Wire Rope Users Manual

August 3, 2017 | Author: PatriciaGuinn | Category: Rope, Wire, Building Engineering, Manufactured Goods, Science
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WIRE ROPE USERS MANUAL Second Edition

COMMITTEE OF WIRE ROPE PRODUCERS American Iron and Steel Institute Washington, D.C.

This publication is a joint effort of the COMMITTEE OF WIRE ROPE PRODUCERS American Iron and Steel Institute and the WIRE ROPE TECHNICAL BOARD The Wire Rope Technical Board (WRTB) is an association of engineers representing companies that account for more than 90 percent of wire rope produced in the United States; it has the following objectives: To promote development of engineering and scientific knowledge relating to wire rope; To assist in establishing technological standards for military, governmental and industrial use; To promote development, acceptance and implementation of safety standards; To help extend the uses of wire rope by disseminating technical and engineering information to equipment manufacturers; and To conduct and/or underwrite research for the benefit of both industry and user.

The material presented in this publication has been prepared in accordance with recognized engineering principles and is for general information only. This information should not be used without first securing competent advice with respect to its suitability for any given application. The publication of the material contained herein is not intended as a representation or warranty on the part of American Iron and Steel Institute-or of any other person named herein-that this information is suitable for any general or particular use or of freedom from infringement of any patent or patents. Anyone making use of this information assumes all liability arising from such use.

COMMITTEE OF WIRE ROPE PRODUCERS American Iron and Steel Institute 1000 16th Street, N.W. Washington, D.C. 20036 Copyright @ 1981 by American Iron and Steel Institute Second Edition, August 1981 First Edition, March 1979 All rights reserved. Printed in the United States of America Permission to reproduce or quote any portion of this book as editorial reference is hereby granted. When making such reproductions or quotations, the courtesy of crediting this publication and American Iron and Steel Institute will be appreciated.

CONTENTS INTRODUCTION / 5 BASIC COMPONENTS / 7 IDENTIFICATION AND CONSTRUCTION / 9 HANDLING AND INSTALLATION / 18 Receiving, Inspection and Storage / 18 Wire Rope Installation / 18 Unreeling and Uncoiling / 20 Seizing Wire Rope / 23 Cutting Wire Rope / 25 End Preparations / 26 End Terminations / 26 Socketing / 29 Wire Rope Clips / 29 How to Apply Clips / 29 Wedge Sockets / 34 Drums-Grooved / 35 Drums-Plain (Smooth) / 36 Drums-Multiple Layers / 37 OPERATION, INSPECTION AND MAINTENANCE OF WIRE ROPE / 38 Sheaves and Drums / 38 Bending Rope Over Sheaves and Drums / 40 Inspection of Sheaves and Drums / 43 Strength Loss of Rope Over Stationary Sheaves or Pins / 46 Fleet Angle / 47 Factors Affecting the Selection of Wire Rope / 47 The "X-Chart9'-Abrasion Resistance vs. Bending-Fatigue Resistance / 50 Breaking-in a New Wire Rope / 51 Wire Rope and Operations Inspection / 51 Guideline to Inspections and Reports / 51 Field Lubrication / 68 Wire Rope Efficiency Over Sheaves / 70 PHYSICAL PROPERTIES / 73 Elastic Properties of Wire Rope / 73 Constructional Stretch / 73 Elastic Stretch / 74 Design Factors / 77 Breaking Strengths / 77 APPENDICES Ordering, Storing and Unreeling Wire Rope / 99 Wire Rope Fittings / 101 Socketing / 112 Shipping Reel Capacity / 117 Weights of Materials / 118 Glossary of Wire Rope Terms / 120 ALPHABETICAL LISTING OF CONTENTS / 131

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1

Acknowledgments Tabular data for wire rope clips, along with related drawings, were provided by The Crosby Group. All other data and illustrations used throughout were furnished by member companies of the Committee of Wire Rope Producers (AISI) and the Wire Rope Technical Board (WRTB) . Drawings, prepared especially for this publication, are based wholly or in part on graphic material that originally appeared in literature issued separately by various member companies of the Committee. Unless credited otherwise, all numerical and factual data were obtained from published and unpublished sources supplied by the Committee (AISI) and by the Wire Rope Technical Board ( WRTB) .

1 Introduction . . . that transmit forces, motion, and energy one to another in some predetermined manner and to some desired end . . . -Webster's Third New International Dictionary

ma-chine: an assemblage of parts

In and of itself, wire rope is a machine. The geometry---or configuration--of its cross-section and the method and material of its manufacture are precisely designed to perform "in some predetermined manner and to some desired end." Hence, as befits any useful machine, it is imperative that the rope's potential use be fully recognized, that its functional characteristics be understood, and that procedures for proper maintenance be scrupulously adhered to. By giving active recognition to these generally accepted concerns, the user can be reasonably certain that maximum service life and safety will be realized for every rope installation or application. A thorough understanding of wire rope characteristics is, of course, a primary essential. This means familarity with operating conditions, load factors, rope grades and constructions. Full recognition of their inherent use-potential derives from a realization of the great number and wide variety of wire ropes available for general and special operating needs. It is of special importance that the user become familiar with the particular characteristics of the various constructions in order to make the right selection for a given function. Fabricated to close tolerances, wire rope is inspected at all significant manufacturing intervals to assure the user of a uniformly high quality product. Immediately after manufacture, wire rope care becomes an absolute necessity. At no time can a proper regard for care and maintenance be neglected; this rule must be observed in handling, shipping, storage and installation procedures. Following this-after the rope is placed in operation-approved maintenance practices and rigorous inspection (of both the rope and its associated equipment) must be carried out on a continuing basis. Only through strict adherence to these care and maintenance procedures can there be positive assurance that the rope will perform with optimal safety and efficiency throughout its entire life span. This publication is the culmination of a joint effort by the wire rope industry. Its intended audience may be viewed, in broadest terms, as comprised of two sectors : One of these-made up of those with a working knowledge of wire ropeswill find in these pages a comprehensive and convenient source of reference data from such areas as properties and characteristics, handling, storage, operation and maintenance-in short, a handy checklist. For the second sector-the not-too-well informed or new user-this publication can serve as a broad-ranging introduction; for those readers, the information provided can help establish sound practices in rope selection and application. This means practices that are efficient and economical. As a cooperative industry effort, this manual brings together a significant portion of the enormous collection of data now scattered about in the files and publications of many individual companies. The text offers many recommendations, both explicit and implied, but these have been made solely for the purpose of providing some initial judgment point from which ultimate decisions as to design and use may be made. The reader is urged to consult with

the wire rope manufacturer as to the specific application planned. The manufacturer's experience can then help the user make the most appropriate choice. In the final analysis, responsibility for design and use decisions rest with the user. The selection of equipment or components is frequently influenced by the special demands of an industry. An equipment manufacturer may, for reasons of space, economy, etc., feel a need to depart from suggested procedures given in these pages. It is important to remember that such variations from recommended practices should be regarded as potential dangers. However, when such circumstances are unavoidable they demand compensating efforts on the part of the user. These "extras" should include (but not necessarily be limited to) more frequent and more thorough inspections by skilled, specifically trained personnel. Additionally, these circumstances may demand the keeping of special maintenance and lubrication records, and the issuance of special warnings regarding removal and replacement criteria.

2 Basic Components

WIRE

CENTER

-WIRE

ROPE

Figure 1, The three basic components of a typical wire rope.

Wire rope consists of three basic components; while few in number, these vary in both complexity and configuration so as to produce ropes for specific purposes or characteristics. The three basic components of a standard wire rope design are: 1) wires that form the strand, 2 ) multi-wire strands laid helically around a core, and 3 ) the core (Fig. 1 ) . Wire, for rope, is made in several materials and types; these include steel, iron, stainless steel, monel, and bronze. By far, the most widely used material is high-carbon steel. This is available in a variety of grades each of which has properties related to the basic curve for steel rope wire. Wire rope manufacturers select the wire type that is most appropriate for requirements of the finished product. Steel wire strengths are appropriate to the particular grade of the wire rope in which they are used. Grades of wire rope are referred to as traction steel (TS), mild plow steel (MPS) ,plow steel (PS) ,improved plow steel (IPS), and extra improved plow steel (EIP). (These steel grade names originated at the earliest stages of wire rope development and have been retained as references to the strength of a particular size and grade of rope.) The plow steel strength curve forms the basis for calculating the strength of all steel rope wires; the tensile strength (psi) of any steel wire grade is not constant-it varies with the diameter and is highest in the smallest wires. The most common finish for steel wire is "bright" or uncoated. Steel wires may also be galvanized, i.e., zinc coated. "Drawn galvanized" wire has the same strength as bright wire, but wire "galvanized at finished size" is usually 10% lower in strength. In certain applications, "tinned" wire is used, but it should be noted that tin provides no sacrificial, i.e., cathodic, protection for the steel as does zinc. For other applications, different coatings are available. "Iron" type wire is actually drawn from low-carbon steel and has a fairly limited use except in older elevator installations. When, however, iron is used for other than elevator applications, it is most often galvanized. Stainless steel ropes, listed in order of frequency of use, are made of AISI Types 302/304, 316, and 305. Contrary to general belief, hard-drawn stainless Type 302/304 is magnetic. Type 3 16 is less magnetic, and Type 305 has a permeability low enough to qualify as non-magnetic. Monel Metal wire is usually Type 400 and conforms to Federal Specification QQ-N-28 1. Bronze wire is usually Type A Phosphor Bronze (CDA # 5 10) although other bronzes are specified at times. Strands are made up of two or more wires, laid in any one of many specific geometric arrangements, or in a combination of steel wires with some other materials such as natural or synthetic fibers. It is conceivable that a strand can be made up of any number of wires, or that a rope can have any number of strands. The following section, IDENTIFICATION and CONSTRUCTION, provides a complete description of wire rope constructions. The core is the foundation of a wire rope; it is made of materials that will provide proper support for the strands under normal bending and loading conditions. Core materials include fibers (hard vegetable or synthetic) or steel. A steel core consists either of a strand or an independent wire rope. The three most

commonly used core designations are : fiber core (FC) , independent wire rope core (IWRC), and wire strand core (WSC) (Fig. 2 ) . Catalog descriptions of the various available ropes always include these abbreviations to identify the core type. To summarize: a wire rope consists, in most cases, o f three components: wires, strands, and a core (Fig. I ) . T o these may be added what can be considered a fourth component: the wire rope's lubricant-a factor vital to the satisfactory performance o f most operating ropes.

FIBER (FC)

INDEPENDENT WIRE ROPE CORE (IWRC)

WIRE STRAND (WSC)

Figure 2. The three basic wire rope cores. In selecting the most appropriate core for a given application, a wire rope manufacturer should be called upon for guidance. The core is the foundation of a wire rope. If the core cannot support the compressive load imposed, the rope will lose its clearance and its service life will be shortened. Steel cores (WSC or IWRC) should be used when there is any evidence that a fiber core will not provide adequate support. Also, if the temperature of the environment may be expected to exceed 180°F (82°C) steel cores must be used.

3 Identification and Construction Wire rope is identified not only by its component parts, but also by its construction, i.e., by the way the wires have been laid to form strands, and by the way the strands have been laid around the core. In Figure 3, "a" and "c" show strands as normally laid into the rope to the right-in a fashion similar to the threading in a right-hand bolt. Conversely, the "left lay" rope strands (illustrations "b" and "d") are laid in the opposite direction. Again in Figure 3, the first two ("a" and "b") show regular lay ropes. Following these are the types known as lang lay ropes ("c" and "d"). Note that the wires in regular lay ropes appear to line up with the axis of the rope; in lang lay rope the wires form an angle with the axis of the rope. This difference in appearance is a result of variations in manufacturing techniques: regular lay ropes are made so that the direction of the wire lay in the strand is opposite to the direction of the strand lay in the rope; lang lay ropes are made with both strand lay and rope lay in the same direction. Finally, "e" called alternate lay consists of alternating regular and lang lay strands.

Figure 3. A comparison of typical wire rope lays: a) right regular lay, b ) left regular lay, c ) right lang lay, d) left lang lay, e) right alternate lay.

Of all the types of wire rope in current use, right regular lay (RRL) is found in the widest range of applications. Nonetheless, in many equipment applications right lang lay (RLL) or left lang lay (LLL) ropes are required. At present, left lay rope is infrequently used. As for alternate lay (R-ALT or L-ALT) ropes, these are only used for special applications. Compared to other types, the superiority of lang lay rope in certain applications derives from the fact that when bent over sheaves, its life span is longer than the others. Stated in another way, the advantage of lang lay rope is its greater fatigue resistance. Yet another claim is made for lang lay ropes: they are more resistant to abrasion. Broadly speaking, this is true, but there are some reservations that should be taken into account. It is important to understand the reasons for the advantages of lang lay rope. To begin with, consider its fatigue and bending properties. Figure 4A shows, in part, how the lang lay construction characteristics result in greater fatigue resistance than is found in regular lay rope. Note, how the axis of the wire relates to the axis of the rope in both cases. When the regular lay rope is bent, the same degree of bend is imparted to the crowns of the outer wires. Superior fatigue life in lang lay rope is also attributable to the longer exposed length of its outer wires. In the upper photograph of a regular lay rope (Fig. 4A), the valley-to-valley length of individual wires is about % ";the length of the lang lay wires in the lower photograph is about 1?h" or 30% longer. Bending the lang lay rope results in less axial bending of the outer wires and greater torsional flexure. These combined stresses notwithstanding, the lang lay rope displays a 15 to 20% superiority over regular lay when bending is the principal factor affecting service life. It is said that lang lay is more flexible, but flexibility should not be confused with fatigue resistance. These two attributes may, under certain circumstances, bear some relationship, but they are distinctly separate characteristics. Flexibility defines the relative ease with which a rope "flexes" or bends. Fatigue resistance defines the rope's ability to endure bending.

Figure 4A. A comparison of wear characteristics between regular lay and lang lay ropes. The lines a-b, on drawings and photographs, indicate the rope axis.

LANG

REGULAR

Figure 4B. The worn crown of the regular lay wire has a shorter exposed length.

Two other factors relate to fatigue; they are discussed here along with abrasion and peening characteristics. Figure 4A illustrates, in drawings and photographs, the wear pattern in regular lay vs. lang lay ropes. The drawings (of a single strand) show the wire direction relative to the rope axis in both types. Dimension lines in the upper drawing set off the exposed length of one wire crown in the regular lay rope. The lower drawing shows the corresponding four wire crowns involved in the lang lay rope. The line a-b shows the relation of the wire crown to the rope axis. Although there is little difference in total contact area between rope and sheave in these two rope types, the forces and wear on the individual wires are quite different (Fig. 4B). The fact that the wires of regular lay rope are subject to higher pressure, increases the rate of wear (abrasion and peening) of both wire and mating surface of the drum or sheave. Moreover, this higher pressure is transmitted to the interior rope structure and this, in turn, decreases fatigue resistance. Finally, the worn crown of the regular lay wire combiied with its shorter exposed length, permits the wire to spring away from the rope axis (Fig. 4B). Subsequent passage on and off a sheave or drum, results in early fatigue breakage. A nore of caution: lang lay rope has two important limitations. First, if either end is not fixed, it will rotate severely when under load, and secondly, it is less able to withstand crushing action on a drum or sheave, than is regular lay rope. Hence, lang lay rope should not be operated without being secured against rotation at both ends; nor should it be operated over minimum-sized sheaves or drums under extreme loads. Additionally, poor drum winding conditions are not well tolerated by lang lay ropes. Pre-forming is a wire rope manufacturing process wherein the strands and their wires are formed-during fabrication-to the helical shape that they will ultimately assume in the finished rope or strand. The wire arrangement in the strands is an important determining factor in the rope's functional characteristics, i.e., its ability to meet the operating conditions to which it will be subjected. There are many basic strand patterns around which standard wire ropes are built; a number of these are illustrated in Figure 5.

1

7 WIRE STRAND

I 9 WIRE WARRINGTON

19 WIRE SEALE

25 F W S T R A N D

1 Figure 5. Four basic strand patterns.

Wire ropes are identified by a nomenclature that is referenced to: 1 ) the number of strands in the rope, 2 ) the number (nominal or exact) and arrangement of wires in each strand, and 3) a descriptive word or letter indicating the type of construction, i.e., the geometric arrangement of wires (Fig. 5 ) . Cross-sections of four basic constructions are illustrated in Figure 6 ; Figure 7 shows combinations of these constructions. At this point, it would be useful to discuss wire rope nomenclature in somewhat greater detail because the subject may generate some misunderstanding. The reason for this stems from the practice of referring to rope either by class or by its specific construction. Ropes are classified by the number of strands as well as by the number of wires in each strand, e.g., 6 x 7, 6 x 19, 6 x 37, 8 x 19, 19 x 7, etc. However, these are nominal classifications that may or may not reflect the actual construction. For example, the 6 x 19 class includes constructions such as 6 x 21 filler wire, 6 x 25 filler wire, and 6 x 26 Warrington Seale. Despite the fact that none of the three constructions named have 19 wires, they are designated as being in the 6 x 19 classification. Hence, a supplier receiving an order for 6 x 19 rope may assume this to be a class reference, and is, therefore, legally justified in furnishing any construction within this category. But, should the job require the special characteristics of a 6 x 25 filler wire, and a 6 x 19 Seale is supplied in its stead, a shorter service life may be expected. To avoid such misunderstandings, the safest procedure is to order a specific construction. In the event that the specific construction is not known or is in doubt, the rope should be ordered by class along with a description of its end use. Identification of wire rope in class groups facilitates selection on the basis of strength and weight/foot since it is customary domestic industry practice that all ropes (from a given manufacturer) within a class have the same nominal strength, weight/foot, and price. As for other-functional-characteristics, these can be obtained by referencing the specific construction within the class. Only three wire ropes under the 6 x 19 classification actually have 19 wires: 6 x 19 two-operation (2-op) , 6 x 19 Seale (S) , and 6 x 19 Warrington (W) . All the rest have different wire counts. In the 6 x 37 class there is a greater variety of wire constructions. However, the commonly available constructions in the 6 x 37 class include: 6 x 3 1 Warrington Seale (WS), 6 x 36 WS, 6 x 41 Seale Filler

I

Wire (SFW), 6 x 41 WS, 6 x 43 Filler Wire Seale (FWS), 6 x 46 WS, etc.none of which contain exactly 37 wires. For the users' convenience, the most widely used rope classifications are listed and described in Table 1. While the interior of a strand is of some significance, its important characteristics relate to the number and, in consequence, the size of the outer wires. This is discussed in somewhat greater detail in the section titled FACTORS AFFECTING THE SELECTION OF WIRE ROPE (p. 47). Wire rope nomenclature also defines the following: Rope Description length size (diameter) Preformed (pref) or non-preformed (non-pref) direction and type of lay finish grade of rope type of core If direction and type of lay are omitted from the rope description, it is presumed to be right regular lay. Two other assumptions are made by the supplier: 1) if finish is omitted, this will be presumed to mean uncoated "bright" finish, and 2) if no mention is made with reference to preforming, preforming will be presumed. (Note that an order for elevator rope must have an explicit statement since both pref and non-pref ropes are used extensively.)

6 x 7 F I B E R CORE

6 x 1 9 WARRINGTON FC

6 x 1 9 SEALE FC

6 x 2 5 FILLER WlRE IWRC

Figure 6. Basic wire rope constructions.

1

6 x 31 WARRINGTON SEALE IWRC

6 x 4 9 SEALE WARRINGTON SEALE IWRC

6 x 4 3 F I L L E R WIRE SEALE FC

6 x 4 6 SEALE F I L L E R WlRE lW RC

Figure 7. A few combinations of basic wire rope constructions.

13

As an example, a complete description would appear thus: 600 ft %I" 6 x 25 FW pref RLL Improved Plow Steel IWRC When a center wire is replaced by a strand, it is considered as a single wire, and the rope classification remains unchanged. There are, of course, many other types of wire rope, but they are useful only in a limited number of applications and, as such, are sold as specialties. Usually designated according to their actual construction, some of these special constructions are listed in Table 2 and shown in Figure 8.

TABLE 1 WIRE ROPE CLASSIFICATIONS Based on the Nominal Number of Wires in Each Strand Classification

Description

6 x7

Containing 6 strands that are made up of 3 through 14 wires, of which no more than 9 are outside wires.

6x19

Containing 6 strands that are made up of 15 through 26 wires, of which no more than 12 are outside wires.

6 x 37

Containing 6 strands that are made up of 27 through 49 wires, of which no more than 18 are outside wires.

6x61

Containing 6 strands that are made up of 50 through 74 wires, of which no more than 24 are outside wires. -

6 x 91

Containing 6 strands that are made up of 75 through 109 wires, of which no more than 30 are outside wires.

6 x 127

Containing 6 strands that are made up of 110 or more wires, of which no more than 36 are outside wires.

8 x19

Containing 8 strands that are made up of 15 through 26 wires, of which no more than 12 are outside wires.

---

19 x 7 and 18x7

-

Containing 19 strands, each strand is made up of 7 wires. It is manufactured by covering an inner rope of 7x7 left lang lay construction with 12 strands in right regular lay. (The rotation-resistant property that characterizes this highly specialized construction is a result of the counter torques developed by the two layers.) When the steel wire core strand is replaced by a fiber core, the decription becomes 18x7.

5 x 1 9 MARLIN CLAD FC

6 x 2 5 B FLATTENED STRAND TRIANGULAR CENTER WIRE FC

6 x 12 GALVANIZED RUNNING ROPE FC

6 x 2 7 H FLATTENED STRAND ( 3 WIRE CENTER) FC

6 x 4 2 T I L L E R ROPE FC

6 x 3 0 G FLATTENED STRAND (PLAITED CENTER) IWRC

Figure 8. Some special purpose constructions.

