Becket hitch Becket hitch A becket hitch, including the double becket or figure-of-eight becket hitch, is any hitch that is made on an eye loop, i.e. on a becket. A becket hitch has the same structure as the sheet bend, which joins, or "bends", the ends of two ropes together. The becket hitch, in contrast, fixes a rope to a closed eye or hook. In this instance, a "becket" means the eye or hook of a pulley block, an eye in the end of a rope, or a rope handle on a sailors sea chest. For greater security, an additional round turn
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