User Manual:

The “Typhoon” class was used by NATO as its reporting name for the Project 941, “Akula” class of submarine built by the Soviet Navy.

With a submerged displacement of 48,000 tonnes and measuring in at 175 meters in length, 25 meters wide the Typhoons are the largest submarines ever built, able to accommodate comfortable living facilities for the crew of 160 when submerged for months on end.

A Typhoon-class submarine can stay submerged for 120 days in normal conditions, and potentially more if deemed necessary as in the case of in the case of nuclear hostilities.

The first unit, conceived as a counter to the U.S. Navy's Ohio class of nuclear-powered ballistic missile submarines was launched in 1980. Indeed, the West became aware of a Soviet Typhoon project in 1974, when then President Leonid Brezhnev told U.S. President Gerald Ford that if he persisted with the Trident program, the Soviets would build “Typhoon”, from where the reporting name would originate.