Lever a fixed point. The lever operates by applying forces at different distances from the fulcrum, or a pivot. Assuming the lever does not dissipate or store energy, the power into the lever must equal the power out of the lever. As the lever rotates around the fulcrum, points farther from this pivot move faster than points closer to the pivot. Therefore, a force applied to a point farther from the pivot must be less than the force located at a point closer in, because power is the product of force and velocity. If "a" and "b" are distances from the
Lever frame Lever frame Mechanical railway signalling installations rely on lever frames for their operation to interlock the signals, track locks and points to allow the safe operation of trains in the area the signals control. Usually located in the signal box, the levers are operated either by the signalman or the pointsman. The world's largest lever frame (191 levers) is thought to have been in the Spencer Street No.1 signal box in Melbourne, Australia, which was decommissioned in 2008. The largest operational lever frame, meanwhile, is located at Severn Bridge Junction in Shrewsbury, England, and it contains 180 levers, although most