(1) A structure used in removing ships from the water to inspect and repair their underwater areas, also used in shipbuilding. A dock is equipped with mechanisms for bringing the ship in and setting it on supports (keel blocks, girders); it is fitted with transfer pumps, traveling cranes, and equipment for providing electric power, steam, compressed air, oxygen, and other materials necessary in repair and construction work. A distinction is made between dry docks, flooding docks, and floating docks.
A dry dock is constructed on a water area protected from the sea; it is a waterproof chamber separated at the end from the sea by a floodgate. The walls and bottom of the dry dock are usually made of concrete or reinforced concrete; less often they are made of metal and stone. During dry-docking, the ship is led into the chamber above the supports and the gate is shut. When the chamber is emptied the ship comes to rest on the supports. Taking the ship from the dock is accomplished in the reverse sequence. A dry dock may be as much as 70 m wide and 500 m long.
A flooding dock differs from a dry dock in that the ships are mounted on platforms above water level. In a flooding dock the ship is led into a canal between the platforms, the floodgate is closed, the dock chamber flooded with water, and the ship is arranged above the piers on which it later comes to rest when the water is removed. Installation of a second gate at the bank end and of tracks for moving the ships on dollies from the working platform and back converts a flooding dock to a launching dock, which is used to lower ships into the water and to raise them from the water. Flooding docks and launching docks are designed for ships of medium size.
A floating dock consists of a flat rectangular pontoon (on whose deck, the dock floor, the ship-supports are set) and two (sometimes one) longitudinal towers. When the compartments of the pontoon and the lower part of the towers are filled with water, the dock tips over and the ship is brought in. When water is pumped from the compartments, the dock surfaces with the ship, which rests on the supports. Floating docks are usually made of steel and less often of reinforced concrete and wood. The length of the larger floating docks is 250-300 m, the width along the dock floor, over 45 m, and the lifting capacity, 100,000 tons. Transport docks, which are used to transport ships, are a variety of the floating dock. A complex consisting of a mother dock and several pontoon docks is also a type of floating dock. The pontoon docks are submerged and surface together with the mother dock; after repeated submersion of the mother dock they are left afloat with the ship, which rests on its supports.
(2) An artificial dock basin with a gate that serves as a berth for ships during loading and unloading in areas where there are major tidal fluctuations in sea level.
G. N. FINKEL’
an aggregate of structures and equipment for mooring and servicing ships and loading and unloading passengers and cargo. Docks are categorized as passenger, cargo, repair, or naval. Depending on its function, a dock may have berthing facilities, loading devices and mechanisms, siding tracks, access roads, warehouses, ticket offices, and waiting rooms. It may also have equipment and devices for mooring and fending off ships.
Docks may be stationary or floating. The latter, called landing stages, are used primarily in river ports. Docks that are positioned in a harbor area to service ships at anchor are called dolphin berths. All the docks together make up the line of moorings, or berthing length, of the port. The length of this line is one of the defining features of a port.
E. V. KURLOVICH