The S-99 experimental submarine

Submarine

A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

 was the only ship of Whale class (known locally in the Soviet Union as Project 617) that the Soviet Union

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 built during the early cold war

Cold War

The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

 period and the only soviet submarine which had a Walter engine fuelled by high test peroxide

High test peroxide

High-test peroxide or HTP is a high -concentration solution of hydrogen peroxide, with the remainder predominantly made up of water. In contact with a catalyst, it decomposes into a high-temperature mixture of steam and oxygen, with no remaining liquid water...

(HTP).

Design

Initial design of submarine was based on project XXVI documentation taken from Germany as a trophy in 1945 and used in the 1945–1946 development of Project 616. The resultant speed of 19 knots submerged and a 10% buoyancy reserve were assessed as a good but insufficient result, leading to a new project from 1949–1951 based in Leningrad.

Construction

The hull of the submarine was divided on six sections

1. torpedo room
2. battery and living quarters
3. command room
4. diesel room, maintenance base of the turbine engine
5. turbine room, unoccupied and sealed
6. electric engine room

Soviet Navy service

The boat was built in 1951-1952 and commissioned in 1956 after sea trials. S-99 became the fastest Soviet submarine of thetime, reaching 20–22 knots submerged. Between 1956-1959 she served in the Baltic fleet then in 1959, prior to planned repairs, S-99 were used for turbine tests. Experiments at depths of 40 to 60 m (131.2 to 196.9 ft) were successful, but there was an explosion at a depth of 80 metres (262.5 ft). The submarine surfaced and reached base under reserve electric power. After the crash S-99 was decommissioned and scrapped.