A winch is a piece of light, compact lifting equipment that uses a drum to wind a steel wire rope or chain for lifting or hauling heavy loads. Winches are capable of lifting loads vertically or hauling them horizontally or along an incline.
A winch converts electrical energy into mechanical energy via an electric motor; the rotation of the motor's rotor is transmitted-through V-belts, shafts, and gear reduction-to drive the rotation of the drum. As the drum winds the wire rope, a pulley system allows the hook to raise or lower the load, thereby converting mechanical energy into mechanical work to accomplish vertical transport and loading/unloading tasks. Winches commonly used in construction are categorized into two types: high-speed and low-speed. High-speed winches are primarily used for vertical and horizontal transport as well as pile-driving operations. Low-speed winches are mainly used for tasks such as structural hoisting and the cold drawing of reinforcing steel. The typical pulling force of commonly used electric winches ranges from 10 to 100 kN.