The Typhoon class submarine is a type of nuclear-powered ballistic missile submarine deployed by the Soviet Navyin the 1980s. With a maximum displacement of 26,000 tonnes (26,000 long tons), Typhoons are the largest class of submarine ever built. It could have 160 person crew and carry 20 ballistic nuclear missiles. Only six of the Typhoon class submarines were built. In its day it was one of the most feared weapons of mass destruction ever made. The cost of operations for the Typhoon submarines was so high that the Russian Navy retired all but one of them in favor of older Delta class SSBNs after the collapse of the Soviet Union.