Funicular from an inclined elevator by the presence of two vehicles which counterbalance each other. The name "funicular" itself is derived from the Latin word "", the diminutive of , which translates as "rope". The basic idea of funicular operation is that two cars are always attached to each other by a cable, which runs through a pulley at the top of the slope. Counterbalancing of the two cars, with one going up and one going down, minimizes the energy needed to lift the car going up. Winching is normally done by an electric drive that turns the pulley. Sheave wheels
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