTION AND MAINTENANCE ................................................................... 118
SECTION 11 OPERATIONAL DESIGN 11.1 SCOPE OF SECTION ............................................................................................. 119 11.2 CONTROL CABIN ................................................................................................. 119 11.3 PENDENT CONTROL STATIONS AND PENDENT CORDS .............................. 121 11.4 OPERATOR CONTROLS AND INDICATORS..................................................... 122 11.5 WARNING DEVICES ............................................................................................ 122 SECTION 12 MANUFACTURE AND CONSTRUCTION 12.1 SCOPE OF SECTION ............................................................................................. 123 12.2 MATERIALS .......................................................................................................... 123 12.3 FABRICATION AND ASSEMBLY ....................................................................... 123 12.4 REWORK................................................................................................................ 123 12.5 FINISH .................................................................................................................... 123 12.6 DRAINING ............................................................................................................. 123 12.7 ACCESS AND CLEARANCES .............................................................................. 123 12.8 REPAIRS................................................................................................................. 124
A1
SECTION 13 INSPECTION AND TESTING 13.1 SCOPE OF SECTION ............................................................................................. 125 13.2 INSPECTION .......................................................................................................... 125 13.3 TESTING ................................................................................................................ 125 13.4 COMMISSIONING................................................................................................. 125 SECTION 14 MARKING 14.1 SCOPE OF SECTION ............................................................................................. 126 14.2 MARKING .............................................................................................................. 126
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SECTION 15 OPERATING ENVIRONMENT 15.1 GENERAL .............................................................................................................. 127 15.2 INDOOR INSTALLATION .................................................................................... 127 15.3 OUTDOOR INSTALLATION ................................................................................ 128 15.4 HAZARDOUS AREAS ........................................................................................... 128 SECTION 16 MANUALS 16.1 GENERAL .............................................................................................................. 129 16.2 CRANE OPERATOR’S MANUAL......................................................................... 129 16.3 MAINTENANCE MANUAL .................................................................................. 129 16.4 SERVICE RECORD (LOGBOOK) ......................................................................... 130 16.5 PARTS BOOK ........................................................................................................ 130 APPENDICES A ORGANIZATION OF AUSTRALIAN STANDARD FOR CRANES .................... 131 B LIST OF REFERENCED STANDARDS AND STANDARDS FOR REFERENCE136 C FAILURE TO SAFETY (FAIL-SAFE SYSTEMS)................................................. 140 D TYPICAL CRANE APPLICATION CLASSIFICATION ....................................... 142 E OBLIQUE TRAVEL FORCES—DETAILED ANALYSIS .................................... 144 F FATIGUE DESIGN OF MECHANISMS ................................................................ 148 G REEVED SYSTEMS—ALLOWANCE FOR FRICTIONAL EFFECTS ................. 150
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H I J K L M
AS 1418.1—2002
Page EXAMPLES OF WIRE ROPE SELECTION .......................................................... 152 ROPE ANCHORAGE POINT LOCATION............................................................. 153 GROOVE PROFILES FOR WIRE ROPE SHEAVES ............................................. 154 GROOVE PROFILES FOR ROPE DRUMS ........................................................... 157 THEORETICAL THICKNESS OF HOIST DRUM................................................. 158 RELATED STANDARDS ....................................................................................... 172
AS 1418.1—2002
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FOREWORD This Standard is an authoritative source of fundamental principles for application by responsible and competent persons and organizations. It has no legal authority in its own right but it may acquire legal standing in one or more of the following ways: (a)
Adoption by a regulatory authority.
(b)
Reference to compliance with the Standard as a contractual requirement.
(c)
Claim, by a manufacturer or manufacturer’s agent (or both), of compliance with the Standard.
This Standard has been prepared bearing in mind that it will be used by a number of different categories of users, with entirely different objectives. Essentially, the users of this Standard are— (i)
crane and hoist manufacturers, importers and agents;
(ii)
crane and hoist owners;
(iii) crane and hoist users and operators; and (iv)
regulatory and legal authorities.
Crane and hoist manufacturers, importers and agents require acceptable data that can be used in the design, manufacture, testing and acceptance inspection of cranes and hoists for both general and particular applications. Crane and hoist owners require data for specification and selection of cranes and hoists. In this situation, applications can be more specific. Crane and hoist users and operators require statements of their responsibilities in the safe use of equipment. Regulatory and legal authorities look to Standards as a framework on which regulations, directives and other legislation can be based. Further legal aspects of crane Standards must be recognized because they may also be utilized as measures of legal responsibility.
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This Standard references the alternative limit states design method in addition to the working stress design method. A general requirement for safety is that, upon the occurrence of a high risk condition, a safety device or system (or both) should halt the condition or revert the crane to a non-dangerous condition. Depending on the risk assessment of the application, it may be necessary to exceed the minimum safety requirements described herein. Where personnel are being conveyed, this principle is modified in one of the following ways: (A)
a fail-safe design, allowing for the simultaneous malfunction of two items, may be required.
(B)
The operator in control is at personal risk.
(C)
An increased factor of safety is applied.
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AS 1418.1—2002
STANDARDS AUSTRALIA Australian Standard Cranes, hoists and winches Part 1: General requirements
SECT ION
1
SCOPE
AND
GENERA L
1.1 SCOPE This Standard specifies the general requirements for cranes, hoists, winches, and their components, and appliances intended to carry out similar functions, as defined in AS 2549. It does not include powered industrial trucks as defined in AS 2359. The term ‘crane’ used herein applies to a crane, hoist or winch as appropriate. NOTES: 1
Specific requirements for particular types of cranes and associated equipment are specified in other parts of AS 1418; these requirements take precedence over corresponding requirements in this Standard where any difference exists. Appendix A outlines the structure of the AS 1418 series of Standards.
2
Requirements for the selection, operation and maintenance of cranes are given in the appropriate part of AS 2550.
1.2 NEW DESIGNS, INNOVATIONS AND DESIGN METHODS This Standard does not preclude the use of materials, designs, methods of assembly, procedures, and the like, that do not comply with a specific requirement of this Standard, or are not mentioned in it, but which can be shown to give equivalent or superior results to those specified.
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A1
Where the limit states design method is used, cranes shall be designed to give a degree of safety not less than that given in this Standard by the working stress design method for strength, buckling, deflection, torsion, fatigue and the like. NOTE: This Standard does not provide specific guidance on the limit state design methods, as the necessary dynamic factors have not been formulated for the complex forces cranes are subjected to. This is a worldwide situation and ISO has established a working group specifically to resolve the issue. Design of structural members by limit state methods, including determination of the partial load factors for individual loads, should comply with the appropriate Australian Standard, e.g., AS 1664.1 for aluminium members and AS 4100 for steel members.
1.3 REFERENCED DOCUMENTS A list of the documents referred to in this Standard is given in Appendix B. 1.4 DEFINITIONS For the purpose of this Standard, the definitions given in AS 2549 and below apply. 1.4.1 Classification The system used to provide a means of establishing a rational basis for the design of structures and machinery. It also serves as a framework of reference between the purchasers and the manufacturers, by the use of which a particular crane may be matched to the service for which it is required. www.standards.com.au
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NOTE: Classification considers only the conditions of operation for the intended life of the crane. These are independent of the type of crane and the way it is operated.
1.4.2 Competent person A person who has acquired through training, qualification, experience or a combination of these, the knowledge and skill enabling that person to correctly perform the required task. 1.4.3 Controlled stop The stopping of a machine motion in a controlled manner, which limits the deceleration to significantly less than the deceleration experienced in a sudden uncontrolled stop. NOTE: An example of one method is to reduce the electrical command signal to zero once the stop signal has been recognized by the control and retain electrical power to the hoisting machine actuators during the stopping process.
1.4.4 Fail-safe A state or condition whereby if the fail-safe component fails, a system exists to prevent any increase of the assessed risk associated with the device. NOTE: Information regarding fail-safe systems is given in Appendix C.
1.4.5 May Indicates the existence of an allowable option. NOTE: Neither inclusion nor exclusion of the option results in non-compliance with the Standard.
1.4.6 Shall Indicates that compliance with a statement is mandatory for compliance with the objectives and intent of his Standard (see Preface). 1.4.7 Should Indicates a recommendation. Neither following nor ignoring the recommendation results in non-compliance with the Standard. 1.4.8 Rated capacity The maximum gross load which may be applied to the crane or hoist or lifting attachment while in a particular working configuration and under a particular condition of use. 1.4.9 Uncontrolled stop
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The stopping of a motion by removing power to the machine actuators, all brakes and/or other mechanical stopping devices being actuated. 1.5 NOTATION Symbols used in equations in this Standard are defined in relation to the particular equation in which they occur. 1.6 CONTACT SURFACE TEMPERATURE Surfaces with temperatures exceeding 55°C, which may cause pain by contact with human skin, shall be protected over all areas that can be touched during normal operation, daily maintenance and assembly/erection, such that the touchable surfaces are below 55°C. Except where surface temperatures can be increased by solar radiation, surfaces on which the temperature exceeds 55°C shall be located more than 300 mm from hand-related access points.
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SECT ION
2
C L ASS I F I C AT I ON
AS 1418.1—2002
O F
CRANES
2.1 SCOPE OF SECTION This Section specifies the classification of a crane (see Clause 1.1) based on the maximum number of in-service cycles to be carried out during the intended life of the crane and a load spectrum. Other parts of AS 1418 define which parts of the classification range are applicable to the various types of cranes. NOTES: A1
1
See Clause 1.4.1 for a definition of classification.
2
The C classification relates to the duty (i.e. load spectrum and number of operating cycles) of the crane as a whole and is intended for contractual and technical reference purposes (see Clause 2.3).
3
The purpose of the ‘S’ and ‘M’ classification is to provide a basis for the load determination and fatigue analysis of the individual structural and mechanical components (see Sections 5 and 7, respectively). The designer takes the estimated load spectrum and the number of load applications to determine the group class of the crane.
4
Cranes for specific applications may require minimum classifications as specified elsewhere in this Standard, or other parts of AS 1418.
2.2 GENERAL The classification of the crane and its constituent parts shall be as follows: (a)
Group classification Overall classification of the crane based on the number and magnitude of operating cycles the crane will be expected to see during its design life (see Clause 2.3.2).
(b)
Structural classification Classification of each part of the crane structure based on the number and magnitude of the load cycles which that part of the structure will see during the design life of the crane (see Clause 5.2.2).
(c)
Mechanical classification Classification of each of the mechanical components of the crane based on the expected magnitude of the applied load and the number of operating hours, at the load, for the design life of the crane (see Clause 7.3.4).
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Unless otherwise specified in the applicable part of AS 1418, the required design life of any crane and its constituent parts shall be as follows: (i)
Structures .................................................................................................... 25 years.
(ii)
Mechanical components............................................................................... 10 years.
For cranes designed for special applications, the design life may be less than that specified in Items (i) and (ii) above, provided that— (A)
the structural and mechanical components of the crane have been designed for a specific task of short duration with no intention of redeployment;
(B)
the design life and design classification of the components are marked on the components and crane;
(C)
the intended service conditions are well defined in writing by the designer; and
(D)
the crane is used in accordance with the designer’s instructions and actual service conditions are monitored and recorded in accordance with AS 2550.1.
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2.3 GROUP CLASSIFICATION 2.3.1 Bases of classification The group classification of the crane shall be determined from the class of utilization (see Clause 2.3.2) and the load spectrum (see Clause 2.3.3) where relevant data is available or selected from typical crane applications in Appendix D. 2.3.2 Class of utilization The maximum number of in-service cycles expected from the crane during its intended life shall be the first basic parameter of classification. The range of classes of utilization are divided into 10 categories, as shown in Table 2.3.2. TABLE 2.3.2 CLASSES OF UTILIZATION OF CRANES Maximum number of operating cycles
Classes of utilization
Description of use
× 104
U0
× 10
4
U1
× 10
4
U2
× 10
5
U3
× 10
5
U4
Fairly frequent use
5
× 10
5
U5
Frequent use
1
× 106
U6
Very frequent use
× 10
6
U7
Continuous or near-continuous use
× 10
6
U8
1.6 3.2 6.3 1.25 2.5
2 4
Greater than 4 × 106
Infrequent use
U9
2.3.3 Load spectrum
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The second basic parameter of classification is the load spectrum, which is concerned with the number of times a load of a particular magnitude, in relation to the capacity of the crane, is hoisted. The four nominal values of load spectrum factor (Kp) shall be as shown in Table 2.3.3 and illustrated in Figure 2.3.3, each numerically representative of a corresponding nominal state of loading. The load spectrum factor for the crane (Kp) is given by the following equation: P Ci i K p = ∑ C T Pmax
3
. . . 2.3.3
where Ci
= number of load cycles that occur at the individual load levels = C 1 , C2 , C 3, ..., C n
CT
= total of all the individual load cycles at all load levels = ΣC i = C 1 + C 2 + C 3 + ... + C n
Pi
Standards Australia
= individual load magnitudes (load levels) characteristic of the duty of the crane www.standards.com.au
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AS 1418.1—2002
= P 1 , P2 , P3 , ... P n P max = rated capacity NOTE: A load cycle accounts for all motions of the crane when operated between an unloaded state through to loaded state and returns to its unloaded state.
The nominal load spectrum factor for the crane shall be established by matching the calculated load spectrum factor to the closest (higher) nominal value of K p in Table 2.3.3.
NOTE: t1, t2, t3 and t∆ are time increments expressed as a percentage of design life.
FIGURE 2.3.3 TYPICAL LOAD SPECTRA
TABLE 2.3.3 NOMINAL LOAD SPECTRUM FACTOR AND STATE OF LOADING FOR CRANES
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Nominal load spectrum factor (Kp )
State of loading
Description of use
0.125
Q1—Light
Cranes that hoist the rated capacity very rarely and, normally, very light loads
0.25
Q2—Moderate
Cranes that hoist the rated capacity fairly frequently and, normally, light loads
0.50
Q3—Heavy
Cranes that hoist the rated capacity frequently and, normally, medium loads
1.00
Q4—Very heavy
Cranes that are frequently loaded close to the rated capacity
2.3.4 Group classification The group classification for the various combinations of classes of utilization and state of loading shall be as given in Table 2.3.4. NOTE: The application of group classification to specific types of cranes is covered in the appropriate parts of AS 1418.
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14
TABLE 2.3.4 GROUP CLASSIFICATION OF CRANES
State of loading
Nominal load spectrum factor (Kp )
Group classification of crane Classes of utilization U0
U1
U2
U3
U4
U5
U6
U7
U8
U9
0.125
C1
C1
C1
C2
C3
C4
C5
C6
C7
C8
Q2—Moderate
0.25
C1
C1
C2
C3
C4
C5
C6
C7
C8
C8
Q3—Heavy
0.50
C1
C2
C3
C4
C5
C6
C7
C8
C8
C9
Q4—Very heavy
1.00
C2
C3
C4
C5
C6
C7
C8
C8
C9
C9
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Q1—Light
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SEC T I O N
3
MA T E R I A L S
AS 1418.1—2002
F OR
CRA N E S
3.1 SCOPE OF SECTION This Section specifies requirements for materials used in the manufacture of cranes (see Clause 1.1). 3.2 MATERIAL SPECIFICATIONS Where applicable, materials shall comply with the relevant Australian Standard specifications. Where the properties of any material are in doubt, the material shall be subjected to sufficient testing in order to determine the properties concerned.
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NOTE: Refer to specific parts of AS 1418 for material Standards applicable to a particular crane type.
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Standards Australia
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S E C T I O N
4
CRA N E
L O A D S
4.1 SCOPE OF SECTION This Section specifies the requirements for the determination of loads and load combinations to be used in the design of crane structures (see Clause 1.1). 4.2 REFERENCE TO OTHER PARTS OF THIS STANDARD The determination of loads in this Section shall be supplemented by the requirements of the other relevant parts of this Standard. 4.3 DETERMINATION OF CRANE LOADS Determination of crane loads shall include all loads resulting from the intended crane operation, and loads caused by the environment, erection, testing and fault conditions. Steady-state loads, such as gravity-induced loads, shall be determined from the masses of all component parts permanently attached to the crane. Live loads induced on in-service cabin floor walkways and platforms shall be determined in accordance with the provisions of this Standard and the referenced Standards including AS 1170.1. Dynamic loads due to acceleration or deceleration of masses shall be determined by either— (a)
dynamic analysis capable of modelling the characteristics of the crane operations; or
(b)
methods of determination of loads specified in this Section.
4.4 CATEGORIZATION OF CRANE LOADS For convenience of referencing, the crane loads are divided into three load groups as follows: (a)
Principal loads (see Clause 4.5).
(b)
Additional loads (see Clause 4.6).
(c)
Special loads (see Clause 4.7).
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Each load group is divided into load types as shown in Table 4.4.
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TABLE 4.4 CATEGORIZATION OF CRANE LOADS Load group
Load
Reference Clause
Principal loads (see Clause 4.5)
Dead loads Hoisted loads Inertia loads Displacement-induced loads
4.5.2 4.5.3 4.5.4 4.5.5
Additional loads (see Clause 4.6)
In-service and out-of-service wind loads Snow and ice loads Temperature-induced forces Oblique travelling forces Bulk material loads
4.6.2 4.6.3 4.6.4 4.6.5 4.6.6
Special loads (See Clause 4.7)
Off-vertical hoisting loads Test loads Buffer impact forces Tilting forces Live loads on walkways and in chutes, etc Loads due to emergency condition Seismic loads Loads during erection Loads during transport
4.7.2 4.7.3 4.7.4 4.7.5 4.7.6 4.7.7 4.7.8 4.7.9 4.7.10
4.5 PRINCIPAL LOADS 4.5.1 General Principal loads comprise the mass of the crane and highly repetitive loads arising from the intended service of the crane. 4.5.2 Dead loads 4.5.2.1 Dead load dynamic factor The loads due to the mass of the crane in operation shall be given by the following equation: P = W φ1 w
. . . 4.5.2.1
where
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P w = factored deadweight load W
= gravitational force induced by the mass of the crane.
φ1
= dynamic factor for the mass of the crane subject to inertial forces and vibrations
The upper bound value of φ 1 shall be as given in Table 4.5.2.1 unless a more accurate determination is made by using an appropriate dynamic analysis. The lower bound value of φ 1 shall be taken as 1.0, except where the vibration of the stabilizing part of the crane structure reduces the resistance to overturning. In such case, the lower bound value of φ 1 shall be taken as 0.9.
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TABLE 4.5.2.1 APPLICATION OF DYNAMIC Factor (φ 1) 1
2
3
4
5
6
7
Dynamic factor (φ 1) Type of runway
Steel rails or beams
Concrete
Roadway or flexible pavement
Condition of runway
Wheel type
Suspension type
Travel velocity, m/s ≤1.0
>1.0 ≤1.5
>1.5
Smooth Steel welded continuously
Unsprung
1.1
1.1
1.2
Sprung
1.1
1.1
1.1
Joints ≤4 mm wide
Unsprung
1.1
1.2
1.2
Sprung
1.1
1.1
1.1
Steel
Smooth no joints
Rubber
Sprung
1.1
1.1
1.1
Jointed
Rubber
Sprung
1.2
1.2
1.25
Rubber
Sprung
1.1
1.1
1.15
Crawler tracks
Sprung
1.1
1.2
1.25
—
NOTES: 1
Do not interpolate, use nearest higher value for φ 1 .
2
It is assumed that the rail joints are in good condition. The detrimental effect on hoisting appliances of rail tracks in poor condition is so great, both for the structure and the machinery, that it is necessary to stipulate that the rail joints must be maintained in good condition: no shock loading coefficient can allow for the damage caused by faulty joints. In so far as high speed appliances are concerned, the best solution is to butt-weld the rails, in order to eliminate entirely the shock loadings that occur when an appliance runs over joints.
4.5.3 Hoisted load 4.5.3.1 Description
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The hoisted load shall include the rated capacity together with the weight of the hook and hook block, full length of hoist cable, and any devices attached to the hook block for the purpose of grappling the hoisted load. Where hoists are equipped with magnets or grabs, allowances shall be made in selecting the hoist’s capacity to account for tear-off or tear-out forces respectively. A tear-out force is equal to the weight of the load plus additional forces applied as a result of removing the load from the heap. 4.5.3.2 Hoisting operations to be considered The basic hoisting operations covered in this Section are the following: (a)
Hoisting a load from rest The effects of the hoisted load shall be determined by the following equation: Phd = Ph φ 2
. . . 4.5.3.2(1)
where P hd = factored hoisted load P h = hoisted load as specified in Clause 4.5.3.1 φ2 Standards Australia
= hoisted load dynamic factor for hoisting as given in Clause 4.5.3.3. www.standards.com.au
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Rapid releasing of a part of the hoisted load Where the intended operation requires rapid releasing of the hoisted load, the effect of rapid release shall be determined by the following equation: Prd = (Ph − Pr ) φ 3
. . . 4.5.3.2(2)
where P rd = the peak intensity of the loads acting on the hoist as a result of the rapid releasing Ph
= hoisted load as specified in Clause 4.5.3.1
Pr
= the upper estimate of the part of the load being released
φ3
= rapid load release dynamic factor for rapid load release as given in Clause 4.5.3.4.
4.5.3.3 Hoisted load dynamic factor (φ 2 ) The value of the dynamic factor for hoisting (φ2) depends on the hoisting velocity (ν h), and the hoisting application group as determined by Table 4.5.3.3(A). The dynamic factor (φ 2) shall be taken from Table 4.5.3.3(B), except where a more appropriate or more accurate determination has been carried out using a dynamic analysis or by certified tests. Where the hoist drive control system automatically selects the steady creep speed at the start of hoisting, such speed shall be used for the determination of the dynamic factor (φ 2). Where the hoist drive is equipped with a stepless variable speed control, the value of the dynamic factor (φ 2) shall be determined for a hoisting velocity of not less than 0.5 times the nominal speed for the unloaded hoist drive. TABLE 4.5.3.3(A) HOISTING APPLICATION GROUP FOR CRANES
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1
2
3
4
5
Fundamental natural frequency of structure (vertical plane) Hz
Hoisting application group
≤0.2
>0.2 to ≤0.4
>0.4 to ≤0.6
>0.6
≤3.2
H1
H1
H2
H3
>3.2 ≤5.0
H1
H2
H2
H3 to H4
>5.0
H2
H2
H3
H4
Hoisting acceleration m/s 2
NOTE: For hoisting accelerations/decelerations greater than 0.6 m/s2 analysis of inertial effects in accordance with Clause 4.5.4 should be considered.
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TABLE 4.5.3.3(B) HOISTING FACTORS φ 2 Hoisting application group H1 H2 H3 H4
νh ≤1.5 1.1 1.2 1.3 1.4
+ + + +
0.13ν h 0.27ν h 0.40ν h 0.53ν h
νh >1.5 1.3 1.6 1.9 2.2
LEGEND: ν h = the nominal speed related to the lifting attachment, derived from the steady rotational speed of the unloaded drive, in metres per second
Where two or more hoists are installed, the dynamic factor (φ 2) shall be applied as follows: (a)
Where the two hoists are designed not to operate simultaneously, the appropriate factor shall be applied to one drive at a time taking into account that drive’s hoisting speed. The other hoist drive shall be considered to be stationary.
(b)
Where the hoists are designed to operate simultaneously, the appropriate factor shall be applied to each hoist in accordance with its hoisting speed.
4.5.3.4 Rapid load release dynamic factor (φ 3 ) (see Figure 4.5.3.4.) The value of φ 3 is given by the following equation: φ 3 = 1 − 1.5 ×
∆W W
for hoisting appliances in the form of grabs; or
φ 3 = 1 − 2. 0 ×
∆W W
for hoisting appliances using magnetic holding devices
where ∆W = released mass = mass of the hoisted load including the load to be released
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W
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FIGURE 4.5.3.4 DYNAMIC FACTOR (φ 3)
4.5.4 Inertia loads 4.5.4.1 General The designer shall determine the inertia forces induced by acceleration, braking and the travel, slewing and luffing drives. 4.5.4.2 Methods of determination of inertia loads The loads due to acceleration of drives shall be determined by one of the following methods: (a)
Simple method of determination based on upper bounds of parameters for drives relying on frictional transfer of the reactive forces. The procedure shall be as given in Clause 4.5.4.3.
(b)
An appropriate method of dynamic analysis for any type of load transfer.
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4.5.4.3 Simplified method of determination of traction forces Where the maximum traction forces are limited by friction, the traction forces shall be determined from the friction between the driven wheels and the runway. To eliminate wheel slip, drives shall be selected so that the maximum traction force does not exceed the minimum frictional force between the driven wheel and the rail. For travel and traverse motions, the maximum traction forces may be determined by the following equations: (a)
For independent drives: TR = N S φ 4 µPwij
. . . 4.5.4.3(1)
NOTE: This equation assumes matched power and rating of motors on each driven wheel.
(b)
For synchronized drive: TR =φ4 µ
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Nt Pw i j j =1 i =1 Ns
∑∑
. . . 4.5.4.3(2)
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where TR
= resultant of the traction forces
Ns
= number of drives—for independent drives = number of driven pairs of wheels—for synchronized drive(s)
φ4
= dynamic factor
µ
= coefficient of friction
P wij
= minimum driven wheel load (see below)
i
= runway number, e.g., 1 = left runway, 2 = right runway (see below)
j
= number of the wheel pair Ns
∑ (P j=1
w1 j
+ P w 2 j ) = minimum sum of the driven wheel loads
The value of φ 4 shall be determined as follows: (i)
φ4 = 1
for centrifugal forces;
(ii)
1 φ 4 ≤1.5
for drives with no backlash or in cases where existing backlash does not affect the dynamic forces and with smooth change of forces;
(iii)
1.5 φ 4 ≤2
for drives with no backlash or in cases where existing backlash does not affect the dynamic forces and with sudden change of forces;
(iv)
φ4 = 3
for drives with considerable backlash, if not estimated accurately by using a spring-mass model.
Where a force that can be transmitted is limited by friction or by the nature of the drives mechanism, the limited force and a factor φ 4 appropriate to that system shall be used. For steel wheels on steel rails, the nominal coefficient of friction (µ) shall be taken as 0.20, unless a more accurate determination has been made. The minimum driven wheel loads of the unladen crane shall be used to calculate the maximum traction forces.
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4.5.4.4 Application of traction forces The traction forces shall be applied to the loaded crane and shall be in accordance with the drive type and the driving system of the crane as illustrated in Figures 4.5.4.4(A) and 4.5.4.4(B). The effect of eccentricity of the resultant traction forces to the centre of mass of the driven system shall be considered. (a)
Acceleration due to cross-travel drives The reactive loads (P HC) from Table 4.5.4.4(A) due to the traction force of the crab (Pc) shall be transmitted to the runway through all travel wheels equally (see Figure 4.5.4.4(A)). Horizontal forces due to inertial forces for cranes with more than two wheels per runway side shall be equally shared by all wheels.
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FIGURE 4.5.4.4(A) ACCELERATION LOADS DUE TO CROSS-TRAVEL DRIVES
TABLE 4.5.4.4(A) LATERAL LOADS DUE TO ACCELERATION FROM CROSS-TRAVEL DRIVES Lateral fixity of crane wheels
Lateral loads P HC11
P HC12
P HC21
P HC22
All wheels laterally fixed
Pc 4
Pc 4
Pc 4
Pc 4
Wheels on only one side laterally fixed
Pc 2
Pc 2
0
0
NOTES: 1
This Table is for four-wheel cranes only; however, similar principles apply for other travel systems.
2
A laterally fixed wheel is a flanged wheel with laterally fixed bearings or side-guide rollers.
(b)
Acceleration due to long-travel drives For the travel drive system illustrated in Figure 4.5.4.4(B), the drive forces (P HT ) are assumed to be distributed equally to the driven wheels. The resulting lateral force (P HB ) due to the eccentricity (ls) of the centre of the drive force with respect to the centre of mass is assumed to be distributed equally to the applicable travel wheels. The moment shall be calculated from the following equation and the forces from Table 4.5.4.4(B): M E = l s TR
. . . 4.5.4.4
where M E = moment due to eccentricity of drive forces ls
= maximum eccentricity of the point of application of the drive force with respect to the centre of mass of the crane including the rated capacity
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T R = resultant of the traction forces P HT1 and P HT2 in Figure 4.5.4.4(B) The effect of acceleration of long travel drives shall be taken into account in designing the crane.
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FIGURE 4.5.4.4(B) ACCELERATION LOADS DUE TO LONG-TRAVEL DRIVES
TABLE 4.5.4.4(B) LATERAL LOADS DUE TO ACCELERATION FROM LONG-TRAVEL DRIVES Long travel drive system
Lateral loads P HB11
P HB21
P HB12
All wheels laterally fixed
ME 2S G
ME 2SG
−
ME 2SG
Wheels on only one side laterally fixed
ME SG
0
−
ME SG
P HB22 ME 2SG
−
0
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NOTES: 1
For a four-wheel crane, SG equals the distance between the means of lateral guidance.
2
For cranes with more than four wheels, S G equals the bogie pivot centre distance (see Figure 4.5.4.4(C)).
3
A laterally fixed wheel is a flanged wheel with laterally fixed bearings or side-guide rollers.
FIGURE 4.5.4.4(C) DISTRIBUTION OF HORIZONTAL FORCES
4.5.4.5 Determination of loads due to slewing and luffing motions The determination of loads due to slewing and luffing motions shall be as follows: (a)
Loads due to the acceleration of slewing drives shall be determined by an appropriate method of dynamic analysis.
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The centrifugal forces acting on slewing cranes shall be from the dead load of the boom components, the counterweight, where used, and the hoisted load without applying the dynamic factor and assuming the hoisted load to be positioned at the tip of the jib or boom. (b)
Loads due to the acceleration of luffing drives shall be calculated by an appropriate dynamic analysis.
4.5.5 Loads induced by displacements Account shall be taken of loads arising from displacements caused by movement of the supporting structure, for example, from prestressing or differential movement due to settlement or temperature. 4.6 ADDITIONAL LOADS 4.6.1 General Additional loads and effects include loads induced by wind, snow, ice, temperature and oblique travel. 4.6.2 Wind forces 4.6.2.1 Principles The determination of wind forces on a crane exposed to wind (e.g., outdoors operation or partially enclosed building) shall be as specified in AS 1170.2. NOTES: 1
This applies to in-service and out-of-service wind forces.
2
Cranes are considered to be high-risk installations. Allowances given in AS 1170.2 to reduce loads on temporary structures should only be applied after the appropriate risk analysis has been carried out by the designer.
4.6.2.2 Wind forces on the hoisted load Wind forces (P D) acting on the hoisted load shall be calculated for the largest dimensions and the least favourable configuration of the load using the drag coefficients (CD ) taken from AS 1170.2. 4.6.3 Snow and ice loads
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Snow and ice loads, where applicable, shall be taken into consideration including— (a)
increased dead load
(b)
increased wind exposure surfaces due to encrustation.
4.6.4 Forces due to temperature variation Forces caused by the restraint of expansion or contraction of a component due to local temperature variation shall be taken into account. 4.6.5 Lateral forces due to oblique travel 4.6.5.1 General The following Clauses outline a simplified method of analysis of lateral forces due to oblique travel. A detailed analysis is provided in Appendix E. Where a crane or crab is subjected to oblique travel in the moment of contact between rail and front guiding element (wheel flange or guide roller), a steering force (POT) develops and straightens the crane in its tracks. The magnitude of the steering force (P OT) depends on the type of crane drives, the crane geometry, and on the coefficient of frictional contact (K O) which is determined by the maximum oblique travel gradient (α). www.standards.com.au
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4.6.5.2 Coefficient of frictional contact (KO ) The coefficient of frictional contact (KO ) shall be obtained from Table 4.6.5.2. NOTE: Interpolation of K O values is permissible under this Standard.
TABLE 4.6.5.2 COEFFICIENT OF FRICTIONAL CONTACT α
2.0
3.0
4.0
5.0
7.0
9.0
12.5
15
>15
KO
0.118
0.158
0.196
0.214
0.248
0.268
0.287
0.293
0.3
LEGEND: α = oblique travel gradient, in millimetres per metre = CL SG where C L = maximum clearance between wheel flange or guide roller and side of rail, in millimetres α
S G = centre distance of track wheels, track wheel groups or guide rollers, in metres
4.6.5.3 Calculation of steering contact force (POTE ) The calculation of the steering contact force (POTE ) and Y 11 and Y21 reactions for a crane supported by four wheels with two independent drives is determined in accordance with Figure 4.6.5.3. Equilibrium condition gives: ΣYij = POTE = 0
where Y ij are the frictional forces between the wheels and the rail Y21 = P OTE − Y11
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= K O P W21 K F
NOTE: Y21 is the force that is to be used for design of crane structure and runway beams; POTE is only important for design of guiding elements and the like. The most adverse condition for analysis is with the crab on the opposite side of the crane girder to the contact force.
FIGURE 4.6.5.3 WHEELS WITH TWO INDEPENDENT DRIVES (EFF) Standards Australia
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4.6.5.4 Calculation of steering contact force (POTW ) The calculation of the steering contact force (P OTW) and Y11 , Y12, Y21 and Y22 reactions for a crane supported by four wheels with two or more mechanically or electrically coupled drive wheels is determined in accordance with Figure 4.6.5.4. NOTE: This method is simplified and the results are slightly conservative, being not more than 15% greater than the exact calculation in Appendix E. Forces parallel with runway beams are very small and can be disregarded.
NOTES: 1
P OTW , Y 11 and Y21 are calculated in accordance with Clause 4.6.5.3.
2
Y 21 and Y 22 are forces to be used for design of crane structure and the runway beams; P OTW is only important for the design of guiding elements and the like.
3
Equilibrium condition gives approximately: ΣYij + POTW = 0 where Y ij are frictional forces between the wheels and the rail.
