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Page 1 of 21 Materials and Qualification Procedures for Ships Book H Procedure 10-2 Approval of a Works for the Manufacture of Offshore Mooring Chain Cable Revision 2, June 2017

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Page 1: Materials and Qualification Procedures for Ships · Materials and Qualification Procedures for Ships Book H Procedure 10-2 Page 3 of 21 Procedure 10-2 Approval of a Works for the

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Materials and Qualification Procedures for Ships

Book H

Procedure 10-2 Approval of a Works for the Manufacture of Offshore Mooring Chain Cable

Revision 2, June 2017

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Lloyd’s Register Group Limited, its subsidiaries and affiliates and their respective officers, employees or agents are, individually and collectively, referred to in this clause as ‘Lloyd’s Register’. Lloyd’s Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Lloyd’s Register entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract.

© Lloyd's Register Group Limited 2015. All rights reserved. Except as permitted under current legislation no part of this work may be photocopied, stored in a retrieval system, published, performed in public, adapted, broadcast, transmitted, recorded or reproduced in any form or by any means, without the prior permission of the copyright owner. Enquiries should be addressed to Lloyd's Register Global Technology Centre, Southampton Boldrewood Innovation Campus, Burgess Road, Southampton, SO16 7QF.

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Procedure 10-2

Approval of a Works for the Manufacture of Offshore Mooring Chain Cable

1 General Requirements

1.1 The Approval Process

1.1.1 The approval scheme is intended to verify the manufacturer’s capability to provide satisfactory products under effective process, production and inspection controls in accordance with the Rules for the Manufacture, Testing & Certification of Materials Chapter 1.

1.1.2 In order that consideration may be given to approval of a works for the manufacture of chain cable, the surveyors are to follow the process defined in Section 2.

1.1.3 Works are to communicate to Surveyors the information which will result in the following reports, each of which is to be submitted to the Materials and NDE Department (MNDE) by the surveyor:

• An initial report giving the information listed in Sections 3 and 4, together with a proposed test programme in accordance with section 5.

• A final report containing the results of approval tests carried out under Sections 5 and 6.

1.1.4 The name of the approved works will appear in Lloyd’s Register’s List of Approved Manufacturers of Chain Cable which is published on Lloyd’s Register’s Class Direct web site (www.cdlive.lr.org).

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1.2 Scope

1.2.1 This document outlines the procedures relating to flash butt welded chain cable for offshore use as referenced in LR Rules for Materials Chapter 10 Section 3 and Section 4 respectively.

1.2.2 Where it is proposed to use any other method of manufacture than flash butt welding, details should be submitted in order that a suitable approval test programme can be agreed.

1.2.3 Approval will be limited to the grades, sizes and supply conditions of cable submitted for approval.

1.2.4 When a manufacturer requests an extension of approval to cover either larger diameters or higher grades of chain cable or a change of supply condition, an additional programme of approval tests is required. This programme is to be agreed with Materials and NDE Department.

1.2.5 Bar used for manufacture of cable shall be sourced from a nominated LR approved supplier. Separate approvals are required if bar is supplied from more than one source.

1.2.6 Chain manufacturers requesting approval to manufacture cable in the offshore grades are to maintain an effective quality assurance system satisfying the requirements of ISO 9001.

1.3 Related Rules

1.3.1 Lloyd’s Register’s Rules and Regulations for the Classification of Ships (hereinafter referred to as the Rules for Ships).

1.3.2 Lloyd’s Register’s Rules for the Manufacture, Testing and Certification of Materials (hereinafter referred to as the Rules for Materials).

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2 Application for Approval

2.1 Stages of approval

2.1.1 This section sets out the five stages involved in the granting of Lloyd’s Register approval as follows.

(a) Preliminary Review [Stage 1]

The purpose of the preliminary review is to confirm the general capabilities of the works and identify any major non-compliance which will need to be addressed prior to further consideration of the approval process. This review may involve a preliminary assessment visit to the works.

During the course of the review the works shall also demonstrate to the satisfaction of the surveyor that they operate a robust Health & Safety Management System.

Based upon the findings of the preliminary review, the surveyor will issue a report to the company :

• Giving a recommendation that the works approval process proceeds to the next stage (see the Flow Chart below) or

• Giving the reasons why the works is not considered suitable for LR approval at this time.

