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"). In its simplest form it consists of a spool and attached hand crank. In larger forms, winches stand at the heart of machines as diverse as tow trucks, steam shovels and elevators. The spool can also be called the winch drum. More elaborate designs have gear assemblies and can be powered by electric, hydraulic, pneumatic or internal combustion drives. Some may include a solenoid brake and/or a mechanical brake or ratchet and pawl device that prevents it from unwinding unless the pawl is retracted.
Electric Winches are most commonly used to pull an automobile, boat, crane, truck, or other piece of equipment from a problematic area. If a car goes off the road and down into a ravine, for example, trucks with electric winches are used to hook the car and pull it back to the road. Electric winches can also be used to tug boats to safety. There have even been rare instances in which electric winches have helped save large animals from tricky holes and pits.
Electric winches come in different shapes and sizes. Typically, electric winches include a two-speed engine. A cable is attached to a spool, which is attached to the motor. A gear lever turns the spool in order to release the cable.
Once the cables of an electric winch are extended to the vehicle or object in need of towing, the gear levers are pushed in the opposite direction of the object. This causes the spool to wind up. As the spool winds, the cables are pulled back in. This causes the object to be pulled safely to where it belongs.
Electric winches are usually capable of handling loads of 500 pounds (267 kg) to two tons. The cables and motors of electric winches are created specifically to handle different weight loads. Electric winches capable of handling larger load capacities are more expensive.
The standard length of the cables on an electric winch is 100 feet (30.5 m). Electric winches also come standard with an automatic brake and a handheld remote control. They can deliver engine performance of one-third horsepower to over 50 horsepower. Electric winches can be easily installed to the back of a truck, boat, or solid surface.
The largest electric winch in the world is rigged to a platform in a deepwater construction vessel called the Balder, which can handle loads of 275 metric tons. The Balder can hold 350 workers and is used to save sinking oilrigs, to assist in the installation of underwater oil lines, and to install oil platforms.