TABLE 2

SPECIAL CONSTRUCTIONS

3x7 3 x 19 6 x 12 6 x 24 6 x 30 6 x 42 6 x 3 x 19 5 x 19 6 x 19 6 x 25B 6 x 27H 6 x 30G

Guard Rail Rope Slusher Running Rope Hawsers Hawsers ( 6 x 6 ~ 7 )Tiller Rope Spring Lay Marlin Clad Marlin Clad Flattened Strand Flattened Strand Flattened Strand

Table 2 is a much abbreviated listing of ropes specifically designed for highly specialized applications. Within the scope of this publication it would not be feasible either to list or to describe all the possible rope design variations. The wire rope cross-sections illustrated in Figures 9 and 10 represent some of the most commonly used configurations, and are arranged under their respective classification groups. Since these are in greater demand, they are more generally available. There are, however, two specialized wire rope categories where the selection of the right rope requires more than ordinary care : elevator and rotation-resistant ropes.

Figure 9. Cross-sections of some commonly used wire rope constructions.

6 x 7 CLASSIFICATION

I

/ /

/

1 1

6 x 19 CLASSIFICATION

6 x 1 9 SEALE lWRr

6 x 2 1 F I L L E R WIRE

6 x 2 5 F I L L E R WIRE

Fr

IWRC

6 x 37 CLASSIFICATION

6 x 3 1 WARRINGTON SEALE l WRC

6x41WARRlNGTONSEALE IWRC

6 x 3 6 SEALE FILLER WlRE IWRC

6x41SEALEFILLERWIRE IWRC

8 x 19 CLASSIFICATION

0 x 1 9 SEALE FC

8 x 2 5 FILLER WIRE IWRC

6 x 3 6 WARRINGTON SEALE IWRC

6x46SEALEFlLLERWlRE IWRC

6 x 2 6 WARRINGTON SEALE IWRC

6 x 3 1 FILLER W l R E IWRC

6 x 4 9 FILLER WIRESEALE

To begin with, elevator rope can be obtained in four principal grades: 1) iron, 2 ) traction steel, 3 ) high-strength steel, and 4) extra-high-strength steel. Additionally, bronze rope is sometimes used for a limited number of functions within this category. It should be noted that the demand for the iron grade is decreasing markedly; its use is generally limited to older existing equipment. The most widely used constructions for elevator rope are 6 x 25 FW, 8 x 19 Seale, and 8 x 25 FW. But, on occasion, a number of other constructions are used. In any case, these ropes differ significantly from one another in their wear and fatigue characteristics, thus they should not be inter-changed indiscriminately. There are, in fact, some applications-such as governor rope-where the ropes may not be interchanged either in grade or construction without re-qualification. A special construction (6 x 42) is still used from time to time as a hand rope to control the elevator, and small diameter ropes (of 7 x 19 construction) are used as control ropes for operating floor selection equipment. From reel to reel, there are slight yet significant differences in the elastic properties of wire rope. Because of such possible variations, it is strongly suggested that all rope for a given elevator be obtained from a single reel. Recognizing the need for such precaution, many codes and purchasing specifications make this a standard requirement. As noted, it is beyond the scope of this publication to discuss, in depth, design and selection considerations for elevator rope. Information concerning sheave diameters, design factors (ratio of nominal strength to working load), groove contours, etc. can be found in the ANSI Code A1 7.1. The second special category-rotation-resistant ropes-differs from "standard" constructions because they are required to meet a different set of service requirements. The essential nature of their construction which gives these ropes the ability to meet the special operational requirements, imposes certain limitations and necessitates special handling that are not encountered with ropes of standard constructions. To obtain current data and sound technical guidance on elevator and rotation-resistant rope or on any other special requirements, consult a wire rope manufacturer beforehand.

8x19 SEALE IWRC

18 x 7 FC

8 x 2 5 F I L L E R WIRE IWRC

Figure 10. Cross-sections

OF some

19x7

rotation-resistant wire ropes.

17

4 Handling and Installation RECEIVING, INSPECTION AND STORAGE For all wire rope, the best time to begin taking appropriate care and handling measures, is immediately upon receiving it. On arrival, the rope should be carefully checked to make certain that the delivered product matches the description on tags, requisition forms, packing slips, purchase order, and invoice. After these necessary preliminary checks, the next concern is that of providing weather-proof storage space. If wire rope is to be kept unused for a considerable time, it must be protected from the elements. The ideal storage area is, of course, a dry, well-ventilated building or shed. Avoid closed, unheated, tightly sealed buildings or enclosures because condensation will form when warm, moist outside (ambient) air envelops the colder rope. Although wire rope is protected by a lubricant, this is not totally effective since condensation can still occur within the small interstices between strands and wires, thereby creating corrosion problems. On the other hand, if the delivery site conditions preclude storage in an inside space and the rope must be kept outdoors, it should be effectively covered with a waterproof material. Moreover, weeds and tall grass, in the assigned storage area, should be cut away; the reel itself should be placed on an elevated platform that will keep it from direct contact with the ground. Providing an adequate covering for the reel also prevents the original lubricant from drying out and thereby losing its protection. Never store wire rope in areas subject to elevated temperatures. Dust and grit, or chemically laden atmospheres, are also to be avoided. Although lubricant applied at the factory offers some degree of protection, every normal precautionary measure should be taken with every coil or reel of wire rope. Whenever wire rope remains in position on an idle machine, crane, hoist, etc., it should be coated with an appropriate protective lubricant. In these circumstances, as with ropes stored outside, moisture, in the form of condensation, rain or snow, may form on the wire rope. Some of the moisture may easily become trapped inside the rope and cause corrosion problems. If the wire rope is to be kept inactive for an extended period while wound on the drum of the idle equipment, it may be necessary to apply a coating of lubricant to each layer as the rope is wound on the drum. Cleaning, inspection and re-lubrication should precede start-up of the equipment.

WIRE ROPE INSTALLATION CHECKING THE DIAMETER It is most important to check the diameter of the delivered rope before installation. This is to make certain that the rope diameter meets the specified requirements for the given machine or equipment. With an undersize diameter rope, stresses will be higher than designed for and the probability of breaking the rope will be increased; an oversize diameter rope will wear out prematurely. This happens because of abuse to the rope caused by pinching in the grooves of the sheave and drum.

In checking, however, the actual rope diameter must be measured. And this is defined as the diameter of the circumscribing circle, i.e., its largest cross-sectional dimension. To insure accuracy this measurement should be made with a wire rope caliper using the correct method (b) shown in Fig. 11. For measuring ropes with an odd number of outer strands, special techniques must be employed. Design specificationsfor wire rope are such that the diameter is slightly larger than the nominal size, according to the allowable tolerances shown in Table 3.

TABLE 3 OVERSIZE LIMITS OF WIRE ROPE DIAMETERS* Nominal Rope Diameter

Allowable Limits

Thru 96f'

-0

+8%

Over 9% " thru $46"

-0

f7%

Over %sf' thru !4

-0

+6%

Over 1/4 " and larger

-0

+5%

*These limits have been adopted by the Wire Rope Technical Board (WRTB), and are being considered for inclusion in the forthcoming revised edition of "Federal Standard RR-W-410." In the case of certain special purpose ropes, such as aircraft cables and elevator ropes, each has specific requirements.

ACTUAL DIAMETER

J

-1

A

B. CORRECT

C. I N C O R R E C T

Figure 11. How to measure (or caliper) a wire rope correctly. Since the "true" diameter (A) lies within the circumscribed circle, always measure the larger dimension (B).

UNREELING AND UNCOILING Wire rope is shipped in cut lengths, either in coils or on reels. Great care should be taken when the rope is removed from the shipping package since it can be permanently damaged by improper unreeling or uncoiling. Looping the rope over the head of the reel or pulling the rope off a coil whiIe it is lying on the ground, will create loops in the line. Pulling on a loop will, at the very least, produce imbalance in the rope and may result in open or closed kinks (Fig. 12). Once a rope is kinked, the damage is permanent. To correct this condition, the kink must be cut out, and the shortened pieces used for some other purpose.

Figure 12. Improper handling helps create open (a) or closed kinks (b). The open kink will open the rope lay; the closed kink will close it. Starting loop (c): Do not allow the rope to form a small loop. If, however, a loop does form and is removed at the stage shown, a kink can be avoided. Kink (d) : In this case, the looped rope was put under tension, the kink was formed, the rope is permanently damaged and must be removed.

Unwinding wire rope fromits reel also requires careful and proper procedure. There are three methods to perform this step correctly: 1 ) The reel is mounted on a shaft supported by two jacks or a roller payoff (Fig. 13). Since the reel is free to rotate, the rope is pulled from the reel by a workman, holding the rope end and walking away from the reel as it unwinds. A braking device should be employed so that the rope is kept taut and the reel is restrained from over-running the rope. This is necessary particularly with powered de-reeling equipment. 2) Another method involves mounting the reel on an unreeling stand (Fig. 14). It is then unwound in the same manner as described above ( 1) . In this case, however, greater care must be exercised to keep the rope under tension sufficient to prevent the accumulation of slack-a condition that will cause the rope to drop below the lower reel head. 3) In another accepted method, the end of the rope is held while the reel itself is rolled along the ground. With this procedure the rope will pay off properly; however, the end being held will travel in the direction the reel is being rolled. As the difference between the diameter of the reel head and the diameter of the wound rope increases, the speed of travel will increase.

Figure 13. The wire rope reel is mounted on a shaft supported by jacks. This permits the reel to rotate freely, and the rope can be unwound either manually or by a powered mechanism.

Figure 14. A vertical unreeling stand.

REEL

A

- CORRECT

A B - WRONG

Figure 15. The correct (a) and the wrong (b) way to wind wire rope from reel to drum.

Figure 16. Perhaps the most common and easiest uncoiling method is to hold one end of the rope while the coil is rolled along the ground.

When re-reeling wire rope from a horizontally supported reel to a drum, it is preferable for the rope to travel from the top of the reel to the top of the drum; or, from the bottom of the reel to the bottom of the drum (Fig. 15). Re-reeling in this manner will avoid putting a reverse bend into the rope as it is being installed. If a rope is installed so that a reverse bend is induced, it may cause the rope to become "cranky" and, consequently, harder to handle. When unwinding wire rope froma coil, there are two suggested methods for carrying out this procedure in a proper manner: 1) One method involves placing the coil on a vertical unreeling stand. The stand consists of a base with a fixed vertical shaft. On this shaft there is a "swift," consisting of a plate with inclined pins positioned so that the coil may be placed over them. The whole swift and coil then rotate as the rope is pulled off. This method is particularly effective when the rope is to be wound on a drum. 2) The most common as well as the easiest uncoiling method is merely to hold one end of the rope while rolling the coil along the ground like a hoop (Fig. 16). Figures 17 and 18 show unreeling and uncoiling methods that are most likely to provide kinks. Such improper procedures should be strenuously avoided in order to prevent the occurrence of loops. These loops, when pulled taut, will inevitably result in kinks. No matter how a kink develops, it will damage strands and wires, and the kinked section must be cut out. Proper and careful handling will keep the wire rope free from kinks.

Figure 17. Illustrating a wrong method of unreeling wire rope.

Figure 18. Illustrating a wrong method of uncoiling wire rope.

Figure 19A. METHOD A: Lay one end of the seizing wire in the groove between two strands; wrap the other end tightly in a close helix over a position of the groove using a seizing iron (a round bar % to %4" diam. x 18" long) as shown above. Both ends of the seizing wire should be twisted together tightly, and the finished appearance as shown below. Seizing widths should not be less than the rope diameter.

Figure 19B. METHOD B: The procedure illustrated at right is the second of the two (A and B) accepted methods for placing seizing on wire rope.

SEIZING WIRE ROPE While there are numerous ways to cut wire rope, in every case, certain precautions must be observed. For one thing, proper seizings are always applied on both sides of the place where the cut is to be made. In a wire rope, carelessly or inadequately seized, ends may become distorted and flattened, and the strands may loosen. Subsequently, when the rope is put to work, there may be an uneven distribution of loads to the strands; a condition that will significantly shorten the life of the rope. The two widely accepted methods of applying seizing are illustrated in Figures 19A and 19B. The seizing itself should be soft, or annealed wire or strand. Seizing wire diameter and the length of the seize will depend on the diameter of the wire rope. But the length of the seizing should never be less than the diameter of the rope being seized. Normally, for preformed ropes, one seizing on each side of the cut is sufficient. But for ropes that are not preformed, a minimum of two seizings on each side is recommended; and these should be spaced six rope diameters apart (Fig. 20). Table 4 lists suggested seizing wire diameters for use with a range of wire rope diameters.

TABLE 4 SEIZING*

Rope Diameters inches

1% and larger

mm

45.0 and larger

Suggested Seizing Wire Diameters* * inches mm

.I24

3.15

*Length of the seizing should not be less than the rope diameter. **The diameter of seizing wire for elevator ropes is usually somewhat smaller than that shown in this table. Consult the wire rope manufacturer for specific size recommendations. Soft annealed seizing strand may also be used.

CUTTING WIRE ROPE Wire rope is cut after being properly seized (Fig. 20). Cutting is a reasonably simple operation provided appropriate tools are used. There are several types of cutters and shears commercially available. These are specifically designed to cut wire rope. Portable hydraulic and mechanical rope cutters are available. In remote areas, however, it may at times be necessary to use less desirable cutting methods. For example, using an axe or hatchet must be recognized as dangerous.

NONPREFORMED

I

;[email protected] BIIIIIIIIIIIIII&IIIIIIIIIIIIII~ BIIIIIIIIUIIII L6:;E4 ~ 6 ~ ~ ~ 4 BEFORE CUTTING

I

~

//

AFTER CUTTING

~ ~ ~ ~ ~ ~~ ~ ~ ~ ~ ~ ~ ~

~~ ~ ~ ~ ~~ ~ ~ ~ I~ I ~ I ~ ~ I ~

PREFORMED

-IIIIIIIIIIIIII&IIIIIIIII1 /

BEFORE CUTTING

~ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ~~ 1 1 1 1 1 1 1 1 1 1 l 1 1 1 ~ AFTER CUTTING

Figure 20. Seizings, either on non-preformed or preformed wire rope, are applied before cutting.

END PREPARATIONS For a number of applications-such as tight openings in drums, or other complicated reeving systems-there may be a need for making special end preparations. When these are required, there are about four basic designs (and combinations) to choose from (Fig. 21 ). Whenever possible end preparations should be removed after the rope is installed (p. 34). Beckets are used when another rope is needed to pull the new rope into place. END TERMINATIONS The rope end must be fastened to the mechanism so that force and motion are transferred efficiently. End terminations thus become items of great importance for transferring these forces. Each basic type of termination has its own individual characteristic. Hence, one type will usually fit the needs of a given installation better than the others. It should be noted that not all end terminations will develop the full strength of the wire rope used. To lessen the possibility of error, the wire rope industry has determined terminal efficiencies for various types of end terminations. Table 5-listing these efficiencies-permits holding power calculations to be made of the more popular end terminations. (Fig. 22 ) . A

PAD EYE

LINK BECKET

C

D

TAPERED 8 WELDED END

TAPERED END WITH LOOP

Figure 21. Beckets, or end preparations, are used on wire rope ends when another rope is needed to pull the operating rope into place. Four commonly used beckets are illustrated.

WIRE ROPE SOCKET-

POURED SPELTER OR RESIN

Wl RE ROPE SOCKET -SWAGED

MECHANICAL SPLICE - LOOP OR T H I M B L E

WEDGE SOCKET

CLIPS - NUMBER OF CLIPS VARIES WITH ROPE SIZE AND CONSTRUCTION

~ ~ ~ ~ 1 1 1 1 1 1 1 1 1,, 1 1 1 1 1 ,,1 l l l l l l l l l l l l l l l ~ ~ ~ ,,

,

LOOP OR THIMBLE SPLICE- HAND TUCKED

Figure 22. End fittings, or terminations, are available in many designs, some of which were developed for particular applications. The six shown are among the most commonly used.

TABLE 5 TERMINAL EFFICIENCIES (APPROXIMATE) Efficiencies are based on nominal strengths -

Efficiency Rope with IWRC* Rope with FC* *

Type of Termination Wire Rope Socket (Spelter or Resin)

100%

Swaged Socket (Regular Lay Ropes Only)

100%

Mechanical Spliced Sleeve 1'dia. and smaller Greater than 1If dia. through 2" Greater than 2" dia. through 3% If

95 % 92% % 90%

100% (Not established)

92% % 90% (Not established)

Loop or Thimble Splice- -Hand Spliced (Tucked) (Carbon Steel Rope)

%iN %sN %" K6"

w

5/sN

%iN 7/s thru 2%"

Loop or Thimble Splice- -Hand Spliced (Tucked) (Stainless Steel Rope)

%in 946''

%"

Ks" %"

5/sN

%in Y8 " Wedge Sockets* * * (Depending on Design) Clips* * * (Number of clips varies with size of rope) *IWRC = Independent Wire Rope Core

80%

* *FC = Fiber Core

* * "Typical values when applied properly. Refer to fittings manufacturers for exact values and method.

80%

SOCKETING Improperly attached wire rope terminals lead to serious-possibly unsafeconditions. To perform properly, all wire rope elements must be held securely by the terminal. If this is not accomplished, the strands will become unequally loaded and there is every likelihood that a strand will become "high". A high strand condition is illustrated in Figure 42. In the case shown, selective abrasive wear of the high strand will necessitate early removal of the rope. Poured Sockets-Spelter or Resin When preparing a wire rope for socketing, it is of extreme importance to follow recommended procedures. (See Appendix D : SOCKETING PROCEDURES. ) Procedures other than those stipulated here, may develop the required strength but this cannot be pre-determined without destructive tests. It is far saferand ultimately less costly-to follow well-established practices. There are many ways to go wrong in socketing procedures. Some of the more common pitfalls that should be guarded against include: 1) Turning back the strands-inward or outward-before the "broom" is inserted into the socket; 2) Turning back the strands and seizing them to the body of the rope; 3 ) Turning back the strands and tucking them into the body of the rope; 4) Tying a knot in the rope; 5) Driving nails, spikes, bolts, and similar objects into the socket after the rope js in, so as to "jam" it tight; this is particularly dangerous-and ruinous. To avoid these and many other dangerous practices, play it safe by following correct procedures.

WIRE ROPE CLIPS Wire rope clips are widely used for making end terminations. Clips are available in two basic designs; the U-bolt and fist grip (Fig. 23). The efficiency of both types is the same. When using U-bolt clips, extreme care must be exercised to make certain that they are attached correctly, i.e., the U-bolt must be applied so that the "U" section is in contact with the dead end of the rope (Fig. 24). Also, the tightening and retightening of the nuts must be accomplished as required. U- BOLT

FIST GRIP

Figure 23. Wire rope clips are obtainable in two basic designs: U-bolt and fist grip. Their efficiency is the same.

HOW TO APPLY CLIPS U-BOLT CLIPS (Table 6, p. 3 1.) Recommended Method of Applying U-Bolt Clips to Get Maximum Holding Power of the Clip 1) Turn back the specified amount of rope from the thimble. Apply the first clip one base width from the dead end of the wire rope (U-bolt over dead end-live end rests in clip saddle). Tighten nuts evenly to recommended torque. 2) Apply the next clip as near the loop as possible. Turn on nuts firm but do not tighten. 3) Space additional clips if required equally between the first two. Turn on nutstake up rope slack-tighten all nuts evenly on all clips to recommended torque.

4) NOTICE! Apply the initial load and retighten nuts to the recommended torque. Rope will stretch and be reduced in diameter when loads are applied. Inspect periodically and retighten to recommended torque. A termination made in accordance with the above instructions, and using the number of clips shown has an approximate 80% efficiency rating. This rating is based upon the nominal strength of wire rope. If a pulley is used in place of a thimble for turning back the rope, add one additional clip. The number of clips shown is based upon using right regular or lang lay wire rope, 6 x 19 class or 6 x 37 class, fiber core or IWRC, IPS or EIP. If Seale construction or similar large outer wire type construction in the 6 x 19 class is to be used for sizes 1 inch and larger, add one additional clip. The number of clips shown also applies to right regular lay wire rope, 8 x 19 i inch and smaller; and right regular lay wire rope, class, fiber core, IPS, sizes 1X 18 x 7 class, fiber core, IPS or EIP, sizes 1 % inch and smaller. For other classes of wire rope not mentioned above, it may be necessary to add additional clips to the number shown. If a greater number of clips are used than shown in the table, the amount of rope turnback should be increased proportionately. ABOVE BASED ON USE OF CLIPS ON NEW ROPE.

IMPORTANT: Failure to make a termination in accordance with aforementioned instructions, or failure to periodically check and retighten to the recommended torque, will cause a reduction in eficiency rating.

I

R I G H T W A Y FOR M A X I M U M ROPE STRENGTH

W R O N G WAY: CLIPS STAGGERED

W R O N G W A Y : CLIPS REVERSED

Figure 24. The correct way to attach U-bolts is shown at the top; the "U" section is in contact with the rope's dead end and is clear of the thimble.

TABLE 6 *

Clip Size

A

B

C

D

E

F

G

Min. no. of H clips

Amount of rope to turn back

Torque in 1b/ft

Weight lb/100

*From The Crosby Group

31

FIST GRIP CLIPS (Table 7, on following page) RECOMMENDED METHOD OF APPLYING FIST GRIP CLIPS 1 ) Turn back the specified amount of rope from the thimble. Apply the first clip one base width from the dead end of the wire rope. Tighten nuts evenly to recommended torque. 2) Apply the next clip as near the loop as possible. Turn on nuts firmly but do not tighten. 3) Space additional clips if required equally between the first two. Turn on nutstake up rope slack-tighten all nuts evenly on all clips to recommended torque. 4) NOTICE! Apply the initial load and retighten nuts to the recommended torque. Rope will stretch and be reduced in diameter when loads are applied. Inspect periodically and retighten to recommended torque. A termination made in accordance with the above instructions, and using the number of clips shown has an approximate 80% efficiency rating. This rating is based upon the catalog breaking strength of wire rope. If a pulley is used in place of a thimble for turning back the rope, add one additional clip. The number of clips shown is based upon using right regular or lang lay wire rope, 6 x 19 class or 6 x 37 class, fiber core or IWRC, IPS or EIPS. If Seale construction or similar large outer wire type construction in the 6 x 19 class is to be used for sizes 1 inch and larger, add one additional clip. The number of clips shown also applies to right regular lay wire rope, 8 x 19 class, fiber core, IPS, sizes 1 % inch and smaller; and right regular lay wire rope, 18 x 7 class, fiber core, IPS or EIPS, sizes 1Y2 inch and smaller. For other classes of wire rope not mentioned above, it may be necessary to add additional clips to the number shown. If a greater number of clips are used than shown in the table, the amount of rope turnback should be increased proportionately. ABOVE BASED ON USE OF FIST GRIP CLIPS ON NEW WIRE ROPE.