(b) Submission of Works Approval Information [Stage 2]

Following the surveyor’s recommendation to progress with the approval process, the manufacturer will be invited to compile and submit the detailed information requested in Sections 3 and 4 to the local Lloyd’s Register office. The report shall be formatted to follow the sections and sub-sections of this procedure and shall preferably be submitted in electronic format. The report and all supporting documents should be presented in English or annotated in English in an appropriate manner.

Additionally, the manufacturer must submit a proposed test programme in accordance with Section 5.

The local surveyor will review the submitted information from the works and shall conduct an on-site survey during which the contents of the submitted information are verified and any technical or procedural issues related to the approval are resolved. On satisfactory review of these documents, the surveyor will submit the following to the Materials & NDE Department:

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• A short visit report

• The information submitted by the works in accordance with Sections 3 & 4

• A proposed test programme in accordance with Section 5

(c) Review of Submission by Materials & NDE Department [Stage 3]

Lloyd’s Register Materials & NDE Department shall review the submitted information before any manufacture and testing commences. In particular, approval of the bar used for the chain cable approval must be underway in accordance with MQPS 3-7 (at Stage 3 as minimum). Any testing carried out for the approval of the chain before notification of test plan acceptance by MNDE shall be at the manufacturer’s risk. Where necessary, clarification will be sought regarding major issues that are discovered during this stage of review of the submitted information.

The outcome of the review will be conveyed to the surveyor and the Materials & NDE Department will confirm the approval test programme and any other actions they require the surveyor to carry out during the surveyor’s attendance at the manufacturer whilst witnessing approval manufacture and testing.

The surveyor will communicate this information to the manufacturer.

(d) Approval Tests & Survey [Stage 4]

Following Materials & NDE Department agreement to the test plan, the Works will manufacture the approval test chain cable. The Lloyd’s Register surveyor will arrange to attend the works to survey the manufacture and witness the testing of the approval test products.

In addition, during attendance, the surveyor will follow up on actions requested by the Materials & NDE Department.

The surveyor will appropriately appraise and endorse all test reports which are required by this procedure.

The surveyor will review a manufacturer’s report which collates all required information in a clear and concise manner. The format of the report must follow the sections and sub-sections of this procedure and it should preferentially be in electronic form. If the report is found to be satisfactory by the surveyor, it will be endorsed by the manufacturer and verified and stamped by the LR surveyor. It will then be forwarded to the Materials & NDE Department for final review and approval.

(e) Review of Results [Stage 5]

The surveyor’s report and endorsed test results will be reviewed by Lloyd’s Register Materials & NDE Department. During this process, points of

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clarification may be required to be followed up with the surveyor in cooperation with the manufacturer. On satisfactory review the works will be added to Lloyd’s Register’s list of approved manufacturers and a Certificate of Approval will be issued.

(f) Unless otherwise agreed with the MNDE Department, the above stages are to be carried out as five distinct entities. In particular, Stage 3 - test plan approval is required before testing is commenced in order to avoid delays in the approval process.

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3 Written information required for the manufacturing capability review

3.1 Works Background Information, History, Contact Details and Scope of Approval Request.

3.1.1 The manufacturer is to provide the following product related details in writing to the local surveyor:

(a) The type of chain, grade, supply condition and maximum diameter for which approval is requested.

(b) Estimated total annual production of finished chain cable.

(c) Details of the sources of starting material. Works supplying the starting material are required to undertake separate approval according to the appropriate MQPS for the product supplied (see 2.1.1(c) above).

(d) Contact details that are to be listed on the published approved list including sales telephone number, fax number, email address and website.

(e) The year of issue of the copy of the Rules for Materials which are held by the Works and the means whereby possible Rule changes are incorporated into company procedures.

(f) The MQPS documents which are used for the approval application, including their revision numbers

(g) Details of the inspection and quality control systems established in the works, including details of the personnel involved

(h) Third party certification held (eg ISO 9001, ISO 14001 and/or ISO 18001, etc), as applicable.

(i) A flow diagram showing all stages of production, testing and inspection points.

(j) An organogram showing the organisational structure shall be submitted indicating the lines of responsibility of the quality manager and production manager and the senior management to whom they report. This should also indicate the quality department with number of personnel qualifications and responsibilities

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3.2 Process Specific Information

3.2.1 Flash-butt welded chain cable.

Manufacturers of flash-butt welded chain cable are to provide supply the following process related details in writing to the local surveyor.

