Pinrail

 

"A belaying pin is a solid metal or wooden device used on traditionally rigged sailing vessels to secure lines of running rigging. Largely replaced on most modern vessels by cleats, they are still used, particularly on square rigged ships.

A belaying pin is composed of a round handle and cylindrical shaft. The shaft is inserted into a hole in various strategically located wooden pinrails (lining the inside of the bulwarks, surrounding the base of masts, or free-standing, called fife rails) up to the base of the handle. A line is then led under and behind the base of the pin then round the top till at least four turns are complete.” — Wikipedia