BEAM, of a ship, is one of the main timbers which aid in supporting the decks. Beams stretch across from side to side, aiding to strengthen and uphold the sides of the hull as well as the decks; and they are themSelves supported at the ends by massive pieces, called knees, standards, and clamps. Each is made of one fine piece of timber, if possible; but if the length be too great for this, two or more timbers are scarfed together. Wherever it is practicable, the beams are upheld at or near the middle by pillars. In the Great Eastern steamship, the beams are of iron, and, like most other parts of the vessel, are cellular in construction. In the old timber-built sailing ships-of war, now rapidly becoming obsolete, the boa/ B. was the broadest in the ship; the Inidshipwas the longest; the orlop was that which supported the orlop deck, and strength ened the hold. The old 74-gun ships had each 24 beams under the lower deck. 31any of these characteristics still prevail; but others have given way to change, owing to the increased length of war-steamers, and to the necessity of making room for the machinery.
The beams of all ships are generally made deeper in the middle than at the ends, in order that the decks supported by them may have a slight convexity on the upper surface, to carry off the rain-water readily, and to lessen the recoil of the gnus.
the position of the beams, stretching, across a ship at right angles to the direction of the keel, has given origin to many technical phrases used on shipboard. " On the star board B." is applied to any distant point out at sea, at right angles to the keel, and on the starboard or right hand—as viewed from the stern—side of the ship. " On the lar board B." similarly applies to the left hand. " On the weather B." is that side of the ship which receives or is towards the wind. " Before the B." is the bearing of any object when seen more in advance than on the beam. "Abaft the B." is the reverse of the expression just noted. " On her beam-ends" is applied to the position of a ship when so much inclined to one side that the beams become nearly vertical.