(a) Sources for the supply of bar material. These must be manufacturers approved by LR as per Section 2.1.1 (C).

(b) The chemical specification of the bar material used in manufacture. This specification is to include all the alloying elements and limits on trace elements, including arsenic, antimony and tin. For grades R4, R4S and R5, steel should contain a minimum of 0.20% Mo. The chemical composition specification for different ranges of diameters shall be provided.

(c) Rolling reduction ratio for the bar to be stated and this is to be at least 5:1.

(d) Heat treatment sensitivity study of the bar simulating chain production conditions shall be carried out in order to verify mechanical properties and limits for temperature and time.

(e) Bar heating and bending including method, temperatures, temperature control and recording.

(f) Bar manufacturer must provide evidence that bar material is resistant to strain ageing, temper embrittlement and hydrogen embrittlement (see Section 5.1.3.1(e))

(g) Flash welding including current, force, time and dimensional variables as well as control and recording of parameters.

(h) Flash removal including method and inspection

(i) When applicable, details of the type and supplier of steel studs.

(j) When applicable, method of fixing studs into links and, where appropriate, details of the procedure for welding the studs into the links (see also Section 5.1.6).

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3.2.3 Chain Cable for offshore mooring

Manufacturers of all types of chain cable are to supply the following information:

(a) Details of heat treatment furnaces including dimensions, type of fuel used and facilities for temperature measurements and control. In the case of continuous heat treatment furnaces, details are required of the method of cooling the chain after austenitising for normalizing or quenching and after tempering. For each size of chain the target cooling rate ranges are to be stated. Furnace calibration is to be verified by measurement and recording of a calibration test piece. Dimensions of the test piece to be equivalent to maximum size of link manufactured. Thermocouples to be placed on the surface and in a drilled hole located to the mid-thickness position of sample piece

(b) Details of the mechanical testing equipment. This is to include information regarding the name of the manufacturer, type number or description, serial number and calibration status of each machine used for tensile and impact testing.

(c) Facilities available for proof and breaking load tests. This is to include information regarding the name of the manufacturer, model number or full description, with details of load application and measurement, serial number and calibration status of all chain testing machines.

(d) Full details of in-house non-destructive testing programme and the NDE procedures used. This should include the type and extent of on-line ultrasonic or eddy current testing. It is expected that on-line testing is carried out on a continuous basis to assure the quality of product. The procedures must be authorised by a Level III qualified inspector.

(e) Details of the manufacturer's proposed specification for chemical composition and the type of heat treatment to be used for each grade of chain cable for which approval is requested. The specified chemical composition is to include all alloying elements, grain refining elements and the maximum contents of residual elements and nitrogen.

(f) Details of any subcontracted activities and particulars relating to the related requirements of the appropriate sections above (eg Section (a) applies to subcontracted heat treatment).

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(i) Non-destructive examination procedures, including the methods and equipment used, the qualifications of NDE personnel, the means of calibration, the method of measurement and the acceptance criteria. Procedures must be ratified by an NDE inspector qualified to ASNT Level III or equivalent.

(j) The manufacturer’s surface quality requirement is to be submitted.

(k) Detail of how defective links are removed. If defective links are removed after the final heat treatment and substitute single links are used to connect the length without re-heat treatment of the whole cable length, the procedure shall be approved in accordance with Sec 5.1.7.

4 Survey of the manufacturing, testing and inspection capabilities

4.1 The local surveyor will carry out a survey of the works and subcontractor as applicable, which will include the manufacturing, inspection and testing processes and procedures. As a minimum, the following manufacturing areas are to be included in the survey; with a view towards verification of the information contained in the manufacturer’s written report (see Section 3.2 above). The general condition of the equipment and orderliness of the works should be noted. During this inspection the opportunity is to be taken to examine visually chain cables at all stages of manufacture. If permitted, photographs might be used to support appropriate information.

(a) Control of chain cable stock bar- inspection and identification system

(b) Manufacturing control processes of chain cable production, including flash butt welding process.

(c) Production of hot working and drawing dies.

(d) Product and test material identification and control

(e) Melting facilities (if applicable)

(f) Melting and charge composition and control (if applicable)

(g) Chemical analysis equipment and practices

(h) Facilities and practices for routine chain inspection, including NDE

(i) Facilities and practices for mechanical testing

(j) Facilities for proof load and break load testing

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4.2 Where responses to any questions raised by the survey are not forthcoming from the manufacturer, the reasons for omission must be clearly stated in writing.

