Windlass

The windlass is the powerful machine on a ship's forecastle whose main job is to work the anchors and their cables. Raising a heavy anchor together with a great length of chain cable from the seabed demands considerable force, and the windlass provides it. Its key component is the cable lifter, or gypsy, a specially shaped wheel with pockets, or whelps, that exactly fit the links of the anchor chain so that as the wheel turns it grips the cable and hauls it in or pays it out without slipping. A powerful brake allows the cable to be held or let run under control when the anchor is let go, and the cable passes down through the hawse pipe to the anchor and up into the chain locker where it is stowed.

Most windlasses are driven hydraulically or electrically, and in addition to the cable lifters they usually carry warping drums, or barrels, at the ends of the shaft, which are used to heave on mooring lines when berthing the ship, so the same machine serves both anchoring and mooring at the fore end. On many ships the fore mooring winches and the windlass are combined into one unit.

Operating the windlass is a routine but demanding part of seamanship, carried out by the anchor party under an officer, and it must be done with care because of the weights and forces involved and the danger of a running cable. The equipment is maintained carefully, since a windlass that fails when a ship needs to anchor in an emergency, or to weigh anchor to get under way, is a serious problem. Together with the anchors, cables, hawse pipes and chain locker, the windlass forms the ground-tackle system that lets a ship anchor safely, and with its warping drums it is also central to mooring the vessel at the bow.