The Project 941 or Akula, Russian "Акула" ("Shark") class submarine (NATO reporting name: Typhoon) is a type of nuclear-powered ballistic missile submarine deployed by the Soviet Navy in the 1980s. With a submerged displacement of 48,000 tonnes, the Typhoons are the largest class of submarine ever built, large enough to accommodate decent living facilities for the crew when submerged for months on end. The source of the NATO reporting name remains unclear, although it is often claimed to be related to the use of the word "typhoon" ("тайфун") by Leonid Brezhnev in a 1974 speech while describing a new type of nuclear ballistic missile submarine, as a reaction to the US Navy Ohio-class submarines.