A come-along is a hand operated ratchet lever winch. A winch is a mechanical device used to wind a rope or cable, while a ratchet is a mechanical brake that keeps the line from unwinding. A come-along is convenient and portable enough to use in almost any situation, because it is small enough to carry in one hand and weighs an average of only ten pounds (about 4.54 kilograms).
A come-along is used for pulling joints together, for straightening heavy panels while putting them in place, as a safety tie, and for pulling the frame of a new construction together during its raising. A come-along can also be used for stretching, lifting, and lowering objects. In addition to construction and industrial applications, a come-along is useful for towing boats, cars, and gliders. On boats and ships, it can be used to pull anchor or mooring lines, sheets, and halyards.
A come-along can be purchased in a variety of sizes and weight lifting capacities for varying construction needs. Lifting capacity generally ranges from one to three tons (907.19 to 2721.6 kilograms), with a six to twelve foot (about 1.83 to 3.66 meters) lift height. It is important to adhere to the recommended weight limits provided with a come-along, as the device is susceptible to fatigue fractures if repeatedly operated at even a small percentage of its tensile breaking strength.