IMPORTANT: Failure to make a termination in accordance with aforementioned instructions, or failure to periodically check and retighten to the recommended torque, will cause a reduction in eficiency rating.

TABLE 7 *

Clip Size

A

B

C

D

E

F

G

L H Approx.

M

Min. no. Amount of Torque of rope to in Weight N clips turn back lb/ft lb/100

*From The Crosby Group

33

WEDGE SOCKETS One of the more popular end attachments for wire rope is the wedge socket. For field, or on the job attachment, it is easily installed and quickly dismantled. The procedure is simple : 1) Inspect the wedge and socket; all rough edges or burrs, that might damage the rope, should be removed. 2) If the end of the rope is welded, the welded end should be cut off. This will allow the distortions of the rope strands, caused by the sharp bend around the wedge, to adjust themselves at the end of the line. If the weld is not cut off, the distortions will be forced up the working line. This may result in the development of high strands and wavy rope. 3 ) Place the socket in an upright position and bring the rope around in a large, easy to handle, loop. Care must be taken to make certain that the live-loadedside of the rope is in line with the ears (Fig. 25). 4) The dead end of the rope should extend from the socket for a distance of six to nine times the rope diameter. The wedge is now placed in the socket, and a wire rope clip is placed around the dead end by clamping a short, extra piece of rope to the tail as close to the wedge as possible. (Do not clamp to the live part.) The U-bolt should bear against the tail; the saddle of the clip should bear against the short extra piece. 5 ) Secure the ears of the socket to a sturdy support and carefully take a strain on the live side of the rope. Pull the wedge and rope into position with tension sufficiently tight to hold them in place. 6) After final pin connections are made, increase the loads gradually until the wedge is properly seated. Avoid sudden shock loads. The foregoing is the recommended procedure. If variations are made to suit special conditions, they should be carefully evaluated beforehand.

Figure 25. The wedge socket is a very popular end attachment; it is easily installed and quickly dismantled. But it must be applied correctly (A).

A RIGHT

B WRONG

DRUMS-GROOVED Drums are the means by which power is transmitted to the rope and thence to the object to be moved. For the wire rope to pick up this power efficiently and to transmit it properly to the working end, installation must be carefully controlled. If the drum is grooved, the winding conditions should be closely supervised to assure adherence to the following recommended procedures : 1) The end of the rope must be secured to the drum by such means as will give the end termination at least as much strength as is specified by the equipment manufacturer. 2 ) Adequate tension must be maintained on the rope while it is being wound so that the winding proceeds under continuous tension. 3 ) The rope must follow the groove. 4) It is preferable to have at least three dead wraps remaining on the drum when the rope is unwound during normal operation. Two dead wraps are a mandatory requirement in many codes and standards. If the wire rope is carelessly wound and, as a result, jumps the grooves, it will be crushed and cut where it crosses from one groove to the other. Another, almost unavoidable problem is created at the drum flange; as the rope climbs to a second layer there is further crushing and the wires receive excessive abrasion. Riser and filler strips may help remedy this condition. Another factor that must be given serious consideration is the pitch of the drum grooves relative to the actual rope diameter. Wire rope is always manufactured to a plus tolerance of up to 5 % of the nominal diameter. If this oversize tolerance in the rope is not taken into account, it can mean severe damage. As an example, a grooved drum made for %-inch rope may have a pitch of .250 inches. Yet, by Federal standards, a % -inch rope may have a diameter as large as .2625 inches. If a rope of this size were to be operated on a drum with a .250-inch pitch, crowding would occur and the rope would be forced out of the groove.

DRUMS-PLAIN (SMOOTH) Installation of a wire rope on a plain (smooth) face drum requires a great deal of care. The starting position should be at the correct drum flange so that each wrap of the rope will wind tightly against the preceding wrap (Fig. 26). Here too, close supervision should be maintained all during installation. This will help make certain that: 1) the rope is properly attached to the drum, 2 ) appropriate tension on the rope is maintained as it is wound on the drum, 3) each wrap is guided as close to the preceding wrap as possible, so that there are no gaps between turns. 4) and that there are at least two dead wraps on the drum when the rope is fully unwound during normal operating cycles. Loose and uneven winding on a plain- (smooth-) faced drum, can and usually does create excessive wear, crushing and distortion of the rope. The results of such abuse are lower operating performance, and a reduction in the rope's effective strength. Also, for an operation that is sensitive in terms of moving and spotting a load, the operator will encounter control difficulties as the rope will pile up, pull into the pile and fall from the pile to the drum surface. The ensuing shock can break or otherwise damage the rope.

UNDERWIND L E F T TO RIGHT USE LEFT LAY ROPE

L E F T LAY UNDERWIND

OVERWIND RIGHT TO L E F T U S E LEFT L A Y R O P E

L E F T LAY OVERWIND START ROPE AT RlGHT F L A N G E

OVERWIND LEFT TO RIGHT U S E RIGHT L A Y R O P E

RIGHT LAY OVERWIND

UNDERW IND RlGHT TO L E F T USE RlGHT LAY ROPE

RIGHT L A Y UNDERWI ND

Figure 26. By holding the right or left hand with index finger extended, palm up or palm down, the proper procedure for applying left- and right-lay rope on a smooth drum can be easily determined.

The proper direction of winding the first layer on a smooth drum can be determined by standing behind the drum and looking along the path the rope travels, and then following one of the procedures illustrated in Figure 26. The diagrams show: the correct relationship that should be maintained between the direction of lay of the rope (right or left), the direction of rotation of the drum (overwind or underwind), winding from left to right or right to left.

Figure 27. After the first layer is wound on a drum, the point at which the rope winds back for each wrap is called the cross-over.

DRUMS-MULTIPLE LAYERS Many installations are designed with requirements for winding more than one layer of wire rope on a drum. Winding multiple layers presents some further problems. The first layer should wind in a smooth, tight helix which, if the drum is grooved, is already established. The grooves allow the operator to work off the face of the drum, and permit the minimum number of dead wraps. A smooth drum presents an additional problem, initially, as the wire rope must be wound in such a manner that the first layer will be smooth and uniform and will provide a firm foundation for the layers of rope that will be wound over it. The first layer of rope on the smooth drum should be wound with tension sufficient to assure a close helix-each wrap being wound as close as possible to the preceding wrap-and most, if not all, of the entire layer being used as dead wraps. The first layer then acts as a helical groove which will guide the successive layers. Unlike wire ropes operating on grooved drums, the first layer should not be unwound from a smooth-faced drum with multiple layers. After the rope has wound completely across the face of the drum (either smooth or grooved), it is forced up to a second layer at the flange. The rope then winds back across the drum in the opposite direction, lying in the valleys between the wraps of the rope on the first layer. Advancing across the drum on the second layer, the rope, following the "grooves" formed by the rope on the first layer, actually winds back one wrap in each revolution of the drum. The rope must then cross two rope "grooves" in order to advance across the drum for each turn. The point at which this occurs is known as the cross-over. Cross-over is unavoidable on the second, and all succeeding layers. Figure 27 illustrates the winding of a rope on the second layer from left to right, and from right to left-the direction is shown by the arrows. At these cross-over points, the rope is subjected to severe abrasion and crushing as it is pushed over the two rope "grooves" and ridemcross the crown of the first rope layer. The scrubbing of the rope, as this is happening, can easily be heard. There are, however, special drum groovings available that will greatly minimize the damage that can occur at cross-over points. Severe abrasion can also be reduced by applying the rule for the correct rope lay (right- or left-lay) to the second layer rather than to the first layer. It is for this reason that the first layer of a smooth drum should be wound tight and used as dead wraps.

5 Operation, Inspection and Maintenance of Wire Rope SHEAVES AND DRUMS In the course of normal operations, wire rope comes into contact with sheaves, drums, rollers and scrub boards-all of which must be maintained in first class condition. What causes wear in both groove and wire rope? Essentially, the answer derives from the fact that wire rope, when loaded, stretches much like a coil spring. When bent over a sheave, the rope's load-induced stretch causes it to rub against the groove. As a result, both groove and rope are subject to wear. Within the rope itself, additional rubbing is encountered as the rope adjusts-by movement of the wires and strands-while bent around the sheave or drum. The smaller the ratio of sheave diameter to rope diameter (D/d), the greater the adjusting movement, and the more rapid the resulting wear. The amount of wear, and the speed at which it takes effect on both the wire rope and grooves of the sheave or drum, are also determined by the sheave material, and the radial pressure between rope and groove. Simply stated, excessive wear can be caused either by sheave or drum material that is too soft, or a diameter (tread diameter) that is too small. To determine the unit radial pressure between rope and groove, use the following formula : 2T P

==

where p = Unit radial pressure in pounds per square inch T = Load on the rope in pounds D = Tread diameter of the sheave or drum in inches d = Nominal diameter of the rope in inches Table 8 gives examples of allowable unit radial bearing pressures of ropes on various materials commonly used in sheaves and drums. The values given are typical for the materials listed; they are not precise values since these materials are made to a wide range of specifications. In the foregoing equation, if the calculated value of "p" exceeds the allowable radial pressure for the sheave or drum material, the groove will wear quite rapidly. Wear will manifest itself in the form of either an undersize or corrugated groove--either of which will contribute to accelerated wear in the rope. Values for the allowable unit radial pressures given in Table 8 are intended solely as-a user's guide. And use of these figures does not guarantee prevention of any trouble. Further, the values should not be taken as restrictive with regard to other or new materials. There are, for example, certain elastomers in current use that are apparently providing excellent service, but since there is insufficient data to support specific recommendations, such products are not mentioned.

TABLE 8 SUGGESTED ALLOWABLE RADIAL BEARING PRESSURES OF ROPES ON VARIOUS SHEAVE MATERIALS IN POUNDS PER SQUARE INCH (PSI) Lang Lay Rope, psi

Regular Lay Rope, psi 6x7

6x19

Wood

150

Cast Iron

Flattened Strand Lang Lay, 6x19 6x37 psi

6x37 8x19

6x7

250

300

350

165

275

330

4-00

On end grain of beech,hickory,gum.

300

480

585

680

350

550

660

800

Based on minimum Brinellhardness of 125.

Carbon Steel Casting

550

900

1,075

1,260

600

1,000

1,180

1,450

30-40 Carbon. Based on minimum Brine11 hardness of 160.

Chilled Cast Iron

650

1,100

1,325

1,550

715

1,210

1,450

1,780

Not advised unless surface is uniform in hardness.

Manganese Steel

1,470

2,400

3,000

3,500

1,650

2,750

3,300

4,000

Grooves must be ground andsheavesbalanced for high-speed service.

Material

Remarks

BENDING WIRE ROPE OVER SHEAVES AND DRUMS Sheaves, drums and rollers must be of a correct design if optimum service is to be obtained from both the equipment and the wire rope. Because there are many different types of equipment and many different operating conditions, it is difficult to identify the one specific size of sheave or drum most economical for every application. The rule to follow is this: the most economical design is the one that most closely accommodates the limiting factors imposed by the operating conditions and the manufacturer's recommendations. All wire ropes operating over sheaves and drums are subjected to cyclic bending stresses, hence the rope wires will eventually fatigue. The magnitude of these stresses depends-all other factors being constant-upon the ratio of the diameter of the sheave or drum to the diameter of the rope. Frequently, fatigue from cyclic, high-magnitude bending stress is the principal reason for shortened rope service. To illustrate, in order to bend around a sheave, the rope's strands and wires must move relative to one another. This movement compensates for the difference in diameter between the underside and the top side of the rope, the distance being greater along the top side than it is on the underside next to the groove. Proper rope action (and service) is adversely affected if the wires cannot move to compensate for this situation. Also, there can be additional motion retardation because of excessive pressure caused by a sheave whose groove diameter is too small, or by lack of rope lubrication. Changing the bending direction from one sheave to another should be scrupulously avoided as this reverse bending still further accelerates wire fatigue. The relationship between sheave diameter and rope diameter is a critical factor that is used to establish the rope's fatigue resistance or relative service life. It is expressed in the tread D/d ratio mentioned earlier in which D is the tread diameter of the sheave and d is the diameter of the rope. Table 9 lists "suggested" and "minimum" values for this ratio for various rope constructions. Tables 10 and 11 show the effect of rope constructions and D/d ratios on service life.

TABLE 9

SHEAVE AND DRUM RATIOS

Construction*

Suggested D/d Ratio* *

Minimum D/d Ratio* *

6x7 19 x 7 or 18 x 7 Rotation Resistant 6x19s 6 x 25 B Flattened Strand 6 x 27 H Flattened Strand 6 x 30 G Flattened Strand 6x21FW 6x26WS 6x25FW 6 x 3 1 WS 6 x 37 SFW 6x36WS 6 x 43 FWS 6 x 4 1 WS 6 x 41 SFW 6 x 49 SWS 6 x 43 FW (2 op) 6 x 46 SFW 6x46WS 8x19s 8x25FW 6 x 42 Tiller *WS -Warrington Seale FWS -Filler Wire Seale SFW C e a l e Filler Wire SWS - 4 e a l e Warrington Seale -Seale S FW -Filler Wire

**D =tread diameter of sheave d =nominal diameter of rope To find any tread diameter from this table, the diameter for the rope construction to be used is multiplied by its nominal diameter (d). For example, the minimum sheave tread diameter for a ?h"6 x 21 FW rope would be % " (nominal diameter) x 30 (minimum ratio) or 15". NOTE: These values are for reasonable service. Other values are permitted by various standards such as ANSI, API, PCSA, HMI, C M A A , etc. Smaller values affectrope life (Fig.28).

TABLE 10 RELATIVE BENDING LIFE FACTORS Rope Construction

Factor

.6 1 6x7 19x 7 or 18 x7 Rotation Resistant .67 6x19s .81 .90 6 x 25 B Flattened Strand 6 x 27 H Flattened Strand .90 .90 6 x 30 G Flattened Strand 6x21FW .89 6x26WS .89 6x25FW 1.OO 6 x 3 1 WS 1.OO 6 x 37 SFW 1.OO

Rope Construction

Factor

6x36WS 6 x 43 FWS 6 x 4 1 WS 6 x 41 SFW 6 x 49 SWS 6 x 43 FW (2 op) 6 x 46 SFW 6x46WS 8x19s 8x25FW 6 x 42 Tiller

If a change in construction is being considered as a means of obtaining longer service on a rope influenced principally by bending stresses, the table of factors may be useful. For example: a change from a 6 x 25 FW with a factor of 1.00 to a 6 x 36 WS with a factor of 1.31 would mean the service life could be expected to increase 1.16 times or 16%. It must be pointed out however that these factors apply only for bending stresses. Other factors which may contribute to rope deterioration have not been considered.

I

Figure 28. This service life curve only takes into account bending and tensile stresses. Its applicability can be illustrated by the following example: A rope working with a D/d ratio of 26 has a relative service life of 17. If the same rope works over a sheave that increases its D/d ratio to 35, the relative1 service life increases to 32. In short, this rope used on a larger sheave, increases its service life from 17 to 32--or 88%.

42

I

SERVICE LIFE CURVE FOR VARIOUS D/d RATIOS

D/d RATIO

I

1

Fignre 29. Cross-sections illustrating three sheave-groove conditions. A is correct, B is too tight, and C is too loose.

INSPECTION OF SHEAVES AND DRUMS Under normal conditions, machines receive periodic inspections, and their over-all condition is recorded. Such inspections usually include the drum, sheaves, and any other parts that may come into contact with the wire rope and subject it to wear. As an additional precaution, rope-related working parts, particularly in the areas described below, should be re-inspected prior to the installation of a new wire rope. The very first item to be checked when examining sheaves and drums, is the condition of the grooves (Figs. 29, 30, and 3 1) . To check the size, contour and amount of wear, a groove gage is used. As shown in Figure 29, the gage should contact the groove for about 150" of arc. Two types of groove gages are in general use and it is important to note which of these is being used. The two differ by their respective percentage over nominal. For new or re-machined grooves, the groove gage is nominal plus the full oversize percentage. The gage carried by most wire rope representatives today is used for worn grooves and is made nominal plus Y2 the oversize percentage. This latter gage is intended to act as a sort of "no-go" gage. Any sheave with a groove smaller than this must be re-grooved or, in all likelihood, the existing rope will be damaged. When the sheave is re-grooved it should be machined to the dimensions for "new and machined" grooves given in Table 11. This table lists the requirements for new or re-machined grooves, giving the groove gage diameter in terms of the nominal wire rope diameter plus a percentage thereof. Similarly, the size of the "no-go" gage is given, against which worn grooves are judged. Experience has clearly demonstrated that the service life of the wire rope will be materially increased by strict adherence to these standards.

3/4 DIAM. + 5%

TREAD DIAM. PITCH DIAM. OUTSIDE DIAM.

Figure 30. These sheave-groove crosssections represent three wire rope seating conditions: A, a new rope in a new groove; B, a new rope in a worn groove; and C , a worn rope in a worn groove. (See also Figs. 29 and 31.)

Figure 31. Illustrating the various dimensions of a sheave, and the use of a groove gage.

43

TABLE 11 MINIMUM SHEAVE- AND DRUM-GROOVE DIMENSIONS* Nominal Rope Diameter 1 inches

*Values given are applicable to grooves in sheaves and drums; they are not generally suitable for pitch design since this may involve other factors. Further, the dimensions do not apply to traction-type elevators; in this circumstance, drum- and sheave-groove tdlerances should conform to the elevator manufacturer's specifications. Modern drum design embraces extensive considerations beyond the scope of this publication. It should also be noted that drum grooves are now produced with a number of oversize dimensions and pitches applicable to certain service requirements.

2 mm

Groove Radius New 3 inches

Worn 4 mm

5 inches

6 mm

If the fleet angle (Fig. 33) is large, it may be necessary to accept a smaller arc of contact at the throat; 130" for example instead of 150". This is done to avoid scrubbing the rope on the flange of the sheave. As previously noted, the groove size is evaluated on the basis of how the gage leaf fits the groove. Daylight under the gage is not tolerable when using the worn groove gage. If a full over-size gage is used, some daylight may be acceptable, but this really must be judged by relating the measurement to the actual size of the rope. For new rope, extra caution should be observed as to its fit in the groove. Characteristically, ropes become smaller in diameter immediately after being placed in service. As a result, they would operate satisfactorily in a "worn" groove; one that was gaged OK by the "worn" groove gage. Nonetheless, in some cases, a rope may not "pull down," and if this happens, abnormal wear may occur. It is important to remember that a tight groove not only pinches and damages the rope but that the pinching prevents the necessary adjustment of the wires and strands. On the other hand, a groove that is too large will not provide sufficient support; in this case, the rope will flatten and thereby restrict the free sliding action of the wires and strands. The size of the groove is not the only critical item to be examined closely. The condition of the groove is also an important factor of concern. Is it smooth or corrugated? If the groove is imprinted then it must be re-machined or, if it is corrugated too deeply, it means that sheave, roller or drum must be replaced. If replacement is indicated, a larger sheave or drum should be installed if possible, or a harder material should be specified for the replacement. Groove examination should also concern itself with how the groove is wearing. If it is worn off-center, thereby forcing the rope to undercut or to rub against the flange, it then becomes necessary to correct the alignment of the reeving system, and to specify a harder material. When checking the grooves, the bearings of the sheaves and rollers should also be examined. They should turn easily. If not, each bearing must be properly lubricated. "Wobble" in the sheave-from broken or worn bearings-is not acceptable. Bad bearings will set up vibrations in the wire rope that can cause rapid deterioration unless the condition is remedied. Bad bearings also increase the force on the rope that is needed to move a given load, since friction forces will be greatly increased. Sheaves with broken flanges may allow the rope to jump from the sheave and become fouled in the machinery. When this happens, the rope is cut, curled, and the crowns of the wires in the strands are burred. There is ample evidence to support the rule that sheaves with broken flanges must be replaced immediately. A sheave or drum with a flat spot can induce a "whip" into the line. This whip, or wave may travel until it is stopped by the end terminal, at which point the rope may bend severely. This condition helps to accelerate the fatigue breakage of wires. Sometimes the reeving is such that the whip or wave is arrested by a sheave, or the drum itself. In these circumstances, the whipping will cause wire breaks along the crowns of the strands. Obviously, sheaves or drums that excite vibrations of this sort, must be repaired or replaced.

In addition to the items discussed, inspection should also focus on any and all conditions that could cause wear and eventual damage to the wire rope. For example, plain-face (smooth) drums can develop grooves or rope impressions that will prevent the rope from winding properly. Imprinting is greatest at the pickup point when the machine is accelerating. If this happens, the surface should be repaired by machining or replaced. The winding should be checked to make sure that the rope is winding "thread wound" (Fig. 27). Excessive wear in grooved drums should be checked for variations either in the depth or pitch of the grooves. This condition is particularly critical when double drums are used because a differential force will be set up that can break the drum and shear the shaft. No matter what type of drum is in use, excessive drum wear will usually result in rapid rope deterioration. This condition will accelerate rapidly when winding in multiple layers.

