Originally Posted by
rogerstg
Gun tackle not luff - sketch it out to prove it to yourself. It's that last line over pulley that makes a luff 3:1
I guess this is not as simple for people as I thought.
The last line over the upper pulley in a luff is irrelevant to the force on the lower pulley.
But since everyone demands a FBD, here is the functional equivalent of the trucker's hitch:
The upper pulley is the tree, the lower is the loop.