Ultrasonic Thickness Measurment Guide

Ultrasonic Thickness Measurment Guide

Table of content 1. Objective and applicability 2. Terms and abbreviations 3. A few basics Procedure for class surveys and thickness measurements onboard ships 4.1

CLASS surveyor to be onboard.

4.2

Kick-off meeting.

4.3

Requirements to cleaning.

4.4

Means of access.

4.5

Execution of the Thickness Measurements on board.

5. Requirements to the UTM company 6. Extent of thickness measurements 6.1 All ships - Systematic requirements 6.2 General dry cargo ships - Systematic requirements 6.3 General dry cargo ships - Measurements i.w.o. close-up inspections 6.4 Bulk carriers ESP - Systematic requirements 6.5 Bulk carriers ESP - Measurements i.w.o. close-up inspections 6.6 All ESP Tankers- Systematic requirements 6.7 Single Hull Oil Tankers, Ore/Oil Ships ESP - Measurements i.w.o. close-up inspections 6.8 Double Hull Oil Tankers, Ore/Oil Ships ESP - Measurements i.w.o. close-up inspections 6.9 Chemical tankers ESP - Measurements i.w.o. close-up inspections

7. Thickness measurement pattern 7.1 Number of measurement points per plate and averaging 7.2 Transverse sections 7.3 Bulkheads and web frames 7.4 Measurements i.w.o. close-up inspections 7.5 Figures with location of measurement points 7.6 Mapping of areas with substantial corrosion Appendix A Kick-off meeting – Agenda and Minutes of Meeting Appendix B Ultrasonic Thickness Measurements of Ship’s Structure. Appendix C Thickness Measurements on Ships, High Speed and Light Craft and Mobile Offshore Units. Appendix D Mapping of areas with substantial corrosion Appendix E Example of UTM report front page Appendix F Calculation of average thickness reduction in deck and bottom. Verification of longitudinal strength Appendix G Guidelines for measurements of side frames in bulk carriers Appendix H Guidelines for measurement specification for Class Condition Assessment Programme (CAP) HULL

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Ultrasonic Thickness Measurment Guide

GLOSSARY

 TRAINING PROGRAME & PROCEDURES 1. On re-confirmation of job order, the Technical Manager delegates the job to a given team for execution. At this point of time, the designated team leader does a pre-survey preparation, in as much as identification of type and class of vessel. This facilitates preparation of relevant working documents for the survey and cycle due on the particular vessel. Thereafter equipment that will be utilized on the given job is thoroughly examined, recalibrated and exhaustively bench tested prior departure of the team for the job in question. The said equipment at this point of time is very pertinently calibrated on IIW reference test pieces. 2. CHECKLIST – On identifying the team to carry out the Gauging Survey, the Team leader then sets about filling up the prescribed CHECKLIST. Which on completion will be maintained, as performance appraisals of the Technicians concerned would be based on the remarks attached to the Check List by the Vessel’s Master, Superintendent & Attending Surveyor. 3. CONFLICT OF INTEREST – Furthermore should the client for whom we are carrying out the said Gauging Survey be any other than the vessel’s owners / Managers, strict attention is paid to the fact of any form of compromise relating to the job in question and should any form of compromise be sought after, the attending surveyor in immediately appraised of the situation. 4. Should the job entail commencement to completion of a special survey, then the technical manager makes it a point to visit the vessel / yard in order to monitor and maintain our stringer quality standards. 5. It is at this point that despite the attending surveyor’s random checks, our Technical Manager conducts his own random checks not only accuracy of gauging but also pertinence of on the job information required of each team member. This in turn acts as our in-house appraisal of all personnel concerned. 6. The next item on the agenda is the documentation. The reporting in the prescribed IACS Formats is prepared insitu, currently with the gauging exercise, should the same entail gauging towards SSH in completion. This is done by having a data entry operator equipped with notebook Computer and laser printer, for complete on board submission, prior the team’s sign off / departure from the said vessel.The onboard documentation facility ensures prompt and speedy reporting, for the attending Bureau surveyor. Moreover, should there be any queries on review of the gauging

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Ultrasonic Thickness Measurment Guide

document, the gauging team is available for verification / clarification of any queries should they arise.

7. Once the team returns to Base, the said gauging report is maintained for a period of 5 years in physical copy and for a period of 10 years on magnetic tape cartridge, which are presently being upgraded to CD ROM’s. 8.

A record will be maintained containing details of job such as job number, type of survey, class, client, technicians etc.

9. We also offer a facility of submission of gauging report on CD ROM’s / Floppy disks for the convenience of handling exhaustive data in an easy to use, easy to read format. Presently, the same is offered as standard practice for all LR Class vessels, on their approved software and Specific formats drawn in MS Excel for DNV CAP survey vessels.

10. Any inconsistencies, if noted either by the Technical Manager / team leader pertaining to any given individual is thoroughly discussed and corrective action if necessary instituted. Furthermore there are occasions where experiences of a given job is related to other team leaders / members so as to inform and educate other members accordingly.

 For More information Ref . to the Ultra Marine Services Guideline for Thickness Measurment Procedure No. UMS / UTG – 001.

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Ultrasonic Thickness Measurment Guide

THE SCOPE OF GAUGING ON BOARD THE VESSEL THE TEAM LEADER DISCUSSES WITH THE ATTENDING SUPERINTENDENT AND THE ATTENDING CLASS SURVEYOR THE COMPLETE SCOPE OF WORK REQUIRED. AS PER THE SURVEY CYCLE TOGETHER WITH ANY SPECIFIC REQUIREMENTS THAT MAY BE DEEMED NECESSARY BY ATTENDING CLASS SURVEYOR, SUCH AS DETERMINE THE FRAME STATIONS WHERE THE TRANSVERSE GIRTH BELTS MAY BE TAKEN, ANY OUTSTANDING CONDITIONS OF CLASS, OR MEMORANDA THAT MAY BE IMPOSED ON THE SUBJECT VESSEL PENDING SPECIFIC GAUGING IN THAT AREA, OR ANY SUSPECT AREAS ON THE VESSEL THAT MAY BE DEEMED NECESSARY BY THE ATTENDING CLASS SURVEYOR. FURTHERMORE NY GAUGING IN WAY OF STRUCTURE UNDER CLOSE UP WOULD BE SCHEDULED SUCH THAT THE ATTENDING CLASS SURVEYOR IS IN SUBSTANTIAL AND IF POSSIBLE TOTAL ATTENDANCE. THE DRAFT REPORT IS THEN MADE AND HANDED OVER TO THE VESSELS MASTER OR ATTENDING SUPERINTENDENT.

PREPARATION OF SURFACES. CORRECT SURFACE PREPARATION IS A VERY IMPORTANT ASPECT OF ULTRASONIC GAUGING. THE CONDITION WILL DETERMINE THE TYPE OF INSTRUMENT AND THE PROBE TO BE USED. ON SURFACES WITHOUT HARD COATING BUT HAS AN APPLICATION OF CONVENTIONAL PAINT AND SCALE UNDERNEATH, EITHER MANUAL CHIPPING OR NEEDLE GUN/ GRINDER SHOULD REMOVE THE SAME. IF THE AREA IS BROUGHT TO NEAR MACHINED LEVEL THEN A TWIN CRYSTAL SINGLE ECHO METER MAY BE USED, HOWEVER FOR AREAS WITH HARD COAT A FLAW DETECTOR NEEDS TO BE USED. THE FAILURE TO DO SO WILL RESULT IN INACCURATE RESULTS.

PROTECTIVE COATINGS . AS PER EXISTING REQUIREMENTS IT IS MANDATORY THAT ANY STRUCTURE HAVING A HARD COAT (EPOXY COAT) IN PLACE E.G. BALLAST TANKS/ CARGO TANKS, HULL ENVELOPE, TRANSVERSE/ LONGITUDINAL BULKHEADS ETC MUST NOT BE DAMAGED AT THE TIME GAUGING. CONTRARY TO THE CONVENTIONAL SYSTEM OF GAUGING WITH SINGLE ECHO DIGITAL EQUIPMENT WHEREIN THE SURFACE HAD TO BE FREE OF ANY PAINT OR HARD COAT, THE GAUGED VALUE WOULD REFLECT THE ACTUAL THICKNESS PLUS THE ADDITIONAL DEPTH OF THE COATING IN WAY. THEREFORE THE SURFACE WOULD THEN EITHER BE CHIPPED OR MACHINE GROUND IN ORDER TO GET THE ACTUAL THICKNESS.THESE NUMEROUS SPOTS ON THE STRUCTURE, CHIPPED OR GROUND TO BARE METAL WOULD SUBSEQUENTLY GIVE RISE TO NUMEROUS DEEP PITS OR PATCHES OF LOCALIZED CORROSION.

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Ultrasonic Thickness Measurment Guide

IT IS THEREFORE BEEN MANDATORY WHILST GAUGING STRUCTURES WITH PROTECTIVE HARD COAT IN PLACE, THE SAME TO BE DONE ONLY UTILIZING EITHER A MULTIPLE ECHO DIGITAL UNIT WITH A SINGLE CRYSTAL NORMAL PROBE OR GAUGED WITH THE AID OF AN ULTRASONIC FLAW DETECTOR WITH A SIMILAR PROBE. THEREBY ENABLING THE STRUCTURE TO BE GAUGED THROUGH COATING. WE SHALL BE UTILIZING AN ULTRASONIC FLAW DETECTOR (A-SCAN) FOR THE MEASUREMENT THROUGH HARD COATING.

CALIBRATION CHECKS . A VERY SIGNIFICANT PART OF GAUGING EXERCISE IS THE CONSTANT NEED TO MAINTAIN CALIBRATION CHECKS, WHICH FORM A VERY VITAL PART OF ENSURING THAT THE GAUGING EQUIPMENT UTILIZED, MEETS THE REQUIRED STANDARDS. THIS IS WELL ESTABLISHED BY PERIODIC CROSS CHECKS WHICH ARE MAINTAINED INITIALLY AT A SPACE OF EERY 5 POINTS GAUGED AND GOING UP TO A MAXIMUM OF 10 POINTS GAUGED. THIS EXERCISE IN TURN ENSURES THAT THE POINTS GAUGED ARE BOTH LINEAR AND ACCURATE, CORRECTED TO 0.1 MM OR THE ORDER OF 1% ON 10 MM PLATES OR 0.5% ON 20 MM PLATES. THE STANDARD REFERENCE BLOCKS USED WILL BE STEP WEDGES FROM 1 MM TO 50 MM.