FIGURE 4.6.5.4 MECHANICALLY OR ELECTRICALLY COUPLED DRIVE WHEELS (WFF)
4.6.5.5 Oblique travel force (POTE ) and reduction factor (K F ) Because of flexibility of the crane and runway, reactions Y in Clauses 4.6.5.3 and 4.6.5.4 shall be reduced by multiplying with factor (K F ) from Table 4.6.5.5. The natural frequency of the crane beams shall be determined for vibrations in the vertical plane. TABLE 4.6.5.5 REDUCTION FACTORS Natural frequency of crane beams, Hz (vertical plane)
Reduction factor (K F )
> 5.0
1.0
Single girder and Double girder cranes
> 3.2 ≤ 5.0
0.83
Single girder and Double girder cranes
≤ 3.2
0.66
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Type of crane Double girder Cranes only
4.6.6 Bulk material loads Where applicable, effects due to the dropping of bulk material shall be taken into consideration. Effects include impact and recoil.
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4.7 SPECIAL LOADS 4.7.1 General Special loads include loads caused by testing, buffer forces and tilting, as well as from emergency cut-out, failure of drive components, and external excitation of the crane foundation. 4.7.2 Loads due to off-vertical hoisting A lateral load of not less than 4% of the rated capacity shall be applied to account for inadvertent off-vertical lifting. Where off-vertical hoisting is required by the crane operation, lateral loads induced by this effect shall be determined by a competent person. 4.7.3 Dynamic effects of test loads The values of test loads and their locations shall be determined as appropriate for the type of crane or hoist tested. The dynamic test load shall be multiplied by a factor (φ 5) from the following equation: φ 5 = 0.5 (1 + φ 2 )
. . . 4.7.3
where φ 2 is calculated in accordance with Clause 4.5.3.3. 4.7.4 Buffer forces The impact force (P B) due to cranes or parts of a crane running against other cranes or stops shall be absorbed by appropriately designed buffers or similar energy-absorbing means. The total buffer capacities required and the maximum buffer force (P B) shall be determined for longitudinal travel at 85% of full travel velocity and for traverse at 100%. Where automatic retarding means are provided, the maximum buffer force (P B ) shall be determined for cranes and crabs at not less than 70% of full travel velocity. For two-speed cranes fitted with fail-safe duplicated automatic retard switching to slow speed and sufficient distance from end stop to slow before impacting buffer, the maximum buffer force (P B ) may be determined for 100% of the slow speed.
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Where two cranes of masses m 1 and m2 and having velocities V F1 and V F2 collide, the kinetic energy released on the collision shall be calculated by the following equation: E=
m1 m 2 (V F 1 + V F 2 ) 2 2(m1 + m 2 )
. . . 4.7.4(1)
The total energy (E) shall be absorbed by all buffers engaged in the collision, with each taking its share of energy in proportion to its rigidity. Where a crane of mass m and having a velocity V collides with an end stop, the kinetic energy released on collision shall be calculated by the following equation: E=
1 2 mV 2
. . . 4.7.4(2)
NOTE: In some circumstances, the effects of the kinetic energy of the rotating long travel components, e.g., motors, brake drums, gearboxes, should be considered.
For calculation of the buffer capacities and the strength of the structure, the forces resulting from the masses in motion (dead loads plus any rigidly guided hoisted loads in the worst position) shall be used, but not the factors mentioned in Clause 4.5.3. Loads suspended from hoisting equipment and freely swinging loads need not be taken into consideration. Standards Australia
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For cranes and crabs with or without attached hoisted loads, no negative wheel loads shall result from 1.1 times the buffer force and the abovementioned dead loads and hoisted loads. For tower cranes and portal slewing cranes, an analysis of the buffer capacity and of the effect that the buffer forces have on the structure need not be made, provided that the rated travelling velocity is lower than 0.67 m/s and reliable limit switches are provided in addition to the buffer stops. The resulting forces as well as the horizontal inertia forces in balance with the buffer forces shall be multiplied by a factor (φ 6) to account for elastic effects that cannot be evaluated using a rigid body analysis. Factor φ 6 shall be taken as 1.25 in the case of buffers with linear characteristics (e.g., springs) and as 1.60 in the case of buffers with rectangular characteristics (e.g., hydraulic constant force buffers). For buffers with other characteristics, other values justified by calculation or by test shall be used (see Figure 4.7.4). Intermediate values of φ 6 shall be calculated as follows: (a)
φ 6 = 1.25 for 0.0 ≤ ξ ≤ 0.5
(b)
φ 6 = 1.25 + 0.7 (ξ − 0.5) for 0.5 < ξ ≤ 1.0
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where ξ is defined in Figure 4.7.4.
FIGURE 4.7.4 DYNAMIC Factor (φ 6) FOR BUFFERS
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4.7.5 Tilting forces If an appliance with a horizontally restrained load (rigidly guided load) can tilt when its load or lifting attachment is in collision with an obstacle, the resulting static forces shall be determined. For the determination of this force, the crab shall be assumed to be in the worst position. The possibility of lifting the crab wheels off one of the crane bridge girders shall be considered. If a tilted appliance can fall back into its normal position uncontrolled, the resulting impact on the supporting structure shall be evaluated and taken into account. 4.7.6 Miscellaneous loads The effects of other loads that may be applied to the crane, for example lights, advertising boards, chutes, maintenance activities and the like shall be considered. Live loads on walkways during maintenance shall be determined in accordance with AS 1657 unless higher loads can be generated, for example, placement of equipment on walkways during maintenance. 4.7.7 Loads caused by emergency conditions 4.7.7.1 Mechanical failure Where protection is provided by emergency brakes in addition to service brakes, failure and emergency brake activation shall be assumed to occur under the least favourable condition. Where mechanisms are duplicated for safety reasons, failure shall be assumed to occur in any part of either system. The value of the dynamic factor (φ 4) shall be taken between 1.5 and 2.0. 4.7.7.2 Emergency cut-out Loads caused by emergency cut-out shall be evaluated in accordance with Clause 4.5.4 taking into account the most unfavourable combination of acceleration and loading at the time of cut-out. The coefficient of friction shall be taken at its upper bound value. The value of the dynamic factor (φ 4) shall be taken between 1.5 and 2.0. 4.7.7.3 Application of loads The resulting loads shall be distributed in accordance with the principles set out in Clause 4.5.4 for traction forces.
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In both these cases, resulting loads shall be evaluated in accordance with Clause 4.5.4, taking into account any impacts resulting from the transfer of forces. 4.7.8 Seismic loads Loads induced by seismic or other vibratory excitations of crane foundations shall be considered. 4.7.9 Loads during erection The loads acting at each stage of the erection and dismantling process shall be taken into account. 4.7.10 Forces during transport The effects of loads occurring during transport shall be considered, where appropriate. 4.8 PRINCIPLES FOR DETERMINATION OF CRANE LOAD COMBINATIONS 4.8.1 Basic considerations Loads shall be combined to determine the maximum stresses an appliance will experience during operation. To achieve this, the appliance shall be taken in its most unfavourable Standards Australia
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AS 1418.1—2002
attitude and configuration while the loads are assumed to act in magnitude, position and direction causing the maximum stresses at the critical points selected for evaluation on the basis of engineering considerations. The load combinations appropriate to individual types of appliances shall be in accordance with Table 4.8, as applicable. The designer shall also consider other load combinations not shown in Table 4.8, as appropriate to the type of appliance and its operation. 4.8.2 Application of load combinations 4.8.2.1 Use of Table 4.8 For each type of load and each load combination, the Table gives— (a)
a dynamic factor (φ) for the particular load;
(b)
numeral 1, which signifies that no dynamic factor is required for that load type unless special conditions of intended operation require that a dynamic factor (different from 1.0) be included; or
(c)
a dash (—), which signifies that the load of that type need not be included in the load combination unless special conditions of operation require its inclusion.
4.8.2.2 Working stress design method Where the working stress design method is used for the verification of the strength and serviceability of the crane structure, the load effects (moments, shear and normal forces) derived from each load combination shall be multiplied by the load combination factor (γ c). NOTE: As an example for load combination 5, the total load (Ptot ) in a girder will be derived from: γ c = 0.9 P tot = 0.9 × [The effect of (φ1 P 1 + φ 2 P 2 + φ 4 P 3 + 1.0 P4 + 1.0 P5 + 1.0 P6 + 1.0 P 7)]
4.8.2.3 Limit states design method The limit states design method uses partial load factors γ P , which differ for each type of load and range generally between 1.2 and 1.5 depending on the statistical variability of the load type in that particular type of crane. Where the limit states design method is used, cranes shall be designed to give a degree of safety not less than that given in this Standard for the working stress design method for strength, buckling, deflection, torsion, fatigue, and the like.
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NOTE: At this stage, Standards Australia is unable to give specific guidance on the range of values of the partial load factors.
4.8.2.4 Proof of fatigue strength The effects of fatigue shall be considered. Where proof of fatigue strength is found to be necessary, it shall be carried out in accordance with the principles set down in Clause 4.8.1. In some applications it may be necessary to also consider occasional loads such as in-service wind, skewing and exceptional loads such as test loads and excitation of the lifting appliance foundation (for example, wave effects). 4.8.2.5 High risk applications In special cases where the human or economic consequences of failure are exceptionally severe (e.g., ladle cranes or cranes for nuclear applications) increased reliability shall be obtained by the use of a risk coefficient γ n > 1, the value of which shall be selected according to the requirements of the particular application.
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AS 1418.1—2002
32
TABLE 4.8 CRANE LOAD COMBINATIONS Load combination number* Load group
Principal loads
Additional loads
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Special loads
Line No.
Description
Infrequently Frequently occurring occurring load load combinations combinations 1
2
3
4
Rarely occurring load combinations
5
6
7
8
9
10
11
12
13
14
15
16
1
Dead loads
φ1
1
0.9
φ1
φ1
0.9
φ1
1
1
1
φ1
φ1
1
φ1
1.2
2
Hoisted loads
φ2
1
φ3
φ2
φ1
φ3
φ2
η†
—
1
1
1
1
1
1
3
Inertia loads
φ4
φ4
1
φ4
φ1
1
1
1
φ4
1
1
1
—
—
—
4
Displacementinduced loads
1
1
1
1
1
1
—
—
—
—
—
—
—
—
1
5
In-service wind forces
1
—
1
1
—
—
1
1
1
1
—
1
6
Snow or ice loads
1
1
—
—
1
—
—
—
—
—
—
—
7
Temperatureinduced forces
1
1
—
—
1
—
—
—
—
—
—
—
8
Oblique travelling forces
—
1
—
—
—
—
—
—
—
—
—
—
9
Off-vertical hoisting loads
1
—
—
—
—
—
—
—
—
10
Out-of-service wind forces
—
1
—
—
—
—
—
—
—
11
Test loads
—
—
φ5
—
—
—
—
—
—
12
Buffer impact forces
—
—
—
φ6
—
—
—
—
—
13
Tilting forces
—
—
—
—
1
—
—
—
—
14
Live loads on walkways and in chutes
—
—
—
—
—
1
—
—
—
15
Loads due to emergency conditions
—
—
—
—
—
—
φ4
—
—
16
Seismic loads
—
—
—
—
—
—
—
1
—
17
Loads during erection
—
—
—
—
—
—
—
—
1.2
18
Loads during transit*
Load combination factor, γ c
1
1.0
0.9
*
Applicable only to cranes that are frequently moved e.g., mobile cranes, elevating work platforms.
†
η is the mass of that part of the hoist load remaining suspended from the appliance.
0.8
NOTE: φ 1 to φ 6 are dynamic factors as described earlier in this Section.
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SE C T I ON
5
DE S IG N
O F
AS 1418.1—2002
CRA N E
ST RU CT U RE
5.1 GENERAL This Section specifies requirements for both the crane structure and its supporting structure (see Clause 1.1). The design life shall be 25 years unless the requirements of Clause 2.2(A) to (D) are followed. 5.2 BASIS OF DESIGN 5.2.1 Design of structure The crane and its supporting structure shall be designed in accordance with this Section and Clause 2.2, except where other parts of AS 1418 take precedence, and with the following: (a)
AS 1163.
(b)
AS 1594.
(c)
AS 1664.1 or AS 1664.2.
(d)
AS 1720.1.
(e)
AS 1726.
(f)
AS 3600.
(g)
AS 3990; or AS 4100.
5.2.2 Classification of crane structures 5.2.2.1 Bases of classification The classification of the structure of a crane or crane components, e.g., the boom, shall be determined from the class of utilization (see Clause 5.2.2.2) and the state of loading (see Clause 5.2.2.3). 5.2.2.2 Class of utilization
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The number of in-service cycles expected from the structure of a crane or crane component during its useful life shall be one basic parameter of classification and shall comply with Table 5.2.2.2.
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TABLE 5.2.2.2 CLASS OF UTILIZATION OF STRUCTURES Maximum number of operating cycles
Class of utilization
Description of use)
× 104
U0
× 10
4
U1
× 10
4
U2
1.25
× 10
5
U3
2.5
× 105
U4
Fairly frequent use
× 10
5
U5
Frequent use
× 10
6
U6
Very frequent use
2
× 10
6
U7
Continuous or near continuous use
4
× 106
U8
6
U9
1.6 3.2 6.3
5 1
Greater than × 10 4
Infrequent use
NOTE: The number of loading cycles is often significantly higher than the number of in-service cycles in Table 2.3.2.
5.2.2.3 State of loading The second basic parameter of classification is the state of loading, which is concerned with the number of times a load of a particular magnitude, in relation to the capacity of the structure of the crane or crane component, is hoisted. The nominal values of the load spectrum factor (K p) shall comply with Clause 2.3.3. 5.2.2.4 Structure classification The structure classification for the various combinations of class utilization and state of loading shall be as given in Table 5.2.2.4. TABLE 5.2.2.4
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CLASSIFICATION OF CRANE STRUCTURES 1
2
State of loading
Nominal load spectrum factor (Kp )
3
4
5
6
7
8
9
10
11
12
Classification of crane structure Class of utilization U0
U1
U2
U3
U4
U5
U6
U7
U8
U9
Q1—Light
0.125
S1
S1
S1
S2
S3
S4
S5
S6
S7
S8
Q2—Moderate
0.25
S1
S1
S2
S3
S4
S5
S6
S7
S8
S8
Q3—Heavy
0.50
S1
S2
S3
S4
S5
S6
S7
S8
S8
S9
Q4—Very heavy
1.00
S2
S3
S4
S5
S6
S7
S8
S8
S9
S9
Load condition
0*
1†
2†
3†
4†
* Fatigue analysis not required. † Corresponds to same loading condition in AS 3990. NOTE: The solid lines in the Table group together the state of loading (Q) and the class of utilization (U), which belong to the same loading condition (see Clause 5.5).
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AS 1418.1—2002
5.3 DESIGN OBJECTIVE Design objectives are to achieve adequate strength and serviceability during the design life of the crane. Design calculation shall be carried out to determine that the crane structure will have adequate strength in service when operated in compliance with the manufacturer’s written instructions. The proof of adequacy shall include proof of safety against yielding, elastic instability or fatigue. Proof of adequacy shall also include stability against overturning. The elastic displacements shall be checked to prove that the appliance shall not become unfit to perform its intended duties, affect stability, or interfere with the proper functioning of mechanisms. 5.4 METHOD OF DESIGN 5.4.1 General The design of the lifting appliance shall be carried out by one of the following methods: (a)
The working stress design method.
(b)
The limit states method.
5.4.2 Working stress design method Design by working stress design method shall be determined in accordance with the provisions of AS 3990, except where otherwise specified in this Standard. 5.4.3 Limit states method Individual specified or characteristic loads (Fj) are determined and amplified where specified in Table 7.9 using the dynamic factors (φ) and multiplied by the appropriate partial load factors (γ p). They are then combined according to the load combination under consideration to give the combined load (M). Partial load factors (γp ) for individual loads shall be determined in accordance with the principles laid down in AS 4100. If a probabilistic proof of adequacy is used, the relevant assumption, particularly the acceptable probability of failure, shall be stated. 5.5 FATIGUE STRENGTH
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5.5.1 General The crane structure shall be checked for fatigue strength under load combinations involving frequently applied loads (i.e. 1, 2, 3 and 4), and for the service life specified in Clause 5.1. 5.5.2 Working stress design Load conditions for fatigue design by AS 3990 are given in Table 5.5.2. The stress ranges shall be determined in accordance with the appropriate load combinations of Section 4. Fatigue assessment shall be carried out in accordance with AS 3990. NOTE: AS 4100 should be referenced for details of connections where such details are not addressed by AS 3990.
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TABLE 5.5.2 LOAD CONDITION AND EQUIVALENT LOAD CYCLES Number of equivalent cycles Classification of crane structure
Load condition from AS 3990
S1, S2, S3
Fatigue analysis not required
S4
1
>20 000
≤100 000
100 000
S6, S7
2
>100 000
≤500 000
500 000
S8
3
>500 000
≤2 000 000
2 000 000
S9
4
>2 000 000
From design by allowable stress method (AS 3990)
For design by limit state method (AS 4100)
—
—
5 000 000
NOTE: The number of equivalent cycles is obtained after conversion of actual loading cycles and load spectrum, as defined in Table 5.2.2.2, to equivalent loading cycles for load spectrum factor Kp = 1.
5.5.3 Limit states design The verification of fatigue strength shall be carried out in accordance with AS 4100. In the absence of a load cycle analysis based on time and motion analysis, an equivalent number of load cycles to be used in the design shall be as given in Table 5.5.2. 5.6 DESIGN FOR SERVICEABILITY DEFLECTION AND VIBRATION 5.6.1 General Deflections of the crane structure shall be kept within the limits imposed by the mechanical and operational requirements as specified in the relevant part of the AS 1418 series of Standards. The actual deflection shall not affect the function of the crane. 5.6.2 Deflection limits of crane structural members The calculated maximum deflection of any crane structural member shall be not greater than the following:
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(a)
Vertical static deflection due to all dead loads and live loads without dynamic factors applied— (i)
between supports: 1/500 span or 60 mm, whichever is the lesser; or
(ii)
cantilever: 1/300 span. NOTE: The effects of adjacent spans on cantilever deflection have to be taken into account in calculating cantilever deflection.
(b)
Lateral deflection induced by inertial forces or off-vertical lift— (i)
bridge beam or truss under the inertial forces acting on dead loads and live loads: 1/600 span; and
(ii)
bridge beam or truss under the inertial forces acting on dead loads only: 20 mm. Load combination factor (γ c) may be applied (see Table 4.8).
5.6.3 Driver exposure to vibration Vibration amplitudes and frequencies experienced by the operators of cabin-controlled cranes shall be in accordance with the applicable parts of AS 2670. Consideration shall be given to the frequency and amplitude of vibration in the design of cranes, ensuring that vibrations do not affect the correct function of the crane. Standards Australia
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SECT ION
6
AS 1418.1—2002
STAB I L I T Y
6.1 SCOPE OF SECTION This Section specifies the requirements for safety against overturning of cranes (see Clause 1.1). 6.2 OVERTURNING Cranes shall have an adequate stability margin against overturning when in service and out of service. In particular, the stability margin against overturning shall be checked under the following loading conditions: (a)
Crane in service.
(b)
For cranes used externally, or cranes out of service, subject to the design wind loading. The loads applied for this check shall be the same as those specified in Section 4 except that a sudden release of full load shall also be included. The loads shall be combined as specified in Section 4 using the most adverse combinations excluding dynamic multipliers. The stability against overturning shall be checked by:
FS =
ΣM S ΣM O
. . . 6.2
where FS
= stability margin against overturning
M S = minimum stabilizing moment MO = maximum overturning moment due to loads and wind force
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The stability margin (F S) shall be not less than the following values: (i)
Crane in service................................................................................................... 1.4.
(ii)
Crane out of service subject to the design wind loading ........................................ 1.2.
The stability calculations shall be carried out for overturning points that can realistically be regarded as giving support to the crane and for the most adverse disposition of crane elements and loads. Where it is intended that the crane be parked and secured with special stabilizing devices, the crane and the stabilizing devices shall be checked for their structural adequacy under design wind load as specified in Section 4. 6.3 STABILITY DURING ERECTION AND MAINTENANCE The crane shall be checked under these conditions of loading and its overturning stability margin shall not be less than 1.2. 6.4 SAFETY AGAINST DRIFTING The minimum design factors against drifting (F d1, F d2) shall be as follows:
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Fd1 =
sum of friction loads total wind drag + gradient gravitational force
Fd2 =
sum of brake capacities total wind drag + gradient gravitational force
The smallest calculated design factor shall be not less than the following: (a)
Using the automatic brakes of the travel drives, against in service wind forces, 1.5.
(b)
Not in service, under design wind forces, 1.10.
The lower-bound value of the coefficient of friction between the driven wheels and the rail shall be determined on the basis of tests or, in the absence of tests, the following values shall be used: (i)
For driven wheels ................................................................................................ 0.2.
(ii)
For rail clamps .................................................................................................. 0.33.
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Where rail clamps are provided, a risk assessment shall be conducted to assess the requirements for automatic actuation. The risk assessment shall consider as a minimum stability, time to apply the clamp, exposure to personnel, consequential damage.
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SECT ION
7
CRANE
AS 1418.1—2002
MECHAN ISMS
7.1 GENERAL This Section specifies requirements for crane mechanisms and related components (see Clause 1.1). The design life of crane mechanisms shall be 10 years unless the requirements of Clause 2.2(A) to (D) are followed. 7.2 MECHANISMS The term ‘mechanism’ incorporates all mechanical components and plant provided for powering, coupling and speed changing and all other components required for the operation of the crane. Mechanisms shall be designed to perform their intended function without loss of serviceability during their design life. Serviceability shall be deemed to include the attributes of shock-free acceleration and braking, positive control of the load or motions during operation and upon the cessation of operation, and for the out of service conditions. 7.3 BASIS OF DESIGN 7.3.1 Design of mechanism Both complete crane mechanism assemblies and each mechanism component shall be designed for all forces due to the mass of the crane and crane mechanism, forces imposed on the crane mechanism during its operation, forces arising from erection, testing and maintenance, and forces due to the effects of the environment to which the crane and crane mechanisms are exposed. Forces due to acceleration and retardation of the moving masses for all crane motions shall be determined by rational dynamic analysis or simplified conservative methods of calculation as specified in this Section.
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The design of the crane mechanism shall be on the following basis: (a)
Manually operated—strength basis only.
(b)
Power-operated— (i)
strength basis; and
(ii)
life basis— (A)
wear; and
(B)
fatigue (finite or infinite).
7.3.2 Design for strength The design for strength of both complete crane mechanism assemblies and each mechanism component shall comply with the following requirements: (a)
Loadings are specified in Clause 7.4, except that for manually operated mechanisms the design shall be based on static loading with a duty factor of 1.1 applied.
(b)
Testing shall be conducted prior to being placed in service as specified in the appropriate part of AS 1418.
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7.3.3 Design for life 7.3.3.1 Wear It is intended that mechanisms of components be designed for a minimum life of 10 years, determined by the in service duration and the load condition applied during the in service period. The service life of specific mechanisms may vary from this period and this shall be documented. NOTE: Devices are available to record the rated life of a crane based on its working conditions and working hours, which enables an assessment of its remaining design life. Guidance on assessing a crane based on its actual rated life is given in ISO 12842-1.
For design purposes, Km and the value for running hours shall be that specified in Tables 7.3.4.2 and 7.3.4.3 for the respective classification. Wear plates or rollers should be provided to guide parts relative to each other. Where required, take-up adjustment should be provided. 7.3.3.2 Fatigue strength One of two methods may be employed to design for fatigue strength as follows: (a)
Finite life Design for finite life allows stress to frequently go higher than the endurance limit of the material of the component under consideration. As a consequence, calculations are much more extensive, since not only the maximum load in the component has to be known, but also the load frequency, the state of loading and the limiting stress ratios.
(b)
Infinite life In the design for infinite life, the magnitude of the stresses in components rarely exceeds the endurance limit of the material used. It is not necessary to assess the load cycle frequencies in the component during its life, that is, the frequency of high loading is negligible.
NOTE: Guidance on the fatigue design of mechanisms is provided in Appendix F.
7.3.4 Classification of crane mechanisms 7.3.4.1 Basis of classification The group classification of the crane mechanism shall be determined from the class of utilization (see Clause 7.3.4.2) and the state of loading (see Clause 7.3.4.3). NOTE: A sample calculation for the classification of crane mechanisms is provided in Appendix D.
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7.3.4.2 Class of utilization The class of utilization of a mechanism shall be determined by the assumed total duration of use in hours, and shall be one of the 10 nominal classes shown in Table 7.3.4.2. The maximum total duration of use may be derived from the assumed average daily utilization time in hours, the number of working days per year, and the number of years of expected service. NOTE: For this purpose, a mechanism is considered to be in use only when it is in motion.
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AS 1418.1—2002
TABLE 7.3.4.2 CLASS OF UTILIZATION OF MECHANISMS Class of utilization
Total duration of use H
T0
H ≤ 200
T1
200 < H ≤ 400
T2
400 < H ≤ 800
T3
800 < H ≤ 1600
T4
1600 < H ≤ 3200
Fairly frequent use
T5
3200 < H ≤ 6300
Frequent use
T6
6300 < H ≤ 12 500
Very frequent use
T7
12 500 < H ≤ 25 000
T8
25 000 < H ≤ 50 000
Continuous or near continuous use
T9
50 000 < H ≤ 100 000
T 10
100 000 < H
Description of use Infrequent use
7.3.4.3 State of loading The state of loading of a mechanism specifies to what extent the mechanism is subjected to its maximum loading or only to reduced loading. There are four different nominal states of loading as shown in Table 7.3.4.3. The load spectrum factor (K m ) for the mechanism is given by the following equation: t Km = ∑ i tT
Pi Pmax
MM
. . . 7.3.4.3
where ti
= duration of use of the mechanism at the individual load levels = t 1, t 2 , t 3, . . . t n
tT
= total of all the individual durations at all load levels = Σt I
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= t 1 + t2 + t 3 + . . . + t n Pi
= individual loading magnitudes (loading levels) characteristic of the duty of the mechanism = P 1 , P2 , P3 , . . . P n
P max = greatest loading magnitude applied to the mechanism (due to rated capacity) MM
= index for the mechanism = 3 unless otherwise determined
The nominal load spectrum factor for the mechanism shall be established by matching the calculated load spectrum factor to the closest (higher) nominal value of K m given in Table 7.3.4.3 and an adjustment for equivalent running hours may be made.
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TABLE 7.3.4.3 NOMINAL LOAD SPECTRUM FACTOR AND STATE OF LOADING FOR CRANE MECHANISMS Nominal load spectrum factor (K m )
State of loading
Description of use
0.125
L1—Very light
Mechanisms subjected very rarely to the maximum load and, normally, to very light loads
0.25
L2—Light
Mechanisms subjected fairly frequently to the maximum load but, normally, to rather light loads
0.50
L3—Medium
Mechanisms subjected frequently to the maximum load and, normally, to loads of moderate magnitude
1.00
L4—Heavy
Mechanisms subjected with high frequency to the maximum load
7.3.4.4 Group classification The group classification for the various combinations of class of utilization and state of loading shall be as given in Table 7.3.4.4. NOTE: The application of group classification to specific types of crane mechanisms is covered in the appropriate parts of AS 1418.
TABLE 7.3.4.4 GROUP CLASSIFICATION OF CRANE MECHANISMS 1
2
State of loading
Nominal load spectrum factor (K m )
3
4
5
6
7
8
9
10
11
12
Group classification of crane mechanism Class of utilization T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
L1—Light
0.125
M1
M1
M1
M2
M3
M4
M5
M6
M7
M8
L2—Moderate
0.25
M1
M1
M2
M3
M4
M5
M6
M7
M8
*
L3—Heavy
0.50
M1
M2
M3
M4
M5
M6
M7
M8
*
*
L4—Very heavy
1.00
M2
M3
M4
M5
M6
M7
M8
*
*
*
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NOTE: Where class utilization calculations give a crane mechanisms group classification of greater than M8, as indicated by an asterisk (*), the mechanism shall be designed for the required rated life.
7.4 MECHANISM LOADINGS 7.4.1 Determination of loads Determination of loads shall include all loads resulting from the intended crane operation, and loads caused by the environment, in and out of service wind, erection, testing and fault conditions. Steady-state loads, such as gravity-induced loads, shall be determined from the masses of all component parts permanently attached to the crane. Live loads on in service cabin floor, walkways and platforms shall comply with the provisions of this Standard, AS 1657, AS 3990 and AS 1170.1. Dynamic loads due to acceleration or deceleration of masses shall be determined by either— (a)
dynamic analysis capable of modelling the characteristics of the crane operations; or
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(b)
AS 1418.1—2002
methods of determination of loads specified in this Section.
7.4.2 Categorization of mechanism loads For convenience of referencing, the mechanism loads are divided into three load groups as follows: (a)
Principal loads (see Clause 7.5).
(b)
Additional loads (see Clause 7.6).
(c)
Special loads (see Clause 7.7).
Each load group is divided into load categories as shown in Table 7.4.3. 7.4.3 Categorization of mechanism loading The types of loading to be considered in the design of a crane mechanism, or mechanism component, shall be as shown in Table 7.4.3. TABLE 7.4.3 CATEGORIZATION OF MECHANISM LOADS Load group
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Principal loads
Loads
Reference Clause
R 1—Loads due to the dead load of the mechanism (or component)
7.5(a)
R 2—Loads due to the dead load of those parts of the crane acting on the mechanism or component (including the empty mass of the crane hook) for those mechanisms (or components) that it acts upon directly or indirectly
7.5(b)
R 3—Loads due to the mass of live load acting on the crane hook
7.5(c)
R 4—Loads due only to the dynamic effects caused by the maximum acceleration (or retardation) of the mass loaded onto the crane hook
7.5(d)
R 5—Loads due to the maximum acceleration (or retardation) of the crane mechanism (or component), including those due to the inertia of the mechanism itself, its prime mover, brakes, associated crane parts and the concurrent operation of other crane motions, as applicable
7.5(e)
R 6—Loads arising from frictional forces
7.5(f)
V 1—Load due to the in service wind acting horizontally in any direction where applicable (see AS 1170.2)
7.5(g)
V 2—Load due to the out of service wind acting horizontally in any direction where applicable (see AS 1170.2)
7.5(h)
Additional loads
Wind, snow, ice, temperature extremes, oblique travel
7.6
Special loads (see Clause 7.7)
B 1—Load due to collision with buffers
7.7(a)
B 2—Emergency conditions
7.7(b)
7.5 PRINCIPAL LOADS Principal loads comprise the mass of the mechanism and highly repetitive loads arising from the intended service of the mechanisms. The typical principal loads are as follows: (a)
R 1—loads due to the dead load of the mechanism (or component).
(b)
R 2—loads due to the dead load of those parts of the crane acting on the mechanism or component (including the empty mass of the crane hook) for those mechanisms (or components) that it acts upon, directly or indirectly.
(c)
R 3—loads due to the mass of live load acting on the crane hook.
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(d)
44
R 4—loads due only to the dynamic effects caused by the maximum acceleration (or retardation) of the mass loaded onto the crane hook. Where acceleration (or retardation) data is not available, the load increment due to the dynamic effects shall be calculated using the maximum suspended design deadload (payload) mass multiplied by (φ −1.0) where φ is typically φ 2 or φ 3 (see Clause 4.5.3.2 for a definition of φ 2 and Clause 4.5.3.4 for a definition of φ 3). Care shall be taken in the determination of the dynamic multiplier for hoisting, that it is not underestimated, especially where high-speed hoisting is an available option.
(e)
R 5—loads due to the maximum acceleration (or retardation) of the crane mechanism (or component), including those due to the inertia of the mechanism itself, its prime mover, brakes, associated crane parts and the concurrent operation of other crane motions, as applicable.
(f)
R 6—loads arising from frictional forces.
(g)
V 1—load due to the in service wind acting horizontally in any direction, where applicable (see AS 1170.2). The loads on the mechanism shall be determined from the most adverse wind conditions on the crane structure and securing devices, e.g., rail clamps. In general, the torque (MAu ) forced onto the driving mechanism by the wind load is limited by sliding of the track wheels or by braking. The maximum value of M Au from one of the following equations shall apply: rL (W Au − PL ) ia
. . . 7.5(1)
rL Σ RAu ia
. . . 7.5(2)
(i)
M Au =
(ii)
M Au = µ
(iii)
M Au = i m M br
. . . 7.5(3)
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
where M Au
= maximum torque on the driving mechanism due to wind load
rL
= radius of track wheel, with driving mechanisms, or distance of the thrust point of the wind from the rotary axle, with slewing, luffing or pull-in mechanisms
ia
= gear ratio of the driving mechanism shaft to be calculated to the track wheel or rotary crane part
W Au
= the wind load acting on the in service driving mechanism in accordance with AS 1170.2
PL
= proportion of the resistance to travelling, traversing, luffing, pullingin or revolving as acting on the driving mechanism
µ
= coefficient of friction between the track wheel and rail to be taken as 0.25
Σ R Au = total of the maximum wheel forces of the track wheels connected to the driving mechanism in the in service condition
Standards Australia
im
= gear ratio from motor to part under consideration
M br
= maximum torque in the motor shaft from the mechanical brake or the motor or the eddy current brake
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AS 1418.1—2002
V 2—load due to the out of service wind acting horizontally in any direction, where applicable (see AS 1170.2). For the out of service condition, the driving mechanisms are generally idle, but frequently they have to perform a static function, e.g., holding in place against the wind. On occasions, they are influenced more unfavourably by a different distribution of the dead load than when operating. For cranes with booms, wind loads shall be considered in fatigue calculations.
7.6 ADDITIONAL LOADS Additional loads and their effects occur relatively infrequently and are usually neglected in fatigue evaluations. Typical additional loads are due to snow, ice, temperature extremes and oblique travel. 7.7 SPECIAL LOADS The combinations of loads to be considered for special loading conditions depend upon the type of crane, the application and the crane motion. It shall include any loading conditions that are known to apply but which are not covered under the loading conditions given in Table 7.9. NOTE: During erection or dismantling operations unless the operation is completed during a period when the wind does not exceed V 1 conditions, the parts being erected or dismantled should be secured so that they are capable of withstanding a wind of V2 conditions.
