BS-MA-56-1974.pdf

BRITISH STANDARD MARINE SERIES BS MA 56:1974 Specification for Ships deck machinery anchor cable stoppers UDC 629.12.015.64 Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 56:1974 This British Standard, having been approved by the Shipbuilding and Marine Industry Standards Committee, was published under the authority of the Executive Board on 31 October 1974 © BSI 02-2000 The following BSI references relate to the work on this standard: Committee reference SME/6 Draft for comment 72/39368 ISBN 0 580 08356 X Amendments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 56:1974 © BSI 02-2000i Contents Page Forewordii 1Scope1 2Definitions1 3Design and construction1 4Performance3 5Acceptance tests3 6Marking4 Appendix A On board acceptance tests and inspection5 Appendix B Information to be provided by the purchaser5 Figure 1 Track-type stopper1 Figure 2 Combined track and roller stopper2 Figure 3 Roller-type stopper2 Figure 4 Shoulder diameter2 Figure 5 Typical track section2 Figure 6 Handing of stoppers3 Table 1 Performance data1 Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 56:1974 ii © BSI 02-2000 Foreword This British Standard has been prepared under the authority of the Shipbuilding and Marine Industry Standards Committee and has been developed from a proposal submitted by the British Ship Research Association. It forms one of a series dealing with deck machinery for ships and provides requirements for the design, construction, safety, performance and acceptance testing of anchor cable stoppers. Other standards in this series are: BS MA 30, Glossary of terms and graphical symbols for ships deck machinery. BS MA 31, Ships deck machinery cargo winches. BS MA 32, Ships deck machinery mooring winches. BS MA 33, Ships deck machinery warping winches. BS MA 34, Ships deck machinery capstans. BS MA 35, Ships deck machinery windlasses1). BS MA 52, Ships deck machinery accommodation ladder winches. An anchor cable stopper is a device secured to the ships structure, separate from the windlass cable lifter for the purposes of securing the anchor cable, in order to: a) relieve the windlass of excessive shock loads caused by movement of the ship when it is riding at anchor. b) prevent outward movement of the anchor cable. c) provide added safety when the anchor is secured in the housed position. The sizes and strength grades of materials for anchor cable are specified on a unified basis by the rules of the classification societies. In terms of strength, anchor cables are classified into three major grades as follows: For the purposes of this standard, the highest tensile grade (687 N/mm2 min.) anchor cable has been selected as the basis to establish the minimum design load for a cable stopper for any particular diameter of cable. It is recognised that this grade is not normally available in sizes below 40 mm. The selection of an anchor cable stopper should be made with reference to BS MA 351). Testing of anchor cable for use in ships registered in the United Kingdom is subject to the provisions of the Anchors and Chain Cables Act 1967 as detailed in the Anchors and Chain Cables Rules 1970 (statutory instrument 1970 No. 1453). Dimensional details for anchor cables are given in BS 3006. This standard makes reference to the following British Standards: BS MA 30, Glossary of terms and graphical symbols for ships deck machinery. BS MA 35, Ships deck machinery windlasses1). BS 1486, Lubricating nipples Part 1: Lubricating nipples and adaptors for use on machinery and vehicles. BS 1856, General requirements for the metal-arc welding of mild steel. BS 3006, Dimensions of ships stud link anchor cables. Certification. Attention is drawn to the certification facilities described on the inside back cover of this standard. 1) In course of preparation. 1st grade:tensile strength 304490 N/mm2 2nd grade:tensile strength 490640 N/mm2 3rd grade:tensile strength 687 N/mm2 minimum. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 56:1974 © BSI 02-2000iii A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 56:1974 © BSI 02-20001 NOTEUsers of this British Standard: Marine Series should note that while observing requirements of the standard they should at the same time ensure compliance with such statutory requirements, rules, and regulations as may be applicable to the individual ship concerned. 1 Scope This British Standard specifies requirements for the design, construction, safety, performance and acceptance testing of ships anchors cable stoppers. 2 Definitions For the purposes of this standard, the terms and definitions given in BS MA 30 shall apply, although the term “cable stopper” has been abbreviated hereinafter to “stopper”. Terms particularly applicable to this British Standard are defined as follows: 2.1 nominal size of stopper the nominal size is derived from the minimum and maximum diameters of anchor cable that the stopper will accept 2.2 class A stopper this stopper is designed to withstand a load of not less than 100 % of the breaking load of the maximum diameter anchor cable that the stopper will accept (see BS 3006) 2.3 class B stopper this stopper is designed to withstand a load of not less than 60 % of the proof load of the maximum diameter anchor cable that the stopper will accept (see BS 3006) NOTEThe range of nominal sizes covered by the standard is listed in Table 1, column 1; associated minimum design loads are listed in Table 1, columns 2 and 3. 3 Design and construction 3.1 Handing. Hinged bar stoppers may be designed as right-hand or left-hand units. A right-hand stopper is one having the hinge point for the bar on the right hand side of the stopper when observed from the windlass and looking towards the hawse pipe, a left-hand stopper having the hinge point for the bar on the left hand side of the stopper when similarly observed (see Figure 6). Table 1 Performance data 123 Nominal size Minimum design loads Class AClass B 22/26 28/32 34/38 40/44 46/50 52/56 58/62 64/68 70/73 76/81 84/87 90/92 95/97 100/105 107/111 114/117 120/122 kg 56 700 84 900 118 000 157 000 200 000 248 000 300 000 357 000 407 000 492 000 561 000 620 000 682 000 785 000 865 000 948 000 1 019 000 kg 23 820 35 640 49 680 66 000 84 000 104 400 126 000 150 000 171 000 207 000 235 800 260 400 286 200 330 000 363 600 398 400 428 400 Figure 1 Track-type stopper Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 56:1974 2 © BSI 02-2000 3.2 Type of stopper. Stoppers shall be designed as track-type, roller-type or combined track and roller type. Variation in design of the stoppers is shown in Figure 1, Figure 3 and Figure 2 respectively. Figure 5 shows a typical track section. 