4.3 Following review of submitted documentation and its verification through the site survey, the surveyor will issue a report of their findings together with a proposed scope of approval testing based upon the guidance given in Section 5 and Section 6. The surveyor will issue a final recommendation stating their opinion as to whether the works should be considered for the next stage of approval. If the surveyor decides that approval application would not be appropriate at this time, this will be communicated to the works together with the reasons why this decision was made and suggestions as to actions which could be undertaken to improve the application.

If the surveyor deems the approval application to be suitable for progression, the documents listed in 3.1.2 and the proposed test programme will be sent to the Materials & NDE Department for specialist review before testing commences.

5 Approval test programme

5.1 Flash butt Welded Chain Cable

5.1.1 Selection of material

(a) Approval tests are to be carried out for each grade on representative length(s) of cable (including permanent attached fittings, if applicable) designed to a national or international standard recognised by LR. The chain length(s) selected for approval testing shall represent the maximum diameter of each composition range for which approval is requested.

(b) Bar used for chain must be from approved bar manufacturers. Chain manufacturers must have separate approvals for each supplier nominated for the particular chain cable products. Approval will only be given for the bar manufacturer after successful testing of final chain. Approval will be limited to up to maximum diameter equal to the diameter of the common link of the tested chain.

5.1.2 Test on chain prior to approval submission

(a) Prior to approval, the manufacturer must carry out a range of tests on typical chains produced to demonstrate acceptability Examples of tests which could be acceptable:

• Fatigue tests • Hot ductility tests – no defects to be seen when hot

bending • Welding parameter research • Heat treatment study • Strain age resistance • Temper embrittlement study

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• Slow strain rate stress corrosion tests (in wet environments)

5.1.3 Tests, test samples and specimens

5.1.3.1 Tests on bar used for chain cable A suitable length (about six times the diameter) of the bar material used for the manufacture of the cable, is to be provided for test purposes. This sample of bar material is to be heat treated in a manner simulating that used for the completed chain cable. The following tests and examinations are to be carried out on each length of bar submitted:

(a) A tensile test from the position specified in Ch 10 of the LR Rules for Materials, i.e. at one third of the radius from the outer surface.

(b) For bar material greater than 75 mm in diameter an additional tensile test is to be taken from the centre of the bar.

(c) Charpy V-notch impact tests from a position in the bar as specified in Ch 10 of the Rules for Ships, i.e. at one third of the radius from the outer surface. Three tests are to be carried out at each of the temperatures +20°C, 0°C, -20°C and -40°C. The absorbed energy and percentage crystallinity are to be reported so that transition curves may be constructed.

(d) For bar material greater than 75 mm in diameter additional Charpy V-notch tests are to be taken from the centre of the bar. These tests are to be carried out at the appropriate temperature for the grade ( see Table 3.9.2 in Ch 3, of the Rules for Materials) and the energy absorbed and percentage crystallinity is to be reported.

The dimensions of test specimens and mechanical testing procedures are to be in accordance with the requirements of Ch 2 of the LR Rules for Materials.

(e) The manufacturer is to provide evidence that the steel is not susceptible to any of the following:

(i) Strain ageing (see Ch 2, Section 5.2 of the LR Rules for Materials).

(ii) Temper embrittlement (see Ch 2, Section 5.1 of the Rules for Materials).

(iii) Hydrogen embrittlement. Tests are to be made on two different heats with, as far as possible, in one sample the alloying elements close to the minimum limits of the specification and in the other close to the maximum. Two tensile test specimens are to be taken from the central region of each bar. The specimens should preferably have a

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diameter of 20 mm, or alternatively 14 mm. One specimen is to be tested within a maximum of three hours after machining for the 20 mm diameter specimen, or 1.5 hours for the 14 mm diameter specimen. The other specimen is to be tested after heating at 250°C for four hours for a 20 mm diameter specimen or two hours for the 14 mm diameter specimen. As an alternative to testing within the specified time limit after machining the specimens may be cooled to -60°C immediately after machining and kept at that temperature for a maximum period of five days before testing.