Special loads occur during operations on such rare occasions that there is no need to take them into consideration with regard to the service life of the respective driving mechanism parts. Three types of special loads that should be taken into consideration are out of service wind, buffer forces and emergency shutdown or power failure. These may be considered as follows: (a)
B 1—driving mechanism loads due to collision with buffers The driving mechanism parts shall be assessed for maximum load sustained during impact of the crane or parts of the crane onto travel buffers or end stops. Where driving mechanisms rely on friction, accurate loads may be calculated by taking the sliding force between the track wheel and the rail as a basis for the calculation of the torque (M SO) in accordance with the following equation:
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
M SO = µ
rL Σ Rmax ia
. . . 7.7
where µ, r L and i a are as defined in Clause 7.5 Σ R max = total of the maximum wheel forces of the track wheels driven by the driving mechanism under consideration during operation (b)
B 2—Emergency conditions Emergency shutdown or power failure Where driving mechanisms, apart from the in service brake, have an additional safety or holding brake that becomes effective without delay in the event of power failure, the torque occurring with application of this brake shall be determined. The maximum braking torque of the in service, safety and holding brakes shall be applied. For driving mechanisms relying on friction, use Equation 7.7.
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7.8 CATEGORIZATION COMBINATIONS
OF
FREQUENCY
OF
MECHANISM
LOAD
For convenience of referencing, the frequency of the occurrence of load combinations are divided into three categories as follows: (a)
Frequently occurring load combinations, i.e. principal loads, without additional or special loads, occurring frequently.
(b)
Infrequently occurring load combinations, i.e. additional loads, including in service with and without wind, in combination with principal loads occurring infrequently.
(c)
Rarely occurring load combinations, i.e. special loads, appropriate to the type of crane and its application that may occur rarely, in combination with both principal and additional loads, during its life, e.g.,— (i)
collision with buffers; and
(ii)
during crane erection.
These categories are set out in Table 7.9. 7.9 PRINCIPLES FOR DETERMINING MECHANISM LOAD COMBINATIONS 7.9.1 General Loads shall be combined so as to determine the maximum stresses that the mechanisms will experience, both during the in service and the out of service conditions, and shall be assumed to act with a magnitude and direction that will cause the maximum stress combinations at critical points. 7.9.2 Application of load combinations 7.9.2.1 Use of Table 7.9 For each type of load combination, Table 7.9 gives the loadings that shall be considered to act simultaneously, that is, where a symbol (e.g., R 1) is used to represent a calculation for the loads due to the deadload acting on a component and where a dash (—) is used it is to signify that a load of that type need not be included in the load combination, unless special conditions of operation require its inclusion. The individual loads shall be combined to produce the most adverse effect on the crane mechanisms during operations. This is typified by the application of Table 7.9. Other applicable load combinations shall be considered for other specific applications. Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
NOTES: 1
Such combination of loads need not necessarily correspond to the combination of the maximum values of each of the individual loads.
2
Where appliances are carrying persons or dangerous substances, variations to the load factors may be required.
7.9.2.2 Working stress design method Where the working stress design method is used for the verification of the strength and serviceability of the crane mechanism, the load effects (moments, shears, normal forces) derived from each load combination may be multiplied by the load combination factor (γ c). NOTE: As an example for load combination 7 of Table 9, the total load (P tot) in an assumed mechanism would be derived from: γ c = 0.9 P tot = 0.9 × [The effect of (R1 + R2 + R3 + R5 + R6 + V 1)]
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AS 1418.1—2002
7.9.2.3 Proof of fatigue strength The effects of fatigue shall be considered. Where proof of fatigue strength is found to be necessary, it shall be carried out in accordance with the principles set down in Clauses 7.9.1 and 7.9.2. In general, load combinations 1, 2, 3 and 4 (regular loads) shall be taken into account. In some applications it may be necessary to consider also occasional loads such as in service or out of service wind, skewing and exceptional loads such as test loads and excitation of the lifting appliance foundation (e.g., wave effects). 7.9.2.4 High-risk applications In special cases where the human or economic consequences of failure are exceptionally severe (e.g., ladle cranes or cranes for nuclear applications) increased reliability shall be obtained by the use of a risk coefficient (γ n > 1), the value of which shall be selected according to the requirements of the particular application. 7.9.2.5 Calculation of loads The applicable loads specified in Table 7.9 shall be utilized. The calculation of the load applied to a power-operated crane mechanism or a component thereof commences from the torque occurring at a drive shaft. The efficiency of the mechanism may be disregarded in the calculation of the torque when the total mechanical efficiency is 0.95 or higher. 7.9.2.6 Static strength In general, the yield point or the 0.2 percent limit of the material of which the respective driving mechanism part is made may be regarded as the strength under static stress. In order to eliminate unintentionally exceeding the yield point for materials with a yield point/strength ratio greater than 0.7, the following equation for allowable yield stress (fictitious yield point) shall be used: σ EF =
σ E + 0.7σ B 2
. . . 7.9.2.6
where σ EF = allowable yield stress (fictitious yield point) = yield strength of material
σB
= ultimate strength of material
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
σE
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TABLE 7.9 LOAD COMBINATIONS FOR CRANE MECHANISMS Loading condition Load group
Additional load
Special loads
Vertical motion
Load type
Line number
Description
Principal loads
Frequently occurring load combinations
Symbol
Raise or lower
Traverse
Travel
Slewing
Horizontal and vertical motion (see Note)
1
2
3
4
5
1
Dead load of mechanism
R1
R1
R1
Rs
R1
R1
2
Dead load of parts of crane acting on mechanism or component
R2
—
Rs
R2
Rs
R2
3
Hook load mass (payload)
R3
R3
R3
R3
R3
R3
4
Dynamic effects of payload
R4
R4
—
—
—
—
5
Dynamic effects due to inertia of mechanism
R5
R5
R5
R5
R5
Rs
6
Frictional forces
R6
R6
R6
R6
R6
R6
7
Service wind (acting horizontal)
V1
—
—
—
—
—
8
Out of service-wind (acting horizontal)
V2
—
—
—
—
—
9
Wind, snow, ice, temperature extremes, oblique travel
—
—
—
—
—
—
10
Collision forces with buffers
B1
—
—
—
—
—
11
Emergency conditions
B2
—
—
—
—
—
γc Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
Horizontal motion
1.0
NOTE: Combined horizontal/vertical motion occurs during the following in service conditions: (a)
Luffing or telescoping with a non-level luffing crane.
(b)
Travel or traverse on an inclined plane.
(c)
Slew on an inclined plane.
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AS 1418.1—2002
TABLE 7.9 (continued) Infrequently occurring load combinations Vertical motion
Raise or Traverse lower
Not applicable
6
Horizontal and vertical Travel Slewing motion (see Note)
Horizontal motion
Rarely occurring load combinations Vertical motion Raise or lower
Horizontal motion Traverse
Travel
Slewing
Horizontal and vertical motion (see Note)
7
8
9
10
11
12 13 14 15 16
17
18
19
20
21
22
23
R1
R1
R1
R1
R1
R1 R1 R1 R1 R1
R1
R1
R1
R1
R1
R1
R1
R2
R2
R2
R2
—
R2 R2 R2 R2 R2
R2
R2
R2
R2
RS
R2
R2
R3
R3
RS
RS
R3
— R3 R3 — R3
R3
—
R3
R3
—
R3
R3
—
—
—
—
R4
— — — — —
—
—
—
—
—
—
—
R5
R5
R5
R5
R5
— — — — —
—
—
—
—
—
—
—
R6
R6
R6
R6
R6
— — — — —
—
—
—
—
—
—
—
V1
VN
V1
V1
—
— — — — —
—
—
—
—
—
—
—
—
—
—
—
—
V2 — — V2 —
—
V2
—
—
V2
—
—
—
—
—
—
—
— B1 — — B1
—
—
B1
—
—
B1
—
—
—
—
—
BS
— — B2 — —
B2
—
—
B2
—
—
B2
0.75
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
0.9
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7.9.2.7 Determination of stresses A uniform basis is required so that the stresses resulting from the loads determined according to Clause 7.4 may be compared. For that reason, stresses are determined as reference quantities for the stress analysis. They are to be calculated according to the following equations from the maximum stresses (see Clauses 7.5, 7.6 and 7.7) of the load combinations: (a)
Tension:
σt =
Pt At
. . . 7.9.2.7(1)
(b)
Compression:
σc =
Pc Ac
. . . 7.9.2.7(2)
(c)
Bending:
σb =
Mb Zb
. . . 7.9.2.7(3)
(d)
Longitudinal shear (due to bending moment):
τl =
QS It
. . . 7.9.2.7(4)
(e)
Torsional shear (for solid member only):
τe =
MT Z ps
. . . 7.9.2.7(5)
(f)
Rolling pressure (according to Hertz): σH
(g)
2E × E2 1 =− × 1 2 2π (1 − µ ) E1 + E 2
P × wr b
1 1 + RCl RC2
1/ 2
. . . 7.9.2.7(6)
For multi-axial stresses and normal and shear stresses acting simultaneously, the most unfavourable reference stress shall be calculated from the following equation:
(
σ V = σ x2 + σ y2 − σ x ⋅ σ y + 3τ 2
)
1/ 2
. . . 7.9.2.7(7)
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
where
Standards Australia
σt
= tensile stress
Pt
= tensile force acting directly on the part
At
= sectional area under tensile stress
σc
= compressive stress
Pc
= compressive force acting directly on the part
Ac
= sectional area under compressive stress
σb
= bending stress
Mb
= bending moment directly on the part
Zb
= axial section modulus
τl
= longitudinal shear stress
Q
= shear force sustained by the part
S
= static moment of the connected cross-sectional part
I
= moment of inertia of the part (about the axis under consideration)
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AS 1418.1—2002
t
= thickness of the part of the cross-sectional fibre under consideration
τe
= torsional shear stress
MS
= torsional moment directly on the part
Z ps
= polar section modulus
σH
= rolling stress
E 1 and E 2
= modulus of elasticity of the two rolling elements
P wr
= stress (load) applied to the rolling elements
µ
= Poisson ratio for the material of the part
b
= (rolling) contact width
R C1 and RC2 = radius of curvature of the two rolling elements σv
= combined stress
σx
= normal stress in x direction
σy
= normal stress in y direction
τ
= combined shear stress
7.9.2.8 Permissible stresses for strength Compressive and tensile stresses, for design on a strength basis shall be not greater than Fc and F t, where Fc and Ft are the permissible compressive and tensile stresses, respectively (in megapascals) and: F c and F t = 0.67 times the yield stress of a material, with yield stress not greater than 0.7 times the tensile strength F t = 0.67 times the value from Equation 7.9.2.6 Shear stress for design on a strength basis shall be not greater than Fs, where Fs is the permissible shear stress (in megapascals) and: Fs =
Ft 3
. . . 7.9.2.8
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
7.10 MECHANICAL COMPONENTS 7.10.1 General Mechanical components, including machine elements (e.g., chains, chain wheels and sprockets, couplings, drive belts, gearing, journal and rolling-element bearings, splines and threaded fasteners) shall comply with the relevant Australian Standards where such exist or with the published recommendations of the manufacturer of the component. The load capacity of each component shall be such as to ensure compliance with Clause 7.3.2 (for strength) and Clause 7.3.3 (for life). Mechanical drive shafts shall comply with AS 1403. The loading factors specified in Table 4.8 shall be considered. 7.10.2 Bearings Bearings shall be designed for the load spectrum factor K m and corresponding total duration in hours (h). These may be either obtained by calculation or selected from Tables 7.3.4.2 and 7.3.4.4. The load applied to ball bearings shall be K m 1/3 times full load and the load applied to roller bearings shall be K m 3/10 times the full load. www.standards.com.au
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7.10.3 Gearing 7.10.3.1 General Gearing shall be designed for the load spectrum factor K m and corresponding total duration in hours (h). These may either be obtained by calculation or selected from Tables 7.3.4.2 and 7.3.4.4. 7.10.3.2 Strength requirements Stresses occurring in any operating condition shall not exceed the permissible values. The following applies: (a)
Non-permissible stresses from elastic and/or thermal deformations shall be avoided.
(b)
Statically determined configurations and components shall be preferred so that the stresses occurring are known and their effects on other components can be determined.
7.10.3.3 Gears Gears shall be in accordance with ISO 6336 (all parts) for spur and helical gears, taking into account ISO 1328-1 for accuracy. Gear wheels shall be made from material that has proven properties for the intended application and life of the gear. The dimensions of the gears shall be derived from the rated torque, material strength, and the driving gear groups. The type of connection shall not produce any non-permissible stresses on the gears. Irreversibility shall be avoided where the moment of inertia of the moved parts is greater than the moment of inertia of the moving parts. 7.10.3.4 Gear enclosures Gearing shall be guarded when it constitutes a hazard during normal operation or maintenance. Where gears are fully enclosed in a gear case, the gear case shall be oil-tight and sealed with a gasket or an appropriate sealing compound. The gear case supporting structure shall firmly secure the case in position and prevent it from coming loose during operation.
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
The gear case construction shall be rigid to ensure that the gear shaft alignments and centre distances are maintained under all working conditions. Drain plugs, breathers and oil-level indicators should be readily accessible. Gear cases should be provided with lifting lugs. For all gear cases, particular attention shall be paid to ensure proper lubrication of all gears and bearings. 7.10.3.5 Bearings and supports A component supported on a bearing, the bearing itself and its support structure shall be so designed that failure of a bearing shall not lead to the dropping of any major part of the crane or the load.
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AS 1418.1—2002
7.10.4 Couplings 7.10.4.1 General Selection of the type of coupling shall be made on the basis of the general design of the mechanism, its use and performance required in order to avoid vibrations and unwanted reactions. Alignment shall comply with the supplier’s instructions. When necessary, rotating parts shall be statically or dynamically balanced. 7.10.4.2 Clutches When sprag-type clutches are used in hoist and derricking systems, they shall incorporate a positive mechanical lock against failure or be designed to transmit twice the maximum torque imposed by the maximum line pull. Dry friction clutches shall be protected against rain and other liquids such as oil and lubricants. Toothed or dog clutches shall have at least four teeth or dogs and their mating recesses shall be undercut sufficiently to prevent inadvertent disengagement of the clutch. Clutches shall be arranged to permit adjustments where necessary to compensate for wear. The maximum permissible torque of the clutch shall be at least as high at any operating temperature as the torque impulses occurring during operations, taking into account the impulse frequency and the permissible wear. 7.11 DRIVING MEDIA The Power mechanism may be an electrical, hydraulic or pneumatic motor or an internal combustion engine. Manual driving mechanisms are also covered. The crane mechanism shall have sufficient power and torque to control the motions under the specified design conditions. Gravitational, inertial, in service wind, friction forces and mechanism efficiency shall be taken into account. Where engine exhaust gases are generated, they shall be discharged in a direction away from the operator and airconditioning system as applicable. 7.12 BRAKING
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
7.12.1 Braking media All methods of braking a crane shall be designed in accordance with the performance requirements Sections of this Standard where they exist, or other recognized national or international Standards. 7.12.2 Size and characteristics Brakes shall be capable of bringing the fully loaded crane to rest, without shock, in the shortest time, consistent with safe working, and shall arrest the crane safely under all in service conditions. Each brake shall be of torque rating, braking characteristics and heat-dissipation characteristics appropriate to its application on the crane. Each brake shall have an effective range of automatic torque adjustment to compensate for wear to maintain braking efficiency during periods of time between normal servicing. At the end of such adjustment range, the brake shall comply with this Clause. Drives which can be operated in an overspeed condition (e.g., frequency drives) shall be checked for the ability of the mechanical braking medium to dissipate the heat energy generated from kinetic energy during an emergency stop or power failure condition. www.standards.com.au
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NOTE: Specific test requirements for the various types of cranes are covered in the respective parts of AS 1418.
7.12.3 Environmental protection Where the crane is exposed to any adverse environmental conditions (e.g., moisture ingress) which may affect the operation of a brake, the brake shall be protected from such adverse environmental conditions so that the effectiveness of the brake shall not be impaired and the brake still complies with the requirements of Clause 7.12.2. 7.12.4 Accessibility Provision shall be made so that all parts of the brake that need regular inspection, service or maintenance are readily accessible. 7.12.5 Materials 7.12.5.1 General Materials shall comply with the relevant Australian Standards. 7.12.5.2 Friction lining Brake linings shall effectively resist wear at speeds, unit pressures and temperatures consistent with the application of the brake on which they are used. 7.12.5.3 Brake cone, disc, drum or equivalent friction-surface component Brake cones, discs, drums and equivalent components shall be manufactured from materials consistent with the mating friction lining. The grade, surface finish, heat treatment, hardness and similar properties of the material shall be such as to limit wear of the friction surface. Grey cast iron of grade less than 200 of AS 1830 and blackheart malleable iron shall not be used for brake components. 7.12.5.4 Springs
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
Springs shall be of the compression type and shall be manufactured from an appropriate grade of spring steel. Helical compression springs shall comply with BS 1726.1 so that— (a)
the pitch of the spring coils shall not allow a broken spring to intercoil when the spring is in the minimum working load condition;
(b)
when the spring is closed solid, the stress is not greater than the permissible design stress specified in BS 1726.1; and
(c)
where the spring is used on cranes of Classes C6, C7 and C8 or only one spring is used to apply the brake, the stress at maximum in service deflection does not exceed 75 percent of the permissible design stress specified in BS 1726.1.
7.12.6 Design The foot effort or hand effort and the movement required to operate a brake shall comply with Clause 11.4.1. Except for automatic brakes, each brake shall have means for maintaining the applied condition other than by continued application of the in service force. Hydraulic or pneumatic means shall not be used for retention of hydraulically and pneumatically applied brakes. 7.12.7 Operation Brake operation shall be fail-safe. Automatic brakes shall apply braking effort immediately power is interrupted to the motion in the mechanism of which the brake is a component.
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AS 1418.1—2002
Brake adjustment should be such that the operation time is appropriate to the type of motion. 7.12.8 Hoisting motion 7.12.8.1 General The hoisting motion brake shall comply with the appropriate part of AS 1418 and shall be designed to provide braking capable of automatically arresting and sustaining the load at any position within the hoisting range, upon: (a)
cessation of the application of the manual or powered hoisting effort; or
(b)
activation of the hoist-limiting device
Brake systems shall comply with the following requirements: (i)
In the static condition, they shall hold a minimum of 1.6 times the rated capacity
(ii)
From the dynamic condition, they shall arrest a minimum of 1.2 times the hoist rated capacity from the maximum lowering speed without a damaging snatch effect and without unacceptable overheating within an acceptable braking distance for the crane operation.
Torque shall be transmitted between the brake and the rope drum or equivalent via rigid mechanical means. 7.12.8.2 Emergency load lowering When emergency load-lowering is required, the hoist brake shall be capable of being released manually. The mechanism shall be arranged to ensure— (a)
the load is under control during lowering;
(b)
the lowering rate is limited to be compatible with the brake heat dissipation characteristics;
(c)
the brake(s) is(are) able to be released and reset without the requirement for tools; and
(d)
the brake will reset automatically upon release of the manual override mechanism.
Instructions for the operation of the manual release mechanism shall be provided on the hoist and in the operating manual. 7.12.8.3 Multiple brake hoists Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
For hoist systems fitted with two or more separate brake assemblies, the brakes shall be— (a)
mechanically independent of each other; and
(b)
arranged to avoid simultaneous application.
For service brakes, failure of any one brake shall not reduce the overall brake static torque below 1.1 times the rated capacity of the hoist. Where the additional brake(s) is used as an emergency or parking brake, each brake in the drive train shall comply with the torque requirements of Clause 7.12.8.1. Means shall be provided to monitor each brake, to verify its condition and operating status. 7.12.8.4 Dangerous goods lifting When lifting dangerous substances, as defined in the Australian Dangerous Goods Code, the hoist rated capacity shall not be less than 1.25 times the maximum lifted load.
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7.12.8.5 Special lifting applications For special lifting applications where a risk assessment has shown that the loss of one component in the hoist drive train would result in damage to the environment, property or personnel, an additional brake shall be fitted to the hoist drum. The following applies to the brake: (a)
The brake shall be controlled so that it is applied automatically the instant a speed no greater than 1.5 times the nominal lowering speed is reached.
(b)
The control equipment shall include an emergency stop function that will activate the brake
(c)
For single wire rope hoist, the coefficient of utilisation (Zp) shall not be less than 8.
For hoists, equipped with two independent wire ropes, failure of one rope shall not reduce the rope system coefficient of utilisation (Zp) below 3. 7.12.8.6 Lifting personnel When personnel are suspended in a work box designed in accordance with AS 1418.17, the requirements of AS 2550.1 shall apply. Otherwise hoists used in the suspension of personnel shall comply with Clauses 7.12.8.2 and 7.12.8.5 or as specified in the applicable part of AS 1418. NOTE: The use of a workbox shall be limited to those situations where it is necessary to elevate personnel to perform special tasks of short duration or where it is not possible to use a scaffold or a device designed specifically to lift personnel.
7.12.8.7 Molten metal handling For hoists lifting molten metal—
A1
(a)
where the hoist is equipped with a single rope and brake, the mechanical rating for the hoist shall not be less than M5 and the mass of the hoisted load shall not exceed 80% of the hoist rated capacity; or
(b)
where the hoist has multiple drives, the brakes shall comply with Clause 7.12.8.3, Items (a) and (b) and the combined braking effort shall be not less than 1.75 times the rated capacity
Failure of any one brake shall not reduce the overall brake static torque below 1.25 times the rated capacity of the hoist.
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The dynamic braking provisions given in Clause 7.12.8.1(ii), shall apply. 7.12.9 Travel and traverse motions The travel and transverse motions, where power driven, shall be provided with an in service brake, and where limiting devices are provided to control the travel motion, the brake shall be automatically applied by such limits. Where the crane is not cabin-controlled, the brake shall be applied automatically. Where the crane is cabin-controlled, the brake shall be capable of being locked on. For outdoor cranes, where automatically applied in service brake or the wheel-to-rail frictional forces, assuming a coefficient of friction between wheel and rail of 0.15, are insufficient to restrain the crane or part of the crane when subjected to out of service forces, e.g., wind forces, then an out of service brake shall be provided. Such brakes shall be automatic for cranes with the dead weight of the structure exceeding 20 t and shall not be applied until the crane is at rest. Where the driving power is transmitted through a hydraulic coupling or other non-positive medium, the brake shall be located on the driven side of such medium. The out of service brake shall be capable of restraining movement assuming a
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AS 1418.1—2002
coefficient of friction between wheel and rail of 0.15, or between hardened serrated pads and rail of 0.25. Outdoor cranes shall be provided with an out of service brake/anchorage system where the in service brake(s) is insufficient to restrain the crane or part of the crane when subjected to out of service forces, e.g., wind forces. Appropriate Parts of the AS 1418 series may provide detailed requirements for out of service brakes. 7.12.10 Luffing motion Luffing motions shall be provided with an automatically applied in service brake. Where luffing motion is achieved by use of a hoist, the requirements of Clause 7.12.8.5 shall apply. The brakes shall be designed to exert a restraining effort equivalent to 1.6 times the effect due to the rated load and the dead weight of the jib and 1.0 times the effect arising from in service wind, with the jib in the most unfavourable position. For the crane in the out of service condition, the brakes shall be designed to exert a restraining effort of at least 1.1 times the effect due to the dead weight of the jib and that due to out of service wind, in the most unfavourable jib position or in the specified out of service position. 7.12.11 Slewing motion Power-driven cranes and hoists shall be provided with brakes designed to bring to a halt, in a suitable time, the slewing motion taking into account the most unfavourable inertia and in service wind conditions, if applicable, and shall operate in the event of a power failure. For purposes of travel without a load, an effective slew-restraining device additional to the slew mechanism shall be provided, e.g., boom restraint. 7.13 MOTION LIMITS, INDICATORS AND WARNING DEVICES 7.13.1 Provision of limits Motion-limiting devices, including physical stops and buffers, shall be provided in accordance with the requirements specified herein and in the appropriate part of AS 1418 to obviate physical damage to the crane, part of the crane, due to movement of the crane, or part of the crane past its designed range of motion.
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Motion limiters, indicators and warning devices shall be selected only after consideration of failure mode and subsequent consequences. These devices shall be selected in accordance with methodology defined in AS 4024.1. 7.13.2 Range of limitation of motion The range of movement between operation of a motion-limiting device and cessation of movement shall be of sufficient magnitude to fulfil the object specified in Clause 7.13.1. 7.13.3 Operation of motion limit Motion-limiting devices shall be automatic. The operation of a motion-limiting device shall not create a hazard, e.g., due to gravity or inertia effects. 7.13.4 Indicators and warning devices Indicators and their associated equipment are applied to cranes to indicate load, working radius and other pertinent operational factors, and determine and display the operational conditions of the crane relative to its rated capacity limitations. The indicators may alert the crane operator when an overload condition is approached, reached or exceeded. www.standards.com.au
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Cranes may be provided with a combination of indicators or warning devices, such as the following: (a)
Load moment system.
(b)
Load indicator.
(c)
Working radius indicator.
(d)
Boom length indicator.
(e)
Boom angle indicator.
(f)
Level indicator (inclinometer).
(g)
Wind velocity indicator (anemometer).
(h)
Working zone indicator.
(i)
Proximity indicator.
(j)
Crane motion indicator.
The types of indicators or warning devices or combination thereof applicable to various types of cranes are specified in the appropriate part of AS 1418. 7.14 ROPES AND REEVED SYSTEMS 7.14.1 Ropes Each rope shall be of construction suitable for its particular application as defined in the appropriate part of AS 1418. 7.14.2 Components Components of fixed-rope systems and reeved systems shall comply with the following Australian Standards, where applicable: AS 1138, AS 2076, AS 2318, AS 2319, AS 2740, AS 2741 and AS 3777. 7.14.3 Tensiometers A tensiometer using deflection sheaves with D/d more than the values given in Table 7.18 shall be fitted only to the running section of the rope and the deflection shall have an included angle not less than 160°.
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7.15 GUYS, OTHER FIXED-ROPE SYSTEMS, AND STATIONARY ROPES Guys, other fixed-rope systems, and stationary ropes are fixed in their relative positions at both rope ends and are not subject to winding on a drum. Selection of such ropes shall be made in accordance with Clause 7.14.2 with Zp values modified in accordance with Table 7.15. The maximum rope tensions shall be established for the rope of the mechanism after consideration of the static forces and those forces resulting from maximum wind and impact conditions.
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AS 1418.1—2002
TABLE 7.15 MINIMUM COEFFICIENT OF UTILIZATION (Z p) FOR OTHER THAN REEVED SYSTEMS Classification of mechanism
Minimum coefficient of utilization (Z P)
M1 M2 M3
2.5 2.5 3.0
M4 M5 M6
3.5 4.0 4.5
M7 M8
5.0 5.0
7.16 REEVED SYSTEMS 7.16.1 Wire rope A1
A1
Except where there is insufficient data, the maximum design load applied to the rope shall be determined by rational dynamic analysis multiplied by Z p from Table 7.16.2.1, or as specified in the applicable part of AS 1418 to determine the minimum wire rope size. Where dynamic analysis cannot be carried out due to unavailable data, then the loadings specified in Clause 7.4 may be applied to determine the design load. Where the reeved system has more than 10 parts, allowance shall be made for frictional effects and the maximum rope tension shall be determined by the method given in Appendix G. 7.16.2 Wire rope selection procedure 7.16.2.1 General The procedure for selection of wire rope shall be in accordance with Clauses 7.16.2.2 to 7.16.2.7.
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NOTES: 1
A worked example of this procedure is given in Appendix H.
2
The lay of the rope is related to the rope anchorage point on the drum. Correct combinations of rope lay and anchorage configuration are given in Appendix I.
7.16.2.2 Selection of Z p values For reeved systems, Table 7.16.2.1 sets out the values of Z p , which shall be used for a particular classification of mechanism.
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TABLE 7.16.2.1 MINIMUM COEFFICIENT OF UTILIZATION (Zp) FOR REEVED SYSTEMS Classification of mechanism
Minimum coefficient of utilization (Z P)
M1 M2 M3
3.15 3.35 3.55
M4 M5 M6
4.0 4.5 5.6
M7 M8
7.1 9.0
7.16.2.3 Rope coefficient (C) The minimum value for C is a function of Z p and shall be calculated by the following equation: Zp
C=
γ × f × R0 ×
π 4
or
Zp K ′ × R0
. . . 7.16.2.2
where K′
= the empirical factor of minimum breaking load of a given rope construction as provided by the rope supplier
R 0 = the minimum tensile strength of the wire used in the rope, in megapascals Zp
= the minimum practical coefficient of utilization
f
= filling factor (factor dependent on rope construction) = total cross-sectional area of wires divided by the circular area defined by actual rope radius
γ
= loss factor = R1 min / R1
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where R1 min
= minimum breaking strength of rope wires (MPa)
R1
= calculated breaking strength of the rope = metallic cross-sectional area × ultimate tensile strength of the rope wires
7.16.2.4 Calculation of minimum rope diameter The minimum diameter of the rope, d min , (mm) shall be calculated by the following equation: d min = C S R
. . . 7.16.2.3
where S R = the maximum wire rope tension, in newtons, which is obtained by considering the following factors:
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AS 1418.1—2002
(a) Rated capacity of the appliance. (b) Mass of the pulley block or other lifting attachments that increase rope tension. (c) Mechanical advantage of rope reeving. (d) Efficiency of the rope reeving. (e) The mass of the suspended length of the hoist rope, which shall be included when the load handled is more than 5 m below the slewing mechanism of the lifting appliance. (f) Load due to acceleration (and retardation) of the load on the hook, if in excess of 10% of the vertical load. (g) Included angle of the rope at the upper hoisted position, if the rope angle is greater than 22.5°. 7.16.2.5 Minimum wire rope breaking load The minimum breaking load (F o) of the particular rope intended for use is given by the following equation: Fo = S R Z p
. . . 7.16.2.4
where Zp
= the minimum practical coefficient of utilization
7.16.2.6 Dangerous goods applications of wire rope For lifting of dangerous goods and the handling of molten metal— (a)
no classification group lower than M5 shall be used; and
(b)
for M5 and higher classifications, the Z p value shall be increased by 25% except for M8.
7.16.2.7 Personnel applications for wire rope For applications involving lifting of personnel, a rope design factor not less than 8 shall be applied to the load comprising the personnel and the lifting cage, where used. 7.16.3 Fleet angle from drum or sheave
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The fleet angle of the rope shall not exceed 5° (1 in 12 slope) from the direction of the groove for grooved drums and sheaves, or 3° (1 in 19 slope) for ungrooved drums. 7.16.4 Rope anchorages Rope anchorages to rope-winding drums shall comply with Clause 7.19.2.3. Other rope anchorages shall be arranged to freely align with the direction of the pull of the rope, and shall be readily accessible. 7.16.5 Rope equalizers The rope equalizer shall ensure that the force on the rope is automatically equalized and rope equalizers shall be readily accessible. Where a sheave or sheave segment is used, the diameter shall comply with Clause 7.18. 7.16.6 Overhauling weight Where an overhauling weight is applied to a hoisting rope, the overhauling weight shall be attached to the rope by means of a swivel. The overhauling weight shall not be attached directly to the rope. www.standards.com.au
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7.16.7 Fibre rope Fibre rope, when designed for use in an application, should have a design factor in accordance with the recommendations of AS 4142. 7.17 SHEAVES 7.17.1 Materials Sheaves shall be made of a material complying with one of the following Australian Standards, of a grade specified below, or of an equally suitable grade of material: (a)
Aluminium—AS 1874.
(b)
Grey cast iron—AS 1830, grade not less than Grade 200.
(c)
Nodular graphite cast iron—AS 1831.
(d)
Steel castings—AS 2074; grades C1, C2 and C3.
(e)
Steel plate—AS 3678.
(f)
Malleable iron castings—AS 1832.
7.17.2 Design The rope groove of a sheave shall be an arc of minimum radius 0.535 times the nominal diameter of the rope and shall be tangential with sides flared with an included angle of 45° symmetrical about the centre-line of the groove. The groove shall be smoothly finished and free from surface defects liable to damage the rope. The edge between grooves shall be rounded. NOTE: For guidance on groove profiles for wire rope sheaves, see Appendix J.
7.17.3 Diameter of sheave The diameter of each sheave shall comply with Clause 7.18. 7.17.4 Sheave guard Where there is a possibility of the rope being dislodged from the sheave, for example, when the rope is not continually under load, the sheave shall be provided with means to retain the rope in the groove.
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Where required, sheave enclosures shall protect personnel from injury and protect the sheaves from falling debris and similar. Such sheave enclosures shall not prevent the wound condition of the wire rope on the sheave from being viewed. 7.18 DRUM AND SHEAVE DIAMETERS The diameter of each drum and sheave shall be measured at the pitch diameter of the groove and, except where specified otherwise in the appropriate part of AS 1418, shall be not less than the value specified in Table 7.18, as appropriate, to the following equation: NOTES: 1
For guidance on groove profiles for wire rope sheaves, see Appendix J.
2
For guidance on groove profiles for rope drums, see Appendix K.
D d ≥ h dd min ; or
. . . 7.18(1)
D s ≥ hsd min ; or
. . . 7.18(2)
D e ≥ he d min
. . . 7.18(3)
where D d = pitch diameter of drum Standards Australia
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hd
= minimum ratio for drum
d
= nominal diameter of rope
AS 1418.1—2002
d min = minimum design diameter of rope D s = pitch diameter of sheave hs
= minimum ratio for sheave
D e = pitch diameter of rope equalizer sheave he
= minimum ratio for rope equalizer sheave
Where a deflection sheave tensiometer is fitted, it shall be fitted only to the running section of the rope. Where the included angle of the deflected rope is not less than 160°, the ratio of deflection the sheave diameter to the rope diameter shall be not less than 3. TABLE 7.18 RATIOS OF DRUM AND SHEAVE PITCH DIAMETERS TO ROPE DIAMETER Minimum ratio of drum and sheave pitch diameter to steel wire rope diameter (D/d) Classification of mechanism
Drums
Sheaves
Rope equalizer sheaves
(hd)
(h s)
(he )
M1 M2 M3
11.2 12.5 14.0
12.5 14.0 16.0
11.2 12.5 12.5
M4 M5 M6
16.0 18.0 20.0
18.0 20.0 22.4
14.0 14.0 16.0
M7 M8
22.4 25.0
25.0 28.0
16.0 18.0
7.19 DRUMS 7.19.1 Materials
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Drums shall be made of a material complying with one of the following Australian Standards, of a grade specified below, or of an equally suitable material and grade: (a)
Grey cast iron—AS 1830, grade not less than Grade 200.
