Finally, "Yarns, twines and ropes can be made by machine nowadays, but the rope makers of older days were accustomed to making all of these in a rope walk. The principal of the walk is that yarns are stretched out between revolving hooks, often 300 yards apart, and these hooks twist the yarns together…." The Navy required a minimum of 120 fathoms (720 feet), which was the minimum needed to anchor a ship.