Auxiliary repair dock  An Auxiliary repair dock (ARD) is a type of vessel employed by the U.S. Navy, especially during World War II, when it commissioned 33 ARD vessels: ARD-1 to ARD-33. ARDs were self-sustaining in World War 2. ARD have a rudder to help in tow moving, making ARDs very mobile. ARD have a bow to cut through waves. ARDs have a stern that could be opened or closed. The stern could be closed with bottom-hinged flap gate, that was operated by hydraulic rams. This stern gate could lowered for ship entrance into the submerged dock and then closed to keep out wave. They were built by the Pacific Bridge Company, in Alameda, California. The "Auxiliary repair dock" was a type Auxiliary floating drydock a type of floating drydock, which could, by design, provide drydock facility to damaged Navy vessels. Floating drydocks of this type were approximately long and weighted about 5,000 tons. The first Auxiliary repair dock was the USS "ARD-1" built by the Pacific Bridge Company and completed in September 1934. "ARD-1" was 2200 tons, 393 ft 6 in (119.94 m) long and could lift 2200 tons. "ARD-1" was so successful that 30 ARDs docks where built, most completed between 1942 and 1944. "ARD-2" and the next five ARD docks were larger at 3500 tons. and 485'8" (148.0m) long. "ARD-1" was taken to a forward Naval base at Kerama Retto, Okinawa Island, to repair the many ships damaged by kamikaze attacks. ARD-1 made many temporary repairs to get ships back into action. Many other ARDs joined "ARD-1" in this important task. This minimized the time ships were out of action for repairs. Floating drydocks, of this and other types, were capable of flooding themselves, opening up a bow door to permit a damaged vessel to enter. Once the damaged vessel was within the bounds of the floating drydock, and the door was closed, the water was pumped out of the floating drydock, permitting repair work to be performed on the damaged vessel. Such work in battle areas was often of a temporary nature, primarily to return the damaged vessel to seaworthy condition. Once the damaged vessel was sufficiently repaired, the floating drydock was flooded, the door opened, and the repaired vessel allowed to depart for further duty or assignment.