(b)
Nodular graphite cast iron—AS 1831.
(c)
Steel castings—AS 2074.
(d)
Steel plate—AS 3678.
7.19.2 Design 7.19.2.1 Grooved drum Grooved drums shall be designed to have not less than two occupied grooves when the rope for each connected rope end is fully paid out. The drum should be of adequate size to accommodate all the rope in a single layer with not less than one groove unoccupied for each part of rope leaving the drum.
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Where it is not possible to accommodate the rope in a single layer, the drum shall be flanged at the ends where the rope is multi-layered, for a radial distance of not less than 1.5 rope diameters beyond the rope in the outer layer when the rope is fully wound on the drum. Where the rope is accommodated in less than two complete layers, the drum shall be flanged at the end, remote from where the rope is anchored. Where the rope is accommodated in two complete layers or more, the drum shall be flanged at each end. Provision shall be made for the rope to be guided from each layer to the next. NOTE: The face of a brake, gear, or other component mounted at the end of the drum may be considered as being a flange provided that it is a flat face and is of the correct outside diameter.
The groove shall be an arc of minimum radius 0.535 times the nominal diameter of the rope and subtending an included angle not less than 130°. Groove profiles for rope drums shall be in accordance with Appendix K. Where the drum is intended to hold only one or two layers of rope, the groove pitch shall be not less than 1.06 times the nominal rope diameter and shall be of dimension such that the rope in leaving the drum does not contact the adjacent turn of rope under any condition of operation. Where the drum is intended to hold more than two layers of rope, the groove pitch shall provide minimal rope clearance, and special provision shall be made to ensure correct coiling of the outer layer of rope under all conditions of operation. The groove shall be smoothly finished and free from surface defects liable to damage the rope. The edge between grooves shall be rounded. 7.19.2.2 Ungrooved drum Ungrooved drums shall be flanged at both ends for a radial distance of not less than two rope diameters beyond the rope in the outer layer when the rope is fully wound on the drum. NOTE: The face of a brake, gear, or other component mounted at the end of the drum may be considered as being a flange, provided that it is a flat face and is of the correct outside diameter.
7.19.2.3 Rope anchorage All drum ropes shall be mechanically anchored and where the anchorage relies on a clamping action it shall comprise two or more clamps.
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Where the rope may wind back on the drum, the rope anchorage without any turns on the drum shall be capable of withstanding not less than twice the load due to the nominal force on the rope. In such circumstances, the rope shall not be damaged. Where the rope is not capable of winding back on the drum and where at least two or more turns of rope remain on the drum when the hook is at the bottom limit of the range of hoisting, the frictional effect of such turns may be considered as fully contributing to the capacity of the anchorage, which shall be capable of withstanding not less than twice the rope load due to the nominal force on the rope at the load-off point on the drum. The rope anchorage shall be located taking into consideration the rope lay and drum rotation. NOTE: For guidance on the method for locating the anchorage point on a drum, see Appendix I.
7.19.3 Diameter of drum The diameter of the drum shall comply with Clause 7.18. 7.19.4 Actual thickness of drum shell The thickness of the drum shall, with due allowance for manufacturing allowance and inaccuracies, e.g., machining, core shift in casting and out-of-roundness in rolling, be not less than the value calculated in accordance with Clause 7.19.5. Standards Australia
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AS 1418.1—2002
A detailed method of stress analysis of a crane drum in accordance with Appendix L may be used in lieu of Clause 7.19.5. The thickness of the drum shell shall be not less than 5 mm for grey iron drums or not less than 3 mm for drums of material other than grey cast iron. 7.19.5 Theoretical thickness of drum shell (abbreviated method) The minimum theoretical thickness of the drum shell shall be calculated by the following equation:
(
2
TD = TDB + TDB TDC + TDC
)
2 1/ 2
. . . 7.19.5
where TD
= minimum theoretical thickness of the drum shell measured, for a grooved drum, to the root of the rope groove, in millimetres ≥ 5 mm for grey cast iron drums (see Clause 7.19.4) ≥ 3 mm for drums of material other than grey cast iron (see Clause 7.19.4)
T DB
= minimum theoretical thickness of drum shell allowing only for beambending stresses, in millimetres = 1250
T DC
M 2
DDM Fb
= minimum theoretical thickness of drum shell allowing only for compressive stresses, in millimetres = 1000 K RL PRS − 0.15 d (for grooved drums) p Fc = 1000 K RL PRS (for ungrooved drums) p Fc
M
= bending moment due to beam action of unfactored, i.e. static, rope load (PRS), in newton metres
Fb
= permissible bending stress, in megapascals
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= 0.185 times the tensile strength for grey cast iron = 0.20 times the tensile strength for nodular graphite cast iron with elongation less than 12 percent = 0.67 times the yield stress for materials with elongation not less than 12 percent D DM = mean diameter of drum shell, in millimetres = DDN − TD D DN = nominal diameter of drum shell = for grooved drums, the diameter measured between the roots of the rope groove, in millimetres = for ungrooved drums, the outside diameter of the drum shell, in millimetres K RL
= rope layer factor and rigidity constant of drum shell = 1.0 for single layer
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= 1.3 for two layers of rope with wire-rope core (WRC) or wire-strand core (WSC) = 1.4 for two layers of rope with fibre core (FC) = 1.5 for three layers of rope with WRC or WSC = 1.6 for three layers of rope with FC = 1.6 for more than three layers of rope with WRC or WSC = 1.8 for more than three layers of rope with FC P RS
= maximum unfactored, i.e. static, rope load, in kilonewtons
p
= pitch of rope coils, in millimetres
Fc
= permissible compressive stress (see Table 7.19.5), in megapascals
d
= nominal diameter of rope, in millimetres TABLE 7.19.5 PERMISSIBLE COMPRESSIVE STRESS
1
2
Material
Standard number
3
4
5
6
7
Permissible compressive stress, MPa
Grey cast iron
Nodular graphite cast iron
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Cast steel
Steel plate
AS 1830
AS 1831
AS 2074
AS/NZS 3678
Grade
Drum diameter, mm ≤250
>250, ≤500
>500, ≤750
>750
T220
77
88
99
110
T260
80
90
101
111
T300
85
85
105
115
T350
95
95
120
130
T400
105
105
135
145
370-17
100
130
130
140
400-12
110
140
140
150
500-7
120
150
150
165
600-3
120
150
150
165
700-2
140
165
165
165
C4-1
125
150
165
170
C5
150
180
180
180
250
125
150
165
170
300
150
180
190
190
350
175
210
210
210
400
200
240
240
240
7.20 WHEEL AND RAIL SYSTEMS 7.20.1 Selection of wheels and rails Crane wheels and rails form a mutually interactive system. Wheels and rails shall comply with Clauses 7.20.3 and 7.20.6 respectively, and their selection shall take into account the following: (a)
Wheel loading (known or assumed).
(b)
The service to which the crane shall be subjected.
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(c)
AS 1418.1—2002
Grade of material of wheels and of rails.
7.20.2 Wheel loading For design purposes, the mean wheel loading (PW mean ) shall be calculated, without application of the dynamic factors specified in Section 4, by the following equation: PW mean =
PW min + 2PW max 3
. . . 7.20.2
where P W mean = the maximum unfactored wheel loading, in kilonewtons P W min
= loading applied by the wheel to the rail with the crane arranged within its normal range of in service conditions (including loading) to produce minimum loading between the wheel and rail, in kilonewtons
P W max
= loading applied by the wheel to the rail with the crane arranged within its normal range of in service conditions (including loading) to produce maximum loading between the wheel and rail, in kilonewtons
For the purpose of design of the wheel, P W max shall be not less than the maximum load due to exceptional circumstances such as where a tall gantry crane in an exposed location is subjected to very high wind loading and where a crane is subjected to frequent buffer collisions. The value of P W min shall be taken for load combinations 1 to 5 (frequently occurring loads) and in no case shall wind load be included. 7.20.3 Wheels 7.20.3.1 Material The material for track wheels shall comply with the relevant Australian Standard (refer Table 7.20.3.3). 7.20.3.2 Load capacity of wheels (P W ) The wheel load (P W mean ) calculated in accordance with Clause 7.20.2 shall be not greater than the permissible wheel load (P W) calculated by the following equation: PW = 0.001 C C C W D W B WE FpW
. . . 7.20.3.2
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P W = permissible wheel loading, in kilonewtons C C = group classification coefficient (see Clause 7.20.3.4) C W = wheel-speed coefficient (see Clause 7.20.3.5) D W = wheel-tread diameter, in millimetres B WE = effective wheel-tread width is equal to B TE in Clause 7.20.6.5(a) and (b) or where not applicable, from Clause 7.20.3.6(c) F pW = permissible unfactored bearing stress between wheel and rail (see Clause 7.20.3.3), in megapascals. 7.20.3.3 Permissible unfactored bearing stress (F pW ) The unfactored bearing stress between wheel and rail (F pW) shall be calculated by the following equation or selected from Table 7.20.3.3: FpW = 1.5 + 0.007 FuW
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. . . 7.20.3.3
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where F pW = permissible unfactored bearing stress between wheel and rail, in megapascals F uW = tensile strength of wheel material or, where the wheel is tyred, the tyre material, in megapascals. Where the wheel tread is surface-hardened, FpW shall apply to the tensile strength of the material prior to surface hardening. For wheels other than ferrous-metal wheels, the value used for F pW shall be as recommended by the manufacturer. TABLE 7.20.3.3 PERMISSIBLE UNFACTORED BEARING STRESS 1
Material
Grey cast iron
Nodular graphite cast iron
Steel fabrication
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Steel forging
2
4
5
Tensile strength of material
Permissible unfactored bearing stress (FpW)
MPa
MPa
AS 1830
T220 T260 T300 T350 T400
200 250 300 350 400
2.9 3.25 3.60 3.95 4.30
AS 1831
370-17 400-12 500-7 600-3 700-2 800-2
370 400 500 600 700 800
4.09 4.30 5.00 5.70 6.40 7.10
—
AS/NZS 3678 AS/NZS 3679
250 300 350 400
410 430 450 480
4.37 4.51 4.65 4.86
—
AS 1448
K3 K4 K5 K6 K8 K9 K10
410 500 540 600 480 540 580
4.37 5.00 5.28 5.70 4.86 5.28 5.56
—
Standard number
3
Grade
6
Remarks
Crane-motion speed shall not exceed 0.65 m/s; runway rails shall be continuous
7.20.3.4 Group classification coefficient (CC ) The value of the group classification coefficient (CC) shall be the appropriate value specified in Table 7.20.3.4 corresponding to the classification applicable for the crane-motion in which the wheel is used.
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AS 1418.1—2002
TABLE 7.20.3.4 GROUP CLASSIFICATION COEFFICIENT (C C) Group classification of mechanism M1 and M2 M3 and M4 M5 M6 M7 M8
Coefficient (C C) 1.25 1.12 1.0 0.9 0.8 0.71
7.20.3.5 Wheel-speed coefficient (CW ) The value of the wheel-speed coefficient (CW) shall be the appropriate value specified in Table 7.20.3.5. TABLE 7.20.3.5 WHEEL-SPEED COEFFICIENT (CW ) Rotational frequency of wheel rev/sec
Wheel-speed coefficient (C W)
Rotational frequency of wheel rev/sec
Wheel-speed coefficient (C W)
3.33 2.66 2.00
0.66 0.72 0.77
0.46 0.41 0.37
1.02 1.03 1.04
1.86 1.66 1.50
0.79 0.82 0.84
0.33 0.30 0.27
1.06 1.07 1.09
1.33 1.18 1.05
0.87 0.89 0.91
0.23 0.21 0.19
1.10 1.11 1.12
0.93 0.83 0.75
0.92 0.94 0.96
0.17 0.13 0.10
1.13 1.14 1.15
0.67 0.59 0.52
0.97 0.99 1.00
0.09 0.08 0
1.16 1.17 1.3
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7.20.3.6 Tread and flange profile The following applies: (a)
Profile Typical tread and flange profiles are shown in Figure 7.20.3.6. Other (special) profiles are used for particular specialized applications. The wheel type shall correspond to the wheel track with which it is used in accordance with Table 7.20.3.6(A).
(b)
Tread and flange dimensions The thickness (T F ) of each flange (see Figure 7.20.3.6) shall be not less than the following when new: (i)
if D W ≤ 400 mm; TF =
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DW +8 50
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(ii)
70
if D W > 400 mm; TF =
DW +6 50
(iii) if the wheel is of grey cast iron; TW =
DW + 10 50
where TF
= flange thickness (see Figure 7.20.3.6), in millimetres
D W = wheel tread diameter, in millimetres The minimum flange thickness (T F ′) shall be calculated as follows, and this information shall be provided with the crane in accordance with Clause 16.3: NOTE: The minimum flange thickness (T F′) is to be provided with the crane to allow users to institute a replacement regime to ensure flange thicknesses below T F ′ are not used. A1
TF N = minimum worn flange thickness ≥
6M F Ft × X
where Ft
= permissible bending strength, MPa (see Clause 7.9.2.8)
X
= length of rail to wheel flange engagement (mm) 2
(D ) (D ) = 2 w + HF − w 2 2
2
where D W = wheel tread diameter (mm) M F = flange bending moment
A1
= H F × POT where
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POT = oblique travel force (see Clause 4.6.5) H F = flange depth (mm)
≥ q=
DW + 10 50
The height of the flange (see Figure 7.20.3.6) shall be not less than
DW + 10 . 50
For a double-flanged wheel, the tread width (see Figure 7.20.3.6) shall be not less than the width of the railhead, plus twice the rail span tolerance (Table 7.20.9), plus the manufacturer’s tolerance of span of the crane, plus 4 mm, except where wheels on the opposite rail are laterally free in position. Where the clearance between wheel flanges and railheads permits lateral float greater than one-fourth of the width of the railhead, care shall be taken to ensure that lateral movement does not affect clearances (see Clause 12.7.4) and correct operation of electrical collectors (see Clause 8.14). Standards Australia
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Effective wheel-tread width (BWE ) The effective wheel-tread width (BWE) shall be as specified in Table 7.20.3.6(B).
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(c)
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FIGURE 7.20.3.6 TYPICAL WHEEL-TREAD PROFILES Standards Australia
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TABLE 7.20.3.6(A) TREAD AND FLANGE PROFILE Wheel track
Standard rail section (i.e. conforming to AS 1085.1)
Wheel type (see Figure 7.20.3.6) A
B
C
D
E
F
G
H
J
Unflanged Square or rectangular billet or similar section
Flanges of each type may be tapered or parallel sided For Types A, D and G, the fillet radius between tread and flange shall be not less than the railhead radius With cylindrical tread
B
E
H
C
F
J
Unflanged
Remarks
Flanges of each type may be tapered or parallelsided With cylindrical tread Flanges of each type may be tapered or parallelsided
Flange, having a horizontal wheeltrack surface, of a beam, girder or similar structural element
G J K L N
Type M may be used where the wheel axle is canted to compensate for the wheel-tread angle In applications of intermittent and light-duty loadings, type M may be used without the provision specified above, although this is not good practice With cylindrical, symmetrical or asymmetricalspherical tread
Unflanged
With tapered tread may be used where the wheel axle is canted to compensate for the wheel-tread angle Flanges for each type may be tapered or parallelsided
Beam flange, having an inclined wheel-track surface (e.g., taperedtread beam)
K L M N
Type G, H or J may be used where the wheel axle is canted to compensate for the beam-flange taper angle In applications of intermittent and light-duty loadings, Type G, H or J may be used without the provision specified above, although this is not good practice
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With tapered, symmetrical-spherical or asymmetrical-spherical tread Unflanged
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With cylindrical tread may be used where the wheel axle is canted to compensate for the beamflange taper angle
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TABLE 7.20.3.6(B) EFFECTIVE WHEEL-TREAD WIDTH (B WE) Wheel track
Rail
Flange of beam, girder or similar
Horizontal flange of beam, girder or similar Tapered flange of beam, girder or similar *
Wheel type
Effective wheel-tread width (B WE)
Double-flanged (see Figure 7.20.3.6)
BTE (see Clause 7.20.6.5)
Single-flanged (see Figure 7.20.3.6)
BT – 2RT or B W (see Figure 7.20.3.6), whichever is applicable
Unflanged
BT – 2RT or B W – 0.75 RT (see Clause 7.20.3.7), whichever is applicable
Or BTE (see Clause 7.20.6.5) if on convex surface rail
Cylindrical or tapered tread (see Figure 7.20.3.6)
B W (see Figure 7.20.3.6 or Clause 7.20.3.7)
Symmetrical spherical tread (see Note) (see Figure 7.20.3.6)
B W or 0.2 R WT *, whichever is the lesser (see Figure 7.20.3.6) B W (see Figure 7.20.3.6) or 0.1 R WT * (see Figure 7.20.3.6), whichever is the lesser
Asymmetrical spherical tread (see Figure 7.20.3.6)
B W (see Figure 7.20.3.6) or 0.2 R WT * (see Figure 7.20.3.6), whichever is the lesser
The values of 0.2R WT and 0.1RWT assume contact between wheel tread and wheel-track surface to extend 0.09 radius of wheel-tread arc from the central point of contact.
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NOTE: Where a wheel with symmetrical spherical tread runs on a tapered flange, the central point of contact is displaced towards the unflanged side by an amount equal to R WT times the sine of the flange-taper angle. Where the remaining distance is less than 0.1R WT, the effective wheel-tread width shall be reduced accordingly (see Figure opposite).
LEGEND: B WE = effective wheel-tread width, in millimetres BT = railhead width, in millimetres RT = railhead radius, in millimetres B W = wheel-tread width, in millimetres R WT = wheel-tread radius (spherical wheel-tread), in millimetres
7.20.3.7 Unflanged wheels Unflanged wheels shall be used only where provision is made for lateral guidance of the crane or part of the crane supported by the wheels, e.g., by guide rollers. The tread width (B WE) of a cylindrical or tapered-tread unflanged wheel shall be the width of the tread, excluding corner radii for flat rails or excluding 4/3 of corner radii for convex rail heads. 7.20.3.8 Matched wheels Where driving wheels are connected together mechanically, the difference in the tread diameter shall not exceed 0.1 percent of the larger diameter or 0.25 mm, whichever is the lesser.
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7.20.3.9 Overhung wheels Where a track wheel or guide roller is overhung, i.e. cantilevered, positive means shall be provided to retain the wheel on its axle in service. 7.20.3.10 Anti-drop and anti-derailment pads For safe operation, anti-drop and anti-derailment pads, where applicable, shall be provided as specified by the appropriate part of AS 1418. For a crane or part of a crane running on rails, means shall be incorporated in the structure of the crane, or part of the crane, to prevent it from falling more than 25 mm and from excessive lateral movement in the event of wheel or axle failure. 7.20.4 Tyres Where a crane wheel is fitted with a steel tyre, the nominal inside diameter of the tyre should conform to Table 7.20.4. TABLE 7.20.4 TYRE INSIDE DIAMETER Nominal tread diameter
Nominal inside diameter
400 500 630
310 400 500
710 800 900
580 670 750
1 000 1 120 1 250
850 970 1 100
7.20.5 Side guide rollers Side guide rollers shall comply with the requirements for unflanged wheels specified in Clause 7.20.3.7. 7.20.6 Rails
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7.20.6.1 Material Rails shall comply with AS 1085.1 or DIN 536-1, or shall be of other suitable rolled-steel section and shall be designed for a 25 year life if permanently attached (e.g., welded) or may be designed for a 10 year life if easily removable (e.g., held by hook-bolts or clips). 7.20.6.2 Load capacity of rail (PT ) The wheel loading (PW mean ) applied to a rail and calculated in accordance with Clause 7.20.2 shall be not greater than the permissible mean wheel load on rail (P T ) calculated by the following equation: PT = C R PTS
. . . 7.20.6.2
where P T = permissible mean wheel loading on rail, in kilonewtons
CR =
20 000 (NXW )2 / 3
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P TS = permissible unfactored wheel loading on rail (see Clause 7.20.6.4), in kilonewtons N XW = number of stress cycles applied by the wheels to the rail at the most frequently used portion of the rail (see Clause 7.20.6.3) NOTE: A stress cycle occurs at any position along a rail when the bearing stress in the railhead fluctuates through a cycle due either to movement of a wheel along the rail or to variation of loading through a stationary wheel when the crane load is handled through a load cycle with the crane, or part of the crane, stationary.
Where cranes of different classes operate on the same section of crane track, P T shall be calculated directly from the equation specified in this Clause, NXW being the sum of the number of stress cycles due to the wheels of each crane. 7.20.6.3 Number of stress cycles applied by wheels to rail (N XW ) The number of stress cycles applied by wheels to a rail (N XW) (see Clause 7.20.6.2) shall be determined by the following equation except where specified otherwise in the appropriate part of AS 1418: N XW = 2U n N w
. . . 7.20.6.3
where N XW = number of stress cycles applied by the wheels to the rail, minimum 8 × 10 5 and maximum 38 × 10 5 Un
= number of load applications of crane over design life of crane where U n varies from U0 to U 9 as defined in Table 2.3.2 NOTE: The values for the number of operating cycles given in Table 2.3.2 may be adjusted proportionally to allow for the lesser design life of components with a minimum being 40% to allow for a minimum design life of 10 years for readily removable rails (e.g., attached by hook-bolts or clips).
NW
= number of wheels which travel along a crane rail
7.20.6.4 Permissible unfactored wheel load (P TS ) For the rails listed in Table 7.20.6.4, the permissible unfactored wheel load on a rail (P TS) shall be calculated from the following equation: PTS = D W p TS
. . . 7.20.6.4(1)
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where P TS = permissible unfactored wheel loading, in kilonewtons D W = wheel tread diameter, in millimetres p TS = permissible load (see Table 7.20.6.4), in kilonewtons per millimetre (of wheel diameter)
A1
For rails other than those listed in Table 7.20.6.4, the permissible unfactored wheel load (P TS) shall be calculated from the following equation: PTS = 0.0049 D W BTE C p
. . . 7.20.6.4.(2)
where B TE = effective railhead width (see Clause 7.20.6.5), in millimetres F C p = YT 400 Standards Australia
2
. . . 7.20.6.4.(3)
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F YT = yield stress of rail material, in megapascals TABLE 7.20.6.4 PERMISSIBLE LOAD (p TS) Rail profile Designation
Standard (if applicable)
Rail mass kg/m
Ultimate tensile strength (min) (MPa)
Permissible load (p TS) kN/mm of wheel diameter
10
JIS E1103
10.1
580
0.071
15
JIS E1103
15.2
580
0.089
22
JIS E1103
22.3
650
0.169
30
JIS E1101
30.1
700
0.246
AS 41
AS 1085.1
40.7
820
0.264
AS 50
AS 1085.1
50.8
940
0.358
53
AS 1085.1
53.0
940
0.424
AS 60
—
61
940
0.383
RE 68
—
67.6
960
0.442
A 45
DIN 536.1
22.1
690
0.153
A 55
DIN 536.1
31.8
690
0.187
A 65
DIN 536.1
43.1
690
0.220
A 75
DIN 536.1
56.2
690
0.248
A 100
DIN 536.1
74.3
690
0.334
A 120
DIN 536.1
100.0
690
0.412
A 150
DIN 536.1
150.3
690
0.527
73
—
73.6
980
0.570
86
—
85.5
980
0.934
192
—
192.0
1080
1.518
7.20.6.5 Effective railhead width (BTE ) The effective railhead width (B TE) shall be calculated by the following equations:
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A1
(a)
Where the top surface of the railhead is flat— BTE = BT − 2RCR
(b)
For standard rail sections with convex top railhead surface with one corner radius— BTE = BT −
(c)
4 RCR 3
For American Railway Engineering Association (AREA) type rail with railhead surface determined by three radii with two corner radii— BTE =
2 BT 3
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7.20.7 Rail fastening and joining 7.20.7.1 Methods Rails shall be secured to the runway beams or crane girder by a method that takes into account— (a)
horizontal wheel forces induced in the rail;
(b)
rail alignment requirements;
(c)
duty of the runway system;
(d)
rail profile; and
(e)
rail material specification.
7.20.7.2 Welding 7.20.7.2.1 Rail section profiles Securing rail to runway girders by welding shall be limited to sections less than or equal to 40 kg/m rail profiles. The welding procedure applied to securing the rail to the runway beam shall take into account the following: (a)
Matching section thicknesses.
(b)
Differences in rail and girder material specification.
(c)
Magnitude of induced stresses, including longitudinal bending shear stress, fatigue and weld shrinkage residual stress.
(d)
Pre-heat-treatment and post-heat-treatment.
7.20.7.2.2 Billet sections The design of the weld, securing the billet to the top flange of the runway or crane girder, shall be sized to take into account the longitudinal shear stresses due to bending. The welding procedure applied to securing the billet to the runway beam shall take into account the factors outlined in Clause 7.20.7.2.1. 7.20.7.3 Direct bolted Where the rail is bolted directly to supporting steelwork, the rail and steelwork shall be match-drilled. Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
7.20.7.4 Hook bolts Hook bolts are suitable for use on standard rail sections less than or equal to 30 kg/m profiles and where the top flange of the runway beam is too narrow for the application of a rail clip or clamp. The hook bolts shall be placed on alternate sides of the rail at 75 mm to 100 mm centres, spaced at centres no greater than 600 mm. Each hook bolt shall be secured by a lock nut after final positioning. Finished hook bolts shall be able to be straightened by at least 50% of the deformation during manufacture under the test without brittle fracture. Verification shall be carried out by testing at least one sample from each batch. NOTES: 1
Ductile hook bolts are necessary to prevent fracture and falling of the bolts and the resulting hazard to personnel under the runway.
2
Hook bolts do not allow longitudinal movement of the rail. Hence, it is recommended that hook bolts, as a rail securing method, should not be used on runways longer than 200 m.
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AS 1418.1—2002
7.20.7.5 Rail clips Rail clips are either forged, cast or fabricated devices that have been shaped to suit the flange shape of a particular rail profile. Rail clips secure the rail in position by a clamping action on the flange with a single bolt. This bolt can be either a through bolt on the top flange of the runway girder or integral with the clip base plate which, in turn, has been welded to the girder top flange adjacent to the rail. Clips shall be designed to— (a)
prevent rotation of the clip due to longitudinal movement of the rail; and NOTE: Where rotation of the clip cannot be prevented, a system of snug block located midway between the clips can be used to prevent lateral drift of the rail. The snug blocks should be welded to the girder top flange adjacent to the rail in its correct position.
(b)
develop the full strength of the securing bolt.
The clip shall be secured by a locking nut to prevent loosening in service. The clips shall be arranged in pairs located on opposite sides of each side of the crane rail and spaced at centres not greater than 600 mm, or as recommended by the competent person or manufacturer. NOTE: Rail clips are best suited for duty on runways with a duty classification of less than or equal to C4.
7.20.7.6 Rail clamps Rail clamps are either forged, cast or fabricated devices that have been shaped to suit the flange shape of a particular rail profile. The clamps secure the rail in position by a clamping action on the flange with two bolts. These bolts can be either a through bolt on the top flange of the runway girder, or integral with the clamp base plate which, in turn, has been welded to the girder top flange adjacent to the rail. The clamps shall be designed to— (a)
prevent rotation of the clip due to longitudinal movement of the rail; and NOTE: Where the clamp design does not prevent lateral drift of the rail, a system of snug blocks located midway between the clamps can be used. The snug block should be welded to the girder top flange adjacent to the rail in its correct position.
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(b)
develop the full strength of the securing bolts.
The clamp bolts shall be secured by a locking nut to prevent loosening during service. The clamps shall be arranged in pairs located on opposite sides of each side of the crane rail and spaced at centres not greater than 900 mm, or as recommended by the clamp designer or manufacturer. NOTE: Rail clamps are best suited for duty on runways with a duty classification of greater than or equal to C5.
7.20.7.7 Laid-on sleepers Where rails are laid on timber, concrete, steel or other types of sleepers, the rail shall be attached by means of dog-spikes or other attachment of strength appropriate to the rail with which they are used. Spacing shall be at sufficiently close centres to retain the rail in alignment as specified in Clause 7.20.9.
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7.20.8 Rail joints The number of gaps in the length of a rail system should be minimized. Where a gap in the rail is needed for expansion or other purposes, the top face of the rail shall be flush, and the gap distance shall be not greater than 3 mm. Rail joints should not coincide with a joint in the rail-supporting structure or a joint on the opposite runway. Fishplates or equivalent means of maintaining joint alignment shall be provided at all non-welded joints of standard rail sections. The shock loading effects of joints on crane runway systems classified greater than C5 cannot be underestimated. It is recommended that fully welded continuous rail is used in these applications. The welding process used for joining rails shall take into account— (a)
the rail material specification;
(b)
appropriate pre-weld heating and post weld cooling;
(c)
the effects of weld shrinkage on the rail system; and
(d)
surface hardness of the welded joint, to minimize dips developing in the joint during service.
7.20.9 Rail alignment Each pair of rails shall be aligned within the limitations set out in Table 7.20.9. 7.20.10 Runway flanges—Lateral support The top flange on all runway beams at the point of support should be braced directly to the column or other supporting structure to prevent lateral movement.
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NOTE: AS 1418.18 gives further guidance on the design of crane runways and monorails.
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TABLE 7.20.9 RAIL ALIGNMENT Description Span, centre-to-centre of rails
Tolerances for crane classes C1 to C4
Tolerances for crane classes C5 to C9
ST ≤ 15 m: A = ±3 mm ST > 15 m: A = ±[3 + 0.25 × (ST – 15)] mm
Where ST is in metres
Tolerance on the plan view centre-line of each rail
B = ±5 mm
However, the following dimension shall not be exceeded over a measuring length of 2 m: b = ±1.0 mm
b = ±1.0 mm
C = ±10.0 mm
C = ±10.0 mm
81
Height tolerance of each rail (along centre-line)
B = ±10 mm
However, the following dimension shall not be exceeded over a measuring length of 2 m: c = ±2.0 mm
c = ±2.0 mm (continued)
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Standards Australia
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Description Height tolerance relative to both rails
Tolerances for crane classes C1 to C4 D = ±1‰ of ST max. ±10 mm
Slope tolerance of both rails in relation to each other
Horizontal tolerance of flat rail head
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NOTE: ‰ equals parts per 1 000 (pro mille).
D = ±0.2‰ of ST max. ±10 mm
E = 0.5‰
F = ±1‰ of ST max. ±20 mm
F = ±0.7‰ of ST max. ±20 mm
G = ±5‰ of railhead breadth (on flat surface) only
82
Position tolerance of end stops in relation to one another
Tolerances for crane classes C5 to C9
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Standards Australia
TABLE 7.20.9 (continued)
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7.21 GUIDES FOR MOVING PARTS Wear plates or rollers should be provided to guide parts that move relative to each other and can come in contact with each other. Where required, take-up adjustment shall be provided. 7.22 DETACHABLE PARTS Parts of cranes which are designed to be removable shall be designed to minimize risk to personnel who will be engaged in assembly and disassembly the crane e.g., pin-up booms, detachable jibs, C-hooks, spreader beams and similar. 7.23 DIRECTLY FITTED HOOKS Hooks directly attached to structural members e.g., booms, jibs, lifting equipment, shall be suspended so that they can be freely displaced so that bending moments in the hook shank are avoided. An allowance shall be made for any increased hook load due to the most unfavourable angle of pull. 7.24 COUNTERWEIGHTS Where used, means shall be provided to adequately secure all counterweights to the crane. Where counterweights are designed to be attached or removed as an operational feature, each counterweight shall be marked with its identification and mass and shall be provided with means by which it may be lifted and secured.
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Cranes with extendible counterweights shall be provided with means for them to be correctly positioned.
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SECT ION
8
E L ECTR I C A L E QU I PME NT CO N T RO L S
AND
8.1 SCOPE OF SECTION This Section specifies the requirements for the electrical equipment and controls used on cranes (see Clause 1.1). 8.2 MATERIALS AND EQUIPMENT Materials and equipment used in electrical and electronic systems for cranes shall comply with Section 3 and Section 15. The electrical installation, including materials, equipment, wiring and their installation shall comply with AS/NZS 3000 except as varied by this Section, and shall be of sufficient capacity to meet all demands for the work it is designed to do, and be used and maintained so that electrical danger to personnel and the possibility of equipment failure is minimized. NOTE: AS/NZS 3000 requires that electrical installations comply with requirements for ‘hazardous areas’ as specified therein. Clause 15.4 lists Standards that give guidance on classification of hazardous areas.
8.3 INFORMATION RELEVANT TO DESIGN OF ELECTRICAL SYSTEM The following information shall be considered in the design of the crane electrical system: (a)
Details of physical dimensions and performance of the crane.
(b)
Details of expected operation of the crane and method of motor control, related to severity of duty of the electrical system, e.g., operating time, nominal energizing frequency, significant aspects of crane operation (e.g., jogging operation of controller, plugging of crane motion, and similar).
(c)
Environmental operating conditions as specified in Section 15.
(d)
Type and tolerance levels of electric power supply. For a.c. supplies the following details should also be provided at the point of supply: (i)
Prospective fault level.
(ii)
Voltage drop during starting.
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(iii) Details of earthing including fault-loop impedance. (iv)
Harmonic distortion.
(v)
Prospective voltage impulse withstand levels.
(e)
Details of any special safety provisions required, for example, emergency alternative power supply in the event of power failure to obviate a potential hazard.
(f)
Special factors affecting servicing.
(g)
Required enclosure rating of electrical equipment according to AS 1939. NOTE: The required IP rating of equipment may be greater than minimum necessary arising from environmental conditions alone. Extra considerations for IP rating specification include the nature of the process, goods handled, operating procedures and safety of personnel.
