I’ve always seen them on TV, and in professional garages and factories. I know they allow you to lift things far heavier than you normally could. But, how do they actually do that? I have seen that you pull one chain alot and it lifts it a little, so I’m sure that has something to do with it.
In: Engineering
Because the rope is supported by pullies which are free to rotate, the tension on the rope is basically the same along it’s whole length.
This means you may be able to supply a downwards force of 350N (78lbs) on the free end of the rope. If the block and tackle system creates 6 returns of rope between the load and the support or anchoring structure, then the system has a Force Multiplication factor of 6. The block and tackle will produce a force of 2100N or or 468lbs.
The force on the load is equal to the number of returns of rope between the load and anchor, multiplied by the tension on the free end.
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