A capstan winch is a device commonly used on sailing vessels to tighten or loosen ropes that can lift or lower sails and other objects. Unlike more modern winches, which have the rope or cable is mounted on a drum, the capstan winch does not hold the entire length of rope but instead acts as an intermediary between one end of the rope and the other. The capstan is a vertical barrel that rotates to apply tension to the rope, and it was traditionally operated by several men using leveraging poles to turn the barrel.
Early designs of the capstan winch were entirely wooden, with a vertical beam extending from the hull of the ship through the deck or decks. The barrel would then be mounted to the beam so it could rotate freely. Later models used metal beams and barrels for added durability, though they were still hand-operated by deckhands. As technology improved, these systems were motorized for ease of use and added safety. The capstan winch is still used on many sailing vessels, although they are usually motorized.
Since the inception of these devices, they have traditionally been used on sailing vessels, but in modern times, the capstan winch has found a home in other applications such as industry and recreation. Loggers sometimes use a motorized capstan winch to move heavy logs through the woods, and in some cases, the winches can be mounted to a vehicle such as a pickup truck or ATV to haul the logs to another location. These devices will have a weight capacity outlined by the manufacturer, and exceeding this weight limit could cause damage to the unit or even injury to the user. Larger winches with larger cables are generally able to haul more weight than smaller units.
A windlass is a device that functions very similarly to capstan winches, but instead of featuring a vertical barrel, the windlass will feature a horizontal pulley or barrel. These devices are often used for the same purposes in different applications as well. Most modern winches tend to mimic the design of the windlass rather than a capstan, as the devices are usually mounted on a horizontal surface and the barrel is parallel with that surface. Like capstans, windlasses do not feature a barrel that has the entire length of rope wrapped around it; instead, the barrel is an intermediary between one end of the rope and the other.