TEAM LEADER/ SUPERVISOR RESPONSIBILITIES RESPONSIBILITIES :THE TEAM LEADER WILL HAVE THE FOLLOWING RESPONSIBILITIES FROM INCEPTION TO COMPLETION.          

AT THE TIME OF INITIAL INQUIRY FROM OWNERS ESTIMATE SCOPE OF WORK WITH THE MANAGER. ASSIST IN COMPOSITION OF TEAM CO-ORDINATE WITH OWNERS FOR DRAWINGS AND ANY PERTINENT INFORMATION. CHECK THE REQUIRED INSTRUMENTS FOR VALIDITY OF CALIBRATION AND COUNTER CHECK ALL INSTRUMENTS PLAN ALL ASSOCIATED TOOLS, SUCH AS DINGHY IF REQUIRED GRINDERS, ETC. CONFIRM ALL TRAVEL ARRANGEMENTS WITH OWNERS ALONG WITH ACCOUNT MANAGER. ONSITE CO-ORDINATE WITH SUPERINTENDENT/MASTER AND CLASS SURVEYOR AND PERFORM GAUGING. ENSURE ACCURACY OF GAUGING BY COUNTER CHECKING THE OPERATORS READINGS. ENSURE THE DRAFT REPORT SUBMITTED IS ERROR FREE. BACK IN BASE FORMULATES THE COMPLETE REPORT AND SUBMITS TO OWNERS AND CLASS SURVEYOR.

CHECKS AND BALANCES:AN INTEGRAL PART OF ANY ORGANIZATION IS PROPER SYSTEM OF CHECKS AND BALANCES. TOWARDS THIS OBJECTIVE THE SUPERVISOR SHALL EVALUATE THE PERSONNEL WORKING UNDER HIM AT THE END OF EACH JOB. Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

THE SUPERVISOR IN TURN WILL DEBRIEF THE MANAGER OR CHIEF ADVISOR, AND THE REPORT PRIOR SUBMISSION SHALL BE CHECKED BY THE CHIEF ADVISOR / MANAG ER

OPERATOR INSTRUCTIONS & RESPONSIBILITIES THE OPERATOR IS A KEY PLAYER IN THE PROCESS OF ULTRASONIC GAUGING AND IT IS VERY IMPORTANT THAT THE OPERATOR EXERCISE UTMOST CAUTION AND CARE IN TAKING THE READINGS.

OPERATING INSTRUCTIONS : THE OPERATOR IS TO VERIFY THE CALIBRATION ON THE STEP WEDGE PRIOR DEPARTURE TO VESSEL.  ONBOARD PRIOR COMMENCEMENT THE INSTRUMENTS CALIBRATION TO BE RECHECKED.  THE AREA TO BE GAUGED IF DEVOID OF HARD COAT SHOULD BE CLEANED OF PAINT AND SCALE TO BRING TO NEAR MACHINE LEVEL.  OPERATOR TO ENSURE COUPLANT IS ADEQUATELY USED.  OPERATOR TO ENSURE THE SATISFACTORY OPERATION AND SELECTION OF THE PROBE.  IF ANY ERROR IS SUSPECTED THE AREA TO REGAUGED.  ALL READINGS MUST BE TAKEN IN PORT –STBD MANNER  IN AREAS OF HIGH CORROSION 5 POINT STAR METHOD OF READINGS TO BE FOLLOWED.  INSTRUMENT TO BE INTERMITTENTLY CHECKED FOR ERRORS BY ON INTRUMENT VERIFICATION.  THE READINGS TO BE NOTED ON A DRAWING FOR PROPER REPRESENTATION ON FINAL REPORT.

RESPONSIBILITIES :THE OPERATOR SHALL BE RESPONSIBLE FOR THE FOLLOWING. CONSTANT CALIBRATION VERIFICATION. BRINGING TO SUPERVISORS IMMEDIATE ATTENTION ANY AREA WITH EXCESSIVE CORROSION. EXPERIENCED OPERATORS ARE TO GUIDE FRESH TECHNICIANS. ENSURING THAT THE READINGS TAKEN ARE ACCURATELY REPRESENTED. ENSURING THAT ALL INSTRUMENTS ARE KEPT IN WORKING CONDITION, ANY FAULT DETECTED IS TO BE BROUGHT TO ATTENTION OF GROUP LEADER IMMEDIATELY.

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Ultrasonic Thickness Measurment Guide

GUIDELINE FOR ULTRASONIC THICKNESS MEASURMENT OF SHIP CLASSED

1. Objective and applicability This guideline is prepared by Ultra Marine Services for ship owners, operators, yards for thickness measurements of ship's structure, in order to facilitate co-operation through a common understanding of the procedures for UTM ( ultrasonic thickness measurements) at Class Surveys. CAP is not covered by this guide. This guide applies to all types of steel ships classed

Fig.1.1 Steel plates in the deck being replaced after UTM. Evenly corroded steel plates might look perfectly acceptable even at close-up distance. Thus, thickness measurements are an essential part of class surveys.

2. Terms and abbreviations Conditions

Conditions are issued to ship owners by class, in order to impose improvements, additional surveys or other actions to ensure compliance with rule requirements.

CA

A condition on behalf of a flag state that will be issued if the condition is related to statutory surveys where class has been authorised.

CAP

Condition Assessment Program. Voluntary hull condition survey, where a ship's hull, machinery or piping system is given one of the following ratings; 1 - Very good condition, 2 - Good condition, 3 - Satisfactory condition or 4 - Poor condition ( below acceptable class standard ).

CAS

Condition Assessment Scheme. Increased survey/reporting scope, where the classification society will send a hull condition report to the flag state for their acceptance to let the ship continue trading. Applies to single skin tankers >15 years on their first intermediate or renewal survey after 5th. of April 2005.

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Ultrasonic Thickness Measurment Guide

CC

A Condition of Class will be issued if a condition is related to requirements set by the rules. A CC is subject to specified rectification (e.g. repairs) or operation (e.g. survey) and shall be carried out within a given time limit, in order that the ship retain class.

C.N.72.1

Classification Notes No.72.1 "Allowable Thickness Diminution for Hull Structure"

ESP

Enhanced Survey Program. Requirements for planning, execution and reporting for hull surveys of oil/chemical tankers, obo and bulk carriers.

Excessive corrosion Extensive corrosion

IACS

An extent of corrosion that exceeds the allowable limit, so that steel must be replaced. Ref. Fig.2.1. An extent of corrosion consisting of hard and/or loose scale, including pitting, over 70% or more of the area under consideration, accompanied by evidence of thickness diminution.

International Association of Classification Societies. DNV is one of 12 member classification societies, which all have to abide by common IACS rules. The other member societies are American Bureau of Shipping, Bureau Veritas, China Classification Society, Germanischer Lloyd, Lloyd's Register of Shipping, Nippon Kaiji Kyokai, Korean Register, Polski Rejestr Statkow, Registro Italiano Navale, Rinave Portuguesa and Register of Shipping of the U.S.S.R.

Minimum thickness list List of minimum acceptable thickness values for the structural parts of a ship. An individual list will be made by class for each and every ship which is to be measured. Substantial corrosion

Tmin

Where less than 25% of the corrosion margin is left, yet thickness is higher than for excessive corrosion. See figure. Limits are stated in the minimum thickness list. Minimum allowable thickness. Calculated by class and entered into a minimum thickness list. If a steel plate or profile corrodes to a thickness less than this value, it will normally have to be replaced.

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Ultrasonic Thickness Measurment Guide

Tmin list

See minimum thickness list

Tsubst

See "Substantial corrosion"

UTM

Ultrasonic Thickness Measurements. Used to determine the thickness of steel plates and profiles.

3.

A few basics

1. All thickness measurements done onboard class ships, where the results are used by the class surveyor to evaluate the strength, shall be done by a class approved ULTRA MARINE with a valid class certificate. 2. Thickness measurements done for class, as described in point 1, shall be done with a class surveyor onboard. 3. IACS CLASS have specific requirements to access and cleaning to be prepared for close-up surveys combined with UTM ( see 4.3 and 4.4 ). Access and cleaning is owner's responsibility. 4. Prior to every major thickness measurement project onboard, such as for intermediate or renewal survey, a meeting between CLASS, the ULTRA MARINE SERVICES and the owner shall be held. If a thickness measurement project is divided up in separate smaller UTM jobs, a new meeting shall be held prior to each job. 5. Ultra Marine provide two operators for all major thickness measurement jobs ( Intermediate Survey and Renewal Survey ) done onboard ships. 6. The surveyor onboard shall be kept continuously informed about discovered areas with under minimum thickness, and other structural defects such as cracks, grooving and buckling. 7. Based on the results coming up, the surveyor may always order additional measurements to be taken. 8. The thickness measurement report made by ULTRA MARINE shall be filled in throughout the project and results made available to the surveyor onboard. A preliminary report shall be given to the attending CLASS surveyor before leaving the ship. 9. The final thickness measurement report for ships shall be issued within 2 weeks after the thickness measurement job is completed.

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Ultrasonic Thickness Measurment Guide

4. Procedure for class surveys and Thickness Measurements onboard ships 4.1 CLASS surveyor to be onboard A CLASS surveyor shall be onboard, to the extent he or she finds necessary to control the process, when thickness measurements are done for class. Measurements which have not been carried out in co-operation with CLASS can not be accepted. The ULTRA MARINE shall inform the owner accordingly. Ref. CLASS Rules.This applies to all steel ships where the measurements will make the basis for the surveyor's decisions during class surveys.Thickness measurements which per our rules are required in connection with close-up examination (such as web frames and transverse bulkheads) shall always be taken with the surveyor in attendance. When onboard the operator/supervisor shall have his certificate and identification papers readily available for verification. The operator shall notify the CLASS surveyor of any structural deficiencies, such as cracks, indents, buckling or abnormal measurements detected.

4.2 Kick-off meeting The CLASS rules require a meeting for planning of the thickness measurements, including Ownersrepresentative, ULTRA MARINE and CLASS. See Appendix A for an agenda/Minutes of Meeting form to be used for these meetings. The meeting shall clarify initial scope of close-up examination and thickness measurements. At the meeting, unless requested earlier, the surveyor will hand over the minimum thickness list. For ESP ships it may be found in the Survey Programme. The minimum thickness list is individual for each and every ship, and shall always be made by CLASS. Upon receiving the minimum thickness list, the UTM operators shall enter the minimum thickness values into the UTM report template, prior to commencing thickness measurements, in order to facilitate the evaluation of the results on a day by day basis onboard.

