To answer your question specifically rather than just repeating your question in another way, the force required to move the load is divided by the number of lines supporting the load. So in the case of your question, the winch needs to exert 1/3 the force that would be necessary with a straight pull.

Likewise, the winch will need to move 3 times the length of line to move the load a specified distance than it would with a straight pull.

Jim Paget
88 YJ with a few changes

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