How Do You Configure Block & Tackle?
Pulleys are generally used for lifting, especially when combined in “blocks,” in which a series of pulleys share the same axle. Two blocks used in conjunction can reduce the amount of force required for a lifting task. One block attaches to some immobile support while the other attaches to the load. Because the line, or “tackle,” threads backs and forth between the two blocks, you have to pull the tackle a great distance to bring the blocks together a small distance. The payback for the extra pulling length is that less force is needed to lift the load. Attach one of your two multi-pulley blocks to the load to be lifted. (The double-pulley blocks listed in Resources have eyelets to attach to the load.) Attach the second pulley block to a stationary support, preferably directly above the load if you’re lifting it vertically. That way no force is wasted on lateral tension. This is also why the pulleys are in a block instead of spread out: to avoid wasted energy through lateral tension. D