4.3 Requirements to cleaning Cleaning is the owner's responsibility. The Owners should ensure that efficient means for de-scaling is available at the survey, i.e. hydro or sandblasting equipment. When satisfactory de-scaling may not be arranged, the surveyor will only be able to provide a preliminary specification of necessary upgrading, without crediting the tank. A new survey will be carried out after de-scaling, additional thickness measurements may be required and the scope of repairs extended

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Ultrasonic Thickness Measurment Guide

Fig 4.3.1 Optimal conditions for inspection : Grit blasted, dry and clean, with all sediments, loose coating and rust flakes removed. Thickness reductions and cracks are easily spotted with the naked eye.

What is sometimes presented for inspection : No cleaning whatsoever. Two men have been sent along to “hack away loose scale where needed”. This is not acceptable according to our rules, and the inspection should be rejected by the surveyor. Please note that the ULTRA MARINE Rules, as well as IACS, do have requirements to the cleanliness during surveys :

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Ultrasonic Thickness Measurment Guide

In preparation for survey and to allow for a thorough examination, all spaces shall be cleaned including removal from surfaces of all loose accumulated corrosion scale. In tanks where soft coatings have been applied, representative areas, and those areas where it is obvious that further close-up examination is required, shall be cleaned free of soft coating. Guidance note: Spaces should be sufficiently clean and free from water, scale, dirt, oil residues etc. to reveal corrosion, deformation, fractures, damage, or other structural deterioration. However, those areas of structure whose renewal has already been decided by the owner need only be cleaned and descaled to the extent necessary to determine the limits of the renewed areas. For more detailed information with regard to a tank where soft coatings have been applied, see IACS Recommendation No. 44. ---e-n-d---of---G-u-i-d-a-n-c-e---n-o-t-e--In preparation for survey and thickness measurements, and to allow for a thorough examination, all spaces are to be cleaned including removal from surfaces of all loose accumulated corrosion scale. Spaces are to be sufficiently clean and free from water, scale, dirt, oil residues etc. to reveal corrosion, deformation, fractures, damages, or other structural deterioration. However, those areas of structure whose renewal has already been decided by the owner need only be cleaned and descaled to the extent necessary to determine the limits of the renewed areas.

4.4 Means of access

Fig. 4.4.1 Temporary staging during renewal survey of an oil tanker Access is the owner's responsibility. Quote : For close-up examination, one or more of the following means for access shall be provided: – permanent staging and passages through structures – temporary staging and passages through structures – lifts and moveable platforms – boats or rafts – other equivalent means. End quote. Please note that in July 2004, IACS introduced restrictions to the use of rafting in the upper area of tanks.

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Ultrasonic Thickness Measurment Guide

Quote : Rafts or boats alone may be allowed for survey of the under deck areas for tanks or spaces, if the depth of the webs is 1.5 m or less.

If the depth of the webs is more than 1.5 m, rafts or boats alone may be allowed only: - when the coating of the under deck structure is in GOOD condition and there is no evidence of wastage; or - if rafts or boats are to be used with a water level above the face plate of the deck girders, anescape route through the air space is to be provided. This may be arranged with a permanent means of access in each bay to allow safe entry and exit with access direct from deck via a vertical ladder and a small platform fitted approximately 2 m below deck. If neither of the above conditions are met, then staging or "other equivalent means" of access shall be provided for the survey of the under deck areas. Unquote The restriction has been made to protect the persons doing the rafting, in the case of an emergency

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Ultrasonic Thickness Measurment Guide

Fig. 4.4.4 Schematic illustration of how close-up may be achieved without rafting underneath deck. Temporary staging is placed between the flanges of the web frames. Tank is partly filled for safety reasons. One example of "other equivalent means" may be to use temporary, portable staging fitted between the flanges of two web frames, with partial filling of the tank ( with a water level well below the web frames ) for safety. Alternatives with climbers doing thickness measurements while carrying a camera, in order to let the surveyor do the close-up survey by watching a TV screen onboard, will only be accepted on a case by case basis, and must be clarified with CLASS well in advance of the survey. 4.5 Execution of the Thickness Measurements on board. Prior to commencing the thickness measurements, the surveyor will : - Check type of equipment and verify that the equipment is calibrated according to recognized national / international standards and properly labelled. - Witness calibration appropriate for size and type of material. - Be satisfied with operator’s competence and documentation. The operators shall keep the equipment and required certificates ready for inspection at commencement of measurements. For requirements to equipment and operators,

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Ultrasonic Thickness Measurment Guide

The surveyor will direct the gauging operation by selecting locations such that readings taken represent, on average, the condition of the structure for that area. Thickness measurements mainly to evaluate the extent of corrosion which may affect the hull girder strength ( transverse sections ), should be carried out in a systematic manner of all longitudinal, structural members. See Ch. 7 for a figure showing correct pattern. The surveyor should be in attendance during this process. The location of the sections longitudinally shall be decided by the surveyor, and will normally be decided after deck and bottom plating has been measured, where required, in order to determine which areas have corroded the most. The sections should be placed where the upper and lower plating has corroded the most. One transverse section will normally be placed amidship Thickness measurements of structures in areas where close-up surveys are required should be carried out simultaneously with the close-up surveys in order to facilitate a meaningful survey. The surveyor may specially consider the extent of ( "waive" ) thickness measurements of certain structures, within spaces where the protective coating is found to be in GOOD condition, but there are restrictions to how much of the measurements may be waived. In any case, ask the surveyor what may be waived in each case. The thickness measurement operators shall keep the surveyor continuously informed ( e.g. at the end of each day of measurements ) about measurement results and structural deficiencies found, such as excessive or substantial corrosion, cracks, indents or buckling. If doubler plates used as repairs are discovered inside oil tanks or on oil/water boundary plating or stiffeners, this shall also be informed to the surveyor. Where thickness measurements indicate substantial corrosion or excessive diminution, the ULTRA MARINE shall contact the CLASS surveyor onboard in order to get directions for additional thickness measurements, in order to map the areas of substantial corrosion, and to identify structural members for repairs / renewals. The CLAS Rules Pt.7 Ch.2 and Appendix D of this document contain tables detailing how such areas shall be mapped. Upon completion of the thickness measurements, the surveyor must have confirmed that no further gauging is needed, before the job of taking measurements can be regarded as completed. The rule requirements detailed in ch.6 are always to be considered the minimum scope for thickness measurements. Upon completion of the thickness measurements onboard, the surveyor shall verify and sign the preliminary thickness measurement report. A copy of the preliminary report shall be given to the attending surveyor before leaving the ship.

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Ultrasonic Thickness Measurment Guide

5. Requirements to the UTM company ULTRA MARINE Ship and with a CLASS Surveyor present. The company shall have a valid CLASS certificate, ULTRA MARINE Ship take Ultrasonic Thickness Measurements of Ship's Structure". Guide line A copy of the programme may be found in this document. Some of the most important, A. Instruments using pulsed echo technique, either with oscilloscope or digital instruments using multiple echo, single crystal technique are required. Single echo instruments are not accepted. ( Previously single echo instruments were accepted on un-coated surfaces ). A confirmation from the manufacturer that the instruments satisfy this requirement shall be enclosed with the instrument record. B. Each major class job Requied ( Intermediate Survey and Renewal Survey ) is to be carried out by at least two qualified operators working together. ULTRA MARINE Operators carrying ID cards with a photo. ULTRA MARINE Operators be able to speak English, understand ship's drawings and be able to choose a representative position for each measurement. C. On coated surfaces, instruments using pulsed echo technique (either with oscilloscope or digital instruments using multiple echo, single crystal technique) are required. Single echo instruments may be used on uncoated surfaces. A record of the equipment used for thickness measurement shall be kept. The record shall contain information on maintenance and calibration. D. The ULTRA MARINE keep records of the approved operators. The record shall contain information on age, formal education, training and experience. E. The operator carrying out the ASNT LEVEL II certificat Level I, ISO 9712 Level I or a corresponding standard and have passed the internal training scheme of the supplier. The operator shall also have at least one year's experience as an assistant operator ( minimum 10 different assignments ).

6. Extent of thickness measurements The rule requirements to the extent of thickness measurements for ships are specified in the CLASS rules Pt.7 Ch.2 Sec.2 Table D3, with enhanced requirements for general cargo ships, bulk carriers and tankers in Pt.7 Ch.2 Sec.2 Tables E2 and Pt.7 Ch.2 Sec.3 F2, G3, G4 and K2. Each table will correspond to one specific ship type. All tables are given with illustrations in 6.1. The requirements vary with ship type, age and survey type, and may generally be divided in three groups: 1. Systematic requirements including measurements of shell plating and transverse sections, to help evaluate the overall strength of the ship. The requirements should not be waived due to GOOD coating, but the extent of measurement points may be reduced to some extent. What may be waived shall always be decided by the surveyor, who may also decide to increase the scope based on findings onboard. The requirements are given in tables 6.1, 6.2, 6.4 and 6.6 below, pending on ship type. Measurement pattern ( number of measurement points per structural part ) is described in ch.7. 2. Measurements for assessment of corrosion level i.w.o. close-up inspections. A guideline for initial extent of measurements is given in tables 6.3, 6.5 and 6.7 to 6.9 below, pending on ship type. The requirements may be partly waived in case original coating is in GOOD condition, to be decided by the surveyor. The surveyor may also decide to increase the scope based on findings onboard. Measurement pattern ( number of measurement points per structural part ) is described in ch.7. Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

3. Mapping of areas found with Substantial Corrosion Areas found with Substantial Corrosion, as defined in ch.2, at previous surveys or through the measurements described in 1 and 2, should be subject to intensive measurements. The required measurement pattern is thoroughly defined in the rules Pt.7 Ch.2 and given in tables in Appendix D of this document.

