Although brakes should slip before the line breaks, under extreme conditions such as ovenightening
of the brake or overriding rope turns, [he winch may be subjected to the full MBL of !be line.
For this reason, it is recommended !hat all structural components of the winch including brakes,
foundations and supporting deck s!ruc!ure should be: designed in accordance with Table 4.3,
Sheet 4.
Where a drive input brake is intended to be the primary brake, all components, including the
reduction gears, must be based on !he full MBL of the mooring line. For winches with undivided
drums, the line must be assumed to be at 1he layer that produccs the highest stress in each individual
component. For split-drum winches the line shall be assumed to be on the first layer.Sh.ip designers should pay special attention to the support structure in way of the rlXed end of band
brakes, as this is the major load transfer point. (See Section 5 for further de!ails.)7.8 WINCH TESTING
In addition to brake testing per 7.5.4, the following acceptance tests are recommended. The tesls are in
general agreemcnt witb ISO Standard 3730.7.8.1 Rules concerning testing at manufacturer'S works for the acceptance of the manll/aclllrer and
purchaser:- Type testing
One winch of each batch must be tested. This test may be replaced by a prototype test certificate
if agreed by the manufacturer and purchaser.
The te-st shall be carried out as fo)tows:(I) operation under load: alternately hauling and rendering at the rated load of the winch for
30 minutes continuously.(2) holding test: to be tested by applying the holding load to a rope led off tbe drum, with no
rotation of the drum; this may be carried out on board ship if agreed between purchaser and
manufacturer.(J) automatic brake system test: t.b.is test may be carried oul on board ship if agreed between
purchaser and manufacturer.(4) chroughout tcsling, the following should be checked:(a) tightness against oil leakages
(b) temperature of bearings
(c) presencc of abnormal noise
(d) power consumption
(e) speed of rotation of the drum.Where tests are required in excess of the type tcst, they should be agreed betwee.n the purchaser
and manufacturer at the time of the contract.- Individual tests
The following tests shouJd be carried out:
(I) operation under no load: running for 30 minutes, 15 minutes continuously in each direction,
at liglll line speed.(2) correct operatioo of brake system.