Block and tackle sheave to change the direction of the pulling line, which increases friction losses without improving the velocity ratio. Situations in which reeving to disadvantage may be more desirable include lifting from a fixed point overhead; the additional pulley allows pulling downwards instead of upwards so that the weight of the lifter can offset the weight of the load. The formula used to find the effort required to raise a given weight using a block and fall: where formula_3 is the force applied to the hauling part of the line (the input force), formula_4 is the weight of the load (the
Rigging (material handling) Rigging (material handling) Rigging is both a noun, which is the equipment and a verb, which is the action of designing and installing the equipment, in the preparation to lift, lower, hoist or move objects. A team of "riggers" design and install the lifting or rolling equipment needed to raise, roll, slide or lift objects such as with a crane or block and tackle. "Rigging" comes from "rig", to set up or prepare. Rigging is the equipment such as wire rope, turnbuckles, clevis, jacks and slings used with cranes and other lifting equipment in material handling and structure relocation. Rigging