5.1.4 Tests on Chain Cable

5.1.4.1 Flash butt welded chain cable The following tests and examinations are to be carried out on each of the lengths of flash butt welded chain cable submitted for approval purposes:

(a) Careful visual examination with special reference to the uniformity of diameter, the shape of links, workmanship and finish.

(b) Magnetic particle inspection is to be made on all welds as well as the whole surface of at least 10%of the links; ultrasonic examination is also to be carried out on 100% of the welds.

(c) An initial load, equal to 10% of the appropriate proof load specified for the cable diameter and grade, is to be applied and the length accurately measured. The specified proof load is to be applied and after unloading to the initial load the length is to be re-measured. The permanent stretch of the test length is to be recorded and the final chain length is not to exceed the allowed tolerance. (See Ch 10, Section 2.15.4 of the LR Rules for Materials).

(d) The length of chain cable is to be re-examined for defects and to confirm that the inside radius of the links is sufficient to permit complete freedom of movement in all directions.

(e) A three-link sample is to be selected from one end of the test length and subjected to a break load test to 110% of the specified breaking load.

(f) The following specimens for mechanical tests are to be prepared from each of two common links (plus any permanent attached end fittings, if applicable) selected from the length of cable after proof loading:

(i) A tensile test from the side opposite the weld.

(ii) A cross-weld tensile test.

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(iii) A cross-weld bend test.

(iv) Three Charpy V-notch impact tests from material clear of welds.

(v) Three Charpy V-notch impact tests notched in the centre of the weld.

(vi) Three Charpy V-notch impact tests from material at the inside of a bend.

(vii) A cross-section through the weld for sulphur printing and macro/ micro examination. See also 5.1.4.1(j).

(viii) For Grades R3, R3S, R4, R4S and R5 cable, a crack opening displacement test. Details of a suitable test are given in Section 6.

(g) The tensile and Charpy V-notch impact test specimens are to be taken from positions at one third of the radius from the outer surface of the link. Additionally, for cable greater than 75 mm in diameter, tensile tests shall be carried out on material from near the outer surface and from the centre of the links. It is recommended that after machining, the appropriate Charpy V-notch test specimens are lightly etched to locate accurately the position of the weld before cutting the notches. The results of all these tests from stud link chain cable are to comply with the requirements of Ch 10 of the LR Rules for Materials.

(h) The cross-weld bend tests may consist of the full diameter of the cable or alternatively for larger sizes may be machined to an approximately rectangular cross-section, 25 mm wide by 20 mm thick. One of the original as rolled/welded surfaces should be retained and this should be tested in tension. The test specimens are to be bent cold, without fracture, through an angle of 120° (i.e. an included angle no greater than 60°) over a former with the maximum diameter of 5t (t=diameter or thickness of bend test specimens)

(i) The macro-sections through the welds are to be full section and for stud link cable are to include the area under the studs and the areas gripped by the electrodes. Representative photomicrographs at x100 magnification of the parent material, weld and heat affected zone, are to be submitted.

(j) When heat treatment is carried out in a batch furnace without a suitable carrier to separate the links, additional tensile and Charpy V-notch impact tests are to be taken from a link cut, after proof loading, from approximately the middle of the test length. These test specimens should be prepared from material clear of the weld.

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5.1.5 Welding of studs

5.1.5.1 Tests and procedures

Where it is intended that studs are to be welded into position, an approved welding procedure is to be submitted.

A procedure test is to be carried out in accordance with the approved welding procedure and the results are to be submitted with the data required by 5.1.4

A separate welding procedure and procedure qualification test is required for each combination of bar and stud material.

5.1.6 CTOD tests on chain of grades R3, R3S, R4, R4S and R5

5.1.6.1 CTOD tests are to be carried out as follows and they are to conform generally with Ch 2, Section 6 of the LR Rules for Materials:

(a) The CTOD test piece is to be a standard 2 x 1 single edge notched bend piece, test location as shown in Figure 1. The minimum test piece size shall be50 x 25mm for chain diameters less than 120mm, and 80 x 40mm for diameters 120mm and above. CTOD specimens are to be taken from both the side of the link containing the weld and from the opposite side. Three links are to be selected for testing, a total of six CTOD specimens. The tests are to be taken at -20º C and meet the minimum values indicated In Table1 below.

5.1.7 Approval of substitute single links

5.1.7.1 Separate approvals are required for each grade of chain cable and the tests are to be made on the maximum size of chain for which approval is sought. Re-approval is required annually.

