The New International Encyclopædia/Deck

​DECK. The flooring or platform formed by covering the deck beams with steel or planking. The term is sometimes used to express the space above a deck to the under side of the next higher deck. In old type rigged men-of-war the upper deck was called the spar deck; the next deck, the gun deck—if guns were carried on it—if not, it was called the berth deck; the next deck below the berth deck was the orlop deck. In old three-deckers (i.e. wooden line-of-battle ships carrying guns on three covered decks) these were called the main, middle, and lower decks. The half-deck, in vessels having one or more covered gun decks, was that portion of the next deck below the spar deck extending from the mainmast to the cabin bulkheads. The quarter-deck was the part of the upper deck which was abaft the mainmast. These terms, quarter and half, were derived from the character of the decks in the days of high castle-like poops and forecastles. ​The half-deck then extended half the length of the ship or less, the quarter-deck being still shorter. The after partial decks were connected with similar partial ones forward by gangways or narrow walks inside the ship’s rail. As time went on, the forecastle became reduced in height and the partial decks became fewer in number, but the quarter-deck was only a partial one until after the beginning of the nineteenth century. For a long time the only partial decks above the upper, or spar, deck were those of the poop and topgallant forecastle, but the advent of the modern ship with its high central superstructure changed this together with the entire deck nomenclature. In ships of the United States Navy the highest deck which extends the full length of the ship is called the main deck; a partial deck above this is called the upper deck; above this are the bridge decks, bridges, etc. The first deck below the main is called the gun deck if any of the main battery guns are mounted on it; the next deck below the gun deck is the berth deck; if there is no gun deck it is the next one below the main deck; the orlop deck is the next below the berth deck; and then the platform decks. The topgallant forecastle deck is the deck over a raised, or topgallant, forecastle; the poop deck is the deck over the poop. The deck over superstructures is called the superstructure deck, hurricane deck, boat deck, texas, etc., according to the character of the vessel. A flush deck is one that extends from bow to stern without a break. A protective deck (fitted in men-of-war only) is one designed to protect the vitals of a ship from being struck by a shell or injured by fragments of one which bursts on board. If flat and laid over the upper edges of an armor belt, it is frequently called the armor deck. The ordinary type of protective decks consists of a flat portion amidships and sloping parts at the sides. The side slope may be a curve, a straight slope, or two short straight slopes; the inclination downward is at an angle of 30° to 45° and the lower edge of the deck where it meets the ship’s side is several feet under water, in order that a projectile shall not get underneath it when the ship is rolling. Both the flat and sloping parts of protective decks are armored, the latter much more heavily, reaching a thickness of six inches in large protected and armored cruisers.