fourfold purchase

noun

1. a tackle that is composed of a rope passed through two fourfold blocks in such a way as to provide mechanical power in the ratio of 1 to 5 or 1 to 4, depending on whether hauling is done on the running or the standing block and without considering friction.

Example Sentences

We all know fifteen tons is enough weight for that size rope, even with a fourfold purchase, and we understand you say this stone weighs twenty-one.'

From Project Gutenberg