Winches

thumb|Self-tailing winch on a sailboat. A Sheet (sailing)|sheet line runs from the sail (left, not shown) behind the winch to a block (lower right, not shown) and only from there back to the winch (lower part). The handle is detachable to ease line handling. thumb|Front of a MAN SE|MAN-based [[fire engine with a built-in winch, e.g. for towing damaged cars after an accident]] A winch is a mechanical device that is used to pull in (wind up) or let out (wind out) or otherwise adjust the tension of a rope or wire rope (also called "cable" or "wire cable").

thumb|Turnbridge windlass lifting road bridge over [[Huddersfield Broad Canal]] thumb|200px|Differential windlass

stationary engine used to control a cable, for example to power a mining hoist at a pit head

relates the hold-force to the load-force if a flexible line is wound around a cylinder