3.3 Class of stopper. The track-type and combined track and roller type stoppers shall comply with the performance requirements of Class A or B as required. The roller-type stopper shall comply with the requirements of Class B only. 3.4 Method of securing. The anchor cable shall be secured by a bar hinged at one end or a pivoting pawl engaging against a vertical link of the anchor cable to restrain the outward movement of the cable. The bar-type stopper produces a line of engagement at right angles to the direction of the anchor cable; the pawl-type stopper involves in-line engagement with the anchor cable. 3.4.1 The stopper shall be so designed to allow the anchor cable to be hove whilst the bar or pawl is in the closed position, the bar or pawl being lifted by the passage of each vertical link of the anchor cable and dropping back by gravity action into the closed position after each vertical link has passed. Both bar- and pawl-type stoppers may be provided with a counterweight arrangement to partially offset the deadweight affect of the bar or pawl as an aid to manual operation and adjustment. 3.4.2 When specified by the purchaser, provision shall be made for a positive form of locking device to secure the bar or pawl in the closed or holding position. 3.4.3 Means shall be provided to adequately secure the stopper to the deck, bearing in mind accessibility for welding. 3.4.4 Cable stoppers may be fitted with a turn buckle for holding housed anchors firmly in place, if this is agreed between the manufacturer and the purchaser. Figure 2 Combined track and roller stopper Figure 3 Roller-type stopper Figure 4 Shoulder diameter Figure 5 Typical track section Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 56:1974 © BSI 02-20003 3.5 Roller diameter. Where guide rollers are fitted, the shoulder diameter shall be not less than 11 times the diameter of the maximum cable capable of being used with stopper (see Figure 4). The maximum clearance between the roller and stopper side plates is not to exceed half the diameter of the smallest size of chain for which the stopper is intended. 3.6 Material stresses The stoppers shall be capable of withstanding minimum design loads on the basis of using anchor cable of 687 N/mm2 minimum tensile strength related to the maximum diameter of the anchor cable for which the chain cable stopper is intended to be used. The maximum allowable stress in any part of the stopper shall not exceed 90 % of the 0.2 % proof stress of the material of that part. On stoppers where rollers are fitted, it is assumed for design purposes that the cable passes through an angle of 90°. 3.7 Materials. Materials used for construction of the stopper shall be in accordance with the appropriate British Standard for the material selected to ensure compliance with 3.6. Materials should have an elongation at fracture of a standard test piece of not less than 12 %. 3.7.1 Welding. All welding shall be carried out in accordance with the requirements of BS 1856. 3.7.2 Lubrication. Adequate and accessible greasing and oiling points shall be provided to ensure that all required surfaces are capable of being properly lubricated. Nipples shall be in accordance with BS 1486-1. 3.7.3 Protection of metallic surfaces. Surfaces shall be free from moisture, oil, grease, dirt, weld spatter, burrs or other imperfections, before applying the protective finish to metallic surfaces. Surfaces shall be primed with an anti-corrosive priming paint adequate to provide protection against a marine environment, as soon as practicable after completion of the surface preparation. 4 Performance Stoppers shall accept the minimum design loads listed in Table 1, column 2 for Class A; or Table 1, column 3 for Class B. 5 Acceptance tests 5.1 Factory inspection. All stoppers shall be subject to a visual inspection at the place of manufacture to ensure: 1) correct operation of the bar or pawl; 2) freedom of rotation of the roller (if fitted); 3) quality of workmanship. 5.1.1 The factory inspection shall be performed by the manufacturer and when agreed between the purchaser and manufacturer, witnessed by a classification society. Figure 6 Handing of stoppers Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 56:1974 4 © BSI 02-2000 6 Marking All stoppers shall be permanently marked by means of a rating plate, prominently displayed. The rating plate shall contain information relevant to the stopper, including the following: 1) Manufacturers name or trade mark reference, type number and serial number. 2) Number of this British Standard (BS MA 56). 3) Nominal size. 4) Class. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 56:1974 © BSI 02-20005 Appendix A On board acceptance tests and inspections It is recommended that the ship owner should arrange for the following inspections and tests to be carried out on board the ship to ensure that the stoppers are fully operable. A.1 Primary inspections 1) Check the securement of the stopper to the deck and its correct alignment relative to the anchor cable. 2) Check the correct operation of the bar or pawl. 3) Ensure the sufficient oil and/or grease of the correct type is provided to ensure adequate lubrication. 4) Ensure the freedom of rotation of the guide roller (if fitted). 5) Ensure that the anchor cable runs freely through the stopper in the open position. 6) Test the bar or pawl in the closed position for effective operation, including any locking device (if fitted). A.2 Additional tests Other tests may be requested by the purchaser at his expense and convenience. Appendix B Information to be provided by the purchaser The purchaser should provide the manufacturer of the stopper with the following basic information at the time of the enquiry. 1) Anchor cable stopper to BS MA 56. 2) Diameter of anchor cable. 3) Nominal size of stopper. 4) Class A or B. 5) Type (see 3.2). 6) Handing (see 3.1). 7) If counterweight is required (see 3.4.1). 8) If locking device is required (see 3.4.2). 9) If additional tests are to be performed. 10) Additional paint specification as required. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 6 blank Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 56:1974 © BSI 02-2000 BSI Certification Trade Mark The Kitemark The Kitemark is the registered certification trade mark of the British Standards Institution. A licence to use the Kitemark on or in relation to a product will be granted to any manufacturer or producer who demonstrates