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Ultrasonic Thickness Measurment Guide

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Ultrasonic Thickness Measurment Guide

All ships - Systematic requirements

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Ultrasonic Thickness Measurment Guide

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Ultrasonic Thickness Measurment Guide

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Ultrasonic Thickness Measurment Guide

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Ultrasonic Thickness Measurment Guide

General dry cargo ships - Systematic requirements

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Ultrasonic Thickness Measurment Guide

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Ultrasonic Thickness Measurment Guide

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Ultrasonic Thickness Measurment Guide

General dry cargo ships - Measurements i.w.o. close-up inspections

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Ultrasonic Thickness Measurment Guide

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Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Bulk carriers ESP - Systematic requirements

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Bulk carriers ESP - Measurements i.w.o. close-up inspections

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

All ESP Tankers- Systematic requirements

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Single Hull Oil Tankers, Ore/Oil Ships ESP – Measurements i.w.o. close-up inspections

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Double Hull Oil Tankers, Ore/Oil Ships ESP - Measurements i.w.o. close-up

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Chemical tankers ESP - Measurements i.w.o. close-up inspections

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

CLASS Condition Assessment Programme. - CAP

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

THICKNESS MEASUREMENT SPECIFICATION FOR CLASS CONDITION ASSESSMENT PROGRAMME (CAP)HULL

1. Objective 1.1 This specification describes the extent of thickness measurements required for CLASS Condition Assessment Programme (CAP) Hull. Requirements to thickness measurements for class surveys are specified in CLASS Rules for Classification of Ships. 1.2 CLASS uses thickness measurement data for a statistical analysis of diminution as a basis for the CAP rating. Representative data for all main structural elements in all tanks/spaces are required. The main structural elements in a CAP context are deck, shipside, bottom, inner bottom, inner deck, longitudinal bulkhead, transverse bulkhead (i.e. tank/space boundaries with plating and stiffeners) and internal structure (i.e. webframes, stringers, girders, floors etc.) 1.3 Failure to carry out thickness measurements according to this specification may prevent completion of CAP.

2. General 2.1 Thickness measurements shall be carried out by a qualified company approved by CLASS. 2.2 A CLASS surveyor shall be onboard while the measurements are taken to the extent necessary to control the process. 2.3 The thickness measurements data shall be reported using the “CLASS UTM Template”. All information required in the template is to be completed by the thickness measurement company. The “CLASS UTM Template” 2.4 One electronic version and one paper version of the thickness measurement report with sketches and relevant documentation is to be submitted to the responsible CLASS unit. 2.5 Readings to be included in the thickness measurement report shall be representative for the area measured and shall normally be single point readings. If a single reading is not considered to be representative for the area it represent, additional readings may be carried out in same area and included in the report together with a comment stating that these are additional readings. Alternatively, the average value of several readings in a small area may be included in the report together with a comment stating that this is an average value. In such cases all the readings to be averaged are to be taken within the affected area.Low readings shall not be averaged out by several readings in adjacent uncorroded areas. 2.6 Pits, grooves and local corrosion are to be measured and included in the report with a suitable comment. 2.7 Cracks, buckling and other deficiencies identified are to be reported to the attending CAP surveyor and included as comments/sketches in the thickness measurement report.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

3. Standard Extent of Thickness Measurements 3.1 The standard extent of measurements is described in this section. Reductions in the standard extent of measurements are only accepted in accordance with criteria listed in Section 4. 3.2 The following structure is to be completely measured with 5 points per plate: - Exposed main deck plating - Bottom plating - Wind and water strakes - Inner bottom plating - Continuous longitudinal stringers and inner deck plating 3.3 Three transverse sections in the cargo area are to be chosen where the largest reductions are suspected to occur or are revealed from deck plating measurements. The transverse sections are normally to be located outside the line of cargo hatch openings if fitted. The complete section is to be measured, including:- Within 0.15D (where D is the moulded depth of the ship) from deck and bottom every longitudinal and girder shall be measured on the web and flange and every plate shall be measured one point between each longitudinal. - Between deck and bottom area every longitudinal and girder shall be measured on the web and flange and every plate strake at least one point per plate. 3.4 All tanks in the cargo area are to be measured in three transverse belts for each tank, normally located in the forward, middle and aft parts of the tank. Measurements in two transverse belts are sufficient for tanks of less than 15 metres length. All structure in and adjacent to these belts are to be measured, including:- Longitudinals and other stiffeners with one representative measurement on both web and flange. - Ship side (outside wind and water strakes) and longitudinal bulkhead plates (2 points per plate strake). - Stringer platforms with associated structure (2 points per plate). - Transverse bulkheads including swash bulkheads with associated structure (plates and stiffeners at three horizontal levels). - Web frames with flanges, stiffeners and brackets. 3.5 The following structure is to be measured in fore and aft peak tanks: - All transverse webs with associated plating and longitudinals. - Transverse bulkhead complete with associated structure. - Deckhead (tanktop) and stringers with associated structure. - Bottom and shipside with stiffeners. 3.6 Any other ballast tanks outside of cargo area are to be measured as described in Section 3.4. 3.7 For cofferdams, voids and other spaces in the cargo area, representative thickness data for all main structural elements are required. 3.8 Cargo hatches with coamings and associated structure are to be measured for all holds. 3.9 Additional measurements are to be carried out if one or more readings indicate corrosion exceeding requirement to CAP 2 (67 % of allowable margin). “Requirements for extent of thickness measurements at those areas of substantial corrosion” in CLASS Rules for Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Classification of Ships should be used for guidance. 3.10 Extent of measurements may be increased as considered necessary by the attending CAP surveyor.

4. Reduced Extent of Measurements 4.1 Extent of measurements in shell plating (ref. Section 3.2) and in three transverse sections in cargo area (ref. Section 3.3) is not to be reduced. 4.2 The number of readings may only be reduced if the structure in question is: - made of solid stainless steel, or - coated with original coating still intact on both sides of the structure, or - located within fuel or cargo tank(s)and - representative thickness measurements reveal no or negligible steel loss, well within he requirements for CAP 1 (33 % of allowable margin). The representative measurements are to be taken in areas expected to represent worst case corrosion. 4.3 Where the number of thickness measurements is reduced, it is to be ensured that representative measurements are obtained for all main structural elements (ref. Section1.2) in all tanks/spaces. An absolute minimum of 10 representative readings for each main structural element in all tanks/spaces are required. If measurements reveal that the conditions given in Section 4.2 are not met, the standard extent of measurements as described in Section 3 is to be carried out. 4.4 No reduction in extent of measurements is to be applied unless accepted by the attending CAP surveyor

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

The Class IACS Condition Assessment Program(CAP) Ship's conditions can remain of a good level throughout their service lives if they are operated in an appropriate manner, the current state of construction and equipment of each ship or structure are clearly understood, and inspections and maintenance are carried out regularly and properly. Ships should be surveyed periodically to verify that they are maintained in an acceptable condition in accordance with international conventions, the Rules of Classification societies, etc. Detailed ship conditions, however, can not usually be all assessed by the regular surveys. A detailed assessment of ship condition is very important for the owner's maintenance program through a ship's service life. The IACS Condition Assessment Program(CAP) is a specialized survey program which offers owners a detailed assessment of a ship's actual condition, based on strength evaluation, and fatigue strength analysis as well as a detailed on site systematic inspection of the hull, machinery and cargo systems. With the CAP, owners can be confident that they have an accurate assessment of the ships actual condition, especially as far as the condition compares with the normal Class requirements. The CAP applies, in principle, to oil tankers and chemical carriers, though other types of ships may be covered, provided that the CAP is properly modified. The CAP consists of two major parts which can be applied independently depending on the needs of the applicant. (1) CAP-HULL (Condition Assessment for Hull Structures) (2) CAP-MACHINERY/CARGO SYSTEM (Condition Assessment for Machinery and Cargo Systems) The results of condition assessment are clearly identified using a rating system. The definitions corresponding to each rating are indicated below.

(1) CAP-HULL RATING (a) Rating Level 1: "Very Good Condition" Items examined and measured found with only superficial reductions from "as new" or current rule scantlings. No maintenance or repair required. (b) Rating Level 2: "Good Condition" Items examined and measured found to have deficiencies of a minor nature not requiring correction or repair and/or found to have all thicknesses significantly above class limits. (c) Rating Level 3 : "Satisfactory Condition" Items examined and measured either found to have deficiencies, which do not require immediate corrective action, or found to have thicknesses, which although generally above class renewal levels, do exhibit substantial corrosion. (d) Rating Level 4 : "Unsatisfactory Condition" Items examined and measured either found to have a deficiency or deficiencies which may affect the ship's potential to remain in class, or found to have, in some areas, thicknesses which are at or below the class renewal levels.

(2) CAP-MACHINERY/CARGO SYSTEM RATING (a) Rating Grade 1: "Very Good Condition" Items and systems examined and function tested, found with no deficiencies affecting safe operation and/or performance. Documentation and maintenance practices considered good. No maintenance or repair required. (b) Rating Grade 2: "Good Condition" Items and systems examined and function tested, found with some minor deficiencies which do not affect safe operation and/or normal performance. Documentation and maintenance practices considered adequate. No immediate maintenance or repair considered necessary.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide (c) Rating Grade 3: "Satisfactory condition" Items and systems examined and function tested, found with deficiencies not affecting safe operation and/or performance. Documentation and maintenance practices considered to be of a minimum standard. Some maintenance and repair may be considered necessary. (d) Rating Grade 4: "Unsatisfactory condition" Items and systems examined and function tested, found with deficiencies significantly affecting operation and/or erformance.Documentation and maintenance practices considered inadequate.Maintenance and repair required to reinstate serviceability. After the completion of the CAP, the certificate of CAP indicating the ship's comprehensive rating (Overall Rating for CAP-HULL and/or CAP-MACHINERY / CARGO SYSTEM) is issued. Detailed assessment results and the relevant records shown below are attached to the certificate of CAP. (1) CAP-HULL (a) CAP-HULL rating for each structural group and strength evaluation (b) Survey record (c) Report for fatigue strength assessment (d) Rating for corrosion protection systems of water ballast tanks and coated cargo tanks (e) Photographic report (f) Thickness measurement record (2) CAP-MACHINERY/CARGO SYSTEM (a) CAP-MACHINERY/CARGO SYSTEM rating for each item (b) Survey record (c) Photographic report

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Calculation of average thickness reduction in deck and bottom. Verification of longitudinal strength F1 General This appendix is a guideline on how to verify a ship's longitudinal strength, i.e. estimate average corrosion reduction in deck and bottom, as required for vessels having had a transverse section measured with UTM as part of the renewal survey scope. The calculation shall either be made by attending surveyor, or by the service supplier doing the thickness measurements, with the surveyor verifying the results. It is not necessary to calculate the ship's section modulus or the cross section's moment of inertia in order to verify the longitudinal strength. For a quick approximation, a quick "adding up" of cross section areas, as shown in the following example, is sufficient for the verification of the longitudinal strength in the field. Only if the calculated reduction percentage gets close to 10% ( or 5%, if so stated in the heading of the minimum thickness list ), is it necessary to contact MTPNO864 for a more accurate approximation of actual loss of longitudinal strength. It is of no less importance that the surveyors carry out this approximation whenever a complete, transverse section is measured, as it forms the very basis for the minimum thickness list. If the steel in plates or longitudinals is mild steel or high strength steel has no influence on the result. The thickness reduction of HS steel and mild steel may be added into one figure. The ship's main drawings shall be used to find as-built thickness values where no min. thickness list is available. For tankers above 130 m length,CLASS will upon request send electronically an Excel sheet for average corrosion calculation/reporting, including original thickness values for applicable area.

