Keel

The timber or bar forming the backbone of the vessel and running from the stem to the stempost at the bottom of the ship.

The backbone of the ship. It is a longitudinal beam or plate in the extreme bottom of a ship from which the ribs or floors start.

The main and lowest timber of a ship, extending longitudinally from the stem to the stern-post. It is formed of several pieces, which are scarphed together endways, and form the basis of the whole structure, of course it is usually the first thing laid down upon the blocks for the construction of the ship.