(h)
Hazardous area classification where applicable.
Where a collector system is used, it shall comply with AS 1418.12.
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8.4 MOTORS 8.4.1 Enclosure and duty type Each electric motor shall comply with AS 1359, and shall have an enclosure type appropriate to the conditions under which the motor is required to operate as determined by the crane application, location of motor on the crane and similar factors, and shall be a duty type not less than Type S3 when not fitted with electrical braking or not less than Type S5 when fitted with electrical braking (see Clause 8.5.2). 8.4.2 Rated output and performance characteristics The characteristics of motors and associated equipment shall be selected in accordance with the anticipated service and physical environmental conditions. In this respect the points that shall be considered include the following: (a)
Type of motor.
(b)
Type of duty cycle.
(c)
Fixed speed or variable speed operation, and the consequent variable influence of the ventilation.
(d)
Mechanical vibration.
(e)
Type of motor speed control.
(f)
Influence of power supply harmonics.
(g)
Influence of peak currents on the power supply.
(h)
Effectiveness of motor counter torque with time and speed.
(i)
Influence of large inertial loads.
(j)
Influence of constant torque or constant power operation.
(k)
Grades of insulation for both temperature rise and voltage grade when supplied from an inverter or converter.
8.4.3 Resistors for motor power circuits
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The characteristics of resistors shall be selected in accordance with the anticipated service and physical environmental conditions. In this respect the points that shall be considered include the following: (a)
Its capacity to absorb and dissipate the required energy including ventilation requirements without adverse effects on other equipment.
(b)
Mechanical vibration during normal crane operations and emergency braking.
(c)
Enclosure requirements to facilitate ventilation while maintaining protection of personnel from inadvertent contact.
8.5 MOTOR CONTROL 8.5.1 Control systems Control systems appropriate to the types of motors and duty cycles should be used. 8.5.2 Electrical braking (Clause 7.12 uses the maximum braking torque arising from requirements in this Clause.) Electrical braking systems appropriate to the type of motor driving system and duty shall be used. Where motors can be operated at speeds in excess of their nameplate rating, an assessment of the mechanical braking system shall be carried out to ensure that this system will satisfactorily operate in the event of a power failure (or emergency stop).
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The system of braking for any motion shall be designed so as to minimize the adverse effects of any equipment malfunction, e.g., braking contactor, relay or other device. Provision shall be made to prevent the motor operating after the brake has been applied. 8.5.3 Motor control circuit Each motor control circuit shall comply with the following requirements, as applicable: (a)
Where a motion can be controlled from more than one control point or mode, the controls shall be interlocked to enable operation from only one point or mode at any time.
(b)
Where the circuit incorporates removable plug connectors, plug-in printed circuit boards or similar equipment, interlocks shall be provided in the circuit to obviate any unsafe condition being caused by removal of any connector, card or similar removable item. All plugs and similar components used for this purpose shall be keyed or clearly identified to prevent connection in any other than the intended manner.
(c)
In the event of interruption of power supply or operation of an electrical protection device in the motor-control circuit, that circuit shall not be capable of being re-energized until the controller has returned to its ‘off’ position.
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Unless specified, this requirement need not apply to pendent pushbutton stations complying with this Standard. (d)
All reversing contactors shall be electrically interlocked.
(e)
An automatic or semi-automatic control system, including its monitoring device, shall be fail-safe in operation.
(f)
Where the circuit incorporates solid-state components, the design and installation shall be such as to obviate malfunction due to overheating, moisture condensation, dust, vibration and similar.
(g)
All control circuits shall be designed so that their de-energization, for whatever reason, shall cause the devices controlled to shut down in a controlled manner. Failure of any relay or contactor or any other control device shall not result in the unsafe operation of any part of the system.
(h)
Where a motor and a brake of a motion are controlled by separate electric circuits or other devices, a positive and fail-safe interlocking system shall be incorporated in the controls in order to de-energize the motor and brake together so as to prevent malfunctioning of the braking system. The operation of such interlocking shall not cause loss of any other motion where loss of such motion could create a potential hazard.
(i)
Electric hoists may be controlled by a whole-current control station. Where the motor is three-phase, the control station shall control either two or three phases.
(j)
Where the power circuit incorporates solid state components and switching, the design and wiring shall comply with the various EMC and RFI requirements.
8.6 CONTACTORS Contactor ratings shall comply with and shall be applied in accordance with AS 1029.1 and AS 3947.1 and AS 3947.4, as appropriate.
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8.7 CONTROLLERS (see also Section 11) 8.7.1 Means of control Crane motions may be controlled by one or a combination of the following, or other, appropriate methods: (a)
Manual controls, i.e. human operator: (i)
Cabin controls (see Clause 8.7.3.1).
(ii)
Pendent control station (see Clause 8.7.3.2).
(iii) Whole-current controller (see Clause 8.7.3.3). (iv)
Master controller or combination controller.
(v)
Cordless controls including radio control, microwave control and infra-red control (see Clause 8.7.3.4).
(b)
Automatic control, i.e. no human operator (see Clause 8.7.5).
(c)
Semi-automatic, i.e. combination of Items (a) and (b).
8.7.2 Requirements common to all controllers
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All controllers and the equipment associated with them shall comply with the following requirements: (a)
The control system and equipment shall provide fail-safe operation at all times including during times when there has been a failure of the power supply, the system or any component thereof.
(b)
All types of manual controls such as pushbuttons, switches, joysticks, levers and pedals which control motion shall be of the hold-to-run type and shall be positive in operation, returning to the neutral position upon release.
(c)
Wiring and equipment shall be of appropriate types and located and enclosed with materials and in a manner appropriate to the most severe environment in which the crane is to operate.
(d)
Wiring shall not carry loads of a physical nature under any of the conditions under which the crane is to operate. Pendent wire and flexible cables shall be supported to ensure compliance with this Clause (see also Clause 8.14.6).
(e)
Where a crane can be controlled by more than one controller or control system, provision shall be made to ensure that only one system can control the crane at any one time.
(f)
Controllers including pushbuttons, switches, and the like, shall be of such shape and arrangement as will enable ready and convenient operation of each such item and obviate inadvertent operation of, or damage to, the item. Where a controller or pushbutton provides stepped speed control, physical movement of the controller shall be in easily distinguishable positive steps.
(g)
An emergency stop control shall be provided at each control station. Operation of the emergency stop control shall immediately cause all crane motions to cease. Emergency stops shall be of the positive break type and require manual reset.
(h)
Cranes fitted with multiple hoists, which can be operated in combination, shall indicate to the operator which hoist is selected. Where indicating lights are provided, a test facility at the operator controls shall be provided to test the condition of the indicators.
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8.7.3 Manual control 8.7.3.1 Cabin control stations The requirements for the cabin are detailed in Clause 11.2. The requirements for the controllers installed within the cabin or adjacent to it or both as applicable are set out in the relevant parts of this Clause. 8.7.3.2 Pendent control station 8.7.3.2.1 Electrical power supply The nominal working voltage shall not exceed 50 V a.c. or 120 V d.c. except where both of the following conditions apply, in which case a low voltage up to 440 V a.c. may be used: (a)
A controller not subject to conditions of external weather, wet or damp situations, condensation or any other adverse conditions;
(b)
Pendent control stations that are double-insulated in accordance with AS/NZS 3100.
Transformers that supply pendent control stations shall comply with Clause 8.9. The electric cable to each pendent control station shall be double-insulated and flexible and shall be securely attached at both ends so that the cable only carries its own mass. Where appropriate the cable shall comply with Clause 8.14.6. 8.7.3.2.2 Design and construction Each pendent control station shall have a rating appropriate to the voltage of the electrical power supply to the control station and shall comply with AS/NZS 3100 and with AS/NZS 3947.5.1. The requirements for the materials of the station are covered in Clause 8.7.2. The type of enclosure for each pendent control station shall be appropriate for the conditions to which the control station is subjected and shall be rated not less than IP55 as defined in AS 1939. 8.7.3.2.3 Pendent support cable The pendent cable supporting a pendent control station (or stations) shall comprise one or more flexible steel wire cores or other suitable material, with the electric cable attached to the support wire. The support cables shall be able to withstand a tensile force of not less than 1 kN.
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Where the pendent control station is double-insulated, the support cable shall be effectively insulated from the crane structure. Where the pendent control station may be used to pull a monorail hoist or crane along its runway, the hoist or crane shall be designed to be pulled by a tensile force of not greater than 1 kN. 8.7.3.2.4 Pendent support cable (see also Clause 11.3) Where controllers are operated by means of pendent cords, means shall be provided to ensure that the controller returns to the ‘off’ position immediately the pendent is released or in the event of the pendent being detached or broken. Where counterweights are used for this purpose, they shall be supported independently of the pendent cord. The pendent cord arrangement shall be designed to obviate inadvertent operation of a pendent cord, particularly when the crane is in motion. Each pendent cord shall be marked in accordance with Section 11 to indicate the motion and direction of movement it controls.
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8.7.3.3 Whole-current controller 8.7.3.3.1 Method of operation Each whole current controller shall be capable of— (a)
interrupting all active conductors, except where otherwise allowed in the appropriate part of AS 1418 or when in the ‘off’ position;
(b)
interlocking in the ‘off’ position;
(c)
where required, effecting motor reversal after operation of a limit switch (see Clauses 8.8.2 and 8.8.3); and
(d)
positive step operation corresponding to the speed steps where the controller provides stepped-speed control.
Whole current controllers shall comply with AS/NZS 3947.5.1. 8.7.3.4 Cordless controllers 8.7.3.4.1 General Cordless controllers may be used to transmit control signals where the use of hard wiring is not considered suitable or appropriate. Examples of cordless controllers are the following: (a)
Radio-wave signals.
(b)
Microwave signals.
(c)
Infra-red signals.
NOTES: 1
Under some circumstances, use of these systems requires licensing of the controller.
2
The Australian Communications Authority (ACA) administers a labelling regime for, amongst other things, radiocommunications equipment. Equipment used for remote control purposes will need to comply with any ACA requirements that exist at the time of supply. In addition, the ACA has various licence requirements for radiofrequency devices.
3
IEC 61603-1 provides guidance for the use of infra-red control systems.
8.7.3.4.2 System design requirements The design and operation of a cordless control system for a crane shall be fail-safe and shall ensure that when the crane is within the range of the control system, power to the motion controllers is possible only when the controller is activated. If the crane is outside the range of the cordless controller, the motions of the crane or monorail shall shut down. Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
The system shall comply with the following requirements: (a)
With any single fault occurring in the receiver or transmitter, it shall still be possible to render the crane safe by operating the emergency stop or keystop.
(b)
Any of the following conditions shall de-energize the main crane contactor: (i)
No valid signal being received for a period exceeding 550 ms.
(ii)
Interference from other sources.
(iii) Keystop to ‘off’ position.
(c)
(iv)
Emergency stop.
(v)
No motion being operated for 5 min. This time restraint need not apply if the normal or safe operation of the crane is hindered.
The carrier and address system of each cordless controller shall be positive, fail-safe and tamper-proof and protected as far as possible from spurious signals. When a number of transmitters for different installations are in one building or area, provision
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shall be made to prevent mutual interference. Each cordless control system shall have a unique address code. This shall not preclude the use of specifically designed systems for tandem handover, and multiple transmitter handover. (d)
Interlocking between cordless and electrical controls of the crane shall be arranged so that only one controller method is operative at any one time and the overall fail-safe characteristic of the whole installation is not adversely affected in any manner.
(e)
Where a battery is the power source for a transmitter or receiver handpiece or console, the transmitter console or handpiece shall include a low battery warning signal, which may be visual or audible, or both. This signal shall indicate to the operator, at least 5 min prior to the battery output voltage falling below its effective working level, that the radio system is about to shut down, giving the operator sufficient time to take the load to a safe area and set it down and take such other action as is necessary to make the situation safe. Low battery shall not cause any unsafe condition to occur.
(f)
The cordless control system shall incorporate sufficient logic such that unless all crane motion actuators are in the off position on start up, there shall be no command output.
(g)
The design shall ensure that no function of the system can be activated by any source of interference from sources such as arc welding and direct sunlight.
(h)
The emergency stop signal shall be an active monitoring type such that the system response time does not exceed 550 ms.
(i)
Where several hoisting machines can be operated by one cordless controller, visual indication shall be provided on each selected hoisting machine indicating it has been selected. A testing facility shall be provided at the cordless controller to test the operation of this indicator.
The console/handpiece shall have a keyswitch capable of being locked in the ‘off’ position to disable the cordless controller. 8.7.4 Electronic control
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Each electronic control circuit shall be designed and installed so that it complies with the following requirements: (a)
The system shall be fail-safe.
(b)
All mandatory devices and interlocks, safety protection, overload protection, start and stop buttons and final limit switches shall be hard wired, i.e. directly connected, external to the electronic control circuits and shall be positive and fail-safe in operation.
(c)
A positive and fail-safe means shall be incorporated in the system of controls to prevent malfunctioning caused by— (i)
the power supply becoming unsuitable for proper operation; and
(ii)
incorrect insertion of any plug, or similar component, or absence of any printed circuit board, or the like.
(d)
The crane shall not be subject to any movement not dictated by the crane operator due to any fault in the system of controls or any interference. A failure of a discrete or integrated circuit component shall not cause an unsafe condition.
(e)
Where provision is made for the equipment to be controlled from a programmable logic controller, computer, or similar device, a positive and fail-safe means shall be provided in the system to ensure that no fault in this type of equipment is capable of
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interfering with the positive isolation of the equipment or result in inadvertent motions when the equipment is in the manual, test, or ‘off’ mode of control. (f)
Where the crane operation has an ‘automatic’ or a ‘semi-automatic’ mode, or both, a function switch shall be provided on the crane operator’s console. The switch shall be positive in operation, and shall be capable of being key-locked in the ‘off’ position only. Provisions shall be made to prevent occurrence of any fault that may cause injury to persons either directly or indirectly, or cause damage within or outside the crane by inadvertent crane motion with the switch in any position.
(g)
Where monitoring devices are not duplicated or of a fail-safe type regardless of whether it is a programmable logic controller or any other type, such system shall be monitored with any operation of the controller. Where monitors are duplicated, they shall be checked automatically one against the other, and shall be interlocked with the system of controls in a positive and fail-safe manner. The system of controls need not be shut down during the automatic checking of the monitoring system, except when the monitor is faulty. On starting of the equipment, overall checking of the safety system of controls shall be done automatically so as to prove its capability of shutting down the equipment. The operation of the main contactor, directional contactors, and all other contactors, relays, and devices, which are required for the safe operation of the equipment, e.g., brake relays or contactors, emergency stop circuits, safety interlocking, limit switch, and similar devices, shall be monitored in a positive and fail-safe manner, so that malfunctioning of these items of the equipment will not result in an unsafe condition.
8.7.5 Automatic control 8.7.5.1 System design requirements The system shall comply with the following requirements: (a)
Provision shall be made that no two modes of control are operative at the same time.
(b)
Each mode of control to be selected via a keyswitch with the key removable in the ‘off’ position only.
(c)
At each control station, on/off and emergency stop controls shall be provided.
8.7.5.2 Safety enclosure
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A crane designed to operate under automatic control (i.e. operatorless) shall have its operating area including safety clearances fully enclosed in accordance with the following requirements: (a)
The enclosure shall be not less than 1800 mm high while the distance between the enclosure and any moving part of the crane or its load including recognition of any rope swing or buffer compression distances shall be not less than 450 mm.
(b)
The enclosure shall be one of the following constructions: (i)
Sheet metal with all gaps less than 50 mm.
(ii)
50 mm wire mesh of thickness not less than 3 mm.
(iii) 9 mm wire mesh of thickness not less than 1.5 mm.
(c)
(iv)
Vertical bars not less than 6 mm diameter or tubes not less than 10 mm with clear spacings not greater than 50 mm.
(v)
An equivalent enclosure.
The entry gate(s) to the enclosure shall be fitted with an electrical interlocking system that removes electrical power from all crane motions whenever entry to the enclosure is attempted. The restoration of power to the motions shall be by operation of a reset
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key switch situated outside the enclosure, preferably with a view over the area of the enclosure. The interlocking system should include the considerations outlined in AS 4024.1 and in particular should include the following features: (i)
The direct interruption of the power medium (power interlocking).
(ii)
The indirect interruption of the power medium by means of a control system (control interlocking). The interlocking system shall be selected from the following:
(d)
(A)
Tongue-operated switch or similar device that is designed to be difficult to defeat.
(B)
Trapped-key control system (key exchange).
(C)
Other interlocking systems given in AS 4024.1, which achieve the equivalent safety features of (A) or (B) above.
The enclosure shall have safety signs in conformance with AS 1319— (i)
mounted externally on every side of the enclosure at a spacing not greater than 25 m cautioning that the automatic crane may move without warning; and
(ii)
mounted on every access gate forbidding entry without opening a crane isolator external to the enclosure.
When an automatic crane is operating wholly over an elevated platform, tank or structure that is not less than 1800 mm above the surrounds then a separate enclosure need not be constructed but the access ways to the top of the elevated structure shall comply with Items (c) and (d)(ii) above. 8.7.5.3 System requirements The electronic equipment used in an automatic control shall comply with Clause 8.7.4 except that movements or actions dictated by the crane operator in Clause 8.7.4 are replaced by the automation programmed outputs.
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Any cordless control system used within the automatic control system to communicate to the crane or to communicate between sections within the crane shall comply with Clause 8.7.3.4. An automatic crane shall have a visual and audible warning system that operates 5 seconds prior to each travel motion and at least the visual warning system shall operate continuously during the operation of each travel motion. 8.7.5.4 Access for power-on faults diagnosis Where it is necessary for personnel to have access to an automatically controlled crane for the purpose of fault diagnosis or equipment adjustment and this can only be undertaken by operating the crane with personnel within the enclosure, then the following shall apply: (a)
Safe areas shall be provided in which personnel can stand.
(b)
Each of these safe areas shall be equipped with an emergency stop that will stop each motion by means of control interlocking.
(c)
The automatic control cycle shall be reset from its isolated state by a hold-to-run type switch from a prime safe area within the enclosure.
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8.7.6 Stop functions 8.7.6.1 General There are three categories of stopping functions: (a)
Category 0: stopping by immediate removal of power to the hoisting machine actuators (i.e. an uncontrolled stop);
(b)
Category 1: a controlled stop with power available to the hoisting machine actuators to achieve the stop and then the removal of power when the stop is achieved; and
(c)
Category 2: a controlled stop with power left available to the hoisting machine actuators.
NOTE: With the exception of emergency stop and/or emergency switching off, and depending upon the risk assessment, removal of power may be accomplished by the use of either electromechanical or solid-state components.
Category 0, Category 1 or Category 2 stops or combinations shall be provided where indicated by the risk assessment and the functional requirements of the hoisting machine. Category 0 and Category 1 stops shall be operational regardless of the operating modes and Category 0 shall take priority. Stop functions shall override related start functions. 8.7.6.2 Emergency stop Except where exempted by Clause 8.10.8, hoisting machines shall have an emergency stop function, which shall at least stop the motion drives. This emergency stop shall function as a category 0 stop and be initiated by a single human action. The emergency stop function shall comply with the following minimum requirements: (a)
It shall be fail-safe.
(b)
The energy source to all motion drives shall be removed as quickly as possible without creating other hazards (e.g., by the provision of mechanical brakes requiring no external energy source for stopping).
(c)
It shall override all other functions and operations in all modes.
(d)
Reset shall not initiate a restart.
8.8 LIMIT SWITCHES (see also Clause 7.13) 8.8.1 Purpose
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A limit switch is required to effectively interrupt an electrical circuit to fulfil one of the following purposes: (a)
To limit range, that is, distance of motion— (i)
as a working limit, that is, the location of the limit switch is within the normal range of the crane motion; or
(ii)
as a final (non-working) limit, that is, the location of the limit switch is outside the normal range of the crane motion, and this limit switch operates only, except when being tested, under emergency or abnormal conditions of operation of the motion, for example, failure of a working limit preceding it or operation of the motion beyond its normal operating range.
(b)
To limit speed of motion.
(c)
To perform an interlocking function.
(d)
To sense mechanical or operational malfunction of the crane by rope slackness, rope out of position, e.g., bunched on winding drum, overspeed operation, or by other means.
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8.8.2 Motion limiting devices Requirements for the provision of motion limiting devices are given in Clause 7.13.1. The construction of each limit switch to be used as a motion limiting device shall comply with the requirements in Clauses 8.8.3 to 8.8.7 inclusive. 8.8.3 Optional limit switches Optional limit switches are those that are provided in addition to the motion limiting devices to change the crane operation, for example, limiting the speed of crane travel when approaching the end stops. 8.8.4 End of travel limit switch When operated, each end of travel limit switch shall cause the power supply to the motor it controls to be interrupted and the brake to be applied, but it shall not prevent reversal of the motion. The limit switch shall be self-resetting when the motion returns to the non-limited section of its range. The end of travel limit switch may operate in a directional control circuit, i.e. it need not be a whole-current switch. 8.8.5 Working-limit switch When operated, each working-limit switch shall cause the power supply to the motion it controls to be interrupted and the corresponding brake to be applied. 8.8.6 Final-limit switch The final-limit switch operation shall be independent of the working-limit switch operation. The following methods are examples of acceptable designs: (a)
Whole current limit switches.
(b)
Shunt limit that operates an independent motion power supply contact e.g., crane main contactor.
Where the final-limit switch is preceded by a working-limit switch, the final-limit switch shall prevent reversal of the motion until it has been manually reset. The means to manually reset the final-limit switch shall not be readily accessible to the crane operator, that is, the final-limit switch is to be manually reset only by service or maintenance personnel.
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8.8.7 Design and construction There are mechanically operated limit switches, and there are proximity-type limit switches; however, all working- and final-limit switches shall be of the mechanically operated and positive break type. Proximity-type limit switches, that is, where no physical contact between the switch and the operating medium is needed to operate the switch, shall be mounted so that, for all conditions of physical side shift or float, the limit switch will operate within the manufacturer’s recommendations. Each whole-current limit switch and contactor operated by a shunt-type limit switch shall be capable of interrupting the locked rotor current. The limit switch circuit shall be effectively designed to prevent contact welding. Anti-collision devices shall be used where they are essential to the safe operation of the equipment in order to prevent damage from collision between two cranes, or a crane and other equipment, or structures. When operated, mechanically operated limit switches that control three-phase motors shall cause interruption of two or three active-supply conductors of the motor circuit.
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8.8.8 Application 8.8.8.1 Hoisting motion Each electric-powered hoisting motion shall be provided with an upper final-limit switch that complies with Clause 8.8.6 except where other effective means, e.g., a slipping clutch, is provided to limit the hoisting motion in the ‘raise’ direction. All hoists not fitted with a torque limiting device shall be fitted with a weight overload protective device. 8.8.8.2 Motions other than hoisting End-of-travel limit switches for motions other than hoisting shall be provided for all automatic and cordless controlled systems. Where cordless controlled cranes operate on a common runway, anti-collision protection shall be provided. Where cordless controllers operate multiple crab cranes, anti-collision protection shall be provided between crabs. 8.8.8.3 Spreader (for container and similar handling) A positive and fail-safe interlocking system shall be provided to prevent— (a)
the hoisting of containers unless the spreader is properly seated and any latching-on device is fully engaged and locked; and
(b)
the disengagement of the container while suspended.
A ‘ready’ light indicator shall be provided to indicate to the operator when the spreader is properly seated upon a container and ready for twistlock operation. 8.8.8.4 Twistlock details (for container similar handling)
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Twistlocks shall comply with the following requirements: (a)
Each twistlock shall have its own separate interlock actuated by a cam fixed directly to the twistlock.
(b)
‘Latched’ and ‘unlatched’ indicator lights shall be provided to indicate to the operator when twistlocks are fully open or fully closed.
(c)
Mechanical interlocks shall be provided to prevent operation of any twistlock while any load is suspended therefrom.
(d)
Interlocks shall be provided to prevent operation of hoist motion unless all twistlocks are fully open or fully closed.
8.9 CONTROL CIRCUITS 8.9.1 Control circuit supply Double-wound transformers complying with AS 3100 and AS 3108 shall be used for supplying the control circuits. Where several transformers are used, it is recommended that the windings of those transformers be connected in such a manner that the secondary voltages are in phase. 8.9.2 Control circuit voltages The value of the control voltage should be consistent with the correct operation of the control circuit. The nominal voltage shall not exceed 277 V when supplied from a transformer. 8.9.3 Protection Control circuits shall be provided with overcurrent protection.
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8.9.4 Connection of Control Devices In control circuits with one side connected to the protective earth, one terminal of each operating coil of each electromagnetically operated device or one terminal of any other electrical control device shall be directly connected to that side of the control circuit. All switching elements of control devices that operate the coil of the device shall be inserted between the other terminal of the coil or device and the other side of the control circuit. 8.10 ELECTRICAL ISOLATION 8.10.1 Purpose Electrical isolation in accordance with AS/NZS 3000 and this Clause shall be incorporated in the electrical system of each crane to electrically isolate the crane or a section thereof primarily to enable servicing, maintenance or repair of the crane to be effected without hazard to personnel due to— (a)
the presence of live electrical machinery, components or conductors;
(b)
unexpected movement of the crane or parts thereof; and
(c)
unexpected direction of movement due to phase failure or reversal.
8.10.2 Arrangement of isolation
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Typical arrangements of electrical isolation are depicted by Figure 8.10.2.
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FIGURE 8.10.2 TYPICAL ARRANGEMENT OF ELECTRICAL ISOLATION
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8.10.3 Main isolator 8.10.3.1 General Each crane installation, including the crane supply conductors, connected to an external power supply shall be provided with a main isolator that complies with Clause 8.10.3.4, to enable isolation of the crane installation from the power supply. The isolator shall be located in a readily accessible place, adjacent to the usual parking or servicing position of one of the cranes, or at some other readily accessible place. In such instances, the location of the isolator shall be indicated by a suitable notice at the usual parking or servicing location of the cranes. Where an installation has maintenance bays, the main isolator may be located remote from the parking or servicing position, but shall be within the crane runway area. Special equipment, such as lifting magnets, may be isolated separately from the crane provided that all main isolators are located together and clearly marked. Where a contactor or circuit-breaker is used in lieu of manual main isolator, the following shall apply: (a)
Unless the contactor or circuit-breaker is withdrawable to a safe isolating position, a manual switch complying with Clause 8.10.3.4 shall be provided on the line side of the device. The switch, unless capable of making and breaking the stall current of the largest motor, shall be at least electrically interlocked with the contactor or circuit-breaker so that the latter opens first.
(b)
Manual means of locking the main isolator in the off position shall be provided.
(c)
Where a local/remote selector switch is provided at the main isolator and the remote-control selector switch is capable of being locked in the remote position during normal operation of the crane, the main isolator shall not be capable of being switched on while the selector switch is in the local or remote position without manually resetting all the remote-control switches at each access point to the crane.
(d)
The contactor or circuit-breaker shall not be used as an isolating switch in lieu of a manual isolating switch except as provided for in Item (a). A notice to this effect shall be displayed at all points from which the contactor or circuit-breaker may be operated. The notice shall read: EMERGENCY STOP SWITCH. MAIN ISOLATOR AT . . .
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(e)
Positive and fail-safe interlocking shall ensure that all control isolators whether of the on/off switch or pushbutton type shall be reset before the remote isolator may be re-energized.
8.10.3.2 Alternative power supplies Where power from alternative sources is supplied to a crane installation, positive means shall be provided to ensure that not more than one source of supply at a time is connected to the crane electrical system or part thereof, and that the same phase relationships to the crane are maintained for each power supply. 8.10.3.3 Sectionalized collector system Where a section of a crane collector system is capable of being isolated from the power supply to the crane by a section-isolator, for example, to provide a safe maintenance bay, the section-isolator shall be located at the access point to the isolated section, arranged and identified so that it can not be confused with the main isolator. Unless the section isolator is adjacent to the main isolator, the location of the main isolator shall be clearly indicated near the section isolator. This isolator shall be lockable in the ‘off’ position only. The section so Standards Australia
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isolated shall be provided with identification to enable the crane operator to correctly place the crane in the isolated area. Lockable means shall be provided to prevent the conductors of the isolated section from becoming energized while the section is isolated. Earthing switches shall be positively interlocked with the other switches so as to prevent earthing of the system in its live condition. 8.10.3.4 Design and construction The isolator, except for a withdrawable contactor or circuit-breaker covered by Clause 8.10.3.1(a), shall be manually operated and shall comply with AS/NZS 3947.3 where applicable and other applicable Standards. NOTE: The terms ‘isolation’ and ‘isolator’ used in this Clause refer to switches, disconnectors, switch-disconnectors, fuse-combination units and contactors as the context requires.
Isolators shall have the following: (a)
A capability of interrupting all active conductors of the power supply.
(b)
A rating of not less than the maximum demand of the circuits they control, which could include all the motions if applicable. Isolators shall in no case be rated at less than the combined full load currents of the two motions of the crane having the largest current.
(c)
An enclosure shall not be rated less than IP45 of AS 1939 except where mounted in an enclosed switchboard, control cabinet or other inherently protected location.
(d)
A capability of being locked in the ‘off’ position only.
(e)
Where mounted in an enclosed switchboard, control cabinet or other inherently protected location (see Item (c)), a capability of being operated and locked from outside the switchboard, control cabinet or location.
(f)
All switches required to be lockable shall have permanent locking facilities.
8.10.3.5 Remote operation of main isolator Where means are provided for remote operation of the main isolator, they shall be capable of being locked in the main-isolator ‘off’ position. A distinct and readily visible indicator, e.g., a flag or pair of lights (white for normal voltage supply ‘on’ and green for no voltage supply, i.e. ‘off’ shall be provided at each remote control station. Each indicator shall be provided with an adjacent clearly stamped or engraved electrical supply status label.
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NOTE: For outdoor installations particularly, exposure to the sun in all seasons should be taken into account.
8.10.4 Crane isolator 8.10.4.1 General A whole-current isolator shall be provided for the crane electrical installation except that it need not control the items listed in Clause 8.10.7. 8.10.4.2 Location The crane isolator may be located at one of the following positions: (a)
Operator’s cabin.
(b)
Entrance point of the crane.
(c)
Crane main equipment panel. Where the crane isolator is not located at this panel, a separate lockable switch shall be provided at the panel.
(d)
At the point where the crane supply is obtained or as close as practicable to it.
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The crane isolator shall be so located as to be readily accessible and provide a clear view of all crane operations. Where the crane isolator is not provided on the crane operator’s route of access to the crane operator’ cabin or in the crane operator’s cabin, a control circuit isolating device, of other than the momentarily off type, lockable in the off position only, shall be provided in the crane operator cabin convenient to the crane operator’s operating position. Where all switches called for in this Clause and in Clause 8.10.7 are not located together, the location of the remaining switches shall be clearly marked at each switch or group of switches. 8.10.4.3 Type of switch All switches required by Clause 8.10.4 shall be lockable in the off position only. The main isolator may serve as the crane isolator. 8.10.5 Access isolators Where sections of a crane move relative to each other, a manually operated access isolator, either whole-current or control circuit, shall be provided at the normal access points to the adjacent sections in a location where it can be conveniently operated from either section to enable safe access from one section to the adjacent section. The access isolator shall be of a positive type, and shall be only capable of being reset manually. 8.10.6 Service isolator Where each motion has its own service isolator, it shall be of a whole-current type lockable in the off position only. Each service isolator shall be such that it can only be reset manually. Where more than one service isolator is provided to isolate a motion, the isolators shall be interlocked with the motion control so that no motor operated by the control can be energized until all service isolators for the motion are reset. Whole-current isolation of the motor circuits of a lockable type shall also be provided at the switchboards. 8.10.7 Accessory, ancillary and auxiliary isolators
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Where circuits for accessory, ancillary and auxiliary equipment are used, they shall be separated from the main crane isolation circuit. Manually operated isolators shall be provided, in convenient locations, to enable isolation of— (a)
accessories, e.g., anti-condensation heaters;
(b)
ancillaries, e.g., lighting, ventilation, heating or cooling; and
(c)
auxiliaries, e.g., magnets.
Anti-condensation heaters and similar accessories shall be capable of being isolated before associated electrical equipment is serviced. A notice shall be provided at each motor containing anti-condensation heaters warning that the heater circuits shall be isolated before working on the motor and indicating where the appropriate switch is located. 8.10.8 Emergency isolation Fail-safe means shall be provided, at the normal operating position, for emergency interruption of power supply to the crane drive motors as follows: (a)
For fixed hoists and monorail, post and wall cranes and the like:
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(i)
Where the crane does not have powered travel motion, no emergency-stop button need be provided.
(ii)
Where the crane has powered travel motion but cannot move further than 4 m from the main isolator and the whole of this distance is unobstructed in the line of sight from the main isolator, no emergency-stop button need be provided. If the distance of 4 m is exceeded, or the operator’s path on the floor is obstructed, a manual-reset emergency-stop button, which, when operated, causes the main contactor to interrupt the power supply to the crane, shall be incorporated in the crane-control station.
(iii) Where two or more hoists are located on one monorail, each hoist shall have its own isolator lockable in the off position. (b)
For pendent controlled cranes (other than those in Item (a)) A manual-reset emergency-stop button or pendent cord which, when operated, causes the main contactor to interrupt the power supply to the crane shall be incorporated in the pendent control system.
(c)
For cabin-controlled cranes A manual-reset emergency-stop button which, when operated, causes the main contactor to interrupt power supply to the crane, shall, except where the crane isolator is located in a readily accessible position in the cabin, be incorporated in the operator’s controls.
8.11 ELECTRICAL PROTECTION 8.11.1 Purpose Electrical protection of the crane installation shall ensure that under electrical fault or overload conditions the electrical fault will be automatically isolated from the supply without causing hazard to personnel or damage to any other part of the crane installation. Where two or more motors concurrently drive the same motion of a crane, the electric protection circuits for such motors shall be interlocked with one another and the system of controls in a fail-safe manner. The operation of protection of the electrical system of a crane motion shall not cause loss of any other motion where loss of such motion could create a potential hazard.