5.1.7.2 Manufacturing and heat treatment of the substitute link shall not affect the strength of the adjoining links. The temperature reached by these links is nowhere to exceed 250°C.

5.1.7.3 Details of the method of manufacture, including heat treatment, are to be submitted.

5.1.7.4 The substitute link included in a chain cable is to be subjected to the proof load appropriate to the grade and size of chain in which it is incorporated.

5.1.7.5 The mechanical test in accordance with the requirement of Sec 5.1.4.1 (f) shall be carried out on the substitute single link. A tensile and an impact test (at the temperature as required by the relevant grade)

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have to be carried out on the base materials of the adjoining links.

6 Specific approval test results

6.1 General

6.1.1 Following Materials & NDE Department agreement to the test plan, the Works will manufacture approval chain cable and stages of manufacture and all approval testing is to be witnessed by the Lloyd’s Register surveyor.

All test results will be endorsed by the surveyor.

All details listed in Section 6.2 together with the test results will be submitted to the Materials & NDE Department for review.

6.2 Approval test submission

6.2.1 For each sample of chain cable selected for approval tests, the Works is to provide the following information:

(a) Verification of the form of the raw material, i.e. bar

(b) The details of welding parameters used including any preheating/ post heating, and the requirements for weld edge cleaning prior to welding

(c) Chemical analysis including residual elements and grain refining elements (where applicable).

(d) Where applicable, details of heat treatment, including copies of the heat treatment charts showing the full thermal cycle for each chain cable submitted.

(e) Dimensions of finished chain cables.

(f) Applicable specification. Copies of specifications should be submitted where these are not National/International standards. English copies are preferred although documents annotated in English will be acceptable.

(g) NDE technique sheets used to assess the chain cable of the approval test program.

Copies of the qualifications of NDE operators and report authorizers (if appropriate) are to be submitted.

The procedures used are to be those that have already been accepted as part of the manufacturer’s submission and reviewed by the Materials & NDE Department.

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(h) Results of tests undertaken in accordance with 5.1.

6.2.2 In addition to selecting and witnessing the above tests, surveyors will carry out a careful visual examination of other products in general production and report on the general quality and surface condition.

6.2.3 The surveyor will submit the information requested in Section 3.1.2 and 6.2 to the Materials & NDE Department together with any additional survey reports that were requested by Materials & NDE Department specialists.

Photographs may be used to support the submitted information.

7 Validity of approval certificate

7.1 Initial approval

7.1.1 On satisfactory review of the submitted approval test report Materials & NDE Department will enter the manufacturer onto the List of Approved Manufacturers and an initial approval certificate will be issued.

7.1.2 The approval certificate will state the approved chain cable type, grade, the maximum diameter of the common link, and the approved chemical specification. The approved suppliers of the bar products will also be given.

7.1.3 The initial approval certificate will have a validity of three years.

7.2 Extension of the scope of approval

7.2.1 Manufacturers who intend to extend their scope of approval will be required to repeat the approval process in Section 2 and the scope of information to be submitted and test program is to be agreed with Materials & NDE Department.

7.3 Re-approval of works

7.3.1 For the validity to be renewed for a further three years the Surveyors should undertake a periodic inspection in accordance with Procedure 1-1. To ensure continuity, this should be carried out within six months of the approval expiry date.

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7.3.2 It is a Rule requirement that during material surveys the works will be subject to regular visits to confirm continued compliance with the original approval. The frequency of visits will depend on the frequency of material surveys. Records of these visits will be kept by the surveyors.

7.3.3 Manufacturers that have not produced products under Lloyd’s Register survey during the approval period must either conduct new approval tests (according to Sections 5 and 6) or contact Lloyd’s Register to agree on any additional requirements to continue approval.

7.3.4 Where a manufacturer physically moves the location of an approved works from the approved location to a new site, the manufacturer will be required to follow the initial approval process in full unless they can present a satisfactory case to the MNDE Dept that this would not be necessary.

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Table 1 Minimum requirements for CTOD Testing

Chain Type

R3 in mm R3S in mm R4 in mm R4S & R5 in mm BM WM BM WM BM WM BM WM

Stud link 0.20 0.10 0.22 0.11 0.24 0.12 0.26 - Studless 0.20 0.14 0.22 0.15 0.24 0.16 0.26 -