Pulley
![](/Images/godic/202501/07/PulleyShip1006.JPG")
![Various ways of rigging a tackle.[5]](/Images/godic/202501/07/Tackles1006.png")
![Pulley in oil derrick](/Images/godic/202501/07/Pulley_in_Oil_Well1006.jpg")
![A hoist using the compound pulley system yielding an advantage of 4. The single fixed pulley is installed on the hoist (device). The two movable pulleys (joined together) are attached to the hook. One end of the rope is attached to the crane frame, another to the winch.](/Images/godic/202501/07/Crane_pulley_4x1006.jpg")
A pulley is a wheel on an axle or shaft that is designed to support movement and change of direction of a taut cable or belt along its circumference. Pulleys are used in a variety of ways to lift loads, apply forces, and to transmit power. In nautical contexts, the assembly of wheel, axle, and supporting shell is referred to as a "block."