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As a minimum requirement, hazards arising from the following shall be considered: (a)
Overcurrent arising from a short circuit.
(b)
Overload current.
(c)
Abnormal temperature.
(d)
Loss of or reduction in the supply voltage.
(e)
Overspeed of motors.
(f)
Earthing.
(g)
Incorrect phase sequence.
(h)
Overvoltage due to lightning and switching surges.
(i)
Electromagnetic and radiofrequency interference. NOTE: Many aspects of electrical protection for cranes depend upon the size, duty and type of a crane and its electrical equipment and other factors. It is desirable that, during the designing of the electrical system of a large, complex or unusual type of crane, close liaison be maintained between the parties concerned, namely the crane user, manufacturer, electrical contractor, electricity supply authority, regulatory authority, and other appropriate authorities.
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8.11.2 Overcurrent protection 8.11.2.1 General Overcurrent protection shall be provided in all active conductors of the crane installation in accordance with AS/NZS 3000. The rated short-circuit breaking capacity shall be at least equal to the prospective fault current at the point of connection. Where the short-circuit current to an overcurrent protective device can include additional currents other than from the supply (e.g., motors, power factor correction capacitors), those current shall be taken into consideration. 8.11.2.2 Motor circuits Each individual motion shall be provided with individual overcurrent protection, e.g., circuit-breakers or fuses, in accordance with AS/NZS 3000 (see Clause 8.11.2.1). Where electrical control and protective panels are provided on the crane, such protection shall be located in these panels. Motors fitted with separately excited brakes shall ensure that if any one phase of the motor supply is interrupted, the brake shall be automatically applied. 8.11.2.3 Control, accessory, ancillary and auxiliary circuits Control, accessory, ancillary and auxiliary circuits shall be protected in accordance with AS/NZS 3000. Control circuits in an earthed supply system shall be arranged so that, if an earth fault occurs in a control circuit, the controlled motion will stop. Where power is supplied by a centre-tap-earthed transformer, the secondary winding shall have ganged double-pole protection. Where a control circuit is supplied from two phases of a three-phase power supply, both phases shall have ganged double-pole protection. No unearthed (floating) control supply system shall be used unless an effective and fail-safe earth-monitoring system is incorporated in the system of controls. Such a system is to prevent the use of the equipment while the system is in a faulty condition. A visible and audible alarm shall be installed to indicate a fault in the system. 8.11.3 Motor protection
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8.11.3.1 Motor overload protection Overload protection of motors shall be provided for each motor rated at more than 2 kW, and is recommended for each motor rated at less than 2 kW. Overload protection of motors can be achieved by the use of devices such as fuses, circuit-breakers, temperature-sensing devices, or current limiting devices, Electronic devices designed to reduce or limit the current in protected devices may also be used. Where motors with special duty ratings are called upon to brake frequently (e.g., motors used for rapid traverse, locking, rapid reversal), it can be difficult to provide overload protection with a time constant comparable with that of the winding to be protected. The use of appropriate protective devices designed to accommodate special duty motors is recommended. The use of motors with built-in thermal protection is recommended in situations where the cooling can be impaired (e.g., dusty environments). Depending upon the kind of motor, protection under stalled rotor or loss of phase conditions is not always ensured by built-in thermal protection, and additional protection should then be provided. 8.11.3.2 Motor temperature protection Where motor overtemperature protection for any crane motion motors is provided, it may be arranged to act in either the main control circuit or in the individual motor circuit. Standards Australia
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Resistance heating or other circuits that are capable of attaining or causing abnormal temperatures should be provided with suitable detection to initiate an appropriate control response. An example is anti-condensation heating of motors. NOTE: In the selection of the means of overtemperature protection, it should be noted that a thermal overload relay may not fully protect some classes of crane motors for the load cycles usually encountered in the crane application and, therefore, other protective means may be required. Some examples of such protective means are— (a)
an electromagnetic or solenoid overload relay with inverse current/time characteristics for slip or ring induction motors; and
(b)
a positive temperature coefficient thermistor or microtherm overtemperature detector embedded in the stator winding.
Any relay used for overload protection shall de-energize upon operation. 8.11.3.3 Motor overspeed protection Overspeed protection shall be provided where overspeeding can occur and could possibly cause a hazardous condition, taking into account motion-limiting devices in accordance with Clause 8.8 NOTE: This protection can consist, for example, of a centrifugal switch or speed limit monitor. The overspeed should operate in such a manner that the mechanical speed limit of the motor or its load is not exceeded.
8.11.4 Earthing Earthing of crane electrical components shall comply with AS/NZS 3000 consistently and continuously in all locations of the crane and under all environmental conditions. The crane structure, metal frame and enclosures of the electrical equipment, metal conduits and cable guards, and the like, shall all be effectively connected to earth through an earth conductor circuit. Where the electricity supply is generated within the crane, all exposed conductive parts shall be equipotential bonded. Where an unearthed system is employed, an earth-fault-detecting device, which indicates by visible or audible means the occurrence of earth leakage, shall be provided, and the metallic components specified in the above paragraph shall be interconnected electrically to prevent electrical potential differences from developing between them.
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Where the crane is connected to the supply by flexible cable, the crane shall be connected to earth by means of an earthing conductor enclosed with the current-carrying conductors within the same sheathing as the live conductors of the flexible cable, except where the conductors are single-core cables larger than 16 mm 2 . Installations that are supplied by sliding contact conductors shall include a separate earthing conductor or other positive earthing means that does not require earthing through the crane wheels. At least one of the hoisting machine runway beam/rails shall be effectively earthed by means of an earth conductor. However, they shall not replace the earth conductor (e.g., cable, collector wire or collector bar) from the supply source to the hoisting machine. If the runway rails are fixed on timber, reinforced concrete or other insulating medium, the rails shall be made electrically continuous by bonding. In cranes provided with a slewing motion, the collector column shall be provided with an earthing collector ring and more than one finger. 8.11.5 Electromagnetic compatibility (EMC) The equipment shall not generate electromagnetic disturbances above levels that are appropriate for its intended places of use. In addition, the equipment shall have an adequate level of immunity to electromagnetic disturbances so that it can operate correctly in its
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8.11.6 Phase sequence protection A hoisting machine with provision for the connection of an auxiliary electric power supply or an alternative supply shall have a phase sequence protection device to ensure the correct motor rotation. NOTE: Conditions of use that can lead to an incorrect phase sequence include— (a)
a hoisting machine transferred from one supply to another;
(b)
a mobile crane with a facility for connection to an external power supply;
(c)
emergency supply to a hoisting machine; or
(d)
auxiliary power supply when carrying out repairs or maintenance to a hoisting machine.
8.11.7 Lightning protection Protection against lightning shall be provided where appropriate. NOTE: AS 1768 provides guidance on this matter.
8.12 HIGH-VOLTAGE SUPPLY TO CRANES High-voltage supply to cranes and installations thereon shall comply with AS/NZS 3000 and AS 3007.1 to AS 3007.3, as applicable. In addition, the protection associated with the high-voltage supply to the crane shall include an earth-leakage protective device which shall ensure that during an earth fault condition the rise in potential on the crane structure or its parts with respect to earth and the time to clear the fault potential shall not exceed the recommended values for touch voltage and time contained in AS 3859 for prospective touch voltage (a.c.) and maximum operating time for transportable and mobile equipment. NOTE: This requirement can be complied with by the use of residual earth-leakage protection or, where greater sensitivity is required, the use of residual current devices current-operated (core-balance) earth-leakage devices.
8.13 CRANES WITH MAGNET ATTACHMENTS 8.13.1 General
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An audible alarm shall be provided and used by the crane operator for the purpose of warning persons to keep away from the restricted area of magnet crane operations. The releasing of the load shall be actuated by a two channel control (momentary switches) i.e. not just two switches in series. The type of the magnet shall be fit to that of the intended load(s) with regards to magnetic flux direction as well as penetration. If more than one magnet is used in conjunction with a lifting beam, the layout and rated capacity of the magnets shall be matched to that of the intended load(s). The share of the load that can foreseeably be imposed on each magnet shall not exceed its rated capacity taking account of the rigidity of both the load and the lifting beam. 8.13.2 Lifting capacity The lifting capacities of the magnet combinations shall be displayed and be easily readable by the crane operator from the operating positions, together with all necessary instructions on their safe use. Where a number of magnets are used in different combinations, a monitoring system shall be provided to detect a drop in magnet current below normal for each combination and to prevent reuse of the magnets until the fault is rectified. Standards Australia
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8.13.3 Magnet controllers The magnet controllers shall comply with the provisions of this Standard (see Clause 8.7). The controller shall remain positively located in ‘lift’ or ‘off’ positions, but shall be fitted with an automatic return from the ‘drop’ to the ‘off’ position. In circumstances where accidental release of the load is to be prevented, the magnet controller shall also incorporate a guard or protector, or a supplementary pushbutton switch, which shall require additional operations to the main magnet control system to cause release, e.g., a hold-to-run control. 8.13.4 Application of magnets Where various physical shapes or sizes of load are to be handled, a multiple magnet assembly on a spreader beam may be used, with each magnet wired to a bank of selector switches enabling the crane operator to energize only the magnets needed to span the particular size of the load. Where control of the lifting power of a magnet by stages is required, e.g., the operation of plate or slab stacking, a varying magnet power control shall be provided in the form of a master switch, drum controller, or manually operated controller. Where the loading operations call for more precise and accurate selection of a portion of a composite load so that a predetermined amount of it may be lifted from the stock pile or discharged in portions from the loaded magnet, such type of control shall be provided. Where persons are not required to be present in the operational area and the area is safely fenced off against entry, an emergency standby power supply is unnecessary, e.g., scrap handling, or automatic processes. Appropriate warning notices shall be displayed. In all other cases where persons are involved, or full fencing is not provided, or in handling plate or shapes where these require positioning manually by safe remote means, a standby supply shall be provided unless a fail-safe magnet is used. 8.13.5 Emergency batteries Where installed, an emergency standby battery supply to a magnet shall be of such capacity as will provide enough power to keep the magnet energized for the time needed to lower the load mechanically, and in any event not less than 10 min. The changeover from the normal supply to the battery shall be automatic and in a fail-safe manner, and in such a way that a maximum load shall not be dropped owing to a power failure of a normal supply.
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Where changeover is performed by a contactor, the following shall be complied with: (a)
Where contactor springs alone are used, they should be of the compression type and at least two springs shall be provided.
(b)
Where gravity and springs are used, only one spring need be provided on condition that the force of gravity is effective on its own. Where tension springs are used, two such springs shall be provided and the stresses shall not exceed those for compression springs. All springs shall be designed in accordance with BS 1726.1 and assumed to be in Category 1 provided that the maximum actual working stress shall not exceed 60% of the maximum permissible stress in the fully compressed condition as specified in the Standard.
(c)
Where gravity and springs, or springs alone, are used to secure full contact pressure, the failure of one spring shall not reduce the contact pressure below that required to carry the rated current for 3 h without damage to the contact or any adjacent parts.
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Springs, where used, shall exert a direct push or pull, that is, they shall not be used as part of a toggle or over centre mechanism. The condition of the battery and the battery-charging equipment shall be constantly monitored and interlocked in a positive and fail-safe manner with the controls of the crane, to prevent the use of a magnet and to give visible and audible alarms where a battery fails during the operation of a crane. A visible and audible indication shall also be provided in the cabin to warn the crane operator that the standby battery supply has come into operation. 8.13.6 Magnet circuits Magnet systems supplied by sliding contact type power supply shall be fitted with tandem collector sets. An isolating switch with overload protection in all lines shall be provided to isolate all supply lines to the magnets. The current rating of the fuses protecting the magnet circuits shall be at least 150% of the working current. Where required, the magnet frame shall be solidly bonded to the crab by the earth connection via the magnet lead, the magnet coupling, the magnet cable, and an extra slip-ring contact on the magnet cable drum. 8.13.7 Rectifiers Where rectifiers are used to supply magnet circuits, they shall be separate rectifiers used solely for this purpose. These rectifiers shall be of adequate capacity to supply continuously the full direct current loads required, and shall be of specially robust construction to withstand severe conditions as specified. Rectifier transformers shall be double-wound and shall comply with AS 3108. Each magnet shall have an enclosure rated to IP55 of AS 1939 and shall be provided with a terminal box having— (a)
an integral construction with the magnet casing;
(b)
a watertight gland through which the magnet lead is brought to the magnet terminals; and
(c)
a cover, which shall be easily removable without interfering with the magnet lead inlet, and which when replaced shall restore the enclosure so that it again complies with a rating of IP55 of AS 1939.
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8.13.8 Magnet leads The magnet lead includes all cabling from the magnet control panel to the magnet terminal box. The cabling shall be suitably selected to meet the current carrying requirements of each magnet and have conductors with a cross-section of not less than 2.5 mm. All cables and termination points shall be effectively protected against mechanical damage. In case of heavy loads, i.e. large coils and/or dangerous operations (e.g., loading/unloading of ships), the cabling shall be redundant and be monitored. 8.13.9 Magnet couplings Where the particular type of magnet coupling is not specified, the coupling shall comply with the following requirements: (a)
The coupling shall be of rugged construction and arranged for protection against abuse both when connected and disconnected.
(b)
At the moment of breaking, the contacts shall be enclosed by insulating material.
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(c)
Provision shall be made to fasten the coupling in the closed position.
(d)
Where an earth connection is required, it shall break last on uncoupling.
(e)
The socket shall be connected to the supply and the plug to the magnet or magnet lead. The magnet cable shall be rigidly attached to the bottom block by a suitable cable clamp at a point just above the magnet coupling. The magnet cable drum shall be— (i)
arranged so that the cable does not foul the hoisting ropes;
(ii)
such that the cable shall become neither unduly taut, nor slack enough to touch the hoisting ropes; and
(iii) capable of accommodating and paying out the length of cable necessary for the magnet to reach its lowest position, including any fall below floor level when specified. Where power is fed to the magnet by a brush and slip-ring arrangement on the magnet cable drum, two brushes per slip-ring shall be provided and the rings shall be of sufficient spacing with an isolation voltage of not less than 2000 V d.c. 8.13.10 Magnet attachments Similar requirements as stated in the preceding Clauses shall apply also to magnet attachments and their use. However the following additional requirements shall be incorporated: (a)
Lifting capacity and conditions for each capacity shall be marked on the attachment.
(b)
Warnings and instructions to the crane operator, when placed on the beam or magnet, shall be in letters of sufficient size and colour contrast to be legible from the operator’s normal working position.
(c)
The instruction on the proper use of the magnet shall be clear, for example: MAGNET LOADS TO BE CARRIED ONLY WITHIN THE MARKED AREAS
(d)
Where both local and remote controls of the magnet attachment are incorporated, a local/remote selector switch shall be provided. Provision shall be made so that only one control method is available at any one time.
(e)
Only switches that are positive in operation shall be used for magnet control.
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8.13.11 Magnet types 8.13.11.1 Battery-fed lifting magnets Battery-fed lifting magnets shall provide a tear-off force of at least 2 times the rated capacity under conditions specified by the manufacturer. An automatic warning device, which monitors the power supply and provides a warning at least 10 min before the supply reaches the level where the load will release, shall be provided. The warning device shall be optical and acoustic. A safety device, which, after the low power warning device has activated and the magnet has been switched off, prevents the magnet from being switched on again until the battery is recharged to the minimum safe operating level, shall be provided. An indicator shall be provided to show if the magnet is magnetizing, de-magnetizing, magnetized or de-magnetized. NOTES: 1
The indicator does not necessarily indicate that there is sufficient magnetic field.
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The recommended maximum load for various material shapes and types shall be clearly indicated on the magnet system.
8.13.11.2 Mains-fed lifting magnets Mains fed lifting magnets shall provide a tear-off force of at least 2 times the rated capacity limit under conditions specified by the manufacturer. A safety device shall monitor the magnet currents in the power cabling to the magnets and the magnets themselves and shall render the magnet system inoperative should the current drop below the safe operating current level. An automatic warning device shall be provided if the mains power supply fails. The warning device shall be optical and acoustic. Magnets for lifting loads, such as plates, sheets, or bars from the top of a stack, shall have controls to reduce the power supply so as to facilitate the shedding of excess load. After the excess load has been shed, the controls shall permit restoration of full power. The controls should only allow reduced power to be applied when the load is initially lifted. Full power shall be applied (within 3 s) after the load has been lifted with the reduced power. This ensures there is a safety buffer to guarantee the magnet grips the load. This procedure shall be automatic and not controlled by the operator. NOTE: This means that if a load has been lifted and is holding at reduced power, then it can be assumed to be safely and correctly attached. For transport, the additional power is to be applied.
For safety, the hoist(s) of the crane shall be prevented from lifting or lowering the load during magnetizing or demagnetizing. An indicator shall be provided to show if the magnet is magnetizing, de-magnetizing, magnetized or de-magnetized. For magnets with variable power control, the indicator(s) shall distinguish between full and partial magnetization. NOTE: The indicator does not necessarily indicate that there is sufficient magnetic field.
8.13.11.3 Permanent lifting magnets
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Permanent lifting magnets shall comply with the following requirements: (a)
They shall provide a tear-off force of at least 3 times the rated capacity under conditions specified by the manufacturer.
(b)
The control shall clearly indicate whether the magnet is ON or OFF.
(c)
The control for operating the magnet shall be placed with regard to the safety of the operator.
8.13.11.4 Electro-permanent lifting magnets Electro-permanent lifting magnets shall provide a tear-off force of at least 3 times the rated capacity under conditions specified by the manufacturer. The magnets shall have an indicator to show when the magnet(s) are magnetized. For magnets with variable power control, the indicator shall distinguish between full and partial magnetization. 8.14 WIRING AND CONDUCTORS 8.14.1 Materials and installation Electrical wiring shall comply with AS/NZS 3000 and with this Clause. Materials used in the wiring installation shall comply with Section 3.
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Insulated conductors shall have not less than seven strands and a minimum cross-sectional area of 1.5 mm 2 for power wiring and 1.0 mm 2 for control wiring. Conductors used for connection to electronic devices, such as encoders and PLCs, can use a smaller wire gauge conductor. 8.14.2 Multi-outlet electrical supply Where the power supply to a crane is by means of flexible cable from plug-socket outlets, all sockets serving the crane shall be identically and correctly phased. Phase sequence relay protection shall be incorporated in the crane control preventing the use of equipment in the case of an incorrectly phased power supply. Residual current device (RCD) protection shall be fitted to the power supply for cranes. Sensitivity of the protection shall not exceed 30 mA. Testing facilities for checking the operation of the RCDs shall be fitted to the protective devices. 8.14.3 Crane collector systems 8.14.3.1 General There are two types of sliding contact systems, as follows: (a)
Bare wire.
(b)
Insulated conductor bar.
Where the power supply to a crane is by means of systems using sliding electrical contact, insulated conductor bar systems shall comply with AS 1418.12 and bare wire systems shall comply with the following clauses. 8.14.3.2 Material Bare collector wires of hard-drawn copper and circular cross section shall be of diameter not less than— (a)
for spans not greater than 10 m ........................................................................ 5 mm;
(b)
for spans greater than 10 m but not greater than 20 m .................................6 mm; and
(c)
for spans greater than 20 m .............................................................................. 7 mm.
Bare collector wires of other material or sections shall have not less than the equivalent mechanical strength of the corresponding hard-drawn circular copper conductor.
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Collectors shall be insulated as appropriate to their application, i.e. indoor or outdoor, and be designed to maintain firm contact with the collector wires and to minimize the accumulation of any conductive dust. 8.14.3.3 End support Collector wires shall be securely anchored to their supports by attachments that shall align themselves with the ends of the collector wires. Double insulators shall be provided at both ends. Insulators shall comply with AS 3608. 8.14.3.4 Intermediate support Intermediate support by means of suitable insulators spaced at intervals not greater than 12 m shall be provided for bare conductors of spans greater than 12 m, unless the wires are in constant tension. 8.14.3.5 Arrangement The spacing of collector wires shall be not less than 100 mm in the horizontal plane, 150 mm in a non-horizontal plane, nor less than the value calculated as follows, where S is the span of the collector wires, in metres— (a)
in the horizontal plane ........................................................................... 16S mm; and
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in a non-horizontal plane ............................................................................. 24S mm.
Support and adjacent structures shall be arranged to prevent a conductor from contacting non-insulated metal in the event of displacement of the conductor. The height of bare collector wires shall comply with the appropriate requirements of AS/NZS 3000. Bare collector wires shall be guarded, where necessary, to prevent contact with hoist ropes, pendent controls and similar moving parts of the crane, and shall be out of reach of any person on the crane or a platform. ‘Danger—live conductor’ signs shall be displayed as required by AS 1418.12. 8.14.4 Collector rings Collector rings, where used to supply power to a rotating section of a crane or for similar purposes, shall be arranged and guarded so as to prevent accidental contact with live parts by persons or objects and shall be readily accessible for inspection and maintenance. The design of the brush contacts shall minimize electrode breakage, which can defeat fail-safe circuitry and render the system of controls unsafe. Design of the rings and brushgear shall eliminate the possibility of bridging the rings in the event of brush breakage and similar, which would render the control system unsafe. 8.14.5 Electrical supply cables Electrical cables supplying power to cranes shall be selected to meet the requirements of this Section. Where such cables are connected to crane collector systems, the requirements of AS 1418.12 shall also be met. 8.14.6 Flexible cable Each flexible cable that supplies power to a crane or hoist shall remain flexible over the full operating temperature range of the crane and shall have a current-carrying capacity complying with AS/NZS 3000.
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The flexible cable shall be supported by one of the following (or not less effective) methods: (a)
A rigid-track from which the cable is supported by means of trolleys.
(b)
A catenary wire from which the cable is supported by means of trolleys.
(c)
A trough or duct in which the cable is laid, which is retrieved and relaid by the crane as the crane moves.
(d)
Suspended without intermediate support between a fixed (in location) cable reeling or gathering drum and the crane, crane part or attachment, e.g., magnet.
The terminal ends of the cable shall be anchored at a suitable insulator in a manner that prevents any physical load from being placed on the electrical terminals or connections. The cable shall be of adequate length to prevent all the stored cable being paid out over the full range of movement of the crane and load attachment. A positive and fail-safe interlock shall prevent over-tensioning of the cables. Where the cable has no intermediate support (see Item (d) above), excessive sag shall be prevented by the use of a cable feeder or other automatic means. Cable support fittings shall prevent distortion or damage of the cable insulation. Cable loops shall be evenly spaced, free from obstruction and the cable shall be adequately protected from mechanical damage.
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8.15 ACCESSIBILITY 8.15.1 General All brush gear, terminal connections and any other parts of electrical equipment subject to regular servicing shall be accessible to enable servicing to be effected without the need to move the equipment from its normal location. Rating plates shall be located so that details recorded on them can be conveniently read. 8.15.2 Servicing platforms The design and location of servicing platforms shall be such that persons working on them who suffer electric shock or any other injury causing loss of bodily control will not fall off the platform. 8.16 ELECTRICAL EQUIPMENT MARKING AND INSTALLATION DIAGRAMS 8.16.1 Marking Every electrical component, cable and terminal shall be identified in a permanent and legible manner. For any device not located within a panel, e.g., a limit switch or solenoid valve, the label shall be visible without removal of the device cover. Sliding contact power supply systems shall be suitably marked in accordance with the requirements of AS 1418.12. 8.16.2 Diagrams The following details of the electrical equipment control system, or systems, shall be provided in English with the crane: Complete wiring diagrams of the system or systems (in the control panels), which should include schematics, panel layouts, connection diagrams, cable schedules, equipment layouts or any other information that may be necessary to allow safe and efficient maintenance and fault rectification to be carried out.
(b)
Identification of each item of electrical equipment and cable terminals.
(c)
A legend of the notation of all symbols used to identify electrical equipment and controls.
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(a)
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SECT ION
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9
HYDRAU L I C EQ U IPM E NT CO N T RO L S
AND
9.1 SCOPE OF SECTION This Section specifies the requirements for hydraulic equipment and controls used on cranes (see Clause 1.1). 9.2 MATERIALS The materials and components used in the hydraulic equipment and controls for cranes shall comply with Section 3. All hydraulic components and fluids shall be compatible with the application and the operational environment (see also Section 15). 9.3 BASIS OF DESIGN 9.3.1 General The overall hydraulic system incorporating the hydraulic components and controls shall be capable of handling the design loads imposed by the crane loading (see Section 4) and shall provide a safe condition of the crane under the following circumstances: (a)
Crane out-of-service or in transit.
(b)
Crane in-service while handling the design loads.
(c)
Failure of power source of the hydraulic system.
(d)
Crane testing.
(e)
Hydraulic system testing.
The designed operation of the hydraulic system or hydraulic components shall not adversely affect, or impose excessive stress on any part of the structure or other components of the crane. To simplify fault finding, pressure test points shall be provided at appropriate places in the system and be indicated on the circuit diagrams. Where required, means shall be provided to purge entrained gas from the hydraulic system.
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
9.3.2 Braking Braking requirements shall comply with Clause 7.12 except that the total restraining torque applied to control, arrest and sustain the load shall be not less than 1.1 times the full-load braking requirements for all operating conditions. NOTE: Any assistance that consistently accrues from the hydraulic system may only be considered to be part of the total braking effort.
9.3.3 Emergency stop For any emergency stop action, the selection of suitably-sensitive hydraulic components, tubing size, hoses and fittings, and the equipment locations and installation shall provide an appropriately safe response. 9.3.4 Tubes, hoses, fittings and fluid passages The cross-sectional area of the bore of the tubes, hoses, fittings and fluid passages in a crane hydraulic system shall be sufficient to minimize— (a)
cavitation;
(b)
starvation; and
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undue temperature rise of the fluid and the system.
9.3.5 Safety features All hydraulic components shall be installed and used in accordance with the recommendations of the component manufacturers. In some hazardous environments, fire-resistant hydraulic fluids are required. NOTE: In environmentally sensitive locations, biodegradable hydraulic fluids should be considered.
Hydraulic circuits shall be designed and constructed, and the components adjusted, so that surge pressures remain within the allowable pressure limits of all affected components of the system. The circuits shall incorporate the following safety features: (a)
Components accessible for easy and safe adjustment, maintenance and periodic testing.
(b)
Safety devices to protect against the effects of the failure of a hose in any support circuit on a crane.
(c)
Overpressure protection on the discharge side of all pumps, capable of handling the maximum flow of the pumps.
(d)
Overpressure protection of all load-bearing hydraulic cylinders.
(e)
Loadbearing hydraulic cylinders shall be fitted with a device that will stop the movement in the event of hose rupture or pipe fracture.
(f)
Where two cylinders operate in parallel, a suitable valve system shall be provided to ensure that in the event of loss of pressure to one cylinder, the other cylinder shall be protected against overloading.
(g)
Where a connection is installed between a cylinder port and a check valve in the form of a welded or fitted pipe, the bursting pressure for the whole construction shall be at least 2 times the maximum working pressure.
(h)
Where a fluid pressure can exceed 5 MPa or the temperature can exceed 50°C and where a hose or connection could break or burst and expose personnel to the fluid, a shield shall be provided to divert the fluid.
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9.4 CIRCUIT DIAGRAM Each crane hydraulic system design shall be recorded in the form of circuit diagrams and shall be available on the crane. The circuit diagrams shall include component identification, the crane manufacturer's operational settings using the standard graphic symbols of AS 1101.1, and shall contain sufficient detail to make all functions clear. 9.5 COMPONENTS 9.5.1 Accumulators Gas accumulators shall comply with AS 1210. Gas accumulators should be charged with nitrogen or other inert gas. Provision should be made to isolate accumulators, with a valve to prevent inadvertent opening of the circuit while there is fluid under pressure in an accumulator. 9.5.2 Cylinders The minimum criteria to be considered for the design and manufacture of cylinders used in crane hydraulic systems shall be as follows: (a)
Nature and magnitude of the load.
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(b)
Operational dimensions (see AS 2019).
(c)
Effective length and slenderness ratio of piston rods.
(d)
Available hydraulic pressure and flow characteristics.
(e)
Type of fluid to be used.
(f)
Mounting, e.g., ball joint ends.
(g)
Cylinder wall thicknesses.
(h)
Piston and rod end retention.
(i)
Types of seals and wipers.
(j)
Types and size of bearings. NOTE: Where applicable, the advantages of hollow piston rods and the use of cushion-ended cylinders or deceleration valves to prevent shock loadings should be considered.
9.5.3 Filters and strainers A filter shall be provided for the continuous removal of contaminants from the hydraulic fluid. Filters should be selected and installed so that the filter medium may be changed without disturbing the hydraulic tubing or draining the fluid from the reservoir. Where brakes are held off hydraulically, filters shall not be placed in the return circuit, as they may block, causing sufficient back-pressure to hold a brake off. 9.5.4 Hydraulic controls All hydraulic controls for pressure, volume and flow shall be selected so that they are not normally adjustable beyond the safe working range of the designed operational parameters for the applicable hydraulic system. All pressure controls shall be adjusted only in accordance with the crane manufacturer’s recommendations. External adjustments shall be locked or sealed to prevent unauthorized adjustment. 9.5.5 Hydraulic pumps and hydraulic motors Hydraulic pumps and hydraulic motors shall be selected in accordance with the manufacturer’s recommendation for the application, e.g., gear, vane, piston or similar. 9.5.6 Hydraulic tubing, hoses, fittings and fluid passages
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Hydraulic hoses shall comply with AS 3791. Hydraulic tubing should not be used to support hydraulic components or other equipment. Hoses shall not be used to support hydraulic components or other equipment. Suitable provisions should be made to control the flexing and twisting of hoses and tubing during normal operation. Guarding should be provided to prevent injury to personnel in the event of hose failure. Provision should be made to minimize chafing of hoses. Where practicable, ports on hydraulic components should be distinguished according to function by the use of fittings different in type or size, for example, male thread on the annular side port of a cylinder and a female thread on the ‘full area’ port. 9.5.7 Reservoirs The design and construction of hydraulic reservoirs shall— (a)
preclude entry of foreign matter;
(b)
minimize aeration of the hydraulic fluids;
(c)
incorporate a breather where the reservoir is not pressurized;
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(d)
incorporate a strainer and filler assembly from which the strainer shall not be removable without the use of hand tools;
(e)
incorporate a fluid-level-indicating device showing maximum and minimum levels under operational conditions, with such conditions being specified adjacent to the filling position; and
(f)
have ample, protected, and accessible provisions to facilitate emptying the reservoir without spillage and complete cleaning.
The reservoir shall maintain the fluid level within a safe margin of the working height during operation. The reservoir should be capable of containing all the fluid that may flow back from the system by gravity with all cylinders in the closed position and hold sufficient reserve of fluid to assist in cooling the hydraulic oil to keep its temperature within the limits specified by the supplier. Reservoirs should be located to facilitate cooling. NOTE: A magnetic plug may be fitted to the reservoir to aid removal of ferrous particles.
9.6 INSTALLATION All care shall be taken to prevent the inclusion of contaminants during assembly and installation of hydraulic equipment and controls, and the hydraulic system should be thoroughly cleaned prior to testing. All components of the hydraulic system shall be located or protected against falling objects so as to minimize the risk of accidental damage, misuse and the effects of vibration. All controls should be protected, where practicable, from any possibility of accidental operation. 9.7 TESTING After assembly and prior to delivery, the hydraulic system shall be given complete performance tests to determine compliance with the design, safe operation and control of the crane for the manufacturer’s specified operating conditions. External leakage from components, tubing and similar shall be kept to a practical minimum. 9.8 MARKING The specific type of hydraulic fluid used in the system shall be permanently and legibly marked at the point for filling the reservoir. Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
Other hydraulic fluids shall not be used, either alone or mixed with the specified fluid. On each accumulator, the precharge pressure and charging medium shall be permanently and legibly marked. 9.9 INSPECTION AND MAINTENANCE The hydraulic systems of the crane shall be inspected and maintained generally in accordance with AS 2550.1.
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10.1 SCOPE OF SECTION This Section specifies the requirements for pneumatic equipment and controls used on cranes (see Clause 1.1). 10.2 MATERIALS The materials and components used in the pneumatic equipment and controls for cranes shall comply with Section 3. All components and lubricants shall be compatible with the application and the operational environment (see also Section 15). 10.3 BASIS OF DESIGN 10.3.1 General The overall pneumatic system incorporating the pneumatic components and controls shall be capable of handling the design loads imposed by the crane loading (see Section 4) and shall provide a safe condition of the crane under the following circumstances: (a)
Crane out-of-service or in transit.
(b)
Crane in-service while handling the design loads.
(c)
Failure of power source of the pneumatic system.
(d)
Crane testing.
(e)
Pneumatic system testing.
The designed operation of the pneumatic system or pneumatic components shall not adversely affect or impose excessive stress on any part of the structure or other components of the crane. To simplify fault finding, pressure test points shall be provided at appropriate places in the system and be indicated on the circuit diagrams.
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10.3.2 Braking Braking requirements shall comply with Clause 7.12 except that the total restraining torque applied to control, arrest and sustain the load shall be not less than 1.1 times the full load braking requirements for all operating conditions. NOTE: Any assistance that consistently accrues from the pneumatic system may be considered to be only part of the total braking effort.
10.3.3 Emergency stop For any emergency stop action, the selection of suitably sensitive pneumatic components, tubing size, hoses and fittings, and the equipment locations and installation shall provide an appropriately safe response. 10.3.4 Tubes, hoses, fittings and air passages The cross-sectional area of the bore of the tubes, hoses, fittings and passages in a crane pneumatic system shall be sufficient to— (a)
provide an appropriately-sensitive control response;
(b)
minimize loss of power; and
(c)
minimize cooling by expansion.
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10.3.5 Safety features All pneumatic system components shall be installed and used in accordance with the recommendations of the component manufacturers. Pneumatic circuits shall be designed and constructed, and the components adjusted, so that shock pressures remain within the allowable pressure limits of all affected components of the system. The circuits shall incorporate the following safety features: (a)
Components accessible for easy and safe adjustment, maintenance and periodic testing.