F2 Example For illustration, only half of the ship's breadth is included in the calculation below. When doing such verification in real life, however, one should calculate the average thickness reduction over the whole breadth, from side to side (see Fig.2). In the bottom one should calculate over the whole breadth, from bilge to bilge. As shown below, it is enough to calculate the average area reduction for the deck ( or the bottom ) itself, even if some of the minimum thickness lists mention the upper or lower 15% of the sides and longitudinal bulkhead as "upper area" or "lower area". However, it's not wrong to include the upper or lower 15%, either.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide If this was the only section to be measured in a ship with a maximum average corrosion limit of 10%, there would not be any problem. The surveyor could just state “average corrosion verified to be below 10%” in the inspection report. However, if the ship’s minimum thickness list has maximum 5% average corrosion in the deck area stated on the front page, then the surveyor shall be notified immediately. The ship could have so much corrosion, that it would need to have the minimum thickness list revised. The bottom should be verified the same way.

Appendix G Guidelines for measurements of side frames in bulk carriers Annex V - Guidelines for the Gauging of Side Shell Frames and Brackets in Single Side Skin Bulk Carriers required to comply with IACS Unified Requirements S31 ( incorporated in CLASS Rules )

General Single Skin Bulk carriers which are to comply with the new rules (IACS Unified Requirements UR S31) will be identified with a Memo to Owner. The new rules require increased control of the side frame scantlings. To assist the Surveyor, a new minimum thickness lists will be prepared for all ships where this requirement is applicable.

Zones of Side Shell Frames and Brackets For the purpose of steel renewal, sand blasting and coating, four zones A, B, C and D are defined, as shown in Figure 1. Zones A & B are considered to be the most critical zones.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Pitting and grooving Pits can grow in a variety of shapes, some of which would need to be ground before assessment. Pitting corrosion may be found under coating blisters, which must be removed before inspection. To measure the remaining thickness of pits or grooving the normal ultrasonic transducer (generally 10mm diameter) will not suffice. A miniature transducer (3 to 5 mm diameter) must be used. Alternatively the gauging firm must use a pit gauge to measure the depth of the pits and grooving and calculate the remaining thickness.

Assessment based upon Area This is the method specified in S31.2.5 and is based upon the intensity determined from Figure 2 below.

If pitting intensity is higher than 15% in an area (see Figure 2), then thickness measurements are to be taken to check the extent of the pitting corrosion. The 15% is based upon pitting or grooving on only one side of the web. In cases where pitting is evident as defined above (exceeding 15 %) then an area of 300mm diameter or more, at the most pitted part of the frame, is to be cleaned to bare metal, and the thickness measured in way of the five deepest pits within the cleaned area. The least thickness measured in way of any of these pits is to be taken as the thickness to be recorded. The minimum acceptable remaining thickness in any pit or groove is equal to: - 75% of the as built thickness, for pitting or grooving in the cargo hold side frame webs and flanges - 70% of the as built thickness, for pitting or grooving in the side shell, hopper tank and topside tank plating attached to the cargo hold side frame, over a width up to 30mm from each side of it.

Gauging methodology Numbers of side frames to be measured are equivalent to those of Renewal Survey or Intermediate Survey corresponding to the ship’s age. Representative thickness measurements are to be taken for each zone as specified below. Special consideration to the extent of the thickness measurements may be given by the Classification Society, if the structural members show no thickness diminution with respect to the as built thicknesses and the coating is found in "asnew" condition ( i.e., without breakdown or rusting ). Where gauging readings close to the criteria are found, the number of hold frames to be measured is to be increased. The Planning Document for vessels where IACS UR S31 apply, will include an additional T-min list valid for the side frames, or the list will be provided separately.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide If renewal or other measures according to S31 are to be applied on individual frames in a hold, then all frames in that hold are to be gauged. There is a variety of construction methods used for side shell frames in bulk carriers. Some have faceplates (T sections) on the side shell frames, some have flanged plates and some have bulb plates. The use of faceplates and flanged sections is considered similar for gauging purposes in that both the web and faceplate or web and flange plate are to be gauged. If bulb plate has been used, then the web of the bulb plate is to be gauged in the normal manner and the sectional modulus has to be specially considered if required. The provided T-min list will normally indicate cases where sectional modulus may be a problem.

Gaugings of Web plating for Zones A, B & D The gauging pattern for Zones A, B & D are to be a five point pattern. See figure 3. The 5 point pattern is to be over the depth of the web and the same area vertically. The gauging report is to reflect the average reading.

Gaugings of Web plating for Zone C Depending upon the condition of the web in way of Zone C, the web may be measured by taking 3 readings over the length of Zone C and averaging them. The average reading is to be compared with the allowable thickness. If the web plating has general corrosion then this pattern should be expanded to a five point pattern as noted above.

Gaugings of flanges for all Zones At least 2 readings on the flange/faceplate are to be taken in way of section a) and b), see figure 4. At least one reading of the attached shell plating is to be taken on each side of the frame (i.e. fore and aft) in way of section a) and section b). At least 2 readings on the flange/faceplate are to be taken in way of one selected section within each of the zones C and D. At least one reading of the attached shell plating is to be taken on each side of the frame (i.e. fore and aft) in way of the selected sections.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Thickness measurement pattern 7.1 Number of measurement points per plate and averaging Measurements shall be taken at the forward, middle and aft area of all plates, minimum 3 measurements per plate. This applies for e.g. deck, bottom and wind- and water strakes. NB ! Requirements at CAP surveys may be stricter, e.g. one measurement in the middle of each plate and one in each corner, five in all. Where plates cross ballast/cargo tank boundaries, separate measurements for the area of plating in way of each type of tank shall be recorded. Where patches of steel plates have been renewed earlier; be careful to check both the new and the old steel plates. There has been incidents where measurements were taken solely of the newest steel plates, and original plating close by was not measured, even though it was heavily corroded.

Fig.7.1.1 Measurement points in main deck, marked as black dots. Full line is plate boundaries. Dotted line is bulkheads underneath. Readings to be included in the UTM report shall be representative for the area measured, and shall normally be single point readings. If a single reading is not considered to be representative for an area , additional readings shall be carried out, with a comment in the report stating that these are additional readings. Alternatively, the average value of several readings in a small area may be included in the report together with a comment stating that this is an average value. In such cases all the readings to be averaged are to be taken within the affected area. The size of such a "small area", shall typically be the spacing of the stiffeners ( longitudinals in tankers or side frames in bulk carriers) with the same length used both in the ship's transverse and longitudinal direction ( Fig. 7.1.2 ). The average thickness of that area shall then be entered in the report, and used to compare with minimum thickness and substantial thickness values, even if single readings within that area are less.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Fig.7.1.2 The only reading noted in the report would be (14.8+15.1+15.0+15.2+14.9+15.5+15.3)/7=15.1 The number of measurement points in the figure were just an example. How many points needs to be taken, in order to get a representative average, will depend on the thickness variations within that space.

Fig.7.1.3 Pitting corrosion If there is pitting corrosion, this should be mapped separately, indicating minimum thickness measured, size of area affected, percentage of area covered by pits and average pitting depth. The surveyor shall be informed. The surveyor will use separate acceptance criteria to decide if the area in question needs to be renewed. Common location for pitting corrosion is the bottom plating underneath pipe suction bellmouths in ballast- and cargo tanks, and at the aft end of crude oil tanks. The thickness of stiffeners may be "averaged" in the same manner as for plates, with the web height or the flange width, as applicable, being the length of each side in a quadratic area. A mean thickness is calculated for that area, as under Fig.7.1.2.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Fig.7.1.4 Grooving corrosion If there is grooving corrosion at the base of a stiffener, the affected area should be mapped, with absolute minimum thickness, average thickness of affected area and length of grooving noted down. The surveyor shall be informed. The surveyor will use separate acceptance criteria for grooving corrosion.

7.2 Transverse sections The transverse sections measured should generally be within 0.5L amidship and where the largest thickness reduction is expected to occur or is revealed from deck and bottom plating measurements The results are used for longitudinal strength evaluation and significant area reduction in deck or bottom i.e. above 5%, may require measurements of additional transverse sections. Further, if significant reduction is revealed in some areas, e.g. in the deck longitudinals, measurements may be extended to ensure satisfactory condition for deck longitudinal in other areas of the tank. Minimum density of readings at each transverse section - Within 0.15D from deck and bottom every longitudinal and girder shall be measured on the web and flange and every plate shall be measured one point between each longitudinal. - Between deck and bottom area every longitudinal and girder shall be measured on the web and flange and every plate strake at least one point pr strake See illustrations in Fig. 7.5.1 for General Cargo, Fig. 7.5.6 for Tankers and Fig. 7.5.8 for Bulk Carriers.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

7.3 Bulkheads and web frames See Fig. 7.5.4, 7.5.5 and 7.5.10 for the bulkheads and Fig. 7.5.7, 7.5.8 and 7.5.9 for the web frames. The figures apply whether the measurements are part of the systematic requirements or as part of the close-up inspection. At least one row of measurements should be taken in the upper part, in the lower part, and in addition one row between each of the stringers. As figure 7.5.4 indicates, where there is a plate joint with different thickness in each of the abutting plates, measurements should be taken of each of the two abutting plates. For bulkheads or web frames not corresponding completely with any of the following figures, use the figures as guidance to work out a pattern for that particular design.

7.4 Measurements i.w.o. close-up inspections The rules specify minimum requirements to thickness measurements for assessment of general corrosion and required extent of measurements will be as found necessary by attending Class Surveyor, to evaluate all corroded structure. Readings from initial measurements showing that more than 50% of corrosion margin is used, will normally require extended scope to confirm satisfactory condition for similar elements in the rest of the tanks. Proposed initial scope of measurements are indicated in the following figures, but final scope of measurements will to a large extent be decided on board.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

THICKNESS MEASUREMENT-OIL TANKERS, OIL TANKERS, ORE/OIL SHIPS, ORE/BULK/OIL SHIPS SPECIAL SURVEY I (SHIPS 5 YEARS OLD)

SPECIAL SURVEY II (SHIPS 10 YEARS OLD)

SPECIAL SURVEY III (SHIPS 15 YEARS OLD)

1.

1. Within the cargo tank length

1. Within the cargo tank length

a. Each deck plate (See Note 1) b. One transverse section

a. Each deck plate (See Note 1) b. Two transverse section (See note 2)

One section of deck plating For the full beam of the ship with 0.5L amidships in way of a ballast tank, if any, or a cargo tank used primarily for water ballast.

