What is the name of tackle number 6 as shown in illustration D029DG below?
Official USCG Answer & Rule Citation
Correct Answer: Option B — Threefold purchase
A threefold purchase utilizes two triple blocks, yielding a theoretical mechanical advantage of 6:1. This is a heavy-duty rigging system. Deck officers must recognize this configuration to accurately assess the force required on the hauling part while accounting for friction losses inherent in multi-sheave systems.
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