(b)
Safety devices to protect against the effects of failure of a hose in any support circuit on a crane.
10.4 CIRCUIT DIAGRAM Each crane pneumatic system design shall be recorded in the form of circuit diagrams and shall be available on the crane. The circuit diagrams shall include component identification and the crane manufacturer’s operational settings using the standard graphic symbols of AS 1101.1 and shall contain sufficient detail to make all functions clear. 10.5 COMPONENTS 10.5.1 Cylinders
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The minimum criteria to be considered for the design and manufacture of cylinders used in crane pneumatic systems shall be as follows: (a)
Nature and magnitude of the load.
(b)
Operational dimensions (see AS 2019).
(c)
Effective length and slenderness ratio of piston rods.
(d)
Available pneumatic pressure and flow characteristics.
(e)
Mounting, e.g., ball joint ends.
(f)
Cylinder wall thicknesses.
(g)
Piston and rod end retention.
(h)
Types of seals and wipers.
(i)
Types and size of bearings. NOTE: Where applicable, the advantages of a hollow piston rod and the use of cushion-ended cylinders or deceleration valves to prevent shock loadings should be considered.
10.5.2 Filters A filter should be provided for the continuous removal of contaminants from the air supply. Filters should be selected and installed so that the filter medium can be changed without disturbing the pneumatic tubing. Filters should be adequately sized to provide 1000 h of operation between services. Preference should be given to filters offering a visible indication of their operational condition. 10.5.3 Pneumatic controls All pneumatic controls for pressure, volume and flow shall be selected so that they are not normally adjustable beyond the safe working ranges of the designed operational parameters for the applicable pneumatic system. All pressure controls shall be adjusted only in accordance with the crane manufacturer’s recommendations.
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10.5.4 Pneumatic motors Pneumatic motors should be selected for as wide a stable operating speed range as practicable to utilize the flexibility offered by pneumatic control and to reduce abrupt starts or directional changes. 10.5.5 Pneumatic tubing, hoses, fittings and air passages Pneumatic tubing shall comply with the appropriate requirements of AS 4041, as applicable. Pneumatic tubing should not be used to support pneumatic components or other equipment. Hoses shall not be used to support pneumatic components or other equipment. Suitable provision should be made to control the flexing and twisting of hoses and tubing during normal operation. Guarding should be provided to prevent injury to personnel in the event of hose failure. Provision should be made to minimize chafing of hoses. Where practicable, ports on pneumatic components should be distinguished according to function by the use of fittings differentiating in type or size, for example, male thread on the annular side port of a cylinder and a female thread on the ‘full area’ port. 10.5.6 Receivers Pneumatic receivers shall comply with AS 1210, and shall be removable from the system. Each receiver shall be fitted with a readily accessible or automatic drain trap. 10.6 INSTALLATION All practical care shall be taken to prevent the inclusion of contaminants during assembly and installation of pneumatic equipment and controls. The pneumatic system should be thoroughly cleaned prior to testing. All components of the pneumatic system shall be located or protected against falling objects so as to minimize the risk of accidental damage, misuse, and the effects of vibration. All controls should be protected, where practicable, from any possibility of accidental operation. Pendent stations, hose runs, hose coils and the like shall be supported in a manner that protects the items or any adjacent components against strain or damage by impact.
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10.7 TESTING After assembly and prior to delivery, the pneumatic system shall be given complete performance tests to determine correct function. External leakage from components, tubing, and similar, shall be kept to a practical minimum. 10.8 MARKING Receivers shall be permanently and legibly marked in accordance with AS 1210. 10.9 INSPECTION AND MAINTENANCE The pneumatic systems of the crane shall be inspected and maintained in accordance with AS 2550.1.
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D E S I GN
11.1 SCOPE OF SECTION This Section specifies the requirements for operational design of cranes (see Clause 1.1). 11.2 CONTROL CABIN 11.2.1 Location of control cabin The control cabin should be located remote from the crane-supply electric conductors. 11.2.2 Space for operator The space, excluding that occupied by equipment, furniture, and the like, provided as the operational position for the crane or hoist operator, shall be not less than 0.5 m2 in area. Where provision is made for a passenger, e.g., trainee operator, the space to accommodate the passenger or passengers shall be additional. Cabin interiors shall be designed so that, when seated, operators are able to conveniently reach all the controls required for normal operation of the crane without subjecting any parts of their bodies to sustained postural stress and without being impeded by fixtures within the cabin. 11.2.3 Seating of operator The seating for the crane or hoist operator, where required, shall be designed and installed so that the operator’s body is not subject to undue vibration during operation, which would have adverse effect on the body or would otherwise affect the ability to safely and efficiently control the crane. The seat shall be capable of supporting the operator in comfort for a period of time equivalent to a workshift and shall permit changes of posture while still providing support particularly in the buttocks and lumbar region of the back. The seat shall be adjustable for the height of the cushion above the floor or pedal controls, and the squab (backrest) shall be adjustable for rake. Where pedal controls are provided for single foot operation, a footrest shall be provided to support the free foot. 11.2.4 Controls and indicators Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
Controls shall be located and arranged for— (a)
optimum consistency between the natural directional movement of the controller and the resulting movement of the load, crane, or part of the crane; and
(b)
convenient operation of controls and groups of controls.
Indicators, gauges, meters and warning devices shall be of suitable design and adequate size and shall be located so that the operators can correctly interpret the information they are intended to convey without moving from their normal operating position. Emergency stop controls shall be prominent from all other controls and shall be operable by being hit by any part of the hand or arm. 11.2.5 Visibility from the cabin Where the crane or hoist operator is intended to view the working area, the cabin of the crane shall be designed to provide the operator, while in the normal operating position, with an uninterrupted view of the working area which the crane is capable of serving and the load handled by the crane. www.standards.com.au
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Windows shall be glazed in accordance with AS 1288 and AS/NZS 2080 and shall be arranged to minimize glare and to enable convenient and safe access for cleaning. Special vision panels, where provided, shall be suitably guarded, for example, where situated at floor level. Where the crane is exposed to inclement weather, windscreen wipers, demisters and similar equipment, which adequately maintain compliance with this Clause under all weather conditions, shall be provided. Where the crane is exposed to sunlight, cabin windows may be of tinted glass. However, if tinted glass is used, it shall be only lightly tinted so that the vision of the crane operator is not impaired during night operation. Where mirrors are provided to enable extended area of vision, the mirrors shall have a flat surface. 11.2.6 Ventilation Each control cabin shall be either naturally ventilated or mechanically ventilated. Where the cabin is naturally ventilated, windows or vents in at least two sides of the cabin shall be capable of being operated. Where the crane operates in a toxic, irritant or obnoxious atmosphere, the control cabin shall be mechanically ventilated. The control cabin should be kept at positive air pressure of not less than 50 Pa above the outside air pressure. Where the atmosphere contains a high concentration of dust or fibrous particles, the air supply shall be effectively filtered. Where the atmosphere contains gas or vapour, the air supply shall be treated by an adsorption or other appropriate device. Where airconditioning is provided for the control cabin, the method of function and source of supply shall not affect or detract from the correct operation of the crane. 11.2.7 Lighting Control cabin lighting shall comply with AS 1680. The local illumination level at the crane operator controls shall be not less than 300 lx. Instrument illumination shall be controlled separately from the cabin lighting. Glare from external, natural or artificial lighting sources shall be prevented by provision of suitably placed visors on or in the cabin or by the use of tinted glass (see Clause 11.2.5). The interior of the cabin shall be finished so as to minimise direct and reflected glare.
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11.2.8 Thermal environment Individual heaters, where provided, shall be permanently fixed, totally enclosed, non-luminous and shall be protected from accidental mechanical damage or from causing injury from accidental contact. Where the control cabin is subjected to intense heat from a manufacturing process or other source, the cabin shall be protected from the effects of such heat by means of guards, baffles, thermal insulation or other appropriate means. 11.2.9 Noise exposure criteria The maximum allowable exposure to noise in cranes shall not exceed the level specified in the National Occupational Health and Safety Commission’s National Standard and National Code of Practice for Noise Management and Protection of Hearing at Work. 11.2.10 Communication Consideration shall be given to the installation of a communications system.
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Where radio communication is used, the transmitting frequencies of the radio equipment shall be selected to prevent interference to or from other radio equipment being used in the vicinity of the crane. 11.2.11 Fire extinguisher Where the crane operator does not have a ready means of exit from the control cabin at all positions of operation of the crane, a portable fire extinguisher of not less than 2 kg of the dry chemical powder type or carbon dioxide type or vaporizing-type complying with AS/NZS 1841.5 or AS/NZS 1841.6 or AS/NZS 1841.7, respectively, shall be provided in a prominent position. 11.2.12 Emergency entry to control cabin Where the size of the control cabin is such that the crane operator, if incapacitated when operating the crane, could fall and prevent the cabin door from being opened from outside, alternative means of entry, e.g., push-in windows or removable panels, shall be provided. 11.2.13 Emergency egress from control cabin In cases where there is no permanent access to the cabin in all positions of the crane, a means of alternative egress shall be provided to allow for escape from the cabin in the event of the breakdown of the crane or other urgent demands for escape. The systems listed in Table 11.2.13 may be suitable when the floor area swept by the crane has at least 25% free of machines or goods, and when the goods being handled do not involve dangerous materials or processes, e.g., hot >100°C, toxic or corrosive materials. Where emergency egress is provided by either a fall arrest system or a control descent device, an anchorage point commensurate with the type of system specified in AS/NZS 1891.4 shall be fitted to an appropriate place in the cabin. Where the emergency egress incorporates a fall arrest system, it shall comply with the appropriate part of AS/NZS 1891. NOTE: Guidance on the selection, use and maintenance of fall arrest systems is given in AS/NZS 1891.4.
TABLE 11.2.13 EMERGENCY EGRESS
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Height above workstation
Device
1 to 10 m
Telescopic/folding ladder
3 to 15 m
Emergency lowering device
Any height
Fixed means of access that may require a fall arrest system to protect the operator from fall over unprotected edges
11.3 PENDENT CONTROL STATIONS AND PENDENT CORDS 11.3.1 Pathway for crane operator Where a crane is operated by a pendent control station or a pendent cord, an unobstructed pathway extending the complete length of the crane travel shall be provided for the crane operator. 11.3.2 Operating level of controls The controlling element shall be capable of being suspended at a height between 1.0 m and 1.2 m above ground or floor level when in use. Where the controlling element can be moved off from its operating position, it shall be capable of being reached in a retracted position from ground or floor level. www.standards.com.au
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Where dual controls, for example, cabin and pendent controls are provided, a positive and fail-safe interlock shall be incorporated so that the alternative control can be operated only when the controlling element is fully retracted. 11.4 OPERATOR CONTROLS AND INDICATORS 11.4.1 Operation of controls The maximum actuating force required to operate controls shall be not greater than the following: (a)
Finger-operated lever.............................................................. 10 N (either direction).
(b)
Pushbutton ....................................................................................................... 25 N.
(c)
Hand-operated lever (console mounted) .................................. 50 N (either direction).
(d)
Hand-operated lever (floor mounted)............................................................... 400 N.
(e)
Pedal .............................................................................................................. 600 N.
(f)
Steering wheel— (i)
manually powered ................................................................................. 250 N.
(ii)
power-assisted— (A)
power assistance operating ........................................................... 250 N.
(B)
power assistance not operating...................................................... 600 N.
11.4.2 Interlocking of controls Controls shall be interlocked in a positive and fail-safe manner to prevent inadvertent or deliberate simultaneous engagement or disengagement of controls in any sequence or combination that could result in loss of control of the crane motion. Where a motion can be either manually operated or power operated, interlocking shall be provided to prevent simultaneous engagement of both manual and power operation. 11.4.3 Controls and indicators for ancillaries Control switches and indicators for lighting, ventilation, heating and similar ancillaries shall be positive in operation, and shall be mounted on a control panel located within convenient access of the operator from the normal operating position.
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11.4.4 Marking of operator controls All operator controls shall be suitably marked to indicate their function or operation or both. Such marking shall be either in English based alphanumerics or graphically as specified in ISO 7296, except pendent controls may not use graphical symbols. 11.5 WARNING DEVICES A visual or audible warning system shall be provided where the crane operator does not have full view of all crane wheels where the wheels operate in an area that is normally accessible to personnel. The warning device shall be able to be controlled by the crane operator and shall also activate automatically when the crane is in motion.
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SECT ION
12 MANUFAC TURE C ON ST RU CT I O N
AS 1418.1—2002
AND
12.1 SCOPE OF SECTION This Section specifies the requirements for the manufacture and construction of, and access to and clearances on, cranes (see Clause 1.1). 12.2 MATERIALS All materials shall be new and shall comply with the relevant Standards specified herein, and the requirements of this Standard. 12.3 FABRICATION AND ASSEMBLY Mechanisms shall be manufactured using the applicable engineering drawings and adhering to the noted tolerances. Welding shall comply with the applicable parts of AS 1554. High-strength fasteners shall be correctly torqued. Appropriate jigs and fixtures shall be utilized during the manufacturing process, as applicable, to assure satisfactory alignment of components as specified by engineering drawings. 12.4 REWORK Where any part or component needs to be reworked or modified, such rework or modification shall be made in such a way that the essential properties of the part or component are not adversely affected. 12.5 FINISH Each part and component shall be protected, where necessary, from corrosion or other surface deterioration which would cause strength deterioration of the part or component, or other adverse effect, by the application of an appropriate external finishing material or process.
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12.6 DRAINING Where a crane is subjected to weather or other conditions where water or other fluid could collect in cavities or similar places, such cavities and places shall have effective means of drainage. 12.7 ACCESS AND CLEARANCES 12.7.1 General Requirements for access and clearances specified in this Standard ensure that effective facilities are provided as part of a crane installation to enable safe and convenient access— (a)
of the crane operator to the normal operating position;
(b)
of service personnel to those parts of the crane that need regular inspection, adjustment or service; and
(c)
of service personnel to those parts of the crane that need periodical inspection, maintenance or repair.
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12.7.2 Access to crane operating position Access shall be provided in accordance with the relevant part of AS 1418 for the crane operator to the normal operating position with the crane situated in its normal out-of-service position. 12.7.3 Access and egress facilities 12.7.3.1 General Access and egress facilities shall be in conformance with the applicable part of AS 1418 or AS 1657 or ISO 11660-1, as applicable. Where requirements differ, the applicable part of AS 1418 shall take precedence over AS 1657, which shall in turn take precedence over ISO 11660-1. 12.7.3.2 Access for inspection and servicing Facilities shall be provided as part of a crane installation to minimize risks and provide convenient access for inspection and servicing. Particular attention shall be given to those components and subassemblies that are exposed to corrosion, fatigue and wear. Provision shall be made for lubrication of gears, as appropriate, and of all bearings and journals. Any point of insertion of lubricants or points where adjustments are to be made by maintenance personnel shall be accessible. 12.7.4 Clearances The clearance between moving parts of a crane or between a moving crane and fixed structures in working areas shall comply with the relevant part of AS 1418, or not less than— (a)
where the crane, parts of the crane or objects approach each other, i.e. as a crushing movement ............................................................................................. 350 mm; and
(b)
where the crane, parts of the crane or objects pass each other, i.e. as a shearing movement ................................................................................................... 450 mm.
For non-working areas, a minimum clearance of 50 mm shall apply. 12.8 REPAIRS Repairs shall only be permitted where the structural integrity of the crane can positively be maintained.
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Repairs shall be carried out in conformance with AS 2550.1.
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13
I NSPECT I ON
AS 1418.1—2002
AND
TES T I NG
13.1 SCOPE OF SECTION This Section specifies the requirements for inspection and testing of cranes. 13.2 INSPECTION Prior to its commissioning tests, the crane shall be inspected to ensure that it has been correctly assembled and erected. Each movement of the crane shall be checked throughout its complete range in both directions under no-load conditions. 13.3 TESTING Prior to being placed in service, the crane shall comply with the commissioning test requirements specified in the appropriate part of AS 1418. A1
13.4 COMMISSIONING
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Cranes shall be erected, or installed, and commissioned in accordance with the specifications of the designer and manufacturer.
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M A RK I NG
14.1 SCOPE OF SECTION This Section specifies the requirements for marking of the crane and associated equipment. 14.2 MARKING 14.2.1 General The crane shall be marked in accordance with the marking requirements specified in the appropriate part of AS 1418. The crane and crane subassemblies shall be marked legibly and permanently with the manufacturer’s traceable marking. Independent hoisting mechanisms shall include marking for the rated capacity. 14.2.2 Marking on lifting devices Each lifting attachment, e.g., lifting beam, magnet or grab, shall be marked in a permanent manner with the following information: (a)
The mass of the lifting attachment expressed in the same unit as the rated capacity of the lifting attachment.
(b)
The rated capacity of the lifting attachment in either kilograms or tonnes.
(c)
Name or mark of the manufacturer or distributor of the attachment, where applicable.
(d)
An identification number.
(e)
Details of wire rope used on the lifting attachment, i.e. (i)
nominal size;
(ii)
grade (quality);
(iii) construction; and (iv)
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(f)
length.
Details of chain used on the lifting attachment, i.e. (i)
nominal size; and
(ii)
grade (quality).
Marking shall be in the English language, and values shall be in SI units (see ISO 1000). Items (a) and (b) shall be of sufficient size to be legible from the working area below the crane to which it is attached, and the other items being marked legibly on a plate or plates permanently fixed to the attachment.
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OP E RA T I N G
AS 1418.1—2002
E N V I RO N ME N T
15.1 GENERAL This Section specifies the information that shall be considered when selecting materials and equipment to be used in the design of the crane (see Clause 1.1) so that the crane is capable of rated performance— (a)
under the normal indoor service conditions specified in Clause 15.2.1; or
(b)
under the normal outdoor service conditions as specified in Clause 15.3.1;
(c)
under special service conditions, examples of which are given in Clauses 15.2.2 and 15.3.2 for indoor and outdoor services respectively, subject to the purchaser advising the manufacturer of the specified service condition applicable.
(d)
in hazardous environments specified in Clause 15.4, subject to the purchaser advising the manufacturer of the hazardous service condition applicable.
15.2 INDOOR INSTALLATION 15.2.1 Normal indoor service conditions Normal indoor service conditions are as follows: (a)
Ambient temperature— (i)
maximum of 40°C;
(ii)
maximum average of 35°C over a 24 h period; and
(iii) minimum of −5°C. (b)
Atmospheric conditions— (i)
pollution degree 3 by agents such as smoke, fumes, dust or chemicals; and
(ii)
relative humidity not exceeding a maximum wet bulb temperature of 30°C.
Allowance shall be made for condensation that may occur owing to temperature variations. (c)
Altitude A maximum of 1000 m above sea level.
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15.2.2 Special service conditions Examples of special service conditions are as follows: (a)
Value of temperatures, relative humidity or altitude differing from those specified in Clause 15.2.1.
(b)
Applications where variations in temperature or air pressure (or both) take place at such a rate that exceptional condensation is liable to occur within electrical enclosures.
(c)
Pollution degree 4 of the air by dust, smoke, corrosive particles, chemicals or vapours.
(d)
Exposure to strong electric or magnetic fields.
(e)
Rate of exposure to extreme temperatures.
(f)
Attack by fungi, insects and vermin.
(g)
Exposure to heavy vibration and shock.
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15.3 OUTDOOR INSTALLATION 15.3.1 Normal outdoor service conditions Normal outdoor service conditions are as follows: (a)
Ambient air temperature— (i)
maximum of 40°C;
(ii)
maximum average of 35°C over a 24 h period; and
(iii) minimum of −10°C. (b)
Atmospheric conditions— (i)
wind;
(ii)
rain; and
(iii) solar radiation. (c)
Altitude A maximum of 1000 m above sea level.
15.3.2 Special service conditions Examples of special outdoor service conditions are as follows: (a)
Temperatures or altitudes differing from those specified in Clause 15.3.1.
(b)
Extreme solar radiation.
(c)
Special conditions in Items (b) to (g) of Clause 15.2.2.
(d)
Snow and ice.
(e)
Water sprayed from any direction, salt-laden spray, chemicals or windborne sand or other abrasive particles.
15.4 HAZARDOUS AREAS Where applicable, equipment, components and the assembly thereof shall be suitable for use in hazardous areas.
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Where a crane is located in a hazardous area, the area shall be classified, e.g., class, zone, maximum surface temperature, gas grouping. NOTE: Guidance is given in AS 2430.1, AS/NZS 61241.3 and the AS/NZS 2430.3 series on the classification of hazardous areas. Requirements for electrical equipment for use in hazardous areas are found in AS 2381 (all parts, as applicable). HB 13 also provides guidance for electrical equipment for hazardous areas.
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SECT ION
16
AS 1418.1—2002
MANUA L S
16.1 GENERAL The manuals that shall be supplied are— (a)
the crane operator’s manual;
(b)
the maintenance manual;
(c)
the logbook; and
(d)
the parts book.
16.2 CRANE OPERATOR’S MANUAL The crane operator’s manual shall be a formal publication, covered in a durable material and of a size suitable for its use. It may be combined with another manual or be an individual manual. It may be cross-referenced to other manuals of the crane. It shall present, in plain English, with explanations and definitions by words, the following information: (a)
The make, model and serial number of the crane or where appropriate, the range of serial numbers to which the information applies, which shall be readily identifiable.
(b)
All technical data of importance to the crane operator to ensure correct operation, travel speed in the unloaded rigged configuration, transportation, erection and dismantling of the crane.
(c)
Description of and location of all indicating and limiting, settings and adjustments.
(d)
Instructions on the duties of the crane operator prior to operation, during operation and after use.
(e)
Instructions on restrictions in environmental conditions of wind and temperature.
(f)
A diagram showing recommended clearances to be observed from overhead conductors.
(g)
Description of all safety precautions to be observed during maintenance and servicing of the crane.
NOTE: Diagrams or illustrations may be added for clarity.
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16.3 MAINTENANCE MANUAL The maintenance manual shall be a formal publication covered in durable material and of a suitable size for the conditions of use. It may be combined with another manual or be an individual manual. It may be cross-referenced to other manuals for the crane. It shall present, in plain English, with explanation and definitions by words, the following information: (a)
The make, model and serial number of the crane or where applicable, the range of serial numbers to which the information applies, which shall be readily identifiable.
(b)
All technical data necessary to enable the correct and safe maintenance of the crane.
(c)
Describe the location, operation and adjustments of all limiting and indicating devices.
(d)
Details of safety precautions to be observed during maintenance and servicing of the crane.
NOTE: Diagrams or illustrations may be added for clarity. www.standards.com.au
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16.4 SERVICE RECORD (LOGBOOK) A crane service record (logbook) shall be provided, which is capable of being maintained current with details of the maintenance, service and repairs carried out on the crane. 16.5 PARTS BOOK
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A crane parts book shall be provided and have all parts and elements adequately illustrated and identified to enable descriptions to be readily given to the crane manufacturer.
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AS 1418.1—2002
APPENDIX A
ORGANIZATION OF AUSTRALIAN STANDARD FOR CRANES (Informative) The organization of the Australian Standard for Cranes, hoists and winches is detailed in the chart shown in Figure A1. At present, the Standard comprises 17 parts; Parts 1 to 10 and Parts 12 to 18.
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A list of Standards used in lifting systems is given in Appendix M. Appendix M also lists other Standards that should be complied with, as applicable.
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FIGURE A1 (in part) STRUCTURE OF STANDARD
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FIGURE A1 (in part) STRUCTURE OF STANDARD
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FIGURE A1 (in part) STRUCTURE OF STANDARD
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FIGURE A1 (in part) STRUCTURE OF STANDARD
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APPENDIX B
LIST OF REFERENCED STANDARDS AND STANDARDS FOR REFERENCE (Normative) B1 REFERENCED DOCUMENTS
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The following documents are referred to in this Standard. AS 1029 1029.1
Low voltage contactors Part 1: Electromechanical (up to and including 1000 V a.c. and 1200 V d.c.)
1085 1085.1
Railway permanent way material Part 1: Steel rails
1101 1101.1
Graphical symbols for general engineering Part 1: Hydraulic and pneumatic systems
1138
Thimbles for wire rope
1163
Structural steel hollow section
1170 1170.1 1170.2
Minimum design loads on structures Part 1: Dead and live loads and load combinations Part 2: Wind loads
1210
Pressure vessels
1288
Glass in buildings—Selection and installation
1319
Safety signs for the occupational environment
1403
Design of rotating steel shafts
1418
Cranes (including hoists and winches) (all parts)
1448
Carbon steels and carbon-manganese steels—Forgings (ruling section 300 mm maximum)
1594
Hot-rolled steel flat products
1657
Fixed platforms, walkways, stairways and ladders—Design, construction and installation
1680
Interior lighting
1720 1720.1
Timber structures Part 1: Design methods
1726
Geotechnical site investigations
1768
Lightning protection
1830
Iron castings—Grey cast iron
1831
Iron castings—Spheroidal or nodular graphite cast iron
1832
Iron castings—Malleable cast iron
1874
Aluminium and aluminium alloys—Ingots and castings
1939
Degrees of protection provided by enclosures for electrical equipment (IP Code)
2019
Fluid power—Hydraulic and pneumatic cylinders—Bore and rod dimensions
2074
Steel castings
2076
Wire-rope grips for non-lifting applications
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AS 2318
Swivels for hoists
2319
Rigging screws and turnbuckles
2381 2381.2 2381.6 2381.7
Electrical equipment for explosive atmospheres—Selection, installation and maintenance Part 2: Flameproof enclosure d Part 6: Increased safety e Part 7: Intrinsic safety I
2430
Classification of hazardous areas (set)
2549
Cranes (including hoists and winches)—Glossary of terms
2550
Cranes—Safe use (all parts)
2670
Evaluation of human exposure to whole-body vibration (all parts)
2740
Wedge-type sockets
2741
Shackles
3007 3007.1 3007.2 3007.3
Electrical installations—Surface mines and associated processing plant Part 1: Scope and definitions Part 2: General protection requirements Part 3: General requirements for equipment and ancillaries
3108
Approval and test specification—Particular requirements transformers and safety isolating transformers
3600
Concrete structures
3608
Insulators—Porcelain and glass, pin and shackle type—Voltages not exceeding 1000 V a.c.
3678
Structural steel—Hot-rolled structural plates, floorplates and slabs
3679 3679.1
Structural steel Part 1: Hot-rolled bars and sections
3777
Shank hooks and large-eye hooks—Maximum 25 t
3791
Hydraulic hose
3859
Effects of current passing through the human body
3990
Mechanical equipment—Steelwork
4024 4024.1
Safeguarding of machinery Part 1: General principles
4041
Pressure piping
4100
Steel structures
4142 4142.1 4142.2 4142.3
Fibre ropes Part 1: Care and safe usage Part 2: Three-strand hawser-laid and eight-strand plaited Part 3: Man-made fibre rope for static life rescue lines
AS/NZS 1269
Acoustics—Hearing conservation
1359
Rotating electrical machines—General requirements
1554
Structural steel welding (all parts)
1664 1664.1 1664.2
Aluminium structures Part 1: Allowable stress design Part 2: Limit state design
1800
Occupational protective helmets—Selection, care and use
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isolating
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AS 1418.1—2002
AS/NZS 1801
Occupational protective helmets
1841 1841.5 1841.6 1841.7
Portable fire extinguishers Part 5: Specific requirements for powder type extinguishers Part 6: Specific requirements for carbon dioxide type extinguishers Part 7: Specific requirements for vaporizing-liquid type extinguishers
1891
Industrial fall-arrest systems and devices (set)
2080
Safety glass for land vehicles
2381 2381.1
Electrical equipment for explosive atmospheres—Selection, installation and maintenance Part 1: General requirements
3000
Electrical installations (known as the Australian/New Zealand Wiring Rules)
3100
Approval and test specification—General requirements for electrical equipment
3947 3947.1 3947.3 3947.4 3947.5.1
Low-voltage switchgear and controlgear Part 1: General rules Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination units Part 4: Contactors and motor starters (all parts) Part 5.1: Control circuit devices and switching elements
61000
Electromagnetic compatibility (EMC)
61241 61241.3
Electrical apparatus for use in the presence of combustible dust Part 3: Classification of areas where combustible dusts are or may be present
IEC 61603 61603-1
Transmission of audio and/or video related signals using infra-red radiation Part 1: General
ISO 1000
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SI units and recommendations for the use of their multiples and of certain other units
1328 1328-1
Cylindrical gears—ISO system of accuracy Part 1: Definitions and allowable values corresponding flanks of gear teeth
6336
Calculation of load capacity of spur and helical gears (all parts)
7296 7296-2
Cranes—Graphical symbols Part 2: Mobile cranes
12842 12842-1
Cranes—Condition monitoring Part 1: General
11660 11660-1
Cranes—Access, guards and restraints Part 1: General
DIN 536
Part 1:
15020
Lighting appliances, principles relating to rope drives
15061
Sheet 1: Sheet 2:
Standards Australia
of
deviations
relevant
to
Cranes rails, Type A (with foot flange); dimensions, static values, steel grades Cranes, grooved profiles for wire rope drums Lifting appliances, groove profiles for wire rope sheaves
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JIS E1101
AS 1418.1—2002
Flat bottom railway rails and special rails for switches and crossings of non-treated steel
E1103
Light rails
BS 1726 1726.1
Coil springs Part 1: Guide for the design of helical compression springs
SAI HB 13
Electrical equipment for hazardous areas
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Ministerial Council for Road Transport “Australian code for the transport of dangerous goods by road and rail (ADG) Code”. 6th Edition. Canberra: AGPS, 1998. Known as the Australian Dangerous Goods Code
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APPENDIX C
FAILURE TO SAFETY (FAIL-SAFE SYSTEMS) (Informative) C1 GENERAL Failure to safety is conceptually applicable to any structural, mechanical, electrical or. Failure to safety is the embodiment, in a system of components, of a characteristic such that the failure of a single component— (a)
does not cause the system to cease its intended service; and
(b)
does not cause the device in which the system exists to reach, or tend toward, a lesser degree of safety than would otherwise be the case.
It is self evident that a single component cannot fail-safe. To satisfy the concept of failure to safety, a single component is replaced by a system of components or by re-configuring the whole so that the failure of the component will be inconsequential. Failure to safety has a rational meaning only on the basis that a given possible failure has a non-zero probability of occurrence and that such a failure is not tolerable. However, for a system devised to be fail-safe, if one of its components fails and the failure of that component is not able to be readily detected, the system does not achieve failure to safety and the probability of the failure of the system becomes equal to that of the probability of failure of the next most critical component. While failure to safety achieves a system with the most desirable level of integrity, in certain circumstances it cannot be invoked and reliance for safety may remain on a single component. Such circumstances involve considerations of practicability where backup, redundancy, duplication, and the like, would not be possible. In these circumstances, the probability of failure could be minimized by design, quality control and concentrated routine inspection and test. C2 COMMON FAIL-SAFE SYSTEMS
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C2.1 Emergency stop systems Typically, failure to safety is provided by a system of components consisting of a master contactor arranged to remove all power from a device when one of a number of serieslinked, normally closed stop buttons is opened and de-energizes the coil of the contactor. The system is fail-safe in that a circuit fault such as a broken wire, jammed button or opencircuited contactor coil causes the safe response, i.e. opening of the contactor. It is generally accepted that because the contactor is dedicated to this purpose and only operates in the unusual circumstance of an emergency, then, if properly sized, its probability to fault closed (e.g. due to welded main contacts) is very low, the probability of failure in this state being of a similar order of magnitude to that ascribed to any other non-redundant system. Further safety is frequently introduced by making the stop buttons latch in the open state mechanically and by requiring a reset by a start button to re-establish the contactor independently of the reset of the stop button contacts. The system described may be characterised as fail-safe provided that the probability that the contactor will open when commanded (its intended service) is within the appropriate ranges.
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C2.2 Fail-safe brake A fail-safe brake is a brake that requires power to be applied to cause it to lift or open, that is, not be applied. The closing (or application) of the fail-safe brake is usually produced by spring energy. Such a brake may not be fail-safe in itself, as the failure of one of its components, e.g. the spring, may cause it to cease its intended service. The term ‘fail-safe brake’ describes the system of braking rather than the brake but rarely, if ever, is there sufficient redundancy built into the brake or sufficient monitoring (to ensure that the brake is not inopportunely disabled because of excessive wear) to make the system intrinsically safe or fail to safety in all circumstances. The duplication of brakes in particular hazardous environments is usually required; however, even this does not guarantee a fail-safe system, and eventually reliance on appropriate and regular tests to prove the system is necessary to secure intrinsic safety. C2.3 Structural elements Where a structure comprises a network of members in which their principals are continuous and where braces, ties and struts are welded or otherwise connected to the principals by joints that are capable of supporting a moment (albeit for a short time), there is a high probability that the structure can be judged to be intrinsically safe. Where, because of the redundancy of the continuity and moment capacity noted above, a member could be removed without occasioning the structure to cease its intended service, and such removal or loss could be evident in a casual inspection, the structure is fail-safe. However, it is up to the designer to establish inspection procedures, both in method and timing, to ensure the timely discovery of an initial failure and the consequent ongoing reliance on secondary members and connections not specifically designed to accommodate the principal loads. Example: Consider a simply supported beam carrying dead and live working loads. If it were to fail (cease its intended service), injury would be likely, and, therefore, it is not fail-safe. Intrinsic safety could be achieved either by— (a)
the installation of a secondary member or trussing elements, which could handle the load on a temporary basis while making it obvious that the primary member had failed; or
(b)
designing the primary (single) component to satisfy the necessary maximum probabilities of failure.
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C2.4 Ratchet locks Where a ratchet lock mechanism is employed, for instance to lock an ‘over the shoulder’ patron restraint, such a mechanism is fail-safe when the ratchet pawl is duplicated, that is, lifted by a separate immediate device to that which lifts the primary ratchet pawl and which acts on secondary ratchet teeth or on a portion of the primary ratchet not in contact with the primary pawl. Intrinsic safety, however, is only secured by such a system when the failure of the primary system is discoverable in a timely manner by immediately observable means without the need for tools, for example, by counting clicks of engagement or by obvious excessive travel to take-up. In certain systems of this type, it is not possible to determine which is the primary and which is the secondary system, and the designer and manufacturer should provide full explanatory information to the user so that those responsible have a good understanding of the operation and service requirements of the total system.
