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1、BRITISH STANDARD MARINE SERIES CONFIRMED JULY 1999 BS MA 93:1981 Code of practice for Structural safety of deck machinery installation UDC 629.12.013.005 Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 93
2、:1981 This British Standard, having been prepared under the direction of the Shipbuilding and Marine Standards Committee, was published under the authority of the Executive Board and comes into effect on 30 April 1981 BSI 02-2000 The following BSI references relate to the work on this standard: Comm
3、ittee reference SME/6 Draft for comment 80/73505 DC ISBN 0 580 12093 7 Foreword This code of practice has been prepared under the direction of the Shipbuilding and Marine Standards Committee and is based on a proposal made by the British Ship Research Association. The marine series of standards for
4、deck machinery specify the manufacturing requirements for each individual item of equipment. Every ship is equipped with its individual arrangement of deck machinery and it is necessary to provide designers with a structural safety code for general guidance. It is not possible to make recommendation
5、s to cover every situation, but an intelligent application of the principles and recommendations given in this standard will satisfy the majority of deck machinery installations. Deck machinery safety considerations should be regarded as coming within the duty of those engaged in the design and cons
6、truction and in the preparation of operating manuals. NOTEUsers of this code of practice should note that in addition to its recommendations, compliance is also required with such statutory requirements, rules and regulations as may be applicable to the individual ship. This code of practice represe
7、nts a standard of good practice and therefore takes the form of recommendations. Compliance with it does not confer immunity from relevant statutory and legal requirements. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 7 and a back cover. T
8、his 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. Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: London South Bank University, London South Bank Unive
9、rsity, Sat Dec 09 02:20:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 93:1981 BSI 02-2000i Contents Page ForewordInside front cover 1Scope1 2References1 3Initial design considerations1 4Installation of deck machinery1 5Supporting structures4 Appendix A Seat design guidance5 Figure 1 Examples o
10、f brake plates6 Figure 2 Examples of abutments7 Table 1 Example of tabulation of design loads for a windlass system2 Table 2 Typical deck thicknesses in way of deck machinery for various sizes of ships6 Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:53 GM
11、T+00:00 2006, Uncontrolled Copy, (c) BSI ii blank Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 93:1981 BSI 02-20001 1 Scope This code of practice recommends factors of safety and assumed loads to be us
12、ed in the design of deck machinery and its seating. NOTEOn board test requirements are given in the individual British Standards for deck machinery, which are listed in the reference section. 2 References This standard makes reference to the following standards publications. BS 5135, Metal-arc weldi
13、ng of carbon and carbon manganese steels. BS 5289, Code of practice for visual inspection of fusion welded joints. BS MA 10, Oval eyeplates. BS MA 11, Horncleats. BS MA 12, Welded steel bollards (vertical type). BS MA 19, Panama-type fairleads. BS MA 21, Deck-end roller fairleads. BS MA 22, Cast rol
14、ler fairleads. BS MA 23, Multi-angle roller fairleads. 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 windlasses. BS MA 36, Ships dec
15、k machinery topping winches. BS MA 53, Ships deck machinery towing winches for deep sea use. BS MA 54, Ships deck machinery trawl winches. BS MA 55, Ships deck machinery lifeboat winches. BS MA 56, Ships deck machinery anchor cable stoppers. BS MA 70, Dimensions of anchor chain cables Part 1: Stud l
16、ink anchor chain cables. BS MA 79, Specification for jib cranes: ship mounted type. ISO 6325, Shipbuilding Cable stoppers. 3 Initial design considerations At any early design stage of the deck machinery arrangement, it is recommended that a tabulated approach should be adopted to identify all items
17、used. Each item of the individual deck machinery system should be checked against the following list and the appropriate design loads (see Table 1). Static and dynamic requirements and usage Relevant British Standards Relevant shipyard standards Owner supplied items: tests, documentation Shipyard su
18、pplied items: tests, documentation if any Regulating body requirements Arrangement of deck machinery area Static mass of item on seating (tonnes) Seating method: continuous weld, bolting and chocking Test programme A formal approach to information logging is recommended, after these items have been
