Rope drive Rope drive A rope drive is a form of belt drive, used for mechanical power transmission. Rope drives use a number of circular section ropes, rather than a single flat or vee belt. The first multiple rope drive was a 9 rope drive of 200 bhp produced by Combe Barbour for their Falls Foundry, Belfast, in 1863. James Combe experimented first with circular ropes laid from leather strips, then from manila hemp. The idea of using rope drives had arisen from his earlier, 1856, experiments in using a rope drive together with an expanding vee pulley, as part of a
Block and tackle more precise estimate of efficiency is possible by use of the sheave friction factor, formula_12 (which may be obtainable from the manufacturer or published tables). The relevant equation is: Typical formula_12 values are 1.04 for roller bearing sheaves and 1.09 for plain bearing sheaves (with wire rope). The increased force produced by a tackle is offset by both the increased length of rope needed and the friction in the system. In order to raise a block and tackle with a mechanical advantage of 6 a distance of 1 metre, it is necessary to pull 6 metres of rope through the