STRENGTH LOSS OF WIRE ROPE OVER STATIONARY SHEAVES OR PINS Rope breaking strength is determined in a standard test wherein fittings are attached to the ends of the rope and the rope is pulled in a straight line. If, however, the rope passes over a curved surface (such as a sheave or pin) its strength "is decreased." The amount of such reduction will depend on the severity of the bend as expressed by the D/d ratio. For example, a rope bent around a pin of its own diameter will have only 50% of the strength attributed to it in the standard test. This is called "50 % efficiency" (Fig. 32) . Even at D/d ratios of 40, there may be a loss of up to 5 % . At smaller D/d ratios, the loss in strength increases quite rapidly. The angle of bend need not be 180°, 90°, or even 45 O; relatively small bends can cause considerable loss. All discussion of strength pre-supposes a gradually applied load not to exceed one inch per minute.

EFFICIENCY OF WIRE ROPE WHEN BENT OVER SHEAVES OR PINS OF VARIOUS SIZES 50

-g

60

70 Z

W

0 LL

h 80 90

Figure 32. Derived from standard test data, this curve relates rope strength efficiency to various D/d ratios. The curve is based on static loads only and applies to 6 x 19 and 6 x 37 class ropes.

100

2

6

10

14

1 1 1 261 1 I I 34I I I l

18 22 D/d RATIO

30

38

FLEET ANGLE The achievement of even winding on a smooth faced drum is closely related to the magnitude of the D/d ratio, the speed of rotation, load on the rope, and the fleet angle. Of all these factors, the one that exerts perhaps the greatest influence on winding characteristics, is the fleet angle. The schematic drawing (Fig. 3 3 ) shows an installation where the wire rope runs from a fixed sheave, over a floating sheave, and then on to the surface of a smooth drum. The fleet angle (Fig. 33 ) may be defined as the included angle between two lines; one line drawn through the middle of the fixed sheave and the drum-and perpendicular to the axis of the drum and a second line drawn from the flange of the drum to the base of the groove in the sheave. (The drum flange represents the farthest position to which the rope can travel across the drum.) There are left and right fleet angles, measured to the left or right of the center line of the sheave, respectively. It is necessary to restrict the fleet angle on installations where wire rope passes over the lead or fixed sheave and onto a drum. For optimum efficiency and service characteristics, the angle here should not exceed 1 % " for a smooth drum, nor 2" for a grooved drum. Fleet angles larger than these suggested limits can cause such problems as bad winding on smooth drums, and the rope rubbing against the flanges of the sheave grooves. Larger angles also create situations where there is excessive crushing and abrasion of the rope on the drum. Conversely, small fleet angles-less than % "-should also be avoided since too small an angle will cause the rope to pile up.

Figure 33. This illustration of wire rope running from a fixed sheave, over a floating sheave, and then on to a smooth drum, graphically defines the fleet angle.

FACTORS AFFECTING THE SELECTION OF WIRE ROPE The key to choosing the rope best suited for the job, lies in an accurate estimation of the important requirements. Correct appraisal of the following will simplify the selection process : 1) Strength-resistance to breaking 2 ) Resistance to bending fatigue 3 ) Resistance to vibrational fatigue 4 ) Resistance to abrasion 5 ) Resistance to crushing 6 ) Reserve strength It is well-nigh impossible for any single rope to have top values in all of the above qualities. The rule, in fact, seems to be that a high rating in one almost always means lower ratings in others. The first task is to make a careful analysis of the job requirements, establishing priorities among these requirements, and then selecting the rope on a trade-off basis. This will provide the best possible balance by sacrificing the least essential advantages in order to obtain maximum benefits in the most important requirements. Following, are brief explanations of the six factors previously listed: 1) Strength-resistanceto breaking As has been noted at the very outset, a wire rope is a machine-a fairly complex device that transmits and modifies force and motion. Thus, the very first consideration in choosing a "machine," is to determine the potential work load. Stated in terms of wire rope, this means establishing the actual load that is

to be moved. To this known dead weight, there must be added those loads that are caused by abrupt starts (acceleration), sudden stops, shock loads, high speeds, friction of sheave bearings. Another item in this equation is the loss of efficiency that occurs when the rope is bent over sheaves. All of these loads must be summed up in order to determine the true total load that will ultimately be handled. For an average operation, this figure is generally multiplied by a "design factor" of 5. For increased mobility or design space economy, a design factor of less than 5 is used at times, but if the load is especially valuable, or if there is danger to human life, a larger design factor (up to 8 or 9 ) is used in some instances. A still larger factor is sometimes found to be desirable. The factored load is now used to choose the size, grade, and core of the wire rope to be considered. (An extended discussion of Design Factors can be found on p. 77. ) 2 ) Resistance to bending fatigue To describe this, a close analogy can be made with a paper clip. If it is repeatedly bent back and forth at one point, it will eventually break. The reason for this is a phenomenon called "metal fatigue." To some degree, the same thing happens when a wire rope is bent around sheaves, drums, and rollers. The sharper-or more acute-the bend, the quicker the fatigue factor does its work. Accelerating the rate of travel also speeds up fatigue; close-coupled reverse bending will speed it up at an even greater rate. But fatigue can be greatly reduced if sheaves and drums have, at the very least, the recommended minimum diameter (Table 9 ) . As for the rope, there is one governing overall rule: the greater the number of wires in each strand, the greater the resistance of the rope to bending fatigue. The subject of metal fatigue is covered by a large and extensive body of literature. It is not the intent of this publication to discuss, even in broad terms, the theoretical concepts of the phenomenon. It will simply be noted here that the concept of fatigue as a cause of metal "crystallization" is incorrect since all metals are at all times crystalline in structure. The crystalline appearance in many fractures is not indicative of "crystallization." 3 ) Resistance to vibrational fatigue Vibration, from whatever source, sends shock waves through the rope. These waves are a form of energy that must be absorbed at some point. This point may appear at various places-the end attachment, the tangent where the rope contacts the sheave, or at any other place where the waves are arrested and the energy absorbed. In the normal operation of a machine or hoist, wire ropes develop a wave action that can be observed either as a low frequency or as a sharp, high frequency cycle. A good example of this is found in shaft hoists. When the cage is just starting up, the rope has a very slow swing within the shaft. But, by the time the cage reaches the top of the shaft, the initially low frequency has become a high frequency vibration. The result is eventual breakage of the wires at the attachment of the cage. Another type of vibrational fatigue is found in operations where there is cyclic loading. Such loadings would be found, for example, in the boom

TABLE 12 Number of Outside Wires

Percent of Reserve Strength

suspension systems of draglines. Here, the energy is absorbed at the end fittings of the pendants or at the tangent point where the rope contacts the sheave. In this case, the "vibration" is torsional as well as transverse. 4) Resistance to abrasion Abrasion is one of the most common destructive conditions to which wire rope is exposed. It will occur whenever a rope either rubs against or is dragged through any soil or other material. It happens whenever a rope passes around a sheave or drum. And, it takes place within the rope itself whenever it is loaded or bent. Abrasive action weakens the rope simply by removing metal from both inside and outside wires. When excessive wear is encountered in an operation, the problem usually stems from faulty sheave alignment, incorrect groove diameters, an inappropriate fleet angle, or improper drum winding. There may, however, be other causes. If, on investigation, none of these common conditions are found to be causative factors, the solution may lie in changing to a more suitable rope construction. In making such a change, it is helpful to remember that larger outer wires and lang-lay ropes are more abrasion resistant than regular-lay ropes. (See p. 10 for limitations of lung-2ay ropes.) 5 ) Resistance to crushing Rope can be crushed 1) by its own pressure against a sheave, 2 ) from improperly sized grooves, and 3) from multiple layers on a drum. The pressure of rope against a sheave is determined by the sheave diameter and the load. The pressure of rope to a drum is influenced in great measure by the support of the groove; smooth drums have a more adverse effect than those that are grooved. Multiple-layer winding is also a cause of wear even when the winding is done in an orderly (thread-winding) manner. Irregular or scramble winding is an even greater cause of damage. Obviously, in each of these cases, reducing the load will ease the condition. If, however, this is not feasible, offending sheaves may be replaced with sheaves that have larger tread diameters. Unsuitable drums and/or winding conditions should be corrected. Otherwise, the rope will have to be replaced by one with a construction better designed to resist the abuse. If the original rope has a fiber core, the replacement should have a steel core because a steel core rope will provide greater physical support. And here it is well to remember that regular-lay ropes are better able to resist crushing than lang-lay ropes. 6 ) Reserve strength The reserve strength of a wire rope is defined as the combined strength of all the wires it contains, except those in the outside layer of the strands. The listing (Table 12) gives the percent of reserve strength for 6- or 8-strand wire rope relative to the number of outside wires in each strand.

Figure 34. The wire rope industry refers to this as the X-chart. It serves to illustrate the inverse relationship between abrasion resistance and resistance to bending fatigue in a representative number of the most widely I tsed wire ropes.

THE "X-CHART"-ABRASION RESISTANCE VS. BENDING-FATIGUE RESISTANCE While there is a possibility, there is little likelihood that an application can be found for which there is a precisely suitable wire rope-one that can satisfy every indicated requirement. As with all engineering design problems, feasible solutions demand compromise to some degree. At times, it becomes necessary to settle for less than optimum resistance to abrasion in order to obtain maximum flexibility; the latter being a more important requirement for the given job. A typical example of this kind of trade-off would be in selecting a highly flexible rope on an overhead crane. Conversely, in a haulage installation, a rope with greater resistance to abrasion would be chosen despite the fact that such ropes are markedly less flexible. Two compelling factors that govern most decisions as to the selection of a wire rope are: abrasion resistance, and resistance to bending fatigue. Striking a proper balance with respect to these two important characteristics demands judgment of a very high order. A graphic presentation of just such comparison of qualities between the most widely used rope constructions and others is given by means of the X-chart (Fig. 34). Referring to this chart when selecting a rope, the mid-point (at the X) comes closest to an even balance between abrasion resistance and resistance to bending fatigue. Reading up or down along either leg of the X, the inverse relationship becomes more apparent as one quality increases and the other decreases. The term flexibility is frequently thought of as being synonymous with resistance to bending fatigue. This is not true. Flexibility refers to the capability of flexing or bending. While a high degree of fatigue resistance may sometimes accompany the flexibility characteristic, it does not necessarily follow that this is so. A fiber core rope, for example, is more flexible than an IWRC rope. Yet, when the IWRC rope is bent around undersize sheaves at relatively high loads, it will usually perform better than the more flexible fiber core rope. The reason for this lies in the ability of IWRC rope to retain its roundness and freedom of internal movement. Under the same conditions, a fiber core rope will flatten and inhibit free internal adjustment, thereby leading to early failure. As noted earlier, a design choice is almost invariably the result of compromise. Ultimately, what is sought is an efficient, economical solution, hence whatever the compromise, it must help achieve this goal.

BREAKING IN A NEW WIRE ROPE A new wire rope requires careful installation and close adherence to following all the appropriate procedures previously noted. After the rope has been installed and the ends secured in the correct manner, the mechanisms should be started carefully and then permitted to run through a cycle of operation at very slow speed. During this trial operation, a very close watch should be kept on all working parts-sheaves, drums, rollers-to make certain that the rope runs freely, and without any possible obstructions as it makes its way through the system. If no problems appear in running the rope, the next step should include several run-throughs of the normal operational cycle under light load and at reduced speed. This procedure allows the component parts of the new rope to make a gradual adjustment to the actual operating conditions. WIRE ROPE AND OPERATIONS INSPECTION It is essential to maintain a well-planned program of periodic inspection. Frequently, there are statutory and/or regulatory agencies whose requirements must be adhered to, but whether or not these exist in a given locale, the wire rope user can be guided by the suggested procedures that follow. Abrasion, bending and crushing represent the ABC's of wire rope abuse, and it is the primary goal of good inspection practice to discover such conditions early enough so that corrections can be made or ropes replaced safely and with minimum effort. When any sudden degradation indicates a loss of original rope strength, a decision must be made quickly as to allowing the rope to remain in service. But such a decision can only be made by an experienced inspector. And his determination will be based on: 1 ) Details of the equipment's operation, 2 ) Frequency of inspection, 3 ) Maintenance history, 4 ) Consequences of failure, 5 ) Historical records of similar equipment. To make certain that sufficient information is obtained, following are guidelines that should be adhered to. GUIDELINE TO INSPECTIONS AND REPORTS FOR EQUIPMENT, WIRE ROPE AND WIRE ROPE SLINGS 1 ) Maintain all inspection records and reports for the length of time deemed appropriate. 2) Prior to each daily use, the following procedure should be followed. a. Check all equipment functions. b. Lower load blocks and check hooks for deformation or cracks. c. During lowering procedure and the following raising cycle, observe the rope and the reeving. Particular notice should be paid to kinking, twisting or other deformities. Drumwinding conditions should also be noted. d. Check wire rope and slings for visual signs of anything that can cause them to be unsafe to use, i.e., broken wires, excessive wear, kinking or twisting, and marked corrosion. Particular attention should be given to any new damage during operation.

3 ) Periodic inspections consistent with applicable standards are recommended with a signed report by an authorized competent inspector. These Periodic Reports should include inspection of the following: a. All functional operating mechanisms for excessive wear of components, brake system parts and lubrication. b. Limit switches. c. Crane hooks for excess throat opening or twisting along with a visual for cracks. d. Wire rope and reeving for conditions causing possible removal. e. Wire rope slings for excessive wear, broken wires, kinking, twisting and mechanical abuse. f. All end connections such as hooks, shackles, turnbuckles, plate clamps, sockets, etc. for excessive wear, and distortion. 4 ) At least one annual inspection with signed report must be made for the following : a. Crane hook for cracks. b. Hoist drum for wear or cracks. c. Structural members for cracks, corrosion and distortion. d. For loose structural connections such as bolts, rivets, and weldments.

WIRE ROPE INSPECTION The following is a fairly comprehensive listing of critical inspection factors. It is not, however, presented as a substitute for an experienced inspector. It is rather a user's guide to the accepted standards by which ropes must be judged. 1) Abrasion Rope abrades when it moves through an abrasive medium or over drums and sheaves. Most standards require that rope is to be removed if the outer wire wear exceeds ?43 of the original outer wire diameter. This is not easy to determine and discovery relies upon the experience gained by the inspector in measuring wire diameters of discarded ropes. 2 ) Rope stretch All ropes will stretch when loads are initially applied. For an extended discussion of stretch, see pp. 73 and following. As a rope degrades from wear, fatigue, etc. (excluding accidental damage), continued application of a load of constant magnitude will produce varying amounts of rope stretch. A "stretch" curve plotted for stretch vs. time (Fig. 35) displays three distinct phases: Phase 1. Initial stretch, during the early (beginning) period of rope service, caused by the rope adjustments to operating conditions (constructional stretch). Phase 2. Following break-in, there is a long period-the greatest part of the rope's service life-during which a slight increase in stretch takes place over an extended time. This results from normal wear, fatigue, etc. On the plotted curve-stretch vs. time-this portion would almost be a horizontal straight line inclined slightly upward from its initial level. Phase 3. Thereafter, the stretch occurs at a quicker rate. This means that the rope has reached the point of rapid degradation; a result of prolonged

Figure 35. This curve is plotted to show the relationship of wire rope stretch to the various stages of a rope's life.

I

i

subjection to abrasive wear, fatigue, etc. This second upturn of the curve is a warning indicating that the rope should soon be removed. 3 ) Reduction in rope diameter Any marked reduction in rope diameter indicates degradation. Such reduction may be attributed to : excessive external abrasion internal or external corrosion loosening or tightening of rope lay inner wire breakage rope stretch ironing or milking of strands In the past, whether or not a rope was allowed to remain in service depended to a great extent on the rope's diameter at the time of inspection. Currently this practice has undergone significant modification. Previously, a decrease in the rope's diameter was compared with published standards of minimum diameters. The amount of change in diameter is, of course, useful in assessing a rope's condition. But, comparing this figure with a fixed set of values can be misleading. These long-accepted minimums are not, in themselves, of any serious significance since they do not take into account such factors as : 1) variations in compressibility between IWRC and Fiber Core; 2) differences in the amount of reduction in diameter from abrasive wear, or from core compression, or a combination of both; and 3 ) the actual original diameter of the rope rather than its nominal value. As a matter of fact, all ropes will show a significant reduction in diameter when a load is applied. Therefore, a rope manufactured close to its nominal size may, when it is subjected to loading, be reduced to a smaller diameter than that stipulated in the minimum diameter table. Yet, under these

J

r

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1

1i {

i

i 1i

I

I 2

!

, %

' i i

f I

a I

circumstances, the rope would be declared unsafe although it may, in actuality, be safe. As an example of the possible error at the other extreme, we can take the case of a rope manufactured near the upper limits of allowable size. If the diameter has reached a reduction to nominal or slightly below that, the tables would show this rope to be safe. But it should, perhaps, be removed. Today, evaluations of the rope diameter are first predicated on a comparison of the original diameter-when new and subjected to a known load-with the current reading under like circumstances. Periodically, throughout the life of the rope, the actual diameter should be recorded when the rope is under equivalent loading and in the same operating section. This procedure, if followed carefully, reveals a common rope characteristic : after an initial reduction, the diameter soon stabilizes. Later, there will be a continuous, albeit small, decrease in diameter throughout its life. Core deterioration, when it occurs, is revealed by a more rapid reduction in diameter and when observed it is time for removal. Deciding whether or not a rope is safe is not always a simple matter. A number of different but interrelated conditions must be evaluated. It would be dangerously unwise for an inspector to declare a rope safe for continued service simply because its diameter had not reached the minimum arbitrarily established in a table if, at the same time, other observations lead to an opposite conclusion. Because criteria for removal are varied, and because diameter, in itself, is a vague criterion, the table of minimum diameters has been deliberately omitted from this manual. 4 ) Corrosion Corrosion, while difficult to evaluate, is a more serious cause of degradation than abrasion. Usually, it signifies a lack of lubrication. Corrosion will often occur internally before there is any visible external evidence on the rope surface. Pitting of wires is a cause for immediate rope removal. Not only does it attack the metal wires, but it also prevents the rope's component parts from moving smoothly as it is flexed. Usually, a slight discoloration because of rusting merely indicates a need for lubrication. Severe rusting, on the other hand, leads to premature fatigue failures in the wires necessitating the rope's immediate removal from service. When a rope shows more than one wire failure adjacent to a terminal fitting, it should be removed immediately. To retard corrosive deterioration, the rope should be kept well lubricated. In situations where extreme corrosive action can occur, it may be necessary to use galvanized wire rope. 5 ) Kinks Kinks are permanent distortions caused by loops drawn too tightly. Ropes with kinks must be removed from service. 6 ) "Bird Caging" Bird caging results from torsional imbalance that comes about because of mistreatments such as sudden stops, the rope being pulled through tight sheaves, or wound on too small a drum. This is cause for rope replacement unless the affected section can be removed.

'

7 ) Localized Conditions Particular attention must be paid to wear at the equalizing sheaves. During normal operations this wear is not visible. Excessive vibration, or whip can cause abrasion and/or fatigue. Drum cross-over and flange point areas must be carefully evaluated. All end fittings, including splices, should be examined for worn or broken wires, loose or damaged strands, cracked fittings, worn or distorted thimbles and tucks of strands. 8 ) Heat Damage After a fire, or the presence of elevated temperatures, there may be metal discoloration, or an apparent loss of internal lubrication; fiber core ropes are particularly vulnerable. Under these circumstances the rope should be replaced. 9 ) Protruding Core If, for any cause, the rope core protrudes from an opening between the strands the rope is unfit for service and should be removed. 10) Damaged End Attachments Cracked, bent, or broken end fittings must be eliminated. The cause should be sought out and corrected. In the case of bent hooks, the throat openings -measured at the narrowest point-should not exceed 15% over normal nor should twisting be greater than 10" . 11) Peening Continuous pounding is one of the causes of peening. The rope strikes against an object such as some structural part of the machine, or it beats against a roller, or it hits itself. Often, this can be avoided by placing protectors between the rope and the object it is striking. Another common cause of peening is continuous working-under high loads--over a sheave or drum. Where peening action cannot be controlled, it is necessary to have more frequent inspections and to be ready for earlier rope replacement. Figure 36 shows the external appearance of two ropes, one of which has been abraded and the other peened. Also shown are the cross-sections of wires in both conditions. 12) Scrubbing Scrubbing refers to the displacement of wires and strands as a result of rubbing against itself or another object. This, in turn, causes wear and displacement of wires and strands along one side of the rope. Corrective measures should be taken as soon as this condition is observed. 13 ) Fatigue Fracture Wires that break with square ends and show little surface wear, have usually failed as a result of fatigue. Such fractures can occur on the crown of the strands, or in the valleys between the strands where adjacent strand contact exists. In almost all cases, these failures are related to bending stresses or vibration. If diameter of the sheaves, rollers or drum cannot be increased, a more flexible rope should be used. But, if the rope in use is already of maximum flexibility, the only remaining course that will help prolong its service life is to move the rope through the system by cutting off the dead end. By moving

Figure 36. These plan views and cross-sections show the effects of abrasion and peening on wire rope. Note that a crack has formed as a result of heavy peening.

abrasion

the rope through the system, the fatigued sections are moved to less fatiguing areas of the reeving. 14 Broken Wires The number of broken wires on the outside of a wire rope are an index of 1 ) its general condition, and 2) whether or not it must be considered for replacement. Frequent inspection will help determine the elapsed time between breaks. Ropes should be replaced as soon as the wire breakage reaches the numbers given in Table 13. Such action must be taken without regard to the type of fracture. 1 5 ) Electric Arc Rope that has either been in contact with a live power line or been used as "ground in an electric welding circuit, will have wires that are fused, discolored and/or annealed, and must be removed. On occasion, a single wire will break shortly after installation. However, if 110 other wires break at that time, there is no need for concern. On the other hand, should more wires break, the cause should be carefully investigated. On any application, valley breaks-i.e., where the wire fractures between strands-should be given serious attention. When two or more such fractures are found, the rope should be replaced immediately. (Note, however, that no valley breaks are permitted in elevator ropes.) It is well to remember that once broken wires appear-in a rope operating under normal conditions-a good many more will show up within a relatively short period. Attempting to squeeze the last measure of service from a rope beyond the allowable number of broken wires (Table 1 3 ) , will create an intolerably hazardous situation. A diagnostic guide to some of the most prevalent rope abuses is given in Table 14. On the following pages these abuses are illustrated and described.

