Akula class

   The steel-hulled submarines of the Project 971 Schuka-B, designated by NATO as Akula class were easier and cheaper to built than the Sierras, and are essentially successors to the prolific Victor class. Today, they make up about half of Russia's dwindling fleet of nuclear-powered attack submarines.

   The first seven boats (designated in the West as the Akula I class) were constructed between 1982-90, and are the Puma, Delfin, Kashalot, Bars, Kit, Pantera and Narval. Five more (the Volk, Morzh, Leopard, Tigr and Drakon built between 1986-95) are classified as the Project 971 U or Improved Akula class, while a 13th boat, the Vepr of the Project 971M or Akula II class, was launched in 1995 but was still incomplete at the end of 2002. Three additional boats the Belgograd, Kuguar and Nerpa launched between 1998-2000 as Akula II boats, are also incomplete. At least two more were projected but were not built. Nepra began sea trials in 2008 and is expected to commission with the Indian Navy as INS Chakra in 2009.

   The design was approved in the early 1970s but modified in 1978-80 to carry the Granat (SS-N-21 Sampson) land attack cruise missiles. The Akula marked a significant improvement in Soviet submarine design as it is far quieter than the Victor and earlier SSNs. Furthermore it was far quitter than Western countries expected. The use of commercially available Western technology to reduce noise levels played an important role in this eroding a long-held NATO advantage in the underwater Cold War. Sensors were also much improved, the use of digital technology enabling them to detect targets at three times the range possible in a Victor.

   The Akulas sport a massive tear-drop shaped pod on the after fin: this houses the Skat-3 VLF passive towed array. There is an escape pod built into the fin. The Improved Akula and Akula II boats are fitted with six additional 533-mm (21-in) external torpedo tubes: as these cannot be reloaded from within the pressure hull, it is considered likely they are fitted with the Tsakra (SS-N-15 Starfish) anti-submarine missile. Additionally, the Akula II boats are credited with an increased operational diving depth.

   Four Akula I boats were paid off in the late 1990s and are unlikely to return, and they surviving boats are divided between the Northern and Pacific Fleets.

   In the future the older Akula class boats will be replaced by the new Graney class nuclear-powered attack submarines.