Block and tackle metres per second. Therefore, the mechanical advantage of a double tackle is 4. The mechanical advantage of any tackle can be increased by interchanging the fixed and moving blocks so the rope is attached to the moving block and the rope is pulled in the direction of the lifted load. In this case the block and tackle is said to be "rove to advantage." Diagram 3 shows three rope parts supporting the load "W", which means the tension in the rope is "W/3". Thus, the mechanical advantage is three-to-one. By adding a pulley to the fixed block of a gun
Wire rope spooling technology its behaviour and affects lifespan. Fleet angle should be between 0.25° and 1.25°, depending on the rope construction. The fleet angle can be varied by moving the first sheave closer to or further away from the drum. If the sheave is too close to the drum, the fleet angle will be greater than 1.25°; if it is too far away, the fleet angle will be less than 0.25°. Sometimes it is not possible to achieve the optimum fleet angle. Where there is no space to rig a sheave the requisite distance from the drum, two additional spooling devices are available.