Block and tackle
Device consisting of two pulleys (or in a borderline case only one movable pulley); device multiplying force; machine used to lift heavy loads
Nº Q2397030 ★★★★
Super Rare · Knowledge
Block and tackle
Device consisting of two pulleys (or in a borderline case only one movable pulley); device multiplying force; machine used to lift heavy loads
A block and tackle, purchase, or only tackle is a system of two or more pulleys with a rope or cable threaded between them, used to provide tension and lift heavy loads. The pulleys are assembled to form blocks and then blocks are paired so that one is fixed and one moves with the load.
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From Wikipedia
A block and tackle, purchase, or only tackle is a system of two or more pulleys with a rope or cable threaded between them, used to provide tension and lift heavy loads. The pulleys are assembled to form blocks and then blocks are paired so that one is fixed and one moves with the load. The rope is threaded through the pulleys to provide mechanical advantage that amplifies the force applied to the rope. Hero of Alexandria described cranes formed from assemblies of pulleys in the first century. Illustrated versions of Hero's Mechanica (a book on raising heavy weights) show early block and tackle systems.
Text: Wikipédia, CC BY-SA 4.0. · Image: Great Britain. War Office (No restrictions) ·
