Working out the mechanical advantage of a given pulley system can seem very complicated but a technique that greatly simplifies this is known as the ‘T Method’.
The ‘T’ stands for tension & the method revolves around the premise that for any given pulley system the ratio of output force to input force will always be ?:1. By starting at the input part (or T1) and then adding up the units of tension through the system we will eventually arrive at the output (the ‘?’), giving us the answer & the overall ratio of the system.
With a simple pulley system (where the rope only travels from load to anchor however many times) its relatively straightforward to add T units. With compounded systems (where one mechanical advantage is pulling on the input part of another) we must remember the T values are compounding through the system as in the diagram of the compound 9:1 system.
Written by Bill Proctor
15 September 2022
