Block and tackle
![](/Images/godic/202502/11/Block-and-tackle-in-use.svg3952.png")
![Various ways of rigging a tackle. All these are rove to disadvantage.[5]](/Images/godic/202502/11/Tackles3952.png")
![A gun tackle has a single pulley in both the fixed and moving blocks with 2 rope parts (n) supporting the load (FB) of 100N. The mechanical advantage is 2, requiring a force of only 50N to lift the load.](/Images/godic/202502/11/Polispasto2B3952.jpg")
![A double tackle has two pulleys in both the fixed and moving blocks with four rope parts (n) supporting the load (FB) of 100N. The mechanical advantage is 4, requiring a force of only 25N to lift the load.](/Images/godic/202502/11/Polispasto43952.jpg")
A block and tackle is a system of two or more pulleys with a rope or cable threaded between them, usually used to lift or pull heavy loads.
The pulleys are assembled together to form blocks and then blocks are paired so that one is fixed and one moves with the load. The rope is threaded, or rove, through the pulleys to provide mechanical advantage that amplifies that force applied to the rope.