Windlass
（重定向自Differential windlass）
![Turnbridge Windlass Lift road bridge over Huddersfield Broad Canal](/Images/godic/202501/09/Turnbridge_Liftbridge_RLH4341.jpg")
![Differential windlass](/Images/godic/202501/09/L-differentialwinde4341.png")
![Comparison of a differential pulley or chain hoist (left) and a differential windlass or Chinese windlass (right). The rope of the windlass is depicted as spirals for clarity, but is more likely helices with axes perpendicular to the image.](/Images/godic/202501/09/Comparison_differential_pulley_windlass.svg4341.png")
- For the tool used to raise paddle gear on canal locks, see Windlass ("lock key")
The windlass is an apparatus for moving heavy weights. Typically, a windlass consists of a horizontal cylinder (barrel), which is rotated by the turn of a crank or belt. A winch is affixed to one or both ends, and a cable or rope is wound around the winch, pulling a weight attached to the opposite end. The oldest depiction of a windlass for raising water can be found in the Book of Agriculture published in 1313 by the Chinese official Wang Zhen of the Yuan Dynasty (fl. 1290–1333).