19、thoroughly examined, and may be tabulated as shown in Table 1. 4 Installation of deck machinery 4.1 General. Deck machinery and associated equipment should be mounted on seatings of adequate strength to absorb the maximum operational forces on either continuous welded seatings or chocks and reinforc
20、ed seatings (see Appendix A). NOTEInformation on chocks and holding down bolts is given in BSRA Shipbuilding Industry Standard number 13 “Chocks and holding-down bolts”. The seating plan of each item of equipment should be examined to determine the bending moments and shear stresses to be withstood
21、by the seating under adverse operating conditions. Checks should be made to ascertain that the mass of equipment on the deck and its operating forces will not produce any buckling of the deck, when snatch loads equivalent to the breaking load of the design anchor cable or ropes are applied. Adequate
22、 safe working area should be provided around each item for normal or emergency operation, and for repair or normal maintenance. Bollards and fairleads, etc., should be so positioned as to ensure that leads to drum ends and capstans are clear and safe and fleet angles kept to a minimum. Consideration
23、 should be given to ergonomic requirements. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 93:1981 2 BSI 02-2000 4.2 Anchoring 4.2.1 Anchor cable (see BS MA 70-1). The Classification Societies and Regula
24、tory bodies establish an equipment number, which determines the minimum size of anchor cable which may be fitted. When the grade and size has been established and the type of bower anchor selected, maximum forces should be calculated at the following positions; a) the bitter end connection (see Clas
25、sification Society Rules); b) duty pull at the cable lifter required to raise the freely suspended submerged anchor cable and anchor. NOTEThe efficiency of the hawsepipe should be taken as 70 %. The stowage arrangements for the anchor cable and the sizing of the anchor cable locker should be examine
26、d to ensure that the locker has adequate space and is designed to accept the mass of cable to be stowed in it. The arrangement should also allow for veering the anchor cable without jamming or kinking and for self stowing. 4.2.2 Anchor cable stopper (see BS MA 56 and ISO 6325). Depending on the type
27、 selected, the locking pawl has to withstand the appropriate percentage of either the breaking load of the anchor cable as specified in ISO 6325 or the breaking load or proof load of the anchor cable, whichever is applicable, as specified in BS MA 56. Strengthening of the deck should allow the holdi
28、ng-down arrangement to withstand the bending moments and shear forces arising from a load equivalent to 1.1 times the minimum design loads given in Table 1 of BS MA 56:1974. 4.2.3 Windlasses (see BS MA 35). The holding-down arrangement should withstand a duty pull measured at the cable lifter exit,
29、equivalent to 1.2 times the minimum breaking load of the grade of cable selected. Where chocks are used with a bolted arrangement, forward bump stops should be fitted to restrict the shear forces in the holding-down bolts. Should the full length of anchor chain be accidentally paid out, the bitter e
30、nd connection may be subjected to an increased load (see Classification Society Rules). This should be taken into account when seating stresses are calculated. Where warping ends are fitted, each seat should be designed for a condition where the cable lifter and the warping ends are working at the s
31、ame time. If double cable lifters are employed, each seating should be capable of withstanding the double load. NOTEFor the selection of anchoring equipment using grade U2 and grade U3 stud link anchor cable, reference should be made to BSRA Shipbuilding Industry Standard number 24 “Method of select
32、ion of mooring equipment”. Table 1 Example of tabulation of design loads for a windlass system Items Friction allowance where applicable Possible double loads, (e.g. fairleads) (tonnes) Minimum breaking load of rope or anchor cable (tonnes) Load on seat (tonnes) Remarks Anchor Anchor cable Hawsepipe
33、 Stoppers Windlass Special features Shackle pins Joining links Emergency slip links Chain pipe sealing Min. tail weight of cable to prevent jumping in gipsy Operational requirements Automatic power controls NOTEWhere systems are used in combination e.g. union purchase, consideration should be given
34、to the possibility that higher loads than the sum of the individual forces may result. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 93:1981 BSI 02-20003 4.3 Mooring 4.3.1 Mooring ropes. Type of rope to
