Deck (ship)

A deck is a permanent covering over a compartment or a hull of a ship. On a boat or ship, the primary or upper deck is the horizontal structure which forms the 'roof' for the hull, which both strengthens the hull and serves as the primary working surface. Vessels often have more than one level both within the hull and in the superstructure above the primary deck which are similar to the floors of a multi-storey building, and which are also referred to as decks, as are specific compartments and decks built over specific areas of the superstructure. Decks for some purposes have specific names.

Structure

The purpose of the upper or primary deck is structural, and only secondarily to provide weather-tightness, and to support people and equipment. The deck serves as the lid to the complex box girder which is the hull. It resists tension, compression, and racking forces. The deck's scantling is usually the same as the topsides, or might be heavier if the deck is expected to carry heavier loads (for example a container ship). The deck will be reinforced around deck fittings such as the capstan, cleats, or bollards.