Victorious class

   Victorious class of ocean surveillance ships consists of four vessels, the USNS Victorious, USNS Able, USNS Effective and USNS Loyal. The lead ship was commissioned in 1991. The USNS Able was taken out of service in 2004, but reactivated in 2008. Currently all ships of this class are in active service and assigned to the US Navy's Special Mission Programme.

   These ocean surveillance ships are used to gather acoustic data, detect and track submarines. Anti-submarine warfare data is transmitted via satellite to shore stations.

   The Victorious class ships have a catamaran-type twin-hull design. It offers greater stability at low speeds under adverse weather conditions. It also prevents vessel from rolling in heavy seas and gives additional deck space.

   Vessels are fitted with two underwater listening devices, with both active and passive capabilities. These ships have a crew of 24 - 27 men, mainly civilian mariners. Vessels carry no armament.

   The Victorious class ships are powered by diesel-electric propulsion system, that generates 1 600 shp. Maximum speed of these ships is less than 10 knots. It is reduced to about 3 knots, when ships tow sonars. Patrols are usually 60 days in duration.

   The USNS Impeccable is based on Victorious class, but is larger and faster.