2. Measurement for general assessment and recording of corrosion pattern of the different structural members subject to Close-up Survey in accordance with Table II, Table III or Table IV. 3.

Critical areas, as required by The Surveyor.

2. Measurements for general assessment and recording of corrosion pattern of the different structural members subject to Close-up Survey on accordance with Table II, Table III or Table IV. 3. Selected wind and water strakes outside the cargo tank length. 4. Critical areas, as required by the Surveyor.

SPECIAL SURVEY IV (SHIPS 20 YEARS OLD AND OVER) 1. Within the cargo tank length a. b.

Each deck plate (See Note 1) Three transverse sections (see note 3) Each bottom plate.

c. 2. Measurements for general assessment and recording of corrosion pattern of the different structural members subject to Close-up Survey in accordance with Table II, Table III or Table IV. 3. All wind and water strakes within the cargo tank length. 4.

Selected wind and water Strakes outside the cargo tank length.

2.

Measurements for general assessment and recording of corrosion pattern of the different structural members subject to Close-up Survey in accordance with Table II, Table III or Table IV.

3.

Selected wind and water strakes Outside the cargo tank length.

4.

All wind and water strakes within The cargo tank length.

5. Critical areas, as required by the Surveyor.

Note 1 : For Ore/Oil and Ore/Bulk/Oil ships only the deck plating outside the line of cargo Hatch opening is to be measured.

Note 2 : One of the two transverse sections is to be in way of any Salt water ballast tank with 0.5L amidships.

Note 3 : Two of the three transverse sections are to be in way of any salt water Ballast tank 0.5L amidships.

CLOSE - UP SURVEY - OIL TANKERS SPECIAL SURVEY I (SHIPS 5 YEARS OLD)

SPECIAL SURVEY II (SHIPS 10 YEARS OLD)

SPECIAL SURVEY III (SHIPS 15 YEARS OLD)

1. ONE TRANSVERSE WEB FRAME RING - in a wing ballast tank, if any, or a cargo wing tank used primarily for water ballast.

1. ALL TRANSVERSE WEB FRAME RINGS - in a wing ballast tank, if any, or a cargo wing tank used primarily for water ballast.

1. ALL TRANSVERSE WEB FRAME RINGS (i) in all ballast tanks (see note 1) (ii) in a cargo wing tank

2. ONE DECK TRANSVERSE (i) in each of the remaining ballast tanks (see Note 1) (ii) in a cargo wing tank (iii) in two cargo centre tanks

2. ONE TRANSVERSE WEB FRAME RING - in each remaining cargo wing tank

2. ONE DECK TRANSVERSE in a cargo tank. 3c. ONE TRANSVERSE BULKHEAD (LOWER PART) (i) in a ballast tank (ii) in a cargo wing tank (iii) in a cargo centre tank

3. BOTH TRANSVERSE BULKHEADS - in a wing ballast tank, if any, or a cargo wing tank used primarily for water ballast. 4. ONE TRANSVERSE BULKHEAD (LOWER PART) (i) in each remaining ballast tank (ii) in a cargo wing tank (iii) in two cargo centre tanks

SPECIAL SURVEY IV (SHIPS 20 YEARS OLD & OVER) As Special Survey III

3. ALL TRANSVERSE BULKHEADS - in all cargo and ballast tank 4. ONE DECK AND BOTTOM TRANSVERSE - in each cargo centre tanks Additional transverse web frames and transverse bulkheads as deemed necessary by the Surveyor.

Definitions of Close-up survey areas see over for sketches of typical close-up survey areas 1. Complete transverse web frame ring including adjacent structural members.

2. Deck transverse including adjacent Deck Structural members.

3. Transverse bulkhead complete including girder system and adjacent members.

4. Transverse bulkhead lower part - including girder system and adjacent structural members.

5. Deck & bottom transverse including Adjacent structural members.

Notes : 1. Ballast tanks includes peak tank.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide CLOSE-UP SURVEY - ORE / OIL SHIPS SPECIAL SURVEY I (SHIPS 5 YEARS OLD)

SPECIAL SURVEY II (SHIPS 10 YEARS OLD)

SPECIAL SURVEY III (SHIPS 15 YEARS OLD)

1. (i) 25% of frames and their end attachments in the forward cargo hold at representative positions.

1. 25% of shell frames including their end attachments and adjacents shell plating in all cargo holds.

1.

2.

(ii) Selected frames and their end attachments in remaining cargo holds. 2. One transverse web with associated plating and longitudinals in two representative water ballast tanks of each type (i.e. topside, hopper side or side tank) 3. Two selected cargo hold transverse bulkheads including internal structure of upper and lower stools where fitted. This is to include the aft bulkhead of the forward cargo hold (see note 2)

One transverse web with associated Plating and longitudinals in each water ballast tank (including topside, Hopper side, side tank or peak tank)

3.

Forward and aft transverse bulkhead in one side ballast tank, including stiffening system.

4.

One transverse bulkhead in each cargo Hold including the internal structure of upper and lower stool where fitted. This is to include the aft bulkhead in the forward cargo hold (see note 2)

2.

3.

5. Selected cargo hold hatch covers and coamings (plating and stiffeners) 6. Selected areas of deck plating inside Line of hatch opening between cargo Hold hatches.

All shell frames in the forward cargo hold and 25% of frames in remaining cargo holds, including their end attachments and adjacent shell pating. All transverse webs with associated plating and longitudinals in each water ballast tank (including topside, hopper side, side tank or peak tanks)

6.

2.

All transverse webs with Associated plating and longitudinals in each water ballast tank (including topside, hopper side, side tank or peak tanks)

3.

All transverse bulkheads in Ballast tanks, including stiffening system.

4.

All cargo hold transverse Bulkheads including internal structure of upper and lower stools, where fitted (see note 2)

5.

All cargo hold hatch covers and coamings (plating and stiffeners)

7.

All deck plating inside line of hatch openings between cargo hold hatches.

All transverse bulkheads in ballast tanks, including stiffening system.

4. All cargo hold tranverse bulkheads including internal structure of upper and lower stools, where fitted (see note 2) 5.

SPECIAL SURVEY IV (SHIPS 20 YEARS OLD & OVER) 1. All shell frames including their End attachments and adjacent shell plating in all cargo holds.

All cargo hold hatch covers and coamings (plating and stiffeners) All deck plating inside line of hatch openings between cargo hold hatches.

Definitions of Close-up survey areas see over for sketches of typical close-up survey areas 1. Transverse frames 2. Transverse web with associated plating, girders and 3. Transverse bulkhead with associated girders and longitudinals stiffeners in topside tank or hopper side tank. 4. Transverse bulkhead in cargo holds with associated girders and stiffeners. Notes : 1. Ballast tank includes peak tanks. 2. Close-up Survey of transverse bulkheads to be carried out at four levels : Level (a) Immediately above the inner bottom and immediately above the line of gussets (if fitted) and shedders for ships wit hout lower stool. Level (b) Immediately above and below the lower stool shelf plate (for those ships fitted with lower stools), and immediately above the line of the shedder plates. Level (c) About mid-height of the bulkhead. Level (d) Immediately below the upper deck plating and immediately adjacent to the upper wing tank and immediately below the upper stool shelf plate for those ships fitted with upper stools, or immediately below the topside tanks.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

THICKNESS MEASUREMENT - DRY BULK CARGO SHIPS SPECIAL SURVEY I (SHIPS 5 YEARS OLD) 1. Measurement, for general assessment and recording of corrosion patter, of those structural members subject to close-up survey according to Table II. 2. Critical areas, as required by the Surveyor.

SPECIAL SURVEY II (SHIPS 10 YEARS OLD) 1. Within the cargo length area Two transverse sections of deck plating outside line of cargo hatch opening. 2. Measurement, for general assessment and according of corrosion patter, of those structural members subject to close-up survey according to Table II. 3. Wind and water strakes in way of the transverse sections considered under point 1 above. 4. Critical areas, as required by the Surveyor.

SPECIAL SURVEY III (SHIPS 15 YEARS OLD) 1. Within the cargo length area : a. Each deck plate outside line of cargo hatch openings.

SPECIAL SURVEY IV (SHIPS 20 YEARS OLD & OVER) 1. Within the cargo length area : a. Each deck plate outside line of cargo hatch openings.

b. Two transverse sections outside line of cargo hatch openings. (A minimum of one of the above transverse sections is to be within 0.5L amidships)

b.

2. Measurement, for general assessment and recording of corrosion pattern, of those structural members subject to close-up survey according to Table II. 3. All wind and water strakes within the cargo length area. 4. Selected wind and water strakes outside the cargo length area.

c.

Three transverse sections Outside line of cargo hatch openings. (A minimum of two of the above transverse sections is to be within 0.5L amidships) Each bottom plate.

2. Measurement, for general assessment and recording of corrosion pattern, of those structural members subject to close-up survey according to Table II. 4.

All wind and water strakes Within the cargo length area.

5.

Selected wind and water Strakes outside the cargo length area.

6.

Critical areas, as required by The Surveyor.

5. Critical areas, as required by the Surveyor.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

CLOSE-UP SURVEY - DRY BULK CARGO SHIPS SPECIAL SURVEY I (SHIPS 5 YEARS OLD) 1. (i) 25% of shell frames and their end attachments in the forward cargo hold at representative positions. (ii) Selected frames and their end attachments in remaining cargo holds. 2. One transverse web with associated plating and longitudinals in two representative water ballast tanks of each type (including topside, hopper side or side tank or peak tanks) 3. Two selected cargo hold transverse bulkheads including internal structure of upper and lower stools where fitted. This is to include the aft bulkhead of the forward cargo hold (see note 1)

SPECIAL SURVEY II (SHIPS 10 YEARS OLD) 1. 25% of shell frames including their end attachments and adjacents shell plating in all cargo holds. 2. One transverse web with associated plating and longitudinals in each water ballast tank (including topside, hopper side, side tank or peak tank) 3.

4.

Forward and aft transverse bulkhead In one side ballast tank, including stiffening system. One transverse bulkhead in each Cargo hold including the internal structure of upper and lower stool where fitted. This is to include the aft bulkhead of the forward hold (see note 1)

SPECIAL SURVEY III (SHIPS 15 YEARS OLD) 1. All shell frames in the forward cargo Hold and 25% of frames in remaining cargo holds, including their end attachments and adjacent shell plating.