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APPENDIX D
TYPICAL CRANE APPLICATION CLASSIFICATION
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(Normative)
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LEGEND: fr = ratio of average hook path to nominal hook path available ↓ Go down in class ↑ Go up in class NOTES: 1
Typical crane application is selected from the centre of the above table.
2
The number of working cycles per day is cross-checked at the right-hand side depending on the duty, i.e. light, moderate, heavy or very heavy.
3
If the selection is correct, a horizontal line is drawn.
4
The lift cycle is calculated from the expression— 0.60 ×
2 × hook path (m) 60 VH (m/s )
5
A vertical line is drawn at the appropriate division. The intersection of both lines indicates the mechanical classification that matches the selected crane classification.
6
The Table shows typical classifications for hoists and cranes as a whole. For classification of other motions where insufficient data exists the following guidance may be used:
7
(a)
Long travel One classification lower than the chosen hoist classification.
(b)
Cross travel, slewing, luffing Two classifications lower.
For monorail travel classification, use one classification lower than the chosen hoist classification. Example: (a)
Indoor gantry crane of medium state of loading = Q2 (see Table 2.3.3).
(b)
Number of lifts during life = 6.3 × 10 4 = U2 (see Table 2.3.2).
(c)
Nominal load spectrum factor (K p ) = 0.25 (see Table 2.3.3).
(d)
Hoisting speed = 6m/min.
(e)
Hoisting path = 6 m.
(f)
Number of operations per day =
63 000 = 10 . 25 × 250
(g)
Average cycle for hoist = 0.60 ×
2 × 6 = 1.2 min . 6
(h)
Enter a line horizontally from the right of the table to the left for gantry crane, 10 working cycles per day with medium (K p) of 0.25.
(i)
Enter a vertical line cycle time of 1 > 2 min.
(j)
The intersection gives— Class of hoist = M2 ; and
(ii)
Class of crane = C2.
The load condition is 0 for which fatigue considerations do not apply.
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(k)
(i)
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APPENDIX E
OBLIQUE TRAVEL FORCES—DETAILED ANALYSIS (Normative) E1 GENERAL All cranes travelling on two fixed parallel runways, such as bridge and gantry cranes, experience oblique travelling. Oblique travel causes, in the instant of contact between the rail and the front guiding element (wheel flange or guide roller), a contact force (P OT) that tends to straighten the crane on its runways. The major dimensions and forces due to oblique travel are set out in Figure E1. NOTES: 1
P OT is the contact force between the front guiding element and the crane rail.
2
K F reduction factor (Table 4.6.5.5) may be used, but has not been included in this Appendix.
3
The most adverse condition for calculation of forces on crane components and crane runway beams and structure is when a fully loaded crab is assumed to be positioned opposite the contact force POT.
E2 GENERAL METHOD OF CALCULATION APPLICABLE TO ALL BRIDGE AND GANTRY CRANES Where a crane bridge skews, that is, where it assumes an oblique travel gradient (α) relative to the runway, a contact force (POT) is produced on the front guiding means or group of guiding means (wheel flange or guide roller) as seen in relation to the direction of movement, and consequently a group of frictional forces (X1i , Y1i and X 2i , Y2i ) act on the contact areas of the track wheels. The contact force (P OT) and the wheel frictional forces (X 1i , Y1i and X2i , Y2i ) are calculated by the following equations:
POT = λK O PG X 1i = λ1ix K O PG
X 2i = λ2ix K O PG
Y1i = λ1iy K O PG
Y2i = λ2iy K O PG
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where P OT = contact force λ
= ..........(see Table E2)
K O = coefficient of frictional contact (see Table E1) P G = the sum of all wheel loads due to the mass of the crane and the hoisted load, without the dynamic multipliers in Clauses 4.5.2.1 and 4.5.3.3 X 1i = frictional force λ1ix = ..........(see Table E3) X 2i = frictional force λ2ix = ..........(see Table E3) Y1i = frictional force λ1iy = ..........(see Table E3) Y2i = frictional force Standards Australia
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FIGURE E1 DIMENSIONS AND FORCES DUE TO OBLIQUE TRAVEL OF A CRANE WITH FOUR PAIRS OF TRACK WHEELS REPRESENTING DIFFERENT DESIGN FEATURES www.standards.com.au
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λ2iy = ..........(see Table E3) α
= oblique travel gradient resulting from the total of all displacements possible for oblique travel of the crane as related to the distance, SG , of the position guiding means = α F + α v + α s≤15 ‰
α F = oblique travel gradient resulting from 75% of the clearance between a straight rail and the positive guiding means, which is not less than 5 mm for guide rollers and not less than 10 mm for wheel flanges α v = oblique travel gradient resulting from wear of not less than 3% of the rail head width for all cranes with guide rollers and for Class C1 to C5 cranes with flanged wheels for Class C6 to C9 cranes with flanged wheels the oblique travel gradient resulting from wear of not less than 10% of the railhead width αo = 1 ‰ ‰ = parts per thousand (pro mille) TABLE E1 COEFFICIENT OF FRICTIONAL CONTACT (K o ) AS A FUNCTION OF THE OBLIQUE ANGLE (α) 1 0
α /00 Ko
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
≤1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
6.0
7.0
8.0
9.0
10.0
12.5
15.0
›15.0
0.094 0.118 0.139 0.158 0.175 0.190 0.203 0.214 0.233 0.248 0.259 0.268 0.275 0.287 0.293 0.300
NOTES: 1
Assume linear interpolation between values.
2
K O = 0.30 (1-e -0.25α ) where e equals 2.71828 (basis of the natural logarithms) and oblique travel gradient α is in 0/00 .
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The factors λ, λ1ix , λ 1iy and λ 2ix , λ2iy for calculating the forces P OT , X 11, Y11, X 21, Y 21 and the position h of the slip pole are given in accordance with Tables E2 and E3 by the dimensions of the crane (see Figure E1), the position of the overall centre of gravity due to the dead loads and the hoisted loads, and the system of the drive and support as defined in AS 2549. The contact force (P OT) due to oblique travel of cranes with flanged track wheels shall be distributed in accordance with Figure E2. For cranes with a total of N W pairs of track wheels arranged each on an axis i, and of which N S are synchronized, and whose wheel loads PWi1 on side 1 and PWi2 on side 2 are of equal magnitude, respectively, for each side, and assuming the usual tolerances for track wheel diameter, axial parallelism of track wheel bores and position of the runway, with a linearized frictional contact relationship applying equally to longitudinal and transverse slip.
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TABLE E2 EXPRESSION FOR THE POSITION OF SLIP POLE h AND FACTOR λ TO CALCULATE THE CONTACT FORCE System
h
λ
FF
N S X 1 X 2 S T + Σ ei Σ ei
FL
N S X 1 S T + Σei Σe i
2
2
2
2
1−
Σ ei Nwh
Σe X 2 1 − i Nwh
TABLE E3 FACTORS FOR CALCULATING THE FRICTION FORCES System
λ1ix
λ1iy
λ2ix
λ2iy
WFF
X1 × X 2 ST × NW h
X 2 ei 1 − NW h
X1 × X 2 ST × NW h
X 1 ei 1 − NW h
0
X 2 ei 1 − NW h
0
X 1 ei 1 − NW h
X 1 × X 2 ST × NW h
0
0
0
EFF
WFL
X 1 × X 2 ST × NW h
EFL 0
X2 NW
ei 1 − h
X 2 ei 1 − NW h
e i = The distance measured at right angles between the line of action of the contact force P OT and the individual pair of wheels under design consideration.
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X 1 and X 2 are coefficients that describe the position of the slip pole (see Figure E1).
FIGURE E2 DISTRIBUTION OF LATERAL FORCES
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APPENDIX F
FATIGUE DESIGN OF MECHANISMS (Informative) F1 INTRODUCTION F1.1 General The designing of engineering parts to prevent fatigue failure is a more complex process than designing on the basis of static strength. The complexities of the variables in crane mechanisms are numerous and it is not practicable to lay down particular design rules for all mechanisms. The Standard is not intended to direct the crane designer to use only those equations and methods provided. Should the designer wish to carry out a detailed analysis of any aspect of crane behaviour, the results of such an analysis may be substituted for the corresponding requirement of the Standard. In general, considerable test data is required for the following: (a)
Evaluation of parameters by a process of logical analysis.
(b)
Demonstration of the applicability of the particular method of analysis.
F1.2 Approaches
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With deterministic fatigue analysis, there are two fundamental approaches to fatigue life estimation: (a)
Stress life (S-N), a traditional approach where a known stress is compared to the statistical survival of a material, drawn from a number of tests that characterize the specific material and geometry used. In general, the stress range is used to calculate fatigue life, as fatigue damage is assumed to occur with stress fluctuations. This technique is primarily intended for low stress, high cycle fatigue. Its validity is limited for high stress, low cycle fatigue where stress does not equal strain, e.g. near local stress concentrations or where residual fabrication stresses are present.
(b)
Strain life (e-N), a method that takes into account the actual stress-strain response of a material and is considered better for high-stress low cycle fatigue design. The total stress (both applied and residual stress) at the point of consideration is required for this form of analysis. The method only accounts for life up to the initiation of a fatigue crack, where life beyond the initiation of a fatigue crack is important, it is normally accounted for by a linear elastic fracture mechanics (LEFM) approach.
F1.3 Choice of approach There are a number of circumstances where neither of the above may be adequate in predicting the fatigue life of a component, such as— (a)
where multi-axial stress occurs;
(b)
in material that exhibits different elastic moduli in tension and compression, (e.g. some cast irons);
(c)
non-homogenous or non-isotropic materials; and
(d)
where fatigue mechanisms interact with other effects (creep, corrosion, etc.).
It is beyond the scope of this Standard to detail these (or other) approaches or to recommend the most appropriate method for particular cases. The method adopted should be based upon acceptable risk and available data. The S-N approach is currently the most
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widely used and has the most data available, but shortcomings in this method have led to a gradual increase in the popularity of other (however, more complicated) methods. One of the significant problems associated with fatigue design, particularly from a designer’s point of view, is determining the actual loads (and stresses) and their associated frequencies. When this is in error, the appropriateness of the analysis methodology is a moot point. F2 DESIGN CRITERIA The design life should be as agreed between the supplier and the purchaser; however, the minimum recommended life is— (a)
for mechanisms, 10 years (where inspection and repair or replacement is feasible); and
(b)
for structures, 25 years.
NOTE: The design life requirements, for a particular type of crane, could be affected by mandatory inspection requirements. Refer to AS 2550.1, and its associated part, and other parts of this Standard for further guidance.
Where statistical approaches are adopted, the minimum recommended survival rate is 90%. NOTE: B10 life or 90% survival (10% failure) is common in the design of bearings. Other codes of practice adopt a minimum 2 standard deviation (97.7% survival, normal distribution).
Where significant risk to personnel or property is present, much larger survival probabilities have to be considered. Irrespective of the design technique or survival probability, the component strength has to be greater than that prescribed by its static capacity.
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Different component types have traditionally adopted different techniques. These have been incorporated in various standards and codes of practice, which have been used successfully in the fatigue design process. Guidance should be sought from the following Standards: AS 2729
Rolling bearings—Dynamic load ratings and rating life
3890
Rolling bearings—System life and reliability
4171
Rolling bearings—Static load ratings
1403
Design of rotating steel shafts
2938
Gears—Spur and helical—Guide to specification and rating
4100
Steel structures
AS/NZS 1554.5 Structural steel welding—Welding of steel structures subject to high levels of fatigue loading The following overseas Standards provide useful information on fatigue design: ASTM E739
Standard Practice for Statistical Analysis of Linear or Linearized Stress-Life (S-N) and Strain-Life (e-N) Fatigue Data
ANSI/ABMA 11 Roller Bearings, Load Ratings and Fatigue Life for 9
Ball Bearings, Load Ratings and Fatigue Life for
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APPENDIX G
REEVED SYSTEMS—ALLOWANCE FOR FRICTIONAL EFFECTS (Normative) Frictional resistance in a reeved system results in an increase in rope tension. This resistance is caused by bearing or journal friction and by internal friction induced in the rope by its flexing and unflexing as it passes over each sheave. Where a number of parts of rope support a load, the sum of the tension in each part is equal to the force applied by the load to the reeved system. When the system is stationary, the tension in each part is equal; when the system is in motion, half the parts have tension greater and half the parts have tension less than the average tension. The value of maximum rope tension (P RM) in a reeved system may be calculated by the following equation: (1 + µ ) N −1 PRM = (1 + µ ) N D PE 2 3 N −1 1 + (1 + µ ) + (1 + µ ) + (1 + µ ) + . . . + (1 + µ )
. . . G(1)
where P RM = maximum rope tension, in kilonewtons µ
= friction allowance
N
= number of falls of rope supporting P E
N D = number of deflection sheaves P E = load applied to the reeved system, in kilonewtons The friction allowance depends on type, arrangement and method of lubrication of the sheave bearings, and the flexibility of the rope.
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Where the number of falls is large, the inherent flexibility of the rope system and the lower speed of motion lowers impact and other dynamic effects and consequently the increase in rope tension is allowed to be absorbed into the load factor. Where the reeved system has more than 10 parts of rope supporting the load, frictional effects become of such significance that they cannot be disregarded. Clause 7.16 requires allowance to be made for frictional effects. Where the system has more than 10 parts of rope supporting the load, frictional effects shall be considered. The following example has been included in this Appendix to clarify the method of making such allowance. Example: Calculate the maximum rope tension (PRM) in the reeved system shown in Figure G1. DATA: PE
= 100 × 9.81 kN
N
= 12
ND
= 3
µ
= 0.02 (assumed)
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1.0211 PRM = × 1.02 3 981 2 3 11 1 + 1.02 + 1.02 + 1.02 + ... + 1.02
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. . . G(2)
= 96.5 kN
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FIGURE G1 EXAMPLE OF SHEAVE SYSTEM
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APPENDIX H
EXAMPLES OF WIRE ROPE SELECTION (Informative) H1 EXAMPLE 1 A lifting appliance is to operate under duty conditions defined in the classification of mechanisms as M4. The maximum rope tension has been established as 79 kN. The type and grade of the rope to be selected has a K′ value of 0.356, as specified by the manufacturer, and its R o value is 1,770 N/mm 2 . From Equation 7.16.2.2 the C value is 0.080. d min = 0.080 × 79 000 = 22,486 mm
For practical purposes, the minimum diameter of the rope selected is not to be less than 22.5 mm or greater than 28.1 mm. Equation 7.16.2.4 gives the minimum breaking force: Fo = 79 × 4 = 316 kN
For practical purposes, the minimum breaking force of the rope selected shall not be less than 316 kN. H2 EXAMPLES 2 Exactly similar parameters are required as indicated in Example 1, but on this occasion the constructor of the appliance wishes to employ a smaller rope size to reduce equipment weight and therefore selects a rope type and grade having a K′ value of 0.497 and Ro value of 1,960 N/mm 2 . From Equation 7.16.2.2: 4 0.497 × 1 960
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C=
= 0.064 1
corrected to 0.065 (Renard number from R40 series) d min = 0.065 × 79 000 = 18.270 mm
For practical purposes, the nominal diameter of the rope selected is not to be less than 19 mm or greater than 22 mm. Equation 7.16.2.4 gives the minimum breaking force: Fo = 79 × 4 = 316 kN
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APPENDIX I
ROPE ANCHORAGE POINT LOCATION (Informative) The correct method for locating the rope anchorage point on a drum is given in Figure I1. Right hand lay ropes should be used in configurations a and c. Left land lay ropes should be used in configurations b and d.
(a) Right-hand lay rope—underwind
(b) Left-hand lay rope—underwind
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(c) Right-hand lay rope—overwind
(d) Left-hand lay rope—overwind
NOTE: Thumb indicates the side of the rope anchorage.
FIGURE I1 LOCATING THE ROPE ANCHORAGE POINT ON A DRUM
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APPENDIX J
GROOVE PROFILES FOR WIRE ROPE SHEAVES (Informative) This Appendix provides guidance on groove profiles for wire rope sheaves. Figure J1 shows the accuracy of surface conditions for groove profiles. The information in this Appendix is drawn from DIN 15061, for general guidance on groove profiles for wire rope sheaves. Groove profiles to this Standard shall fall within permissible deviations governed by nominal rope diameters given in Tables J1 and J2. TABLE J1 GROOVE DEVIATION Rope nominal diameter (d 1)
≤3
>3 ≤6
>6 ≤7
>7
Permissible deviation, %
+8 0
+7 0
+6 0
+5 0
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NOTE: Maximum fleet angle of 5° each side permissible subject to requirements of DIN 15020-1.
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FIGURE J1 SHEAVE GROOVE PROFILE
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TABLE J2 ROPE SHEAVE DATA Groove radius permanent deviation for accuracy range
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r1 mm 1.6 2.2 2.7 3.2 3.7 4.2 4.8 5.3 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 12 12.5 13 13.5 14 15 16 17 18 19 20 21 22 23 24 25
1
2
+0.2
+0.1
+0.6
+0.3
+0.2
+0.8
+0.4
+0.2
+1.6
+0.8
+0.4
27 28 29 30 31 32
M
hg† Guiding values
3*
+0.4
26
i
8 10 12.5 12.5 15 15 17.5 17.5 20 20 22.5 25 25 27.5 30 30 32.5 35 35 35 35 37.5 40 40 40 45 45 50 55 55 60 60 65 65 67.5 70 70 72.5 72.5 75 77.5 82.65 82.65 85
9 11 14 15 17 18 21 22 25 25 28 31 31 34 37 38 40 43 44 45 46 48 51 52 53 59 60 65 71 72 78 79 84 86 89 91 93 95 96 99 103 110 110 113
Rope nominal diameter (d 1) mm
2 2 2 3 4 4 4.5 4.5 5 5 5 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 8 10 10 11 11 11 11 12.5 12.5 12.5 12.5 12.5 12.5 12.5 12.5 12.5 12.5 12.5
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27.28 29.30 31.32 33.34 35.36 37.38 39.40 41 42.43 44.45 46 47 48 49 50 52 54 56 58 60
* For production cranes, e.g. steel mill crane, accuracy range 3 is recommended. † hg min. = d s.√2.
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APPENDIX K
GROOVE PROFILES FOR ROPE DRUMS (Normative) Figure K1 shows details of the drum groove profile. The information in this Appendix is drawn from DIN 15061. These details are not applicable to serial hoists. Drum groove profiles shall fall within permissible deviations governed by nominal rope diameters given in Table K1. TABLE K1 DRUM GROOVE DEVIATION Rope nominal diameter (d 1)
≤3
>3 ≤6
>6 ≤7
>7
Permissible deviation, %
+8 0
+7 0
+6 0
+5 0
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NOTES: 1
Maximum fleet angle of 5° each side permissible subject to requirements of Clause 7.16.3.
2
Deviation of flank angle is permissible related to slope and position tolerances, if groove profile is maintained.
NOTE: Diagram of groove profile for a rope pulley of groove radius r1 = 11 mm Groove profile DIN 15061-2-11.
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APPENDIX L
THEORETICAL THICKNESS OF HOIST DRUM (Normative) L1 APPLICATION This Appendix may be used to determine the theoretical thickness of a crane drum (see Clause 1.1). The method is more precise and less conservative than that specified in Clause 7.19.5, and, consequently, in the manufacture of the drum, close control over manufacturing inaccuracies, e.g., machining eccentricity, core shift in casting or out-of-roundness in rolling, needs to be maintained. Allowance for such inaccuracies shall be added to the theoretical drum-shell thickness in accordance with Clause 7.19.4. L2 NOTATION The following notation is used in this Appendix: D DM = mean diameter of drum shell (see Figure L7), in millimetres = D DN – TD D DN
= nominal diameter of drum shell, in millimetres = for grooved drum, the diameter between the roots of the rope groove = for ungrooved drum, the outside diameter of the drum shell
D FI
= inner diameter of drum flange or stiffener (see Figure L7), in millimetres
D FO
= outer diameter of drum flange or stiffener (see Figure L7), in millimetres
D RO
= diameter of outer coil of rope on drum, in millimetres
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= D DM + T D + (1 + 0.82 N L ) d d
= nominal rope diameter, in millimetres
E RC
= cross-sectional modulus of elasticity of wire rope, in megapascals
Fc
= permissible compressive stress (see Clause L3), in megapascals
Ft
= permissible tensile stress (see Clause L3), in megapascals
fb
= bending stress (due to beam action) (see Clauses L5 and L6), in megapascals
f bf
= bending stress between flange or stiffener and drum shell (see Clause L6), in megapascals
f bfa
= bending stress in flange due to axial force exerted by rope layers on drum flange (see Clause L6), in megapascals
f bft
= resultant bending stress between flange and drum shell due to drum deflection and axial force exerted by rope layers on drum flange (see Clause L6), in megapascals
f bL
= local bending stress under turn of rope adjacent to a vacant groove (see Clauses L5 and L6), in megapascals
fcL
= local compressive stress under turn of rope adjacent to a vacant groove (see Clauses L5 and L6), in megapascals
fcm
= accumulated compressive crushing stress in the middle of the fully-wound drum (one layer of rope) (see Clauses L5 and L6), in megapascals
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fcmn
= accumulated compressive crushing stress in the middle of the fully wound drum (N layers of rope) (see Clause L6), in megapascals
fco
= reference compressive stress (see Clauses L5 and L6), in megapascals
feq
= resultant equivalent stress due to local-bending beam action and to local crushing (see Clauses L5 and L6), in megapascals
hg
= height of rope groove, in millimetres
KF
= rigidity constant of drum flange = 18.865 T F 3 , where the material has its tensile strength equal to its compressive strength = 10.762 T F 3 , where the material has its tensile strength significantly different from its compressive strength
KR
= relative-rigidity constant, drum flange to drum shell (see Clause L7)
KS
= rigidity constant of drum shell = 34.294
(TDE )5 D DM
where the material has a tensile strength approximately equal to
its compressive strength = 19.965
(TDE )5 D DM
where the material has a tensile strength significantly different
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from its compressive strength K1
= ratio of reference compressive stress (fco) to actual maximum compressive stress induced in central area of an infinitely long drum shell under a single layer of rope without considering the reduction in stress due to additional deflection of the shell caused by neighbouring coils of rope (see Figure L1)
K2
= stress-reducing factor allowing for reduction of compressive stress due to deflection of shell caused by neighbouring coils of rope (see Figure L2)
K3
= rope-layer factor (see Figure L3)
K4
= stress-increasing factor for the bending stress at the connection between the drum shell and the flange assuming the connection to be completely rigid (see Figure L4)
K5
= stress-reducing factor for the bending stress at the drum shell-to-flange connection allowing for the relative rigidity of the shell and flange (see Figure L5)
K6
= stress-increasing factor for the bending stress at the drum shell-to-flange connection allowing for the axial force of rope layers on the flange (see Figure L6)
M
= bending moment due to beam action of unfactored, i.e. static, rope load PRS , in newton metres
NL
= number of rope layers on a fully-wound drum
P RS
= maximum unfactored, i.e. static, rope load, in kilonewtons
P
= pitch of rope coils, in millimetres
TD
= minimum theoretical thickness of drum shell measured, for a grooved drum, to the roots of the rope groove, in millimetres
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T DE
160
= equivalent thickness of drum shell, in millimetres for an ungrooved drum = TD
A1
for a grooved drum where h g ≤ TD = TD for a grooved drum where h g > T D =
4 TD 3
TF
= thickness of flange or stiffener, in millimetres
φ1
= dynamic multiplier (see Clause 4.5.2.1)
φ2
= dynamic multiplier (see Clause 4.5.3.3)
L3 PERMISSIBLE STRESSES Permissible stresses Fc and F t for use in Clauses L5 and L6 shall be as follows: Fc
= permissible compressive stress, in megapascals = 0.45 times the compressive strength
Ft
= permissible tensile stress, in megapascals = 0.67 times the yield stress of a material with yield stress not greater than 0.7 times the tensile strength = 0.60 times the yield stress of a material with yield stress greater than 0.7 times but not greater than 0.9 times the tensile strength = 0.30 times the tensile strength of a material with yield stress greater than 0.9 times the tensile strength
L4 LIMITATIONS ON DRUM-SHELL THICKNESS The minimum theoretical thickness of drum shell (T D) shall be not less than 5 mm for grey cast iron drums nor less than 3 mm for drums of material other than grey cast iron.
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L5 STRESSES IN SINGLE-LAYER DRUM* The following stresses calculated in accordance with this Clause shall be not greater than the corresponding permissible stresses specified in Clause L3: NOTE: It is necessary to know the value of the drum-shell thickness T D to calculate drum-shell stresses. The abbreviated method of determining drum-shell thickness specified in Clause 7.19.5 may be used to select a suitable value of TD for use in this Clause.
(a)
Accumulated compressive crushing stress in the middle of the fully-wound drum fcm : f cm = K 1 K 2 f co ≤ Fc
(b)
. . . L5(1)
Resultant equivalent stress due to local bending beam action and to local crushing f eq:
* Paragraphs L5 and L6 are based on the papers ‘Ein Verfahren zur Berechnung ein—und mehrlagig bewickelter Seiltrommeln’ by Dip.-Ing. Peter Dietz, published in the Journal of Verein Deutscher Ingenieure (VDI-Verlag GmbH, Dusseldorf) Series 13, No. 12, July 1972, and ‘Untersuchungen uber die Beanspruchung der Seiltrommeln von Kranen und Winden’ by Dr.-Ing. Helmut Ernst, published in Mitt. Forsch. Anst. GHH-Konzern, September 1938. Standards Australia
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(i)
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where the drum-shell material has its tensile strength approximately equal to its compressive strength:
[
f eq = ( f b + f bL ) + ( f b + f bL ) f cL + f cL 2
]
2 1/ 2
≤ Ft
(ii)
. . . L5(2)
where the drum-shell material has its tensile strength significantly different from its compressive strength: tensile strength of drum- shell material F eq = f b + f bL + f cL compressive strength of drum- shell material . . . L5(3) ≤ Ft
(c)
Bending stress between flange or stiffener and drum shell due to drum deflection f bf : f bf =
K4 K5 f cm K1 K 2
. . . L5(4)
≤ Ft
Stresses f co , f b, fbL and fcL shall be calculated by the following equations: f co =
1000 PRS pTDE
f b = φ1φ 2
f bL = φ 1φ 2
. . . L5(5)
1250M
. . . L5(6)
2
D DM TD
(D
700 PRS DM
TDE
3
)
1
2
f cL = 0.5 f cm
. . . L5(7) . . . L5(8)
L6 STRESSES IN MULTILAYER DRUM* The following stresses calculated in accordance with this Clause shall be not greater than the corresponding permissible stresses specified in Clause L3:
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NOTE: It is necessary to know the value of the drum-shell thickness T D to calculate drum-shell stresses. The abbreviated method of determining drum-shell thickness specified in Clause 7.19.5 may be used to select a suitable value for T D for use in this Clause.
(a) A1
Accumulated compressive stress in the middle of the fully-wound drum (N layers of rope) f cmn : f cmn =
D 4 K 3 DM f cm 3 DRO
. . . L6(1)
≤ Fc
* See Footnote to Paragraph L5. www.standards.com.au
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(b)
162
Resultant equivalent stress due to local bending beam action and to local crushing f eq: (i)
where the drum-shell material has its tensile strength approximately equal to its compressive strength:
[
f eq = ( f b + f bL ) + ( f b + f bL ) f cL + f cL (ii)
2
. . . L6(2)
where the drum-shell material has tensile strength significantly different from its compressive strength: Feq = f b + f
(c)
]
2 1/ 2
bL
tensile strength of drum- shell material + f cL . . . L6(3) compressive strength of drum- shell material
Resultant bending stress between flange and drum shell due to drum deflection and axial force exerted by rope layers on the drum flange f bft: f bft = f bf + f bfa
. . . L6(4)
≤ Ft
Stresses f cm , f co , f b, fbL , f cL , f bf and fbfa shall be calculated by the following equations: f cm = K 1 K 2 f co f co =
. . . L6(5)
1000 PRS pTDE
f b = φ1φ 2
. . . L6(6)
1250M
. . . L6(7)
2
DDM TD
f bL = φ 1φ 2
(D
700 PRS DM
TDE
3
f cL = 0.5 f cm f bf =
K4 K5 f cmn K1 K 2
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f bfa = 6 K 6
PRS × 103 3 TF
)
1
2
. . . L6(8) . . . L6(9) . . . L6(10)
. . . L6(11)
L7 DRUM DESIGN FACTORS Values of factors K 1 to K6 for determining the stress in single-layer drums (see Clause L5) and multilayer drums (see Clause L6) shall be selected by means of Figures L1 to L6 respectively. Factor K5 (see Figure L5) is related to relative-rigidity constant (drum flange to drum shell) (KR) calculated from the appropriate equation from Table L1 (see Figure L7).
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TABLE L1 EXPRESSIONS FOR RELATIVE-RIGIDITY CONSTANT, DRUM FLANGE TO DRUM-SHELL (KR) Drum flange and shell arrangement
Flange of drum welded to drum axle or bearing block
Drum with stiffener
(a) and (b)
(c)
(d)
Expressions for calculating (K R ) Drum material has its tensile strength approximately equal to its compressive strength
KF 4 KS DDM
KF 4 KS DDM
2 D 0.7 + 1.3 FO DFI DDM − 1 0.7 + 1.3 DFO D D DM FI
2
1 2 2 DFO DDM − 1 D D −1 DM FI + 2 2 DFO 0.7 + 1.3 1.3 + 0.7 DFO D DDM DM
KF 4 KS DDM
KF 4 KS DDM
2 D 0.9 + 1.1 FO DFI DDM − 1 0.9 + 1.1 DFO D D FI DM
2
1 2 2 D D DM − 1 FO − 1 D DFI + DM 2 2 DFO DFO 1.1 + 0.9 0.9 + 1.1 DDM DDM 2 DDM − 1 K F 1.98 DFI 2 KS DDM DDM 1.1 + 0.9 D FI
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2 DDM − 1 K F 1.82 DFI 2 KS DDM DDM 1.3 + 0.7 D FI
Drum material has its tensile strength significantly different from its compressive strength
163
Drum with gearwheel fitted to flange
Reference Figure L7
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FIGURE L1 (in part) FACTOR K 1
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FIGURE L1 (in part) FACTOR K 1
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NOTE: K S = 34.294
(T DE ) 5 D DM
where the material has its tensile strength approximately equal to its compressive
strength. K S = 19.965
(T DE ) 5 where the material has its strength significantly different from its compressive strength. D DM
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FIGURE L2 FACTOR K2
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NOTE: Where the value of ERC is not known and is not readily obtainable, the following values may be assumed: E RC = 250 for ropes with wire-rope core (WRC) or wire-strand core (WSC) E RC = 125 for ropes with fibre core (FC)
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FIGURE L3 FACTOR K3
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FIGURE L4 FACTOR K4
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FIGURE L5 FACTOR K5
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FIGURE L6 FACTOR K6
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FIGURE L7 DRUM FLANGE AND SHELL ARRANGEMENTS
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APPENDIX M
RELATED STANDARDS (Informative) M1 STANDARDS FOR COMPONENTS USED IN LIFTING SYTEMS
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The following is a list of Standards for components that are used in lifting systems: AS 1138
Thimbles for wire rope
1353 1353.1 1353.2
Flat synthetic-webbing slings Part 1: Product specification Part 2: Care and use
1380 1380.1 1380.2
Fibre-rope slings Part 1: Product specification Part 2: Care and use
1438 1438.1 1438.2
Wire-coil flat slings Part 1: Product specification Part 2: Care and use
1666 1666.1 1666.2
Wire-rope slings Part 1: Product specification Part 2: Care and use
2076
Wire rope grips for non-lifting applications
2089
Sheave blocks for lifting purposes
2317
Collared eyebolts
2318
Swivels for hoists
2319
Rigging screws and turnbuckles
2321
Short-link chain for lifting purposes
2740
Wedge-type sockets
2741
Shackles
2759
Steel wire rope—Application guide
2841
Galvanized steel wire strand
3569
Steel wire ropes
3585
End fittings for flat-webbing slings
3775
Chain slings—Grade T
3776
Lifting components for Grade T chain slings
3777
Shank hooks and large-eye hooks—Maximum 25 t
4142 4142.2
Fibre ropes Part 2: Three-stand hawser-laid and eight-strand plaited
Standards Australia
www.standards.com.au
173
AS 1418.1—2002
M2 OTHER RELATED DOCUMENTS The following documents are not referenced elsewhere in this Standard. However, they should be complied with, as applicable: AS 1055 1055.2
Acoustics—Description and measurement of environmental noise Part 2: Application to specific situations
1170 1170.3
Minimum design loads on structures Part 3: Snow loads
1250
The use of steel in structures
1360
Rotating electrical machines of particular types or for particular applications
2752
Preferred numbers and their use
2759
Steel wire rope—Application guide
2938
Gears—Spur and helical—Guide to specification and rating
3569
Steel wire ropes
3998
Non-destructive testing—Qualification and certification of personnel— General engineering
BS 2573 2573.1
Rules for the design of cranes Part 1: Specification for classification, stress calculations and design criteria for structures
8004
Code of practice for foundations
DIN 50100
Testing of material, continuous vibration test Part 10: Insulation coordination within low-voltage systems including clearances and creepage distances for equipment
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
VDE 0109
www.standards.com.au
Standards Australia
AS 1418.1—2002
174
AMENDMENT CONTROL SHEET AS 1418.1—2002 Amendment No. 1 (2004)
REVISED TEXT SUMMARY: This Amendment applies to the Preface, Clauses 1.2, 2.1, 7.12.8.7, 7.16.1, 7.20.3.6, 7.20.6.4, 7.20.6.5, Section 13.4 and Appendix L.
Accessed by BP AUSTRALIA LIMITED on 06 Jun 2010
Published on 4 November 2004.
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