S-80 was a diesel-electric

Diesel-electric

Diesel-electric transmission or diesel-electric powertrain is used by a number of vehicle and ship types for providing locomotion.A diesel-electric transmission system includes a diesel engine connected to an electrical generator, creating electricity that powers electric traction motors...

 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...

 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...

.

Her keel was laid down on 13 March 1950 at Krasnoye Sormovo as a Project 613 unit (NATO

NATO reporting name

NATO reporting names are classified code names for military equipment of the Eastern Bloc...

 : ). She was launched

Ship naming and launching

The ceremonies involved in naming and launching naval ships are based in traditions thousands of years old.-Methods of launch:There are three principal methods of conveying a new ship from building site to water, only two of which are called "launching." The oldest, most familiar, and most widely...

 on 21 October, and delivered to Baku

Baku

Baku , sometimes spelled as Baki or Bakou, is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. It is located on the southern shore of the Absheron Peninsula, which projects into the Caspian Sea. The city consists of two principal...

 on the Caspian Sea

Caspian Sea

The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...

 on 1 November for tests, then transferred north via inland waterways in December. She was commissioned

Ship commissioning

Ship commissioning is the act or ceremony of placing a ship in active service, and may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most commonly applied to the placing of a warship in active duty with its country's military...

 into the 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 2 December 1952, and operated there until mid-1957.

Beginning in July 1957, S-80 was overhauled at Severodvinsk

Severodvinsk

Severodvinsk is a city in the north of Arkhangelsk Oblast, Russia, located in the delta of the Northern Dvina River, west of Arkhangelsk. Administratively, it is incorporated as a town of oblast significance . Municipally, it is incorporated as Severodvinsk Urban Okrug. The