BS ISO 7364-2016 pdf free.Ships and marine technology – Deck machinery一 Accommodation ladder winches.
4.1 The winches shall be equipped with one or two drums. The drum shall be a split drum where two ropes are to be wound on it.
4.2 The drum length shall be such that the rope in effective working length can be wound on fully, in
not more than three layers, while the rope can be wound on fully, in not more than five layers.
4.3 The drum diameter shall be not less than 14 times the rope diameter given in Table 1.
4.4 The flange height shall be such that it will project at least 1,5 times the rope diameter beyond the outermost layer of the rope.
4.5 Double drum winches intended for double flight accommodation ladders shall be fitted with a suitable device to allow independent holding. hoisting or lowering of each flight.
4.6 The winch shall be provided with a device capable of holding the drum at 1,5 holding load. For powered winches, such device shall automatically operate when the drive is being shut off or if the power fails. Manual lowering and hoisting of the accommodation ladder shall be possible. A self-braking worm gearbox (or equivalent) may be considered a holding device ii agreed between the purchaser and the manufacturer.
4.7 For design purposes, the drum shall be based on the use of 6 x 37 galvanized steel wire rope with fibre core of 1 770 N/mm2 tensile grade, as specified in ISO 2408. Wire rope diameters are listed in Table 1. This requirement does not preclude the use of other types of rope in service.
In every case, the safety factor of the rope shall be not less than five in relation to the holding load as specified in ISO 5488:2015, 6.1.3.
NOTE Attention is drawn to the possibility of national authorities requiring a safety factor of more than five.
4.8 The winch shall be designed to ensure that all bearing surfaces and corresponding sliding and rotating component parts of the winch are lubricated during operation.
4.9 Stresses in component parts of the winch being acted upon with the drum load and holding load shall not exceed 0,4 times the proof stress of the material.
4.10 The winch shall be fitted with a local emergency stop.
4.11 Powered winches shall also be also provided with manual drive.
4.12 Winches shall be provided with safety precautions to protect the operator against the possibility of being struck by a revolving crank handle.
4.13 Electrical equipment of winches shall be installed in accordance with IEC 60092-401.
4.14 Winches shall not be made of asbestos-containing material.BS ISO 7364 pdf download.