October 23, 2020

Purchases and tackles

Purchase. A purchase is a combination of blocks or pulleys rove with a rope, wire or chain. Tackle. A tackle is a purchase consisting of a rope rove and through two or more blocks, in such a way that any pull applied to the hauling part, is increased by an […]
October 23, 2020

Mechanical advantage

All of the above tackles/purchases are designed to increase the power utilised to the effect achieved. Because of friction between the ropes and sheaves, the actual (theoretical) weight lifted can be roughly calculated as being: Weight + (1/10 x weight) for each sheave. The mechanical advantage gained can be found […]