Soviet submarine B-37 was a Project 641 or Foxtrot-class

Foxtrot class submarine

The Foxtrot class was the NATO reporting name of a class of diesel-electric patrol submarines that were built in the Soviet Union. The Soviet designation of this class was Project 641....

 diesel submarine of the Soviet Navy

Soviet Navy

The Soviet Navy was the naval arm of the Soviet Armed Forces. Often referred to as the Red Fleet, the Soviet Navy would have played an instrumental role in a Warsaw Pact war with NATO, where it would have attempted to prevent naval convoys from bringing reinforcements across the Atlantic Ocean...

's Northern Fleet

Northern Fleet

The Red Banner Northern Fleet is a unit of the Russian Navy that has access to the Barents and Norwegian Seas, the Arctic and Atlantic Oceans, and is responsible for the defense of northwestern Russia. It was established in 1937 as part of the Soviet Navy...

.

On 11 January 1962, the submarine was tied up at the pier in Ekaterininsky bay of Polarny naval base, with all watertight doors open, while conducting maintenance and testing of her torpedo

Torpedo

The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...

es. A fire broke out in the torpedo compartment, probably due to hydrogen gas igniting when electrical equipment was energized. All eleven torpedoes cooked off

Cooking off

Cooking off refers to ammunition exploding prematurely due to heat in the surrounding environment. It can also refer to a technique used when throwing grenades to achieve a controlled, predictable explosion....

. The submarine was instantly destroyed with all hands except the commanding officer Captain Second Rank Begeba who was on the pier at the time of explosion, and Captain Third Rank Jakubenko, who was on another part of the sub base.

, a Project 633 or Romeo-class

Romeo class submarine

The Romeo class is a class of Soviet diesel-electric submarine, built in 1950s. The origin of the Romeo class can be traced to the World War II German Type XXI Elektroboot U-boat. At the end of World War II, the Soviets obtained several Type XXIs, from which they were able to obtain certain key...

submarine tied up next to B-37, was badly damaged by the explosion as well, and several men from other ships and the shipyard were killed.

In total, 122 people were killed: 59 B-37 crewmen, 19 S-350 crewmen, and 44 others. The explosion hurled B-37s anchor nearly 2 kilometres (1.2 mi) from the dock.