35、 be used will be determined usually by the shipowner. NOTEFor guidance on sizes of fibre or wire mooring ropes, reference should be made to BSRA Shipbuilding Industry Standard number 24. 4.3.2 Mooring winches (see BS MA 32). The choice of winch type and size will determine the forces which are appli
36、ed to the deck seating under normal operations. However the calculation of stress in the base and seating arrangement should allow for the bending moments and shearing forces which would result from a load equivalent to 1.5 times the minimum breaking load of the selected rope being applied to the dr
37、um. Constant tension winches used in conjunction with spring ropes need special consideration. 4.3.3 Capstans (see BS MA 34). It is possible to load the capstan head throughout a full 360 even if a foot control system makes it desirable to operate in one direction only. It is recommended that the ca
38、lculations of stresses acting in the capstan base and seatings should allow for safe working through 360 with an assumed load of 5 times the hauling load. 4.3.4 Warping winches (see BS MA 33). A warping winch or warping ends fitted to other machinery will normally be used to take forces parallel to
39、the deck and at right angles to the drive shaft. However it should not be overlooked that forces from an elevated position may be applied and any structure and seating arrangement should be structurally designed to allow for these alternative or emergency arrangements. The calculation of stresses in
40、 the base and seatings should allow for safe working with an assumed load of 5 times the hauling load. 4.4 Other winches 4.4.1 Cargo winches (see BS MA 31). Generally, the lead of wire rope from the winch will be parallel to the deck, taken to a cargo block. However, in an emergency, the load may be
41、 applied to the winch drum from an elevated position, and the seating should be designed to withstand these forces. The calculation of stresses in the base and seatings should allow for safe working with an assumed load of 5 times the holding load, acting throughout the full 360 from the drum. 4.4.2
42、 Topping winches (see BS MA 36). The lead of the wire rope from the winch drum depends upon the type of installation. It is recommended that stresses in the seating should be calculated on an assumed load of 5 times the holding load, acting throughout the full 360 from the drum. 4.4.3 Trawl winches
43、(see BS MA 54). Special consideration should be given to the extremely high loads which may be taken when trawling. The forces on the drum are usually parallel to the deck, but with an unusual machinery arrangement this direction may change. The breaking load of the type of wire rope selected as the
44、 trawl warp will be used as the basis for determining the load on the drum, and this load should be utilised in any calculation of forces acting on the seatings. Consideration should be given to the fitting of dowel pins or collision chocks. 4.4.4 Towing winches (see BS MA 53). Towing systems may in
45、corporate a load limiting device to regulate the load below the winch holding load capacity. Even if this feature is fitted, it is recommended that the seatings should withstand 1.5 times the tow line minimum breaking load. It is recommended that dowel pins or collision chocks are fitted. 4.4.5 Life
46、boat winches (see BS MA 55). Statutory tests should be carried out after the installation is completed. The position for mounting the winch may be determined by the Shipbuilder or the winch and davit manufacturer, but when in position it should be capable of holding 1.5 times the working load on the
47、 winch brake. The wire rope rating should be determined from the statutory requirements for the particular ship. The seatings should be designed to withstand forces equivalent to 1.5 times the minimum breaking load of the wire rope selected. 4.5 Jib cranes: ship mounted type (see BS MA 79). The type
48、 of jib crane mounting used will depend on the handling configuration and use permitted by an installed set of jib cranes. Manufacturers normally supply a seating plan for single mounting, but the forces transmitted to the seatings will depend upon operating factors, such as twin crane lifts, slewin
49、g limits and the maximum permitted angle of inclination of the deck under operating conditions, and also whether the crane is to be used at sea. The seatings and forces involved cannot be fully assessed from a manufacturers catalogue and each installation should be considered when the mode of operation is known. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:20:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS MA 93:1981 4 BSI 02-2000 4.6 British Standard equipment used with deck machinery. A
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