29 C.F.R. § 1926.606 – Definitions applicable to this subpart.

(a) Apron—The area along the waterfront edge of the pier or wharf.
(b) Bulwark—The side of a ship above the upper deck.
(c) Coaming—The raised frame, as around a hatchway in the deck, to keep out water.
(d) Jacob's ladder—A marine ladder of rope or chain with wooden or metal rungs.
(e) Rail, for the purpose of § 1926.605, means a light structure serving as a guard at the outer edge of a ship's deck.