SPECIAL SURVEY IV (SHIPS 20 YEARS OLD & OVER) 1. All shell frames including their end attachments and adjacent shell plating in all cargo holds.

2. All transverse webs with associated plating and longitudinals in each water ballast tank (including topside, hopper side, side tank or peak tanks)

2. All transverse webs with associated plating and longitudinals in each water ballast tank (including topside, hopper side, side tank or peak tanks)

3. All transverse bulkheads in ballast tanks, including stiffening system. 4. All cargo hold transverse bulkheads including internal structure of upper and lower stools, where fitted (see note 1) 5.

All cargo hold hatch covers and Coamings (plating and stiffeners)

6. All deck plating inside line of hatch openings between cargo hold hatches.

3. All transverse bulkheads in ballast tanks, including stiffening system. 4. All cargo hold transverse bulkheads including internal structure of upper and lower stools, where fitted (see note 1) 5. All cargo hold hatch covers and coamings (plating and stiffeners) 6. All deck plating inside line of hatch openings between cargo hold hatches.

5. Selected cargo hold hatch covers and coamings (plating and stiffeners)

6. Selected areas of deck plating inside line of hatch opening between cargo hold hatches. Definitions of Close-up survey areas see over for sketches of typical close-up survey areas 1. Transverse frames 2. Transverse web with associated plating, girders and 3. Transverse bulkhead with associated girders and longitudinals stiffeners in topside tank and hopper side tank. 4. Transverse bulkhead in cargo holds with associated girders and stiffeners. Notes : 1. Close-up Survey of transverse bulkheads to be carried out at four levels : Level (a) Immediately above the inner bottom and immediately above the line of gussets (if fitted) and shedders for ships wit hout lower stool. Level (b) Immediately above and below the lower stool shelf plate (for those ships fitted with lower stools), and immediately above the line of the shedder plates. Level (c) About mid-height of the bulkhead. Level (d) Immediately below the upper deck plating and immediately adjacent to the upper wing tank and immediately below the upper stool shelf plate For those ships fitted with upper stools, or immediately below the topside tanks.

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Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Wastage Allowances for E.S.P. SHIP

SR.

GAUGED AREA

TM FOME

I.A.C.S

NKK

1

MAIN DECK PLATING

TM 1

20%

20%+1

2

SIDE SHELL PLATING

TM 2

20%

20%+1

3

BOTTOM PLATING

TM 3

20%

20%+1

4

INNER BOTTOM PLATING I.W.O CARGO HOLD (TANK TOP) FULL LENGTH

TM 4

25%

20%+1

5

LONGI BHD PLATING (FULL LENGTH)

TM 5

20%

20%+1

6

DB HOPPER PLATING (FULL LENGTH)

TM 6

25%

20%+1

7

TST SLOPPING PLATE (FULL LENGTH)

TM 7

25%

20%+1

8

STRENGTH DECK & SHEER STRAKE PLATING (ONLY GIRTH BELT)

TM2a

20%

20%+1

9

SIDE SHELL & BOTTOM PLATING (ONLY GIRTH BELT)

TM2b

20%

20%+1

10

DECK LONGI & DECK GIRDER (GIRTH BELT/ I.W.O. TANK)

TM3

20%

30%

11

INNER BOTTOM LONGI (TANK TOP LONGI) (GIRTH BELT / I.W.O. TANK)

TM3

20%

30%

12

LONGI BHD LONGI / DB HOPPER LONGI (GIRTH BELT / I.W.O. TANK)

TM3

20%

30%

13

DB HOPPER LONGI (GIRTH BELT / I.W.O. TANK)

TM3

20%

30%

14

TST SLOPPING PLATE LONGI (GIRTH BELT / I.W.O. TANK)

TM3

20%

30%

15

SIDE SHELL LONGI (GIRTH BELT / I.W.O. TANK)

TM3

20%

30%

16

BOTTOM LONGI & BOTTOM GIRDER (GIRTH BELT / I.W.O. TANK)

TM3

20%

30%

TRANSVERSE FRAME / FLOOR 17

DECK TRANSVERSE PLATING

TM 4

25%

25%

18

DECK TRANSVERSE STIFFENERS

TM 4

25%

30%

19

BOTTOM TRANSVERSE PLATING

TM 4

25%

25%

20

BOTTOM TRANSVERSE STIFFENERS

TM 4

25%

30%

21

SIDE SHELL VERTICAL FRAMES PLATING

TM 4

25%

25%

22

SIDE SHELL VERTICAL FRAMES STIFFENERS

TM 4

25%

30%

23

LONGI BHD VERTICAL FRAMES PLATING

TM 4

25%

25%

24

LONGI BHD VERTICAL FRAMES STIFFENERS

TM 4

25%

30%

25

ALL HORIZ GIRDER ( STRINGER ) I.W.O. WING TANK

TM 6

25%

25%

TRANSVERSE BULKHEAD 26

COLLISON BULKHEAD PLATING

TM 5

25%

20%+1

27

CARGO HOLD No.1 AFT BHD

TM 5

25%

20%+1

28

CARGO HOLD TRANSVERS BHD

TM 5

25%

20%+1

29

TANK TRANSVERS BHD

TM 5

25%

20%+1

30

SWASH BHD PLATING

TM4

25%

25%

31

SWASH BHD STIFFENERS

TM4

25%

30%

32

ALL TRANSVERS BULKHEAD STIFFENERS

TM 5

25%

20%+1

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

FORE & AFT PEAK TANK 33

TANK TOP PLATING / BOUSON DECK / STRINGER GEAR ROOM

TM 6

25%

30%

34

ALL HORIZ STRINGER

TM 6

25%

25%

35

TRANSVERS WEB FRAME PLATING

TM 4

25%

25%

36

TRANSVERS WEB FRAME STIFFENERS

TM 4

25%

30%

37

SIDE SHELL LONGI I.W.O. FORE PEAK

TM 3

25%

30%

38

ONLY SIDE SHELL PLATING I .W.O. FORE PEAK ( SUPPLAY VESSEL )

TM 6

25%

20%+1

39

ONLY SIDE SHELL PLATING I .W.O. FORE PEAK ( ESP SHIP )

TM 1

20%

20%+1

40

ALL SEA CHEST

TM 6

25%

20%+1

41

ENG, ROOM STUB PICES

TM 6

25%

30%

42

AIR WANTLETER ON DECK

TM 6

25%

30%

43

SIDE SHELL FRAMES I.W.O. CARGO HOLD NO.1

TM 7

20%

30%

44

SIDE SHELL FRAMES I.W.O. OTHER CARGO HOLD

TM 7

25%

30%

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

(LRS)

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

PART -3 Thickness Measurement and close-up Survey for *General Dry Cargo Ships This chapter includes the outline of close-up surveys and thickness measurement required in Part B of Rules at each special survey of General Dry Cargo ships* (including ships carrying timber cargoes* ) *1: “General Dry Cargo Ships” are ships constructed or converted to carry solid cargoes other than: > bulk carrier > container carrier > dedicated forest product carriers (except for ships carrying timber cargoes) > ro-ro cargo ships > car carrier > refrigerated cargo ships > dedicated wood chip carriers and > dedicated cement carriers *2: “Ships carrying timber cargoes” are cargo ships which belongs to general dry cargo Ships specified in the above and which marked timber load lines in accordance with requirement in Rule or primarily carrying log cargo

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

PART- 2 Thickness Measurement and close-up Survey for Bulk Carrier (Including Ore Carrier) This chapter includes the outline of close-up surveys and thickness measurement required in Part B of Rules at each special survey of bulk carriers*. * “Bulk Carrier” means following ships:  ships constructed or converted with a single deck, top-side tanks and hopper side tanks in cargo area and Intended primarily to carry dry cargo in bulk (See the figure below); or  ore carrier; or  combination carriers such as ore/oil carriers and ore/bulk /oil carriers. “Ore Carriers” :- means ships constructed or converted with a single deck, two longitudinal bulkheads and a double bottom throughout the cargo area and intended for the carriage of ore cargoes in the center holds only. “ Combination Carriers ” :- means ships designed to carry either oil or solid cargoes in bulk. Note:For ore carriers,close-up surveys and thickness measurement for structural members in wing ballast tanks and wing void spaces are to be carried out in accordance with requirements for oil tankers specified in part 1.