TABLE 13 WHEN TO REPLACE WIRE ROPE--BASED ON NUMBER OF BROKEN WIRES Number Broken Wires In Running Ropes ANSI* Standard

In One Rope Lay

Equipment

In One Strand

Number Broken Wires In Standing Ropes In One Rope Lay

At End Connection

Not Specified

Overhead & Gantry Cranes

B30.4

Portal, Tower & Pillar Cranes

6

3

3

2

B30.5

Crawler, Locomotive & Truck Cranes

6

3

3

2

B30.6

Derricks

6

3

3

2

B30.7

Base Mounted Drum Hoists

6

3

3

2

B30.8

Floating Cranes & Derricks

6

3

3

2

B30.16

Overhead Hoists

A10.4

Personnel Hoists

6**

3

A10.5

Material Hoists

6**

Not Specified

Not Specified 2**

2 Not Specified

"American National Standards Institute **Also remove for 1 valley break

Figure 37. A wire broken under a tensile load that exceeds its strength is recognized by the "cup and cone" configuration at the fracture point (a). The necking down of the wire at this point shows that failure occurred while the wire retained its ductility. Shear-tensile fracture (b) occurs in wire subjected to a combination of transverse and axial loads. Fatigue breaks are usually characterized by squared-off ends perpendicular to the wire either straight across or Z-shaped (c & d).

TABLE 14 DIAGNOSTIC GUIDE TO COMMON WIRE ROPE DEGRADATION Mode

1

Symptoms

Possible Causes

Fatigue

Wire break is transverse--either straight across or Z shape. Broken ends will appear grainy.

Check for rope bent around too small a radius; vibration or whipping; wobbly sheaves; rollers too small; reverse bends; bent shafts; tight grooves; corrosion; small drums & sheaves; incorrect rope construction; improper installation; poor end terminations. (In the absence of other modes of degradation, all rope will eventually fail in fatigue. )

Tension

Wire break reveals a mixture of cup and cone fracture and shear breaks.

Check for overloads; sticky, grabby clutches; jerky conditions; loose bearing on drum; fast starts, fast stops, broken sheave flange; wrong rope size & grade; poor end terminations. Check for too great a strain on rope after factors of degradation have weakened it.

Abrasion

Wire break mainly displays outer wires worn smooth to knife edge thinness. Wire broken by abrasion in combination with another factor will show a combination break.

Check for change in rope or sheave size; change in load; overburden change; frozen or stuck sheaves; soft rollers, sheaves or drums; excessive fleet angle; misalignment of sheaves; kinks; improperly attached fittings; grit & sand; objects imbedded in rope; improper grooving.

Abrasion plus Fatigue

Reduced cross-section is broken off square thereby producing a chisel shape.

A long term condition normal to the operating process.

Abrasion plus Tension

Reduced cross-section is necked down as in a cup and cone configuration. Tensile break produces a chisel shape.

A long term condition normal to the operating process.

Cut or Gouged or Rough Wire

Wire ends are pinched down, mashed and/or cut in a rough diagonal shear-like manner.

Check on all the above conditions for mechanical abuse, or either abnormal or accidental forces during installation.

Torsion or Twisting

Wire ends show evidence of twist and/or cork-screw effect.

Check on all the above conditions for mechanical abuse, or either abnormal or accidental forces during installation.

Mashing

Wires are flattened and spread at broken ends.

Check on all the above conditions for mechanical abuse, or either abnormal or accidental forces during installation. (This is a common occurrence on the drum.)

Corrosion

Wire surfaces are pitted with break showing evidence either of fatigue tension or abrasion.

Indicates improper lubrication or storage, or a corrosive environment.

-

Figure 38A. An outer strand (top) from a 19 x 7 rope shows nicking that occurs between adjacent strands as well as between strands and the inner rope (bottom). Similar nicking patterns occur in other ropes with an IWRC.

Figure 38B. A single strand removed trom a wire rope subjected to strand nicking. Resulting from adjacent strands rubbing against one another, this condition is usually caused by core failure resulting from continued operation of the rope under high tensile load. Ultimately, there will be individual wire breaks in the valleys of the strands.

Figure 39A. A tightly spiralled pig-tailed rope; this condition is a result of the rope being pulled around an object that has a small diameter.

Figure 39B. Drum crushing and spiralling in a winch line. This is caused by the small drums, high loads, and multiple layer winding conditions frequently found on winches.

Figure 40. When a reel has been damaged in transit, it is a safe assumption that there can be irreparable damage to the rope.

Figure 41. Wire rope abuses during shipment create serious problems. One of the more common causes is improper fastening of rope end to reel, e.g., nailing through the rope end. These photos show two acceptable methods: a ) one end of a wire "noose" holds the rope, and the other end is secured to the reel; and b) the rope end is held in place by a J-bolt or U-bolt that can be fixed to a reel.

Figure 42. Wire rope with a high strand. In this condition, one or two strands are worn before adjoining strands. This is caused by improper socketing or seizing, kinks or dog legs. The top illustration ( a ) is a close view of the concentration of wear, the lower ( b ) shows how this recurs in every sixth strand (in a six-strand rope).

Figure 43. This rope was damaged on the reel while being rolled over a sharp object.

Figure 44. These rope damages-the result of bad drum winding-are referred to as: a ) layer-to-layer crushing, b ) scrubbing at cross-over or flange turnback, and c) layer-to-layer crushing.

Figure 45. In this rope, subjected to drum crushing, the individual wires are distorted and displaced from their normal position. Uwally, this is caused by the rope scrubbing on itself.

i I

' ! 1 3

Figure 46. A deeply corrugated sheave.

I

Figure 47. This rope condition is called a dog leg.

63

The following conditions (Figs. 48 and 49) can be caused by a sudden release of tension and the resulting rebound of the rope from its overloaded condition. The strands and wires will not return to their original position. These conditions can also result from the rope operating through a tight groove.

--

Figure 48. An occurrence that is called a popped core.

Figure 49. This condition is called a bird cage and is caused by a sudden release of tension and the resulting rebound of the rope from its overloaded condition. The strands and wires will not return to their original positions.

Figure 50. Here the strand wires were snagged and gouged.

Figure 51. This is an example of a wire rope that has jumped a sheave. The deformation is in the shape of a curl-as if it had been bent around a circular shaft. On close examination, the wires show two types of breaks-the normal tensile cup and cone and the shear break which appear as having been cut with a cold chisel on an angle (see Fig. 37).

Figure 52. This is the appearance of a typical tension break; a result of overloading.

65

Figure 53. Here, the rope was subjected to repeated bending over sheaves while under normal loads. Fatigue breaks in the individual wires was the result; these breaks are square and are usually on the crown of the strand.

Figure 54. An example of fatigue fractures in a wire rope that was subjected to heavy loads while over small sheaves. The usual crown breaks are here accompanied by breaks in the valleys between the strands; the latter breaks are caused by strand nicking-a result of the heavy loads.

Figure 55. A typical example of localized wear. The development of this condition might be reduced if suitable cut-off practice is employed.

ROPE INSPECTION SUMMARY Any wire rope that has broken wires, deformed strands, variations in diameter, or any change from its normal appearance, must be considered for replacement. It is always better to replace a rope when there is any doubt concerning its condition or its ability to perform the required task. The cost of wire rope replacement is quite insignificant when considered in terms of human injuries, the cost of down time, or the cost of replacing broken structures. Wire rope inspection includes examination of basic items such as: 1) Rope diameter reduction 2 ) Rope lay 3) External wear 4 ) Internal wear 5 ) Peening 6 ) Scrubbing 7 ) Corrosion 8) Broken wires Some wire rope sections can break up without any visible warning. Sections where this occurs are usually found at end terminations, and at points where the rope enters or leaves the sheave of boom hoists, suspension systems, or other semi-operational systems. Because of the "working" that takes place at those sections, neither appreciable external wear nor crown breaks will appear. Under such conditions the core fails thereby allowing adjacent strand nicking. When this happens, valley breaks appear. As soon as the first valley break is detected at the end termination, or two valley breaks are found elsewhere, the rope should be removed. If preventive maintenance is performed diligently, rope life can be prolonged. Cutting off an appropriate length of rope at the end termination before the core degrades and valley breaks appear, minimizes degradation at these sections. EQUIPMENT INSPECTION Any undetected fault on a sheave, roller, or drum-be it of relatively major or minor signscance-can cause a rope to wear out many times faster than the wear resulting from normal operations. As a positive means of minimizing abuses and other-than-normal wear, the procedures here set forth should be adhered to. Every observation and measurement should be carefully recorded and kept in some suitable and accessible file. 1) Give close examination to the method by which the rope is attached both to the drum and to the load. Make certain that the proper type of attachment is applied correctly, and that any safety devices in use are in satisfactory working order.

2 ) Carefully check the groove and working surface of every sheave, roller, and drum, to determine whether each (groove and surface) is as near to the correct diameter and contour as circumstances will permit, and whether all surfaces that are in contact with the rope are smooth and free of corrugations or other abrasive defects. 3) Check sheaves and rollers to determine whether each turns freely, and whether they are properly aligned with the travel of the rope. All bearings must be in good operating condition and furnish adequate support to the sheaves and rollers. Sheaves that are permitted to wobble will create additional forces that accelerate the degradation of the rope. 4) If starter, filler, and riser strips on drums are used, check their condition and location. Should these be worn, improperly located or badly designed, they will cause poor winding, dog legs, and other rope damage. 5) Wherever possible, follow the path that the rope will follow through a complete operating cycle. Be on the lookout for spots on the equipment that have been worn bright or cut into by the rope as it moves through the system. Ordinarily, excessive abrasive wear on the rope can be eliminated at these points by means of some type of protector or roller.

FIELD LUBRICATION During fabrication, ropes receive lubrication; the kind and amount depending on the rope's size, type, and use, if known. This in-process treatment will provide the finished rope with ample protection for a reasonable time if it is stored under proper conditions. But, when the rope is put into service, the initial lubrication will normally be less than needed for the full useful life of the rope. Because of this, periodic applications of a suitable rope lubricant are necessary. Following, are the important characteristics of a good wire rope lubricant: 1) It should be free from acids and alkalis, 2 ) It should have sufficient adhesive strength to remain on the ropes, 3 ) It should be of a viscosity capable of penetrating the interstices between wires and strands, 4) It should not be soluble in the medium surrounding it under the actual operating conditions, 5) It should have a high film strength, and 6) It should resist oxidation.

Before applying lubrication, accumulations of dirt or other abrasive material should be removed from the rope. Cleaning is accomplished with a stiff wire brush dipped in solvent, compressed air or live steam. Immediately after it is cleaned, the rope should be lubricated. When it is normal for the rope to operate in dirt, rock or other abrasive material, the lubricant should be selected with great care to make certain that it will penetrate and, at the same time, will not pick up any of the material through which the rope must be dragged. As a general rule, the most efficient and most economical means to do field lubrication/protection is by using some method or system that continuously applies the lubricant while the rope is in operation. Many techniques are used; these include the continuous bath, dripping, pouring, swabbing, painting, or where circumstances dictate, automatic systems can be used to apply lubricants either by a drip or pressure spray method (Fig. 56).

PAINTING

CONTINUOUS BATH

'

DRIPPING

1

SWABBING SPRAY NOZZLE

Figure 56. Methods of lubricant application in general use at present, include continuous bath, dripping, pouring, swabbing, painting, and spraying. When the rope is bent, the lubricant will penetrate much easier. Arrows indicate the direction of the rope's movement.

WIRE ROPE EFFICIENCY OVER SHEAVES (TACKLE BLOCK SYSTEM) Some portion of a wire rope's strength-when operating over sheaves-is expended in turning the sheaves and in flexing. This lost strength is not available to lift the load, and in a multi-part tackle block system (Fig. 57) this loss factor can be significant. The load on the lead line (fast line) under static (no-movement) conditions can be readily calculated if the load is divided by the number of parts of line as expressed in the following formula: Total load (incl. slings, containers, etc. ) Fast line load = No. of parts of line For example, in a four-part system (Fig. 57d) to lift 6000 lb, the lead line load will equal:

1

A.

ONE-PART LINE

6. TWO-PART LINE

C.

THREE- PART LINE

D. FOUR-PART LINE

E. FIVE-PART LINE

I

Figure 57. Commonly used single- and multiple-sheave blocks (tackles). Static loading on the of the supported load. rope is: A) equal to, B) M of, C) 1/3 of, D) 1/4 of, and E)

Moreover, if this system has ball or roller bearings in the sheaves, the lead line load will increase to 1651 lb when the load starts to move. On the other hand, if the sheaves have plain bearings such as bronze bushings, the lead line load will increase to 185 1 lb. In an 8-part system with plain bearings, the lead line load jumps from 750 lb to 1086 lb--an increase of 45 % ! Derricks often use 8 or more parts in the boom support system. The schematic diagram (Fig. 58) shows 4-part reeving. This system has the same number of sheaves as there are parts of line. The following procedure presumes this condition throughout. Provision for extra lead sheaves are given at the end of this discussion. To calculate the lead-line load, the combined load of the container, contents and lifting attachments is multiplied by the lead line factor as follows: Lead line load = lead-line factor x load Figure 58. Schematic representation of a four-part reeving system. N= the number of parts of line supporting the load (W), and S=the number of rotating sheaves.

TABLE 15 Parts of Line

LEAD-LINE FACTORS'' With Plain Bearing Sheaves

*In using this table, the user should note that it is based on the assumption that the number of parts of line ( N ) is equal to the number of sheaves (S). When S exceeds N, refer to the text.

With Roller Bearing Sheaves

Figure 59. Schematic representation of a 4-part reeving system with an extra (idler) sheave.

Fig. 59 shows a similar 4-part system with an additional lead-in sheave. In such cases, for each additional sheave the tabulated value is multiplied by 1.09 for plain bearings, or 1.04 for anti-friction bearings. Example: What is the lead-line factor for a piain bearing tackle block system of 5 parts of line and two extra lead-in sheaves? The tabulated value is .257. Since there are two additional sheaves, the computation is: .257 x 1.09 x 1.09 = .305 What is the lead-line load on this system when the load is 5000 lbs? 5000 x .305 = 1525 lb It should be emphasized that the "dead-end" may also be subjected to this augmented load. Systems in which both rope ends are attached to a drum such as may be found in overhead cranes are not within the scope of this discussion. It is suggested, therefore, that information on such systems be obtained directly from a wire rope manufacturer.

6 Physical Properties ELASTIC PROPERTIES OF WIRE ROPE The following discussion relates to conventional 6- or %strand ropes that have either fiber or steel cores; it is not applicable to rotation-resistant ropes since these constitute a separate case. Wire rope is an elastic member; it stretches or elongates under load. This stretch derives from two sources: 1) constructional, and 2 ) elastic. In actuality, there may be a third source of stretch-a result of the rope rotating on its own axis. Such elongation, which may occur either as a result of using a swivel, or from the effect of a free-turning load, is brought about by the unlaying of the rope strands. Because the third source is a subject that is beyond the scope of this publication, discussion will be directed to constructional and elastic stretch. CONSTRUCTIONAL STRETCH When a load is applied to wire rope, the helically-laid wires and strands act in a constricting manner thereby compressing the core and bringing all the rope elements into closer contact. The result is a slight reduction in diameter and an accompanying lengthening of the rope. Constructional stretch is influenced by the following factors: 1) type of core (fiber or steel), 2 ) rope construction (6 x 7 , 6 x 25 FW, 6 x 41 WS, 8 x 19 S, etc.), 3 ) length of lay, 4 ) material. Ropes with wire strand core (WSC) or independent wire rope core (IWRC) have less constructional stretch than those with fiber core (FC) . The reason for this is the fact that the steel cannot compress as much as the fiber core. Usually, constructional stretch will cease at an early stage in the rope's life. However, some fiber core ropes, if lightly loaded (as in the case of elevator ropes), may display a degree of constructional stretch over a considerable portion of their life. A definite value for determining constructional stretch cannot be assigned since it is influenced by several factors. The following table gives some idea of the approximate stretch as a percentage of rope under load. Rope Construction

6 strand FC 6 strand IWRC 8 strand FC

Approximate Stretch* Y2%-%% %%-Y2% %i%1%

*Varies with the magnitude of the loading.

73

ELASTIC STRETCH Elastic stretch results from recoverable deformation of the metal itself. Here, again, a quantity cannot be precisely calculated. However, the following equation can provide a reasonable approximation for a good many situations. Changes in length (ft) =

Change in load (Ib) x Length (ft) Area (inches2) x Modulus of Elasticity (psi)

The modulus of elasticity is given in Table 16, and the area can be found in Table 17.

TABLE 16 APPROXIMATE MODULUS OF ELASTICITY (Pounds per square inch) Zero through 20 % Loading

Rope Classification

21 % to 65 % Loading

--

6 x 7 with fiber core 6 x 19 with fiber core 6 x 37 with fiber core 8 x 19 with fiber core 6 x 19 with IWRC 6 x 37 with IWRC

11,700,000 10,800,000 9,900,000 8,100,000 13,500,000 12,600,000

"Applicable to new rope, i.e., not previously loaded.

EXAMPLE: How much elastic stretch may occur in 200 ft of 1/2 -inch 6 x 25 FW IPS FC rope when loaded to 20% of its nominal strength? Nominal strength = 10.7 tons (2 1,400 lb) 20% of which = 4,280 lb Area of 1/2 -inch is found by squaring the diameter and multiplying it by the area of 1-inch rope given in Table 17 under the "Fiber Core" heading and opposite6x25 FW,i.e., 1/2 x 342 x .417 = .104. The modulus of elasticity is found in Table 16 opposite the 6 x 19 fiber core (because 6 x 25 FW is a member of this class) and under the "Zero through 20% Loading." Substituting these values, the equation reads as follows: Change in length =

4280 x 200 -104 x 10,800,000

= .76 ft (9.1 inches) A word of caution concerning the use of Table 16: the higher modulus given under the "21 % to 65 % Loading" is based on the assumption that both the initial and the final load fall within this range. If the above example were restated to the effect that the load was 35 % (or 7,490 lb) of the nominal strength, it would be incorrect to rework the problem simply by making two substitutions: the new load and the higher modulus of 12,000,000 psi. To do so would ignore the greater stretch that occurs at the lower modulus during the initial loading.

TABLE 17 APPROXIMATE METALLIC AREAS OF ONE-INCH ROPE OF VARIOUS CONSTRUCTIONS*

*Values given are based on 3% oversize because this is a common design "target." But, this figure often varies and is not to be considered a standard. Wire sizes in specific constructions also vary, thus the given values are approximate. They are, however, within the range of accuracy of the entire method that is, in itself, approximate.

Construction

Fiber Core

IWRC or WSC

6x33FW 6x36WS 6~3718/19W 6x37FW 6 x 41 SFW

.423 .419 .393 .427 .425

.490 .485 .459 .493 .49 1

6 x 4 1 WS 6 x 42 Tiller 6 x 43 FWS 6 x 46 SFW 6x46WS

.424 .231 .392 .425 .426

.490

6 x 61 FWS 7x7 7 x 19 12/7 7xl9W 8x7

.408

.343

Cable Laid

.458 .492 .492 .474 .471 .466 SO5 .474

As indicated, it is necessary to know the rope area in order to solve the previously given stretch equation. For diameters other than I inch, multiply the area given in this table by the square of the nominal rope diameter. Example: To find the area of 1/2" 6 x 36 WS IWRC From the table: .485 Diameter squared: (1/2)2=% or .5 x .5 = .25 Multiply table value by diameter squared: Area: =.25 x .485 = .12 1 inches2 Example: To find the area of 1%" 6 x 25 FW FC Answer: (1.25)2 x .417= 1.563 x .417= .652 inches2

75

In this instance, the problem would be worked out in two parts: the first follows the above equation, and, in the second part, the load starts at 4,280 Ib and ends at 7,490 Ib, and 12,000,000 psi is used as the modulus. Thus: Change in length =

(7,490-4,280) 200'76 = -52 ft (6.2 inches) .lo4 x 12,000,000

To this figure, the previously determined 9.1 inches must be added. Hence, total stretch of this rope at 35 % of its nominal strength would be approximately : Constructional stretch ( % % ) * : .0075 x 200 = 1.5 ft (18 inches) Elastic stretch : @ 0 through 20% = .76 ft (9.1 inches) @ 21%-35% = .52 ft (6.2 inches) TOTAL STRETCH = 2.78 ft ( 33.3 inches) As noted earlier, this analysis is predicated on the assumption that the rope in question is new-not having been previously loaded-and is free from rust or other corrosion. Where it is necessary to have precise data on elastic characteristics, a load vs. elongation test must be performed on a representative sample of the rope under consideration. *The higher figure of % % is used here because of the heavy (35% ) load.

170 1 60

150 140 W

130

5 120 -

I10

2 I00 W

90 W

1

80

3

70

I-

W

a 60 50 40

30 20

Figure 60. This graph is called the Relative Service Life Curve. It relates the service life to operating loads. A design factor of 5 is chosen most frequently.

10 0

I

2

3

4

5 6 DESIGN FACTOR

7

8

9

For certain applications, ropes may be pre-stretched in order to remove some of the constructional stretch. Frequently, this treatment is used on structural members such as bridge rope and strand. In some cases, pre-stretching is applied to operating ropes where elongation may present problems, e.g., elevator and skip hoist ropes. While a pre-stretching technique has value, some of the benefit is lost in reeling and handling.

