''M-256'' was a Project 615 (

NATO The North Atlantic Treaty Organization (NATO, ; french: Organisation du traité de l'Atlantique nord, ), also called the North Atlantic Alliance, is an intergovernmental military alliance between 30 member states – 28 European and two No ...

: " Quebec-class") short-range,

diesel Diesel may refer to: * Diesel engine, an internal combustion engine where ignition is caused by compression * Diesel fuel, a liquid fuel used in diesel engines * Diesel locomotive, a railway locomotive in which the prime mover is a diesel engin ...

attack submarine of the Soviet Navy. She was commissioned into the Baltic Fleet.

Design

Project 615 submarines were fitted with two regular diesel engines and a third, closed-cycle diesel engine, which used

liquid oxygen Liquid oxygen—abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries—is the liquid form of molecular oxygen. It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an app ...

(LOX) to provide air-independent propulsion while the submarine was submerged. This system produced remarkable submerged speed and range, but greatly increased the hazard of a fire. Project 615 submarines were referred to by their crews as "matchsticks."History Channel: Soviet Top Secret Weapons

Sinking

On 26 September 1957, while operating in gale conditions in the Gulf of Finland of the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and ...

, one of ''M-256''’s

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-ca ...

s exploded. Fire immediately engulfed the diesel compartment, and soon spread to the next compartment. The boat surfaced and because of the likelihood of further explosions her crew evacuated onto her weather deck. None of the four ships keeping station nearby were able to take her under tow or evacuate her crew because of the gale conditions. About four hours after the beginning of the fire the boat suddenly lost longitudinal stability, took on a steep down-bubble, and sank. Of the 35 men on the boat's deck, only seven were rescued.

References

Книга памяти - M-256
{{DEFAULTSORT:M-256 Quebec-class submarines Ships built in the Soviet Union 1953 ships Cold War submarines of the Soviet Union Maritime incidents in 1957 Lost submarines of the Soviet Union 1957 in the Soviet Union Shipwrecks in the Gulf of Finland