Lever is obtained as which is the mechanical advantage of the lever. This equation shows that if the distance "a" from the fulcrum to the point "A" where the input force is applied is greater than the distance "b" from fulcrum to the point "B" where the output force is applied, then the lever amplifies the input force. If the opposite is true that the distance from the fulcrum to the input point "A" is less than from the fulcrum to the output point "B", then the lever reduces the magnitude of the input force. Lever A lever ( or )
Lever frame as it requires more force to move the lever. Therefore, later, especially in Germany, lever frames with pivots inside the signaller's room were used, that allow for a lever angle of approximately 180° (as seen on the photo on the right). By the movement of individual levers (or sometimes cranks), signals, points, track locks, level crossing gates or barriers and sometimes movable bridges over waterways are operated via wires and rods. The signaller chooses the correct combination of points, facing point locks and signals to operate, which will control the movement of each train through their area of control. The