Russian submarine Severstal

Severstal (TK-20; Russian: ́Северста́ль ТК-20) is a retired submarine of the Project 941 Akula (NATO reporting name Typhoon) class of the Russian Navy and formerly the Soviet Navy. The boat was laid down on 6 January 1987, launched in July 1988, and commissioned on 22 December 1989, with the designation TK-20. It spent its entire career in the Northern Fleet, and received the name Severstal in 2000.

Severstal was designed to operate in the Arctic Ocean and to carry R-39 submarine-launched ballistic missiles, with each of them capable of holding several nuclear warheads. As part of the country's nuclear deterrent, its main armament consisted of twenty missile tubes. The submarine conducted training missions at the North Pole multiple times, and during some of them it launched all twenty of its rockets at the same time. Severstal carried out a total of eight missions and 55 missile launches during its career. It was inactive from c. 1999–2000, and, in 2004, it was laid up and placed in the reserve as Russia retired the R-39 missile. Since then it has remained docked in Severodvinsk, next to its sister ship Arkhangelsk. Despite some reports that they could be modernized and restored to active service, by March 2015 they had been decommissioned, and, as of 2019, they are waiting to be scrapped.