Severodvinsk is the second-largest city in Arkhangelsk Oblast. Its main industry remains defense-related — the construction and repair of  submarines  at the huge Northern Machine-building PLANT. The Soviet Union's first  nuclear submarine   was built here in 1957. At the beginning of the 1980s the world's largest submarine, a  Typhoon class , was also built here, later recorded in the  Guinness Book of World Records .

The Severodvinsk nuclear submarine, which has been under construction for over two decades – the longest, most expensive build of any submarines produced by Russia or the Soviet Union

Range:unlimited except by food suppliesTest depth:600 m (2,000 ft)