Project 685 Plavnik K-278 "Komsomolets" Mike kit. 

About the original Submarine 

In the 1960’s The Soviet Union invested massive resources in the development of advanced Nuclear submarines in order to reach parity with the United States. The development of the Project 705 Lira (Alfa) class submarines gave rise to the idea of a second generation submarine along similar lines. Design work under the direction of Kormalitsin at the RUBIN design bureau started in the late 1960’s and was completed by 1974.  However her keel was not laid down till April 1978 and she was finally launched in May 1983.

The Komsomolets was intended as a demonstration test bed for advanced technologies.  Intelligence on her capabilities turned towards her being a successor to the Alfa class boats. Like them she had a titanium hull however the initial belief of western intelligence that she also possessed a liquid metal reactor turned out to be false, she would not have the high speed of the Alfa.

The Komsomolets engaged in numerous patrols and in August 1984 reached a depth of 1,020 metres, a record depth for a nuclear submarine and one that still stands. In April 1989 whilst on patrol in the Norwegian Sea she suffered at fire that forced her to surface. She remained surfaced for 5 hours before succumbing to the fire and sinking in over 1,500 metres of water.