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

MAXIMUM PERMISSIBLE ORG

SUB

THK

7.5%

CROP

SUB CR / SC 10.0% 11.25% 15.0%

CROP

6.0

5.6

5.4

5.3

5.1

4.8

6.5

6.0

5.9

5.8

5.5

7.0

6.5

6.3

6.2

7.5

6.9

6.8

8.0

7.4

8.5

SUB

CROP

SUB

CROP

ORG

SUB

25.0%

22.5%

30.0%

THK

7.5%

CROP

SUB

CROP

25.0%

22.5%

4.9

4.5

4.7

4.2

26.0

24.1

23.4

23.1

22.1

20.8

30.0%

21.1

19.5

20.2

5.2

5.3

4.9

5.0

4.6

26.5

24.5

23.9

23.5

22.5

18.2

21.2

21.5

19.9

20.5

6.0

5.6

5.7

5.3

5.4

4.9

27.0

25.0

24.3

24.0

18.6

23.0

21.6

21.9

20.3

20.9

6.7

6.4

6.0

6.1

5.6

5.8

5.3

27.5

25.4

24.8

18.9

24.4

23.4

22.0

22.3

20.6

21.3

7.2

7.1

6.8

6.4

6.5

6.0

6.2

5.6

28.0

25.9

19.3

25.2

24.9

23.2

22.4

22.8

21.0

21.7

7.9

7.7

7.5

7.2

6.8

6.9

6.4

6.6

6.0

28.5

19.6

26.4

25.7

25.3

24.2

22.8

23.2

21.4

22.1

9.0

8.3

8.1

8.0

7.7

7.2

7.3

6.8

7.0

6.3

20.0

29.0

26.8

26.1

25.7

24.7

23.2

23.6

21.8

22.5

9.5

8.8

8.6

8.4

8.1

7.6

7.7

7.1

7.4

20.3

6.7

29.5

27.3

26.6

26.2

25.1

23.6

24.0

22.1

22.9

10.0

9.3

9.0

8.9

8.5

8.0

8.1

7.5

20.7

7.8

7.0

30.0

27.8

27.0

26.6

25.5

24.0

24.4

22.5

23.3

10.5

9.7

9.5

9.3

8.9

8.4

8.5

21.0

7.9

8.1

7.4

30.5

28.2

27.5

27.7

25.9

24.4

24.8

22.9

23.6

11.0

10.2

9.9

9.8

9.4

8.8

21.4

8.9

8.3

8.5

7.7

31.0

28.7

27.9

27.5

26.4

24.8

25.2

23.5

24.0

11.5

10.6

10.4

10.2

9.8

21.7

9.2

9.3

8.6

8.9

8.1

31.5

29.1

28.4

28.0

26.8

25.2

25.6

23.6

24.4

12.0

11.1

10.8

10.7

22.1

10.2

9.6

9.8

9.0

9.3

8.4

32.0

29.6

28.8

28.4

27.2

25.6

26.0

24.0

24.8

12.5

11.6

11.3

22.4

11.1

10.6

10.0

10.2

9.4

9.7

8.8

32.5

30.1

29.3

28.8

27.6

26.0

26.4

24.4

25.2

13.0

12.0

22.8

11.7

11.5

11.1

10.4

10.6

9.8

10.1

9.1

33.0

30.5

29.7

29.3

28.5

26.4

26.8

24.8

25.6

13.5

23.1

12.5

12.2

12.0

11.5

10.8

11.0

10.1

10.5

9.5

33.5

31.0

30.2

29.7

28.5

26.8

27.2

25.1

26.0

23.5

14.0

13.0

12.6

12.4

11.9

11.2

11.4

10.5

10.9

9.8

34.0

31.5

30.6

30.2

28.9

27.2

27.6

25.5

26.4

23.8

14.5

13.4

13.1

12.9

12.3

11.6

11.8

10.9

11.2

10.2

34.5

31.9

31.1

30.6

29.3

27.6

28.0

25.9

26.7

24.2

15.0

13.9

13.5

13.3

12.8

12.0

12.2

11.3

11.6

10.9

35.0

32.4

31.5

31.6

29.8

28.0

28.4

26.3

27.1

24.5

15.5

14.3

14.0

13.8

13.2

12.4

12.6

11.6

12.0

11.2

35.5

32.8

32.0

31.5

30.8

28.4

28.8

26.6

27.5

24.9

16.0

14.8

14.4

14.2

13.6

12.8

13.0

12.0

12.4

11.6

36.0

33.3

32.4

32.0

30.6

28.8

29.3

27.0

27.9

25.2

16.5

15.3

14.9

14.6

14.0

13.2

13.4

12.4

12.8

11.9

36.5

33.8

32.9

32.4

31.0

29.2

29.7

27.4

28.3

25.6

17.0

15.7

15.3

15.1

14.5

13.6

13.8

12.8

13.2

12.3

37.0

34.2

33.3

32.8

31.5

29.6

30.1

27.8

28.7

25.9

17.5

16.2

15.8

15.5

14.9

14.0

14.2

13.1

13.6

12.6

37.5

34.7

33.8

33.3

31.9

30.0

30.5

28.1

29.1

26.3

18.0

16.7

16.2

16.0

15.3

14.4

14.6

13.5

14.0

13.0

38.0

35.2

34.2

33.7

32.3

30.4

30.9

28.5

29.5

26.6

18.5

17.1

16.7

16.4

15.7

14.8

15.0

13.9

14.3

13.3

38.5

35.6

34.7

34.2

32.7

30.8

31.3

28.6

29.8

27.0

19.0

17.6

17.1

16.9

16.2

15.2

15.4

14.3

14.7

13.7

39.0

36.1

35.1

34.6

33.2

31.2

31.7

29.3

30.2

27.3

19.5

18.0

17.6

17.3

16.6

15.6

15.8

14.6

15.1

14.0

39.5

36.5

36.5

35.6

33.6

31.6

32.1

29.6

30.6

27.7

20.0

18.5

18.0

17.8

17.0

16.0

16.3

15.0

15.5

14.4

40.0

37.0

36.0

35.5

34.0

32.0

32.5

30.0

31.0

28.0

20.5

19.0

18.5

18.2

17.4

16.4

16.7

15.4

15.9

14.1

40.5

37.5

36.5

35.9

34.4

32.4

32.9

30.4

31.4

28.4

21.0

19.4

18.9

18.6

17.9

16.8

17.1

15.8

16.3

15.1

41.0

37.9

36.9

37.2

34.9

32.8

33.3

30.8

31.8

28.7

21.5

19.9

19.4

19.1

18.3

17.2

17.5

16.1

16.7

15.4

41.5

38.4

37.4

36.8

35.3

33.2

33.7

31.1

32.2

29.1

22.0

20.4

19.8

19.5

18.7

17.6

17.9

16.5

17.1

15.8

42.0

38.9

37.8

37.3

35.7

33.6

34.1

31.5

32.6

29.4

22.5

20.8

20.3

20.0

19.1

18.0

18.3

16.9

17.4

16.1

42.5

39.3

38.3

37.7

36.1

34.0

34.5

31.9

32.9

29.8

23.0

21.3

20.7

20.4

19.6

18.4

18.7

17.3

17.8

16.1

43.0

39.8

38.7

38.2

36.6

34.4

34.9

32.3

33.3

30.1

23.5

21.7

21.2

20.9

20.0

18.8

19.1

17.6

18.2

16.5

43.5

40.2

39.2

38.6

37.0

34.8

35.3

32.6

33.7

30.5

24.0

22.2

21.6

21.3

20.4

19.2

19.5

18.0

18.6

16.8

44.0

40.7

39.6

39.1

37.4

35.2

35.8

33.0

34.1

30.8

24.5

22.7

22.1

21.7

20.8

19.6

19.9

18.4

19.0

17.2

44.5

41.2

40.1

39.5

37.8

35.6

36.2

33.4

34.5

31.2

25.0

23.1

22.5

22.2

21.3

20.0

20.3

18.8

19.4

17.5

45.0

41.6

40.5

39.9

38.3

36.0

36.6

33.8

34.9

31.5

25.5

23.6

23.0

22.6

21.7

20.4

20.7

19.1

19.8

17.9

45.5

42.1

41.0

40.4

38.7

36.4

37.0

34.1

35.3

31.9

20.0% 18.75%

CROP

SUB CR / SC 10.0% 11.25% 15.0%

CROP

SUB

20.0% 18.75%

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

On Board kick-off Meeting-Agenda Minutes For Thickness Measurment (With Reference to Requirements of IACS) Type of Vessel :- _____________________________________ Vessel Name :- _____________________________________ I.M.O. No :______________________________________ Date of Built :- ______________________________________ Owener :_______________________________________

Equiment Used & Sr. No:1.Cygnus Sr. No:

Class :_______________________________________ Type of Survey :- ____________________________________ Place of Survey :- ____________________________________ Report No :_____________________________________ No.of Copy of Report :- ______________________ No.of Copy of CD Disc :- _____________________

Attending Technician Name:-

Belt Gauging to be Carried out at following Position :Frame no. I.W.O. Hold/Tank No.

Company Approval Certificates:-

Suspect area / C.O.C :CAS Belt Fr No. CAP Belt Fr No. Allowable Dimniution :- (Check with class) Requirements of survay as per class rules & attending surveyour Requirement :-

Availabilty onboard of Original Drawings :-

Aman Ship Maintenance

Attending Surveyor

Master / Owner Represenative

Name:-

Name:-

Name:-

Technician Cont No :-

Surveyor Cont No:-

Cont No:-

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Signature

Signature

Signature

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Example of UTM report front page

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

Antiqua Marine & engg. U.A.E.

Ultrasonic Thickness Measurment Guide

SAFETY PRECAUTIONS :ULTRASONIC MEASUREMENT IS MORE OFTEN THAN NOT CARRIED OUT IN CLOSED SPACES AND TANKS BE IT BALLAST OR FUEL OIL, CARGO SPACES ETC, THESE CAN BE POTENTIALLY HAZARDOUS AND EVEN FATAL IF PROPER PRECAUTIONS ARE NOT TAKEN. GIVEN BELOW ARE A FEW ESENTIAL CHECKS TO BE MADE BY PERSONNEL UNDERTAKING THICKNESS MEASUREMNT ON BOARD VARIOUS SHIPS. THE CHECKS ARE GUIDELINES BUT MOST IMPORTANT POINT WOULD BE “COMMON SENCE ” AND FOR ALL PERSONELL TO

REMEMBER A POINT THAT CANNOT BE STRESSED OFTEN ENOUGH “ SAFETY FIRST ”

PRECAUTIONS TO BE TAKEN BEFORE ENTERING ANY COMPARTMENT FOR INSPECTION OR FOR ULTRASONIC THICKNESS GAUGING. 1.

ENCLOSED TANK OR ANY SPACE TO BE GAS FREE AND CHECKED WITH EXPLOSIVE METER AND CONFIRMED.

2. TANK TO BE WELL VENTILATED AND ASCERTAINED FOR PROPER OXYGEN AND AIR CONTENT FOR LIFE SUPPORT PURPOSE. 3. PRIOR STARTING GRINDING IN NON COATED AREAS TANK/ AREA TO BE GUAGED TO BE SUITABLE FOR HOT WORK TO ENSURE NO RISK FROM SPARKS. 4. FOR WORKING ON HEIGHTS , PROPER STAGING TO BE MADE AND PERSON CLIMBING ON TOP MUST HAVE SAFETY BELT AND WEAR PROPER GEAR INCLUDING USING HELMET, IS SAME NOT AVAILABLE WITH TECHNICIAN , TO BE OBTAINED FROM SHIP STAFF. 5. WHEN WORKING OUTBOARD SIDE OF SHIP , LIFE JACKETS MUST BE WORN AND PROPER STAGING SHOULD BE MADE FOR EASE OF WORKING. 6. LIFE BOUY TO BE KEPT HANDY AND HANGING FOR USE IF REQUIRED. 7. WHILE CARRING OUT U/T IN BALLAST TANKS , THESE SHOULD BE WELL VENTILATED AND CHECKED FOR OXYGEN AND AIR CONTENT TO ENSURE LIFE SUPPORT. 8. TANK SHOULD BE WELL LIGHTED FOR EASY MOVEMENT OF PERSONNEL. 9. WHILE USING BOATS OR DINGHY IN BALLAST /CARGO TANKS TO ENSURE CALM WATERS AND BOATS PROPERLY HANDLED BY CREW. 10. INCASE OF ANY ACCIDENT THE NECK/SPINE OF INJURED PERSON TO BE SECURED AND MASTER CONTACTED FOR EVACUATION. 11.

INCASE OF ANY DIZZINESS OBSERVED IN THE TANKS OR STRANGE ODOURS , TANKS TO BE EVACUATED AT ONCE AND TO IMMEDIATELY MOVE TO A WELL VENTILATED AND AIRY AREA.

Antiqua Marine & engg. U.A.E.