page_title: Akula-class submarine
section_title: Design
hierarchical_section_title: Akula-class submarine / Design
context_page_description: The Akula class, Soviet designation Project 971 Shchuka-B are a series of nuclear-powered attack submarines first deployed by the Soviet Navy in 1986. There are four sub-classes or flights of Shchuka-B, consisting of the original seven Project 971 boats, commissioned between 1984 and 1990; six Project 971Is, commissioned between 1991 and 2009; one Project 971U, commissioned in 1995; and one Project 971M, commissioned in 2001. The Russians call all of the submarines Shchuka-B, regardless of modifications.
  Some confusion may exist as the name Akula was used by the Soviets for a different class of submarines, the Project 941, which is known in the West as the Typhoon class. The Project 971 was named Shchuka-B by the Soviets but given the designation Akula by the West after the name of the lead ship, K-284.
  According to defense analyst Norman Polmar, the launch of the first submarine in 1985, "shook everyone [in the West] up", as Western intelligence agencies had not expected the Soviet Union to produce such a boat for another ten years.
context_section_description: The Akula incorporates a double hull system composed of an inner pressure hull and an outer "light" hull. This allows more freedom in the design of the exterior hull shape, resulting in a submarine with more reserve buoyancy than its western analogs.
  The distinctive "bulb" or "can" located on top of the Akula's rudder houses its towed sonar array, when retracted. Most Akulas have the wake detection system (Russian: Система обнаружения кильватерного следа) (SOKS) hydrodynamic sensors, which detect changes in temperature and salinity. They are located on the leading edge of the sail, on the outer hull casing in front of the sail and on the bottom of the hull forward of the sail.
  Akulas (excluding Nerpa) are armed with four 533 mm torpedo tubes which can use Type 53 torpedoes or the RPK-2, RPK-6 missile, and four 650 mm torpedo tubes which can use Type 65 torpedoes or the RPK-7 missile. These torpedo tubes are arranged in two rows of four tubes each. The external tubes are mounted outside the pressure hull in one row, above the torpedo tubes, and can only be reloaded in port or with the assistance of a submarine tender. The 650 mm tubes can be fitted with liners to use the 533 mm weaponry. The submarine is also able to use its torpedo tubes to deploy naval mines. The modernized versions, like Vepr, will be equipped with the Kalibr cruise missiles.
caption: Descriptions of the Akula-class SSN