Pulley system, the massless and frictionless pulleys do not dissipate energy and allow for a change of direction of a rope that does not stretch or wear. In this case, a force balance on a free body that includes the load, "W", and "n" supporting sections of a rope with tension "T", yields: The ratio of the load to the input tension force is the mechanical advantage "MA" of the pulley system, Thus, the mechanical advantage of the system is equal to the number of sections of rope supporting the load. A belt and pulley system is characterised by two or
Elevator the ropes by the grip of the grooves in the sheave, thereby the name. As the ropes age and the traction grooves wear, some traction is lost and the ropes must be replaced and the sheave repaired or replaced. Sheave and rope wear may be significantly reduced by ensuring that all ropes have equal tension, thus sharing the load evenly. Rope tension equalization may be achieved using a rope tension gauge, and is a simple way to extend the lifetime of the sheaves and ropes. Elevators with more than of travel have a system called compensation. This is a separate