winch, mechanical device for hauling or lifting consisting essentially of a movable drum around which a cable is wound so that rotation of the drum produces a drawing force at the end of the cable. A windlass is essentially the same device as a winch, except that a winch may be power-driven whereas a windlass is usually hand-powered and somewhat less sophisticated. Winches are normally equipped with a ratchet wheel and a pawl to prevent slippage of the load, and brakes that allow a load to be lowered or released at a controlled rate. A hoist is another closely related device, mounted so as to be movable (as in a traveling crane). Winches and hoists are widely used in cargo handling, e.g., in ships, factories, and warehouses, and also function as the power unit in derricks, power cranes, and power shovels. A car puller is a winch with a vertical drum axis, used to position railroad cars in freight yards. Certain military and construction vehicles designed for off-road use are equipped with engine-powered winches that can be used for lifting and hauling or to extricate the vehicle should it become stuck in areas where traction is poor.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
See more Encyclopedia articles on: Technology: Terms and Concepts