DESIGN FACTORS The design f a t o r is defined as the ratio of the nominal strength of a wire rope to the total load it is expected to carry. Hence, the design factor that is selected plays an important part in determining the rope's service life. Excessive loading, whether continuous or sporadic, will greatly impair its serviceability. Usually, the choice of a certain wire rope size and grade will be based on static loading and, under static conditions, it is sufficient for its task. However, where a machine is working and dynamic loads are added to the static load, it is quite possible to exceed the material's elastic limit. As was noted in the earlier discussion, a "common" design factor is 5. Figure 60, the Wire Rope Relative Service Life Curve, shows how the service life is reduced as operating loads are increased. A change in the design fccctor from 5 to 3 decreases its life expectancy index from 100 to 60-a drop of 40% ! BREAKING STRENGTHS The breaking strength is the ultimate load registered on a wire rope sample during a tension test. The nominal strengths given (Tables 18 through 36), have been calculated by a standardized, industry-accepted procedure, and manufacturers design wire rope to these strengths. When making design calculations, it should be noted that the given figures are the static strengths. All discussion of strength is predicated on the assumption of there being a gradually applied load that will not exceed one inch per minute. Designers should base their calculations on these strengths. A minimum acceptance strength, 2% % lower than the published nominal breaking strengths, was established as the industry tolerance. It serves to offset variables that occur during the sample preparation and actual physical test of a wire rope. This tolerance is used in the basic wire rope governmental specifications. Wire rope testi~g,whether it is performed for the purpose of determining grade or for adherence to specifications, requires the sample to be tested to comply with certain standards. For example: the sample's length must not be less than 3 ft (0.91 m) between sockets for ropes with diameters of from I/s inch (3.2 mm) through 3 inches (77 mm) ; on ropes with larger (over 3 inches) diameters, the clear length must be at least 20 times the rope diameter. The test is considered valid only if failure occurs 2 inches (51 mm) or more from either of the sockets, or from the holding mechanism.

TABLE 18 NOMINAL STRENGTHS OF WIRE ROPE 6 x 7 Classification/Bright (Uncoated), Fiber Core Nominal Diameter

Approximate Mass

Nominal Strength* Improved Plow Steel**

inches

mm

lb/ft

kg/m

tons

metric tonnes

*To convert to Kilonewtons (kN),multiply tons (nominal strength) by 8.896; 1 Ib = 4.448 newtons (N) . **Available with galvanized wires at strengths 10% lower than listed, or at equivalent strengths on special request.

TABLE 19 NOMINAL STRENGTHS OF WIRE ROPE 6 x 7 Classification/Bright (Uncoated), IWRC Nominal Diameter

Approximate Mass

Nominal Strength* Improved Plow Steel**

inches

mm

lb/ft

kg/m

tons

metric tonnes

*To convert to Kilonewtons (kN),multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N) . **Available with galvanized wires at strengths 10% lower than listed, or at equivalent strengths on special request.

TABLE 20 NOMINAL STRENGTHS OF WIRE ROPE 6 x 19 Classification/Bright (Uncoated), Fiber Core Nominal Diameter

Approximate Mass

Nominal Strength* Improved Plow Steel**

inches

mm

lb/ft

kg/m

tons

metric tonnes

*To convert to Kilonewtons (kN), multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N) . **Available with galvanized wires at strengths 10% lower than listed, or at equivalent strengths on special request.

TABLE 21 NOMINAL STRENGTHS OF WIRE ROPE 6 x 19 Classification/Bright (Uncoated), IWRC Nominal Diameter

Approximate Mass

Nominal Strength* Improved Plow Steel**

inches

mm

lb/ft

kg/m

tons

metric tonnes

Extra Imp. Plow Steel** tons

*To convert to Kilonewtons (kN), multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N). **Available with galvanized wires at strengths 10% lower than listed, or at equivalent strengths on special request.

metric tonnes

TABLE 22 NOMINAL STRENGTHS OF WIRE ROPE 6 x 37 ClassificationIBright (Uncoated), Fiber Core Nominal Strength*

*To convert to Kilonewtons (kN) ,multiply tons (nominal strength) by 8.896; 1 Ib= 4.448 newtons (N). **Available with galvanized wires at strengths 10% lower than listed, or at equivalent strengths on special request. Note: For four of the listed diameters, Vt" through 7/1(3" with two-operation strands, the given nominal strengths will be reduced b y approximately 5%%.

Nominal Diameter

Approximate Mass

inches

lb/ft

mm

kg/m

Improved Plow Steel** tons

metric tonnes

TABLE 23 NOMINAL STRENGTHS OF WIRE ROPE 6 x 37 Classification/Bright (Uncoated), IWRC

Nominal Diameter inches

- -

*To convert to Kilonewtons (kN), multiply tons (nominal strength) by 8.896; 1 lb= 4.448 newtons (N). **Available with galvanized wires at strengths 10% lower than listed, or at equivalent strengths on special request. Note: For four of the listed diameters, 92" through 7/16" with two-operation strands, the given nominal strengths will be reduced by approximately 595%.

mm

Approximate Mass lb/ft

kg/m

Nominal Strength* Improved Extra Imp. Plow Steel** Plow Steel** metric metric tons tonnes tons tonnes

-

2% 2% 2% 2% ---2% 3 3% 3% 3% 3112 3% 3%

86 90 96 103

21.0 22.7 24.3 26.0

31.3 33.8 36.2 38.7

459 491 523 557

416 445 458 505

529 564 602 641

480 512 528 58 1

TABLE 24 NOMINAL STRENGTHS OF WIRE ROPE 6 x 61 Classification/Bright (Uncoated), Fiber Core Nominal Strength* Nominal Diameter inches

mm

Approximate Mass lb/ft

kg/m

Improved Plow Steel tons

metric tonnes

*To convert to Kilonewtons (kN), multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons ( N ) .

TABLE 25 NOMINAL STRENGTHS OF WIRE ROPE 6 x 61 Classification/Bright (Uncoated), IWRC Nominal Strength*

Nominal Diameter inches

mm

Approximate Mass lb/ft

kg/m

Improved Plow Steel

tons

metric tonnes

Extra Imp. Plow Steel

tons

*To convert to Kilonewtons (kN),multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N)

.

metric tonnes

TABLE 26 NOMINAL STRENGTHS OF WIRE ROPE 6 x 91 Classification/Bright (Uncoated), Fiber Core Nominal Strength* Nominal Diameter

Approximate Mass

Improved Plow Steel

inches

mm

lb/ft

kg/m

tons

metric tonnes

2 2 1/8 2% 2948

51 54 57 61

6.77 7.59 8.51 9.48

10.1 11.3 12.7 14.1

146 164 183 203

132 149 166 184

*To convert to Kilonewtons ( k N ) , multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N) .

TABLE 27 NOMINAL STRENGTHS OF WIRE ROPE 6 x 91 ClassificationIBright (Uncoated), IWRC Nominal Strength*

Nominal Diameter inches

mm

Approximate Mass lb/ft

kg/m

Improved Plow Steel

tons

metric tonnes

Extra Imp. Plow Steel

tons

*To convert to Kilonewtons (kN), multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N).

metric tonnes

TABLE 28 NOMINAL STRENGTHS OF WIRE ROPE 6 x 25B, 6 x 27H & 6 x 3 0 6 Flattened StrandIBright (Uncoated), Fiber Core

Nominal Strength * Nominal Diameter inches

mm

Approximate Mass lb/ft

kg/m

Improved Plow Steel tons

metric tonnes

*To convert to Kilonewtons (kN),multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N) .

TABLE 29 NOMINAL STRENGTHS OF WIRE ROPE 6 x 25B, 6 x 27H & 6 x 306 Flattened StrandIBright (Uncoated), IWRC Nominal Strength*

Nominal Diameter inches % 94s s/s

%

Approximate Mass

mm

lb/ft

13 14.5 16 19

0.47 0.60 0.73 1.06

kg/m 0.70 0.89 1.09 1.58

Improved Plow Steel

Extra Imp. Plow Steel

tons

metric tonnes

tons

metric tonnes

12.6 16.0 19.6 28.1

11.4 14.5 17.8 25.5

14 17.6 21.7 31

12.7 16 19.7 28.1

*To convert to Kilonewtons (kN), multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N) .

TABLE 30 NOMINAL STRENGTHS OF WIRE ROPE 8 x 19 Classification/Bright (Uncoated), Fiber Core Nominal Strength " Nominal Diameter inches

mm

Approximate Mass

Improved Plow Steel

lb/ft

tons

kg/m

metric tonnes

*To convert to Kilonewtons (kN), multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N) .

TABLE 31 NOMINAL STRENGTHS OF WIRE ROPE 8 x 19 Classification/Rotation Resistant/Bright (Uncoated), IWRC Nominal Strength* Nominal Diameter inchesmm

Approximate Mass Ib/ft

kg/m

Improved Plow Steel

tons

metric tonnes

Extra Imp. Plow Steel

tons

metric tonnes

*To convert to Kilonewtons (kN), multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N). The given strengths for 8 x 19 rotation resistant ropes are applicable only when a test is conducted on a new rope fixed at both ends. When the rope is in use, and one end is free to rotate, the nominal strength is reduced.

TABLE 32 NOMINAL STRENGTHS OF WIRE ROPE 18 x 7 ConstructionIRotation ResistantIBright (Uncoated), Fiber Core Nominal Strength*

Nominal Diameter inches

mm

Approximate Mass lb/ft

kg/m

Improved Plow Steel** tons

metric tonnes

Extra Imp. Plow Steel** tons

metric tonnes

*To convert to Kilonewtons (kN), multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N). **Available with galvanized wires at strengths 10% lower than listed, or at equivalent strengths on special request. The given strengths are applicable only when a test is conducted on a new rope fixed at both ends. When the rope is in use, and one end is free to rotate, the nominal strength is reduced.

TABLE 33 NOMINAL STRENGTHS OF WIRE ROPE 19 x 7 ConstructionIRotation ResistantIBright (Uncoated), IWRC Nominal Strength*

Nominal Diameter inches

mm

Approximate Mass lb/ft

kg/m

Improved Plow Steel** tons

metric tonnes

Extra Imp. Plow Steel** tons

metric tonnes

*To convert to Kilonewtons (kN), multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N). **Available with galvanized wires at strengths 10% lower than listed, or at equivalent strengths on special request. The given strengths are applicable only when a test is conducted on a new rope fixed at both ends. When the rope is in use, and one end is free to rotate, the nominal strength is reduced.

TABLE 34A NOMINAL STRENGTHS OF WIRE ROPE 1 x 7 and 1 x 19 Small Diameter Specialty Strand, Galvanized and Corrosion Resistant Nominal Strength Nominal Diameter

inches mm

-

Approximate Mass

lb/ 100ft

kg/ lb/ 30.5m* 100ft

Galvanized

kg/ 30.5m*

lb

kg

lb

Corrosion Resistant

kg

lb

kg

1b

kg

TABLE 34B NOMINAL STRENGTHS OF WIRE ROPE 7 x 7 and 7 x 19 Small Diameter Specialty Cord, Galvanized and Corrosion Resistant Nominal Strength Nominal Diameter

inches mm

Approximate Mass

lb/ 100 ft

*3 x 7 Construction **30.5m = 100 ft

kg/ 30.5m**

lb/ kg/ 100 ft 30.5m**

Galvanized

lb

kg

lb

Corrosion Resistant

kg

lb

kg

lb

kg

TABLE 35 NOMINAL STRENGTHS OF WIRE ROPE 6 x 12 Construction/Galvanized, Fiber Core Nominal Strength* Nominal Diameter inches

mm

Approximate Mass

lb/ft

kg/m

Improved Plow Steel tons

metric tonnes

*To convert to Kilonewtons (kN), multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N).

TABLE 36 NOMINAL STRENGTHS OF WIRE ROPE 6 x 24 Construction/ Galvanized, Fiber Core

Nominal Strength* --

Nominal Diameter inches

mm

Approximate Mass lb/ft

kg/m

Improved Plow Steel tons

metric tonnes

*To convert to Kilonewtons (kN), multiply tons (nominal strength) by 8.896; 1 lb = 4.448 newtons (N).

Appendix A ORDERING, STORING AND UNREELING WIRE ROPE A. Ordering When ordering wire rope, it must be described as completely as possible. The generally accepted nomenclature conventions, defined elsewhere in this publication, should be carefully noted. These, along with other applicable information will not only enable the rope manufacturer to satisfy the purchaser's requests, but will also provide data for technical advice or suggestions. Following, is a check list of these data: 1) The application or use intended for the wire rope. 2) Description of the rope itself: Length-standard or tape measured Diameter-nominal diameter Construction-e.g., "6 x 19 Seale" Preformed or non-preformed-pref or non-pref Lay-Right or Left; Regular or Lang Lay Finish-bright or galvanized Grade--e.g., improved plow steel, traction steel, or other Core-independent wire rope, wire strand, or fiber Lubrication-standard or special 3) Describe end terminations if required. 4) Describe special spooling or reel requirements. B. Storing No matter how the delivered rope is packaged, it should always be kept away from moisture. This means storing under a weatherproof cover overhead, and no direct contact with the ground or floor. Ocean spray, acid fumes, or similarly corrosive atmospheres should be avoided. When reels will remain stored for long periods, the supplier should be asked to ship the ropes with a protective wrapping. Where this has not been done, the outer layers of rope should be coated with an approved lubricant. When a rope is to be removed from service and stored, it should be thoroughly cleaned, lubricated, and carefully coiled on a reel. In this case, the same storage conditions that are required for new rope, should be maintained. Ambient temperature for rope in storage should be low. Elevated temperatures tend to liquefy or thin out rope lubricants. Thus, wire rope storage areas should not only be normally cool spaces, but possible sources of high heat should be kept at some distance.

APPENDIX A 1

C. Unreeling Wire rope must always be handled with care. This is particularly important when reels or coils are received, moved about, unreeled or uncoiled. Reels or coils should never be dropped. When this happens, the rope may shift and cause the reel to collapse and thus the rope itself may be damaged. Removing rope from a collapsed reel may often result in rope damage. Coiled rope, if dropped on the edge of the coil, can sustain a permanent bend. Coils and reels should only be rolled on relatively smooth, hard surfaces. Rolling through loose dirt, standing water, or across sharp, hard objects, or over uneven surfaces can cause deformations or harm the lubricant protection. Careful handling before installation and proper maintenance procedures afterward will ensure the longest possible service life for wire rope. Improper handling can prove quite costly for the user, yet, for the most part, abuse is easily avoidable.

Appendix B

WIRE ROPE FITTINGS

CLOSED WIRE ROPE SOCKETS (POURED)

TABLE 37 DIMENSIONS (inches)

W- DIAM.

Rope Diam.

A

B

C

D

G

J

R

T

W

Approx. Wt Lb

NOTE: Dimensions are for reference only. Consult your supplier of the specific fittings for exact details.

APPENDIX B OPEN WIRE ROPE SOCKETS (POURED)

-

TABLE 38 DIMENSIONS (inches)

Rope Diam.

A

B

C

D

E

G

J

K

L

N

P

Approx. Wt Lb

NOTE: Dimensions are for reference only. Consult your supplier of the specific fittings for exact details.

APPENDIX B OPEN SWAGED WIRE ROPE SOCKETS

TABLE 39

DIMENSIONS (inches) (after swaging)

After Rope Swaging diam. A

B

Jaw opening C

Pin diam. D

E

F

H

L

Approx. wt/lb

NOTE: Dimensions are for reference only. Consult your supplier of the specific fittings for exact details.

APPENDIX B

OPEN SWAGED STRAND SOCKETS

TABLE 40 DIMENSIONS FOR 19-WIRE AND 37-WIRE STRAND (inches) (after swaging)

Strand diam.

A

B

Jaw Pin opening diam. C D

E

F

H

L

Approx. wt/lb without Pin

NOTE: Dimensions are for reference only. Consult your supplier of the specific fittings for exact details.

APPENDIX B

CLOSED SWAGED WIRE ROPE SOCKETS

TABLE 41 DIMENSIONS (inches) (after swaging)

After Eye Rope Swaging thickness A B diam.

-

C

---

Hole diam. D

E

F

L

Approx. wt (lb

-

NOTE: Dimensions are for reference only. Consult your supplier of the specific fittings for exact details.

APPENDIX B

CLOSED SWAGED STRAND SOCKETS

TABLE 42 DIMENSIONS FOR 19-WIRE AND 37-WIRE STRAND (inches) (after swaging)

Strand diam.

A

Eye thickness B

C

Hole diam. D

E

F

L

Approx. wt (lb)

NOTE: Dimensions are for reference only. Consult your supplier of the specific fittings for exact details.

APPENDIX B

OPEN SWAGED SOCKETS

TABLE 43 DIMENSIONS OF SOCKETS (inches) OPEN WIRE ROPE WEDGE-TYPESOCKETS These wedge-type sockets are easily and quickly attached in the field by bending the rope end around the tapered wedge. This type of socket is normally furnished without pins.

Diameter of rope

Center of pin hole to end of socket A

Opening between ears B

Diameter of pin hole C

Approximate wt (lb)

NOTE: Dimensions are for reference only. Consult your supplier of the specific fittings for exact details.

APPENDIX B

WIRE ROPE ASSEMBLIES When ordering wire rope with end attachments, lengths-as shownshould be specified. Additionally, the load at which this measurement is taken should be specified, i.e., at no load, at a percentage of nominal strength, etc. The drawings (opposite page) do not show all possible combinations of fittings; in any case, the same measuring methods should be followed.

Zinc-attached closed wire rope socket at one end; zinc-attached open wire rope socket at other end. Measurement: Pull of closed socket to centerline of open so.cket pin.

b Closed swaged wire rope socket at one end; open swaged wire rope socket at other end. Measurement: Centerline of pin to centerline of pin.

Closed bridge socket attached to one end; open bridge socket attached to other end. Measurements : Centerline of closed socket pin to centerline of open socket pin; include two of the three values : takeup, contraction, and expansion. The values of C and 0 are also required.

Thimble spliced at one end. Measurement: Pull of thimble to end of rope.

Link spliced at one end; hook spliced at other end. Measurement: Pull of link to pull of hook.

Thimble spliced at one end; loop spliced at other end. Measurements: Pull of thimble to base of loop, and circumference of loop.

APPENDIX B

APPENDIX B

BOOM PENDANTS WITH SWAGED FITTINGS

I

I

SINGLE-ROPE LEGS AND OPEN SWAGED SOCKETS

SINGLE-ROPE LEGS AND OPEN AND CLOSED SWAGED SOCKETS

I

I

SINGLE- ROPE LEGS AND CLOSED SWAGED SOCKETS

BOOM PENDANTS WITH SWAGED FITTINGS

Length of Pendant is measured as indicated on sketches. Note: When ordering, customer should specify parallel or right angle (90") socket pins.

APPENDIX B

TABLE 44 RATED CAPACITIES IN TONS OF 2,000 LB. 6 x 19 & 6 x 37 IWRC IMPROVED PLOW STEEL *

Diam. of rope (inches)

Min. Length (SL) of pendant ft-inches

Two Pendants When Used Singlepart vertical

30"

45"

0 inches

D inches

R inches

-

*Values given apply when pendants are used as slings or sling assemblies. When used in a Boom Suspension System, other values apply; consult rope manufacturer. **Dimension symbols (0,D, R, K & W) are described in drawings on opposite page (118).

Closed Swaged Socket **

Open Swaged Socket **

p p

Weight Ib

-

-

K inches

W inches

Weight lb

Appendix C

SOCKETING

SOCKETING PROCEDURES Zinc-Poured Socketing The following steps, in the order given, should be carefully adhered to. 1. Measure the Rope Ends to be Socketed The rope end should be of sufficientlength so that the ends of the unlaid wires (from the strands) will be at the top of the socket basket. (Fig. C . l ) . 2. Apply Serying at Base o f Socket Apply a tight wire serving band, at the point where the socket base will be, for a length of two rope diameters. (Figs. C.2 & C.3). 3. Broom Out Strand Wires Unlay and straighten the individual rope strands and spread them evenly so that they form an included angle of approximately 60". Unlay the wires of each individual strand for the full length of the rope end-being careful not to disturb or change the lay of the wires and strands under the serving band. Unlay the wires of an independent wire rope core in the same manner. A fiber core should be cut out and removed as close to the serving band as possible (Fig. C.3 ) . 4. Clean the Broomed-Out Ends A suggested cleaning solvent for this step is SC-5 Methyl Chloroform. It is also known under the names Chlorothane VG and 1-1-1 Trichlorethane. CAUTION: Breathing the vapor of this solvent is harmful; it should only be used in a well-ventilated area. Be sure to follow the solvent manufacturer's instructions, and carefully observe all instructions printed on the label.

Swish the broomed-out rope end in the solvent, then brush vigorously to remove all grease and dirt-making certain that the wires are clean to the very bottom close to the serving band (Fig. C.4). Additionally, a solution of muriatic acid may also be used. If, however, acid is used the broomed-out ends should be rinsed in a solution of bicarbonate of soda so as to neutralize any acid that may remain on the rope. Care should be exercised to prevent acid from entering the core; this is particularly important if the rope has a fiber core. Where it is feasible, the best and preferred cleaning method for rope ends prior to socketing is ultrasonic cleaning. After this cleaning step, place the broomed-out end upright in a vise allowing it to remain until all solvent has evaporated and the wires are dry. Solvent should never be permitted to remain on the rope or on the serving band since it will run down the wires when the rope is removed from the vise. 5. Dip the Broomed-Out Rope Ends in Flux Prepare a hot solution of zinc-ammonium chloride flux comparable to Zaclon K. Use a concentration of 1 lb of zinc-ammonium chloride to 1 gallon of water; maintain this at a temperature of 180" to 200" F. Swish the broomed-out end in the flux solution, then place the rope end upright in the vise until such time as the wires have dried thoroughly (Fig. C .5 ) . 6. Close Rope Ends and Place Socket Use clean wire to compress the broomed-out rope end into a tight bundle that will permit the socket to be slipped on easily over the wires (Fig. C. 6). Before placing the socket on the rope, make certain that the socket itself

APPENDIX C C.4

is clean and heated. This heating is necessary in order to dispel any residual moisture, and to prevent the zinc from cooling prematurely. A word o f caution: Never heat a socket after it is placed on the rope. To do so may cause heat damage to the rope. After the socket is on the rope end, the wires should be distributed evenly in the socket basket so that zinc can surround each wire. Use extreme care in aligning the socket with the rope's centerline, and in making certain that there is a minimum vertical length of rope, extending from the socket, that is equal to about 30 rope diameters (Fig. C.7). Seal the socket base with fire clay or putty but make certain that this material does not penetrate into the socket base. Should this occur, it would prevent the zinc from penetrating the full length of the socket basket thereby creating a void that would collect moisture after the socket is placed in service. 7. Pour the Zinc The zinc used should meet ASTM Specification designation B6-49 Grade ( 1) High Grade, and Federal Specification QQ-Z-35 1-a Amendment 1, interim Amendment 2. Pour the zinc at a temperature of 950" to 970' F (Fig. C. 8) ; make allowances for cooling if the zinc pot is more than 25 ft from the socket. A word of caution: Do not heat zinc above 1200°F or its bonding properties will be lost. The zinc temperature may be measured with a portable pyrometer or a Tempilstik. Remove all dross before pouring. Pour the zinc in one continuous stream until it reaches the basket top and all wire ends are covered; there should be no "capping" of the socket. 8. Remove Serving Remove the serving band from the socket base; check to make certain that zinc has penetrated to the socket base (Fig. C.9). 9. Lubricate the Rope Apply wire rope lubricant to the rope at the socket base, and on any rope section where the original lubricant may have been removed.

APPENDIX C Thermo-Set Resin Socketing Before proceeding with a thermo-set resin socketing procedure, check manufacturer's instructions carefully. Give particular attention to selecting sockets that have been specifically designed for resin socketing. Follow the steps, outlined below, or manufacturer's directions, in the order given. 1. Seizing and Cutting the Rope Follow rope manufacturer's directions for a particular rope size or construction with regard to the number, position, length of seizings and the seizing wire size. The seizing, located at the base of the installed fitting, must be positioned so that the ends of the embedded wires will be slightly below the level of the top of the fitting's basket. The best means to cut the rope is with an abrasive wheel. 2. Opening and Brooming the Strand Wires Before opening the rope end, place a short temporary seizing directly above the seizing that represents the broom base. Temporary seizing prevents brooming the wires the full length of the basket and also prevents loss of lay in the strands and rope outside the socket. Remove all seizing between the end of the rope and the temporary seizing. Unlay the strands comprising the rope. Starting with the IWRC, or strand core, open each strand of the rope and broom or unlay the individual wires. (Note: A fiber core in the rope may be cut at the base of the seizing; some prefer to leave the core in. Consult the manufacturer's instruction.) When the brooming is completed, wires should be distributed evenly within a cone so that they form an included angle of approximately 60". Some types of sockets will require a somewhat different brooming procedure, in which case the manufacturer's instructions should be followed. 3. Cleaning the Wires and Fittings Different types of resin with different characteristics require varying degrees of cleanliness. In some cases, merely using a soluble cleaning oil has been found effective. For one type of polyester resin, on which over 800 tensile tests on ropes in sizes 94If to 3 1/2 " diameter were made without failure in the resin socket attachment, the cleaning procedure was as follows: Clean wires thoroughly so as to obtain resin adhesion. Ultrasonic cleaning in recommended solvents such as trichloroethylene or 1- 1- 1 trichloroethane or other non-flammable grease-cutting solvents is the preferred method of cleaning the wires in accordance with OSHA Standards. Where ultrasonic cleaning is not available, brush or dip-cleaning in trichloroethane may be used; but fresh solvent should be used for each rope and fitting and discarded after use. After cleaning, the broom should be dried with clean compressed air or in other suitable fashion before proceeding to the next step. The use of acid to etch the wires before resin socketing is unnecessary and not recommended. Also, the use of a flux on the wires before pouring resin should be avoided since this adversely affectsresin bonding to the steel wires. Since there is much variation in the properties of different resins, manufacturers' instructions should be carefully followed. 4. Close Rope Ends and Place Socket Place rope in a vertical position with the broom end up. Close and compact

APPENDIX C the broom to permit insertion of the broomed end into the base of the fitting. Slip the fitting on, removing any temporary banding or seizing as required. Make certain the broomed wires are uniformly spaced in the basket, with wire ends slightly below the top edge of the basket, and that the axis of the rope and the fitting are aligned. Seal the annular space between the base of the fitting and the exiting rope to prevent leakage of the resin from the basket. A non-hardening butyl rubber-base sealant is satisfactory for this purpose. Make sure that the sealant does not enter the base of the socket so that the resin will be able to fill the complete depth of the socket basket. 5. Pouring the Resin Controlled heat-curing (no open flame) at a temperature range of 250"-300" F is recommended. If ambient temperatures are less than 60" F, this is required! When controlled heat curing is not available and ambient temperatures are not less than 60" F the attachment should not be disturbed and tension should not be applied to the socketed assembly for at least 24 hours. 6. Lubrication After Socket Attachment After the resin has cured, re-lubricate the wire rope at the base of the socket to replace any lubricant that may have been removed during the cleaning operation. 7 . Acceptable Resin Types Commercially-available resin properties vary considerably. Hence, it is important to refer to the individual manufacturer's instructions before using any one type. General rules cannot, of course, be established. When properly formulated, most thermoset resins are acceptable for socketing. These formulations, when mixed, form a pourable material which will harden at ambient temperatures, or upon the application of moderate heat. No open flame or molten metal hazards exist with resin socketing since heat-curing when necessary, requires a relatively low temperature (250-300" F) obtainable by electric resistance heating. Tests have demonstrated that satisfactory wire rope socketing performance can be obtained with resins having characteristics and properties as follows:

General Description The resin shall be a liquid thermoset material that will harden after being mixed with the correct proportion of catalyst or curing agent. A. Properties of Liquid (Uncured) Material Resin and catalyst are normally supplied in two separate containers. After thoroughly mixing them together, the liquid can be poured into the socket basket. Liquid resins and catalysts shall have the following properties: 1) Viscosity o f the Resin-Catalyst Mixture 30-40,000 CPS at 75" F immediately after mixing. Viscosity will increase at lower ambient temperatures and resin may need warming prior to mixing in the catalyst if ambient temperatures drop below 40" F. 2 ) Flash Point Both resin and catalyst shall have a minimum flash point of 100" F. 3 ) Shelf Life Unmixed resin and catalyst shall have a minimum of 1 year shelf life at 70 " F.

APPENDIX C 4) Pot Life and Cure Time After mixing, the resin-catalyst blend shall be pourable for a minimum of eight minutes at 60' F and shall harden in 15 minutes. Heating of the resin in the socket to a maximum temperature of 250" F is permissible to obtain full cure. B. Properties of Cured Resin 1 ) Socket Performance Resin shall exhibit sufficient bonding to solvent-washed wire in typical wire rope end fittings to develop the nominal strength of all types and grades of rope. No slippage of wire is permissible when testing resin-filled rope socket assemblies in tension. After testing, however, some "seating" of the resin cone may be apparent and is acceptable. Resin adhesion to wires shall be capable of withstanding tensile-shock loading. 2 ) Compressive Strength The minimum allowable compressive strength for fully cured resin is 12,000 psi. 3 ) Shrinkage Maximum allowable shrinkage is 2 % . To control shrinkage, an inert filler may be used in the resin provided that viscosity requirements as specified above (A. 1) for the liquid resin are met. 4) Hardness The desired hardness of the resin is in the range of Barcol40-55. Resin Socketing Compositions Manufacturer's directions should be followed in handling, mixing and pouring the resin composition. Performance of Cured-Resin Sockets Poured-resin sockets may be moved after the resin has hardened. Following the ambient- or elevated-temperature cure, recommended by the manufacturer, resin sockets should develop the nominal strength of the rope, and have the capability of withstanding shock loading to a degree sufficient to break the rope, without cracking or breakage. Manufacturers of resin socketing material shall be required to test these criteria before resin materials will be approved for rope socketing use. A final note of caution: the foregoing discussion is a generalized description of but one o f many commercially available thermo-set resins suitable for wire rope socketing. Characteristics o f these products vary significantly and each must be handled diflerently. Thus, as noted earlier, specific information of any kind concerning any resin must be obtained from the individual manufacturer before setting up a resin socketing procedure.

Appendix D

SHIPPING REEL CAPACITY

SHIPPING REEL CAPACITY While it is virtually impossible to calculate the precise length of wire rope that can be spooled on a reel or drum, the following formula provides a sufficiently close approximation. The formula is: where:

L = (A+D)

A B K

L = length of rope (ft) A = depth of rope space on drum (inches) B = width of drum between flanges (inches) D = drum barrel diameter (inches) K = constant for given rope diameter (see table below) H = diameter of reel flanges (inches) X = clearance

TABLE 45 "K" FACTORS* (0.2618 -+ rope diameter )** Diam. (inches)

K

Diam. (inches)

K

*The values given for "K" factors take normal rope oversize into account. Clearance ( " X" ) should be about 2 inches unless rope-end fittings require more. **This formula is based on uniform rope winding on the reel, It will not give correct results if the winding is non-uniform. The formula also assumes that there will be the same number of wraps of rope in each layer. While this is not strictly correct, there is no appreciable error in the result unless the traverse of the reel is quite small relative to the flange diameter ("H").

Diam. (inches)

K

Appendix E

WEIGHTS OF MATERIALS*

Substance

"Weights are derived from average specific gravities. except where noted as bulk. heaped or loose material. ere.

Weight (lb/ft3)

METALS. ALLOYS. ORES Aluminum. cast-hammered 165 Albminum. bronze ............ 48 1 Antimony .......................... 4 16 Arsenic .............................. 358 Bismuth ............................ 608 Brass. cast-rolled .............. 534 Bronze (gun metal) copper 88. tin 10. zinc 2% ........................ 544 Bronze (Phosphor) copper 80. tin 10. lead 10% ...................... 562 Chromium ........................ 428 Cobalt ................................ 552 Copper. cast-rolled ............ 556 Copper. ore. pyrites .......... 262 Gold. cast-hammered ........ 1205 Iron. cast. pig .................... 450 Iron. wrought .................... 485 Iron. Spiegel-eisen ............ 468 Iron. ferro-silicon .............. 437 Iron. ore. hematite ............ 325 Iron. ore. hematite in bank 160-180 Iron. ore. hematite loose .... 130- 160 Iron. ore. limonite ............ 237 Iron. ore. magnetite .......... 3 15 Iron. slag .......................... 172 Lead .................................. 706 Lead ore. galena ................ 465 Magnesium ........................ 109 Manganese ........................ 456 Manganese ore. pyrolusite 259 Mercury ............................ 848 Molybdenum .................... 562 Nickel .............................. 545 Nickel monel metal .......... 556 Platinum. cast-hammered .. 1330 Silver. cast hammered ...... 656 Steel .................................. 490 Tin. cast-hammered .......... 459 Tin. babbitt metal .............. 443 Tin. ore. cassiterite ............ 41 8 Tungsten .......................... 1180 Vanadium ........................ 350 Zinc. cast-rolled ................ 440 Zinc. ore. blende ................ 253

Substance VARIOUS SOLIDS Carbon. amorphous. graphitic ........................ Cork .................................. Ebony ................................ Fats .................................. Glass. common. plate ........ Glass. crystal .................... Glass. flint ........................ Phosphorous. white .......... Porcelain. china ................ Resins. Rosin. Amber ........ Rubber. caoutchouc .......... Silicon ................................ Sulphur. Amorphous ........ Wax .................................. TIMBER. U.S. SEASONED Ash. white ........................ Beech ................................ Birch. yellow .................... Cedar. Port Orford ............ Cedar. white. red .............. Chestnut ............................ Cypress. southern .............. Douglas Fir. coast type ...... Douglas Fir. mountain ...... Elm. American .................. Hemlock. eastern. western Hickory. bigleaf ................ Hickory. pignut ................ Larch. western .................. Maple. red. black .............. Maple. silver .................... Oak. Oregon white ............ Oak. red ............................ Pine. red ............................ Pine. white. yellow. western .......................... Poplar. yellow .................. Redwood .......................... Spruce. black. red .............. Spruce. Engelmann .......... Tamarack .......................... Walnut .............................. Moisture Contents : Seasoned timber 12% Green timber up to 50%

Weight (lb/ft3)

APPENDIX E

Substance

Weight (lb/ft3)

VARIOUS LIQUIDS Alcohol. 100% .................. Acids. Muriatic 40% ........ Acids. nitric 9 1% .............. Acids. sulphuric 87% ........ Lye. soda 66% .................. Oils. vegetable .................. Oils. mineral. lubricants .... Petroleum .......................... Gasoline ............................ Water. 4°C. max . density .. Water. 100°C .................... Water. ice .......................... Water. snow. fresh fallen .. Water. sea water ................ GASES Air. O°C. 760 mm ...............08071 Ammonia ...........................0478 Carbon dioxide ...................1234 Carbon monoxide ...............078 1 Gas. illuminating .............. .028.. 036 Gas. natural .......................038.. 039 Hydrogen ...........................00559 Nitrogen .............................0784 Oxygen ...............................0 892 MINERALS Asbestos ............................ Barytes .............................. Basalt ................................ Bauxite .............................. Borax ................................ Chalk ................................ Clay. marl ........................ Dolomite .......................... Feldspar. orthoclase .......... Granite. gneiss .................. Greenstone. trap .............. Gypsum. alabaster ............ Hornblende ...................... Limestone. crystalline ...... Limestone. oolitic .............. Magnesite .......................... Marble .............................. Phosphate rock. apatite .... Porphyry .......................... Pumice. natural ................ Quartz. flint ...................... Sandstone. bluestone ........

Substance Slate. shale ........................ Soapstone. talc .................. STONE. QUARRIED. PILED Basalt. granite. gneiss ........ Limestone. marble. quartz Sandstone .......................... Shale .................................. Greenstone. hornblende .... BITUMINOUS SUBSTANCES Asphaltum ........................ Coal. anthracite ................ Coal. bituminous .............. Coal. lignite ...................... Coal. peat. turf. dry .......... Coal. charcoal. pine .......... Coal. charcoal. oak ............ Coal. coke .......................... Graphite ............................ Paraffine ............................ Petroleum. crude .............. Petroleum. relined ............ Petroleum. benzine ............ Petroleum. gasoline .......... Pitch .................................. Tar. bituminous ................ COAL AND COKE. PILED Coal. anthracite ................ Coal. bituminous. lignite .. Coal. peat. turf ................ Coal. charcoal .................. Coal. coke ........................ ASHLAR MASONRY Granite. gneiss .................. Limestone. crystalline ...... Limestone. oolitic .............. Marble .............................. Sandstone. bluestone ........ MORTAR RUBBLE MASONRY Granite. gneiss .................. Limestone. crystalline ...... Limestone. oolitic .............. Marble .............................. Sandstone. bluestone ........

Weight (lb/ft3) 172 169

Substance BRICK MASONRY Pressed brick .................... Common brick .................. Soft brick ..........................

Weight (lb/ft3) 140 120 100

CONCRETE Cement. stone. sand .......... Cement. slag. etc............... Cement. cinder. etc........... VARIOUS BUILDING MATERIAL Ashes. cinders .................. Cement. Portland. loose .... Cement. Portland. set ........ Lime. gypsum. loose ........ Mortar. set ........................ Slags. bank slag ................ Slags. bank. screenings ...... Slags. machine slag ............ Slags. slag sand .................. EARTH. ETC., EXCAVATED Clay. dry ............................ Clay. damp. plastic ............ Clay and gravel. dry .......... Earth. dry. loose ................ Earth. dry. packed ............ Earth. moist. loose ............ Earth. moist. packed ........ Earth. mud. flowing .......... Earth. mud. packed .......... Riprap. limestone .............. Riprap. sandstone .............. Riprap. shale .................... Sand. gravel. dry. loose ...... Sand. gravel. dry. packed .. Sand. gravel. wet ..............

78 96 108 115 80-85 90 105 90- 105 100-120 118- 120

EXCAVATIONS IN WATER Sand or gravel .................. Sand or gravel and clay .... Clay .................................. River mud ........................ Soil .................................... Stone riprap ......................

60 65 80 90 70 65

Appendix F

A GLOSSARY OF WIRE ROPE TERMS ABRASION Frictional surface wear on the wires of a wire rope. ACCELERATION STRESS The additional stress that is imposed on a wire rope as a result of an increase in the load velocity (see DECELERATION STRESS). AGGREGATE AREA See AREA, METALLIC. AGGREGATE STRENGTH The strength derived by totalling the individual breaking strengths of the elements of the strand or rope. This strength does not give recognition to the reduction in strength resulting from the angularity of the elements in the rope, or other factors that may affect efficiency. AIRCRAFT CABLES Strands, cords and wire ropes made of special-strength wire, designed primarily for use in various aircraft industry applications. ALBERTS LAY See LAY, TYPES. ALTERNATE LAY See LAY, TYPES. AREA, METALLIC Sum of the crosssectional areas of all the wires either in a wire rope or in a strand.

BACK-STAY Wire rope or strand guy used to support a boom or mast; or that section of a main cable, as on a suspension bridge, cableway, etc., leading from the tower to the anchorage. BAIL a) U-shaped member of a bucket, or b) U-shaped portion of a socket or other fitting used on wire rope.

BAILING LINE In well drilling, it is the wire rope that operates the bailer that removes water and drill cuttings. BARNEY CAR A relatively small car permanently attached to a haulage rope that pushes cars along a haulage system. BASKET OF SOCKET The conical portion of a socket into which a broomedrope-end is inserted and then secured. BECKET An end attachment to facilitate wire rope installation. BECKET LOOP A loop of small rope or strand fastened to the end of a larger wire rope. Its function is to facilitate wire rope installation. BENDING STRESS Stress that is imposed on the wires of a strand or rope by a bending or curving action. BICABLE A term usually applied to a wire rope aerial tramway that has a fixed cable or strand to support the load, as well as a traction or haul rope that moves the load about the system. BIRDCAGE A colloquialism descriptive of the appearance of a wire rope forced into compression. The outer strands form a cage and, at times, displace the core. BLOCK A term applied to a wire rope sheave (pulley) enclosed in side plates and fitted with some attachment such as a hook or shackle. BOOM HOIST LINE Wire rope that operates the boom hoist system of derricks, cranes, draglines, shovels, etc. BOOM PENDANT A non-operating rope or strand with end terminations to support the boom.

APPENDIX F BREAKING STRENGTH Breaking Strength is the ultimate load at which a tensile failure occurs in the sample of wire rope being tested. (Note: The term breaking strength is synonymous with actual strength.) Minimum Acceptance Strength is that strength which is 21/2% lower than the catalog or nominal strength. This tolerance is used to offset variables that occur during sample preparation and actual physical test of a wire rope. Nominal Strength is the published (catalog) strength calculated by a standard procedure that is accepted by the wire rope industry. The wire rope manufacturer designs wire rope to this strength, and the user should consider this strength when making design calculations. BRIDGE CABLE (Structural Rope or Strand) The all-metallic wire rope or strand used as the catenary and suspenders on a suspension bridge. BRIDGE SOCKET A wire rope or strand end termination made of forged or cast steel that is designed with baskets -having adjustable bolts-for securing rope ends. There are two styles: 1) the closed type has a U-bolt with or without a bearing block in the U of the bolt, and 2) the open type has two eye-bolts and a pin. BRIDLE SLING A multi-leg wire rope SLING. BRIGHT ROPE Wire rope fabricated from wires that are not coated. BRONZE ROPE Wire rope fabricated from bronze wires. BULL WHEEL A term applied to a large-diameter wire rope SHEAVE, e.g., the sheaves at the end of a ski lift. BUTTON CONVEYOR ROPE Wire rope to which buttons or discs are attached at regular intervals to move material as in a trough.

CABLE A term loosely applied to wire rope, wire strand and electrical conductors. CABLE-LAID WIRE ROPE A type of wire rope consisting of several wire ropes laid into a single wire rope (e.g., 6 x 42 (6 x 6 x 7) tiller rope). CABLE TOOL DRILLING LINE The wire rope used to operate the cutting tools in the cable tool drilling method (i.e., rope drilling). CABLEWAY Aerial conveying system for transporting single loads along a suspended track cable. CASING LINE Wire rope used to install oil well casings. CATENARY A curve formed by a strand or wire rope when supported horizontally between two fixed points, e.g., the main spans on a suspension bridge. CENTER The axial member of a strand about which the wires are laid. CHANGE OF LAYER POINT That point in the traverse of a rope across the face of the drum where it reaches the flange, reverses direction and begins forming the next layer. Also referred to as the drum cross-over or TURN-BACK POINT. CHOKhR ROPE A short wire rope sling that forms a slip noose around an object that is to be moved or lifted. CIRCUMFERENCE Measured perimeter of a circle that circumscribes either the wires of a strand, or the strands of a wire rope. CLAMPS, STRAND A fitting for forming a loop at the end of a length of strand, consisting of two grooved plates and bolts.

APPENDIX F CLASSIFICATION Group, or family designation based on wire rope constructions with common strengths and weights listed under the broad designation. CLEANING OUT LINE Wire rope used in conjunction with tools that are used to clean an oil well. CLEVIS See SHACKLE. CLIP Fitting for clamping two parts of wire rope to each other. CLOSED SOCKET A wire rope end termination consisting of basket and bail made integral. CLOSER A machine that lays strands around a core to form rope. CLOSING LINE Wire rope that performs two functions: 1) closes a clamshell or orange peel bucket, and 2) operates as a hoisting rope. COARSE LAID ROPE Term generally used in oil fields to designate a 6 x 7 wire rope. COIL Circular bundle or package of wire rope that is not affixed to a reel. COME ALONG Device for making a temporary grip on a wire rope. CONICAL DRUM Grooved hoisting drum with a varying diameter. See DRUM. CONSTRUCTION Geometric design description of the wire rope's cross section. This includes the number of STRANDS, the number of WIRES per strand and the pattern of wire arrangement in each STRAND.

CONSTRUCTIONAL STRETCH The stretch that occurs when the rope is loaded -it is due to the helically laid wires and strands creating a constricting action that compresses the core and generally brings all of the rope's elements into close contact. CONTINUOUS BEND Reeving of wire rope over sheaves and drums so that it bends in one direction, as opposed to REVERSE BEND. CONVEYOR ROPE Endless wire rope used to carry material. See BUTTON CONVEYOR ROPE. CORD Term applied to small diameter specialty wire rope or strand. CORE The axial member of a wire rope about which the strands are laid. CORING LINE Wire rope used to operate the coring tool that is used to take core samples during oil well drilling. CORROSION Chemical decomposition of the wires in a rope through the action of moisture, acids, alkalines or other destructive agents. CORROSION-RESISTING STEEL Chrome-nickel steel alloys designed for increased resistance to corrosion. CORRUGATED Term used to describe the grooves of a SHEAVE or DRUM after these have been worn down to a point where they show an impression of a wire rope. COTTON CENTER See FIBER CENTER. COTTON CORE See FIBER CORE. COUPLING Device for joining the ends of two lengths of track cable. COVER WIRES Outer layer of wires.

APPENDIX F CRACKER Manila rope spliced or otherwise attached to the end of a wire drilling line. CREEP The unique movement of a wire rope with respect to a drum surface or sheave surface resulting from the asymmetrical load between one side of the sheave (drum) and the other. It is not dissimilar to the action of a caterpillar moving over a flat surface. It should be distinguished from slip which is yet another type of relative movement between rope and the sheave or drum surf ace. CRITICAL DIAMETER For any given wire rope, it is the diameter of the smallest bend that permits both wires and strands to adjust themselves by relative movement while retaining their normal cross-section position. CROSS LAY See LAY, TYPES. CROWD ROPE A wire rope used to drive or force a power shovel bucket into the material that is to be handled. CYLINDRICAL DRUM A hoisting drum of uniform diameter. See DRUM.

DEAD-LINE In drilling, it is the end of the rotary drilling line fastened to the anchor or dead-line clamp. DECELERATION STRESS The additional stress that is imposed on a wire rope as a result of a decrease in the load velocity. See ACCELERATION STRESS. DEFLECTION a) The sag of a rope in a span. Usually measured at mid-span as the depth from the chord joining the tops of the two supports. b) Any deviation from a straight line. DESIGN FACTOR In a wire rope, it is the ratio of the nominal strength to the total working load.

DIAMETER A line segment which passes through the center of a circle and whose end points lie on the circle. As related to wire rope it would be the diameter of a circle which circumscribes the wire rope. DOG-LEG Permanent bend or kink, in a wire rope, caused by improper use or handling. DRAGLINE a) Wire rope used for pulling excavating or drag buckets, and b) name applied to a specific type of excavator. DRILLING LINE See CABLE TOOL DRILLING LINE and ROTARY LINE. DRUM A cylindrical flanged barrel, either of uniform or tapering diameter, on which rope is wound either for operation or storage; its surface may be smooth or grooved.

EFFICIENCY Ratio of a wire rope's actual breaking strength and the aggregate strength of all individual wires tested separately-usually expressed as a percentage. ELASTIC LIMIT Stress limit above which permanent deformation will take place within the material. ELLIPTIC SPOOL An endless-rope drive drum with a face in the shape of an elliptic arc. ELONGATION See STRETCH. END PREPARATION The treatment of the end of a length of wire rope designed primarily as an aid for pulling the rope through a reeving system or tight drum opening. Unlike END TERMINATIONS, these are not designed for use as a method for making a permanent connection.

APPENDIX F END TERMINATION The treatment at the end or ends of a length of wire rope, usually made by forming an eye or attaching a fitting and designed to be the permanent end termination on the wire rope that connects it to the load. ENDLESS ROPE Rope with ends spliced together to form a single continuous loop. EQUALIZING SHEAVE The sheave at the center of a rope system over which no rope movement occurs other than equalizing movement. It is frequently overlooked during crane inspections, with disastrous consequences. It can be a source of severe degradation. EQUALIZING SLINGS Multiple-leg slings composed of wire rope and fittings that are designed to help distribute the load equally. See SLING. EQUALIZING THIMBLES Special type of load-distributing fitting used as a component of certain wire rope slings. EXTRA FLEXIBLE WIRE ROPE An ambiguous and archaic term sometimes applied to describe wire ropes in the 8 x 19 class and 6 x 37 class. The term is so indefinite as to be meaningless and is in' disfavor today. EXTRA HIGH-STRENGTH STRAND A grade of galvanized strand. EXTRA IMPROVED PLOW STEEL ROPE A specific wire rope grade. EYE OR EYE SPLICE A loop, with or without a thimble, formed at the end of a wire rope.

FACTOR OF SAFETY In the wire rope industry, this term was originally used to express the ratio of nominal strength to the total working load. The term is no longer used since it implies a permanent existence for this ratio when, in actuality, the rope strength begins to reduce the moment it is placed in service. See DESIGN FACTOR. FATIGUE As applied to wire rope, the term usually refers to the process of progressive fracture resulting from the bending of individual wires. These fractures may and usually do occur at bending stresses well below the ultimate strength of the material; it is not an abnormality although it may be accelerated due to conditions in the rope such as rust or lack of lubrication. FERRULE A metallic buttorl, usually cylindrical in shape, normally fastened to a wire rope by swaging but sometimes by spelter socketing. FERRY ROPE Refers to wire rope that is suspended over water for the purpose of guiding a boat. FIBER CENTER Cord or rope of vegetable or synthetic fiber used as the axial member of a strand. FIBER CORE Cord or rope of vegetable or synthetic fiber used as the axial member of a rope. FILLER WIRE Small spacer wires within a strand which help position and support other wires. Also the name for the type of strand pattern utilizing filler wires. FITTING Any functional accessory attached to a wire rope. FLAG Marker placed on a rope so as to locate the load position.

APPENDIX F FLAT ROPE Wire rope that is made of a series of parallel, alternating right-lay and left-lay ropes, sewn together with relatively soft wires. FLATTENED STRAND ROPE Wire rope that is made either of oval or triangular shaped strands in order to form a flattened rope surface. FLEET ANGLE That angle between the rope's position at the extreme end wrap on a drum, and a line drawn perpendicular to the axis of the drum through the center of the nearest fixed sheave. See DRUM and SHEAVE. FLEXIBLE WIRE ROPE An archaic and imprecise term to differentiate one rope construction from another; such as, 6 x 7 (least flexible) and 6 x 19 classification (somewhat more flexible).

A Utilities grade is also made to meet special requirements and its strength is usually greater than High Strength.

GRAIN SHOVEL ROPE 6 x 19 Marline clad rope used for handling grain in scoops. GROMMET An endless circle or ring fabricated from one continuous length of strand or rope. GROOVED DRUM Drum with a grooved surface that accommodates the rope and guides it for proper winding. GROOVES Depressions-helical or parallel-in the surface of a sheave or drum that are shaped to position and support the rope. GUY LINE Strand or rope, usually galvanized, for stabilizing or maintaining a structure in fixed position.

GALVANIZED Zinc coating for corrosion resistance. GALVANIZED ROPE Wire rope made up of galvanized wire.

HAULAGE ROPE Wire Rope used for pulling movable devices such as cars that roll on a track.

GALVANIZED STRAND Strand made up of galvanized wire.

HAWSER Wire rope, usually galvanized, used for towing or mooring marine vessels.

GALVANIZED WIRE Zinc-coated wire.

HIGH-STRENGTH STRAND Grade of galvanized strand.

GRADE Wire rope or strand classification by strength and/or type of material, i.e., Improved Plow Steel, Type 302 Stainless, Phosphor Bronze, etc. It does not imply a strength of the basic wire used to meet the rope's nominal strength.

HOLDING LINE Wire rope on a clamshell or orange peel bucket that suspends the bucket while the closing line is released to dump its load.

GRADES, ROPE Classification of wire rope by the wire's metallic composition and the rope's nominal strength.

IDLER Sheave or roller used to guide or support a rope. See SHEAVE.

GRADES, STRAND Classification of strand by the wire's metallic composition and the strand's nominal strength. In the order of increasing nominal strengths, the grades are Common, Siemens Martin, High-Strength and Extra-High Strength.

IMPROVED PLOW STEEL ROPE A specific grade of wire rope. INCLINE ROPE Rope used in the operation of cars on an inclined haulage.

APPENDIX F INDEPENDENT WIRE ROPE CORE (IWRC) A wire rope used as the axial member of a larger wire rope. INNER WIRES All wires of a strand except the outer or cover wires. INTERNALLY LUBRICATED Wire rope or strand having all of its wire components coated with lubricants. IRONING See MILKING. IRON ROPE A specific grade of wire rope. IWRC See INDEPENDENT WIRE ROPE CORE.

KINK A unique deformation of a wire rope caused by a loop of rope being pulled down tight. It represents irreparable damage to and an indeterminate loss of strength in the rope.

LAGGING a) External wood covering on a reel to protect the wire rope or strand, or b) the grooved shell of a drum. LGNG LAY ROPE See LAY, TYPES. LAY a) The manner in which the wires in a strand or the strands in a rope are helically laid, or b) the distance measured parallel to the axis of the rope (or strand) in which a strand (or wire) makes one complete helical convolution about the core (or center). In this connection, lay is also referred to as LAY LENGTH or PITCH. LAY, TYPES 1) Right Lay: The direction of strand or wire helix corresponding to that of a right hand screw thread. 2) Left Lay: The direction of strand or wire helix corresponding to that of a left hand screw thread.

3 ) Cross Lay: Rope or strand in which one or more operations are performed in opposite directions. A multiple operation product is described according to the direction of the outside layer. 4) Regular Lay: The type of rope wherein the lay of the wires in the strand is in the opposite direction to the lay of the strand in the rope. The crowns of the wires appear to be parallel to the axis of the rope. 5) Lang Lay: The type of rope in which the lay of the wires in the strand is in the same direction as the lay of the strand in the rope. The crowns of the wires appear to be at an angle to the axis of the rope. 6) Alternate Lay: Lay of a wire rope in which the strands are alternately regular and lang lay. 7 ) Alberts Lay: An old, rarely used term for lang lay. 8) Reverse Lay: Another term for alternate lay. 9) Spring Lay: This is not definable as a unique lay; more properly, it refers to a specific wire rope construction.

LAY LENGTH See LAY (b). LEAD LINE That part of a rope tackle leading from the first, or fast, sheave to the drum. See DRUM and SHEAVE. LEFT LAY See LAY, TYPES. LINE Synonymous term for WIRE ROPE. LOCKED COIL STRAND Smoothsurfaced strand ordinarily constructed of shaped, outer wires arranged in concentric layers around a center of round wires. LOOP A 360" change of direction in the course of a wire rope which when pulled down tight will result in a kink. See EYE and EYE SPLICE.

APPENDIX F MARLINE A prelubricated fiber material. MARLINE-CLAD ROPE Rope with individual strands spirally wrapped with Marline. MARLINE SPIKE Tapered steel pin used as a tool for splicing wire rope. MARTENSITE A brittle micro-constituent of steel formed when the steel is heated above its critical temperature and rapidly quenched. This occurs in wire rope as a result of frictional heating and the mass cooling effect of the cold metal beneath. Martensite cracks very easily, and such cracks can propagate from the surface through the entire wire. MESSENGER STRAND Galvanized strand used as support for telephone and electrical cables. METALLIC CORES See WIRE STRAND CORE and INDEPENDENT WIRE ROPE CORE. MILD PLOW STEEL ROPE A specific grade of wire rope. MILKING Sometimes called IRONING, it is the progressive movement of strands along the axis of the rope, resulting from the rope's movement through a restricted passage such as a tight sheave.

NON-PREFORMED Rope or strand that is not preformed. See PREFORMED STRANDS and PREFORMED ROPE. NON-ROTATING WIRE ROPE Term, now abandoned, referring to 19 x 7 or 18 x 7 rope. See ROTATION RESISTANT ROPE. NON-SPINNING WIRE ROPE See ROTATION RESISTANT ROPE.

OPEN SOCKET A wire rope fitting that consists of a basket and two ears with a pin. See FITTING. OUTER WIRES See COVER WIRES.

PEENING Permanent distortion resulting from cold plastic metal deformation of the outer wires. Usually caused by pounding against a sheave or machine member, or by heavy operating pressure between rope and sheave, rope and drum, or rope and adjacent wrap of rope. PITCH See LAY (b). PLOW STEEL ROPE A specific grade of wire rope. PREFORMED STRANDS Strand in which the wires are permanently formed during fabrication into the helical shape they will assume in the strand.

MODULUS OF ELASTICITY Mathematical quantity expressing the ratio, within the elastic limit, between a definite PREFORMED WIRE ROPE Wire rope in which the strands are permanently range of unit stress on a wire rope and formed during fabrication into the helical the corresponding unit elongation. shape they will assume in the wire rope. MONOCABLE A term usually applied to a wire rope conveyance designed with PRESSED FITTINGS Fittings attached by means of cold forming on the wire a single wire rope that not only supports rope. the load but conveys it as well. MOORING LINES Galvanized wire rope, usually 6 x 12,6 x 24, or 6 x 3 x 19 spring lay for holding ships to dock.

PRESTRESSING An incorrect reference to PRESTRETCHING.

APPENDIX F PRESTRETCMING Subjecting a wire rope or strand to tension prior to its intended application, for an extent and over a period of time sufficient to remove most of the CONSTRUCTIONAL STRETCH. PROPORTIONAL LIMIT As used in the rope industry, this term has virtually the same meaning as ELASTIC LIMIT. It is the end of the load versus elongation relationship at which an increase in load no longer produces a proportion1 increase in elongation and from which point recovery to the rope's original length is unlikely.

RATED CAPACITY The load which a new wire rope or wire rope sling may handle under given operating conditions and at an assumed DESIGN FACTOR. REEL A flanged spool on which wire rope or strand is wound for storage or shipment. REEVE To pass a rope through a hole or around a system of sheaves. REGULAR LAY ROPE See LAY, TYPES.

ROTARY LINE On a rotary drilling rig, it is the wire rope used for raising and lowering the drill pipe, as well as for controlling its position. ROTATION-RESISTANTROPE A wire rope specially constructed to reduce the tendency of the rope to rotate. ROUND-WIRE TRACK STRAND Strand composed of concentric layers of round WIRES, used as TRACK CABLE, sometimes called SMOOTHCOIL TRACK STRAND. RUNNING ROPE Term used to describe 6 x 12 galvanized wire rope.

SAFETY FACTOR See DESIGN FACTOR. SAFE WORKING LOAD This term is potentially misleading and is, therefore, in disfavor. Essentially, it refers to that portion of the nominal rope strength that can be applied either to move or sustain a load. It is misleading because it is only valid when the rope is new and equipment is in good condition. See RATED CAPACITY. SAG See DEFLECTION.

RESERVE STRENGTH The strength of a rope exclusive of the outer wires.

SAND LINE See BAILING LINE

REVERSE BEND Reeving a wire rope over sheaves and drums so that it bends in opposing directions. See REEVE.

SASH CORD Small, 6 x 7 wire ropes, commonly made of iron wires, are referred to by this term.

REVERSE LAY See LAY, TYPES.

SEALE The name for a type of strand pattern that has two adjacent layers laid in one operation with any number of uniform sized wires in the outer layer, and with the same number of uniform but smaller sized wires in the inner layer.

RIGHT LAY See LAY, TYPES. ROLLERS Relatively small-diameter cylinders, or wide-faced sheaves, that serve as support for ropes.

SEIZE To make a secure binding at the end of a wire rope or strand with SEIZING WIRE or SEIZING STRAND.

APPENDIX F SEIZING STRAND Small diameter STRAND usually made up of 7 wires. SEIZING WIRE A wire for seizing. See SEIZE. SERVE To cover the surface of a wire rope or strand with a fiber cord or wire wrapping. SEWING WIRES See FLAT ROPE. SHACKLE A U- or anchor-shaped fitting with pin.

SPIRAL GROOVE A continuous helical groove that follows a path on and around a drum face, similar to a screw thread. See DRUM. SPLICING 1) Making a loop or eye in the end of a rope by tucking the ends of the strands back into the main body of the rope. 2) Formation of loops or eyes in a rope by means of mechanical attachments pressed onto the rope. 3) Joining of two rope ends so as to form a long or short splice in two pieces of rope. SPRING LAY See LAY, TYPES.

SHEAVE A grooved pulley for wire rope. SIEMENS-MARTIN STRAND A grade of galvanized strand. SLING, WIRE ROPE An assembly fabricated from WIRE ROPE which connects the load to the lifting device. SLING, BRAIDED A flexible sling, the body of which is made up of two or more WIRE ROPES braided together. See SLINGS. SMOOTH-COIL TRACK STRAND Strand composed of concentric layers of round WIRES, used as track cable, more commonly called ROUND WIRE TRACK STRAND.

STAINLESS STEEL ROPE Wire rope made up of corrosion resistant steel wires. STANDING ROPE See GUY LINE. STIRRUP The eyebolt attachment on a bridge socket. See SOCKET. STONE SAWING STRAND A 2-wire or 3-wire strand used in stone and slate quarrying operations. STONE SAWING WIRE A shaped and twisted wire used in stone and slate quarrying operations. STRAND A plurality of round or shaped wires helically laid about an axis. STRAND CENTER See CENTERS.

SMOOTH-FACED DRUM Drum with a plain, ungrooved surface. See DRUM. SOCKET Generic name for a type of wire rope fitting. See BRIDGE SOCKETS, CLOSED SOCKETS, OPEN SOCKETS and WEDGE SOCKETS. SPECIAL FLEXIBLE WIRE ROPE Term sometimes used to describe 6 x 37 classification wire rope. SPIN RESISTANT An abandoned term referring to a ROTATION-RESISTANT rope of the 8 x 19 classification.

STRAND CORE See WIRE STRAND CORE. STRANDER A machine that lays wires together helically to form a strand. STRESS The force or resistance within any solid body against alteration of form; in the case of a solid wire it would be the load on the rope divided by the crosssection area of the wire. STRETCH The elongation of a wire rope under load.

APPENDIX F SWAB LINE See CLEANING OUT LINE.

TRAMWAY An aerial conveying system for transporting multiple loads.

SWAGED FITTING Fitting into which wire rope can be inserted and then permanently attached by cold pressing (swaging) the shank that encloses the rope.

TURN Synonymous with the term WRAP; it signifies a single wrap around a drum. TURN BACK POINT See CHANGE OF LAYER.

TAG LINE A small wire rope used to prevent rotation of a load. TAPERED DRUM See CONICAL DRUM. TAPERING AND WELDING Reducing the diameter of a wire rope at its end, and then welding the wires so as to facilitate reeving. See END PREPARATION. THIMBLE Grooved metal fitting to protect the eye, or fastening loop of a wire rope. TILLER ROPE A highly flexible rope constructed by cable-laying six 6 x 7 ropes around a fiber core. TINNED WIRE Wire that is coated with tin. See WIRE. TRACK CABLE On an aerial conveyor it is the suspended wire rope or strand along which the carriers move. TRACTION ROPE On an aerial conveyor or haulage system it is the wire rope that propels the carriages. TRACTION STEEL ROPE A specific grade of wire rope.

WARRINGTON The name for a type of strand pattern that is characterized by having one of its wire layers (usually the outer) made up of an arrangement of alternately large and small wires. WEDGE SOCKET Wire rope fittings wherein the rope end is secured by a wedge. See FITTINGS. WHIPPING A synonymous term for SEIZING. Also, it has been suggested as punishment for those who neglect the cautionary rules in this publication. WIRE (ROUND) A single, continuous length of metal, with a circular crosssection that is cold-drawn from rod. WIRE (SHAPED) A single, continuous length of metal with a non-circular crosssection that is either cold-drawn or coldrolled from rod. WIRE ROPE A plurality of wire strands helically laid about an axis. WIRE STRAND CORE (WSC) A wire strand used as the axial member of a wire rope. WRAP See TURN.

ALPHABETICAL LISTING OF CONTENTS Basic Components / 7 Bending Rope Over Sheaves and Drums / 40 Breaking in a New Wire Rope / 51 Breaking Strengths / 77 Clips, How to Apply / 29 Constructional Stretch / 73 Cutting Wire Rope / 25 Design Factors / 77 Drums, Grooved / 35 Multiple Layers / 37 Plain (Smooth) / 36 Elastic Properties of Wire Rope / 73 Elastic Stretch / 74 End Preparations / 26 End Terminations / 26 Factors Affecting the Selection of Wire Rope / 47 Field Lubrication / 68 Fleet Angle / 47 Glossary of Wire Rope Terms (Appendix F) / 120 Handling and Installation / 18 Identification and Construction / 9 Inspections and Reports, Guidelines to / 51 Introduction / 5 Operation, Inspection and Maintenance of Wire Rope / 38 Ordering, Storing and Unreeling Wire Rope (Appendix A) / 99 Physical Properties / 73 Receiving, Inspection and Storage / 18 Seizing Wire Rope / 23 Sheaves and Drums / 38 Inspection of / 43 Shipping Reel Capacity (Appendix D) / 117 Socketing / 29 Procedures (Appendix C) / 112 Sockets, Wedge / 34 Strength Loss of Wire Rope Over Stationary Sheaves and Pins / 46 Unreeling and Uncoiling / 20 Weights of Materials (Appendix E) / 118 Wire Rope Clips / 29 Efficiency Over Sheaves / 70 Fittings (Appendix B) / 101 Identification and Construction / 9 Installation / 18 and Operations Inspection / 51 "X-Chart: Abrasion Resistance vs. Bending-Fatigue Resistance / 50

COMMITTEE OF WIRE ROPE PRODUCERS American Iron and Steel Institute Washington, D.C. WIRE ROPE TECHNICAL BOARD Bethesda, Maryland

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