Block and tackle in the line that either attach to or run through the moving blocks—in other words, the number of supporting rope sections. An ideal block and tackle with a moving block supported by "n" rope sections has the mechanical advantage (MA), where F is the hauling (or input) force and F is the load. Consider the set of pulleys that form the moving block and the parts of the rope that support this block. If there are "n" of these parts of the rope supporting the load "F," then a force balance on the moving block shows that the tension in
Fly system hoist (of an automated line set). Rope line (hemp) head blocks are typically upright blocks that mount to the rope line head block well channels at the grid level. In a counterweight rigging system the head block sheave is grooved for both the steel cable lift lines and an operating line, with the groove for the operating line provided at the middle of the multi-grooved sheave, between the lift lines. Counterweight head blocks mount atop or at the underside of the head block beam, depending on the beam's vertical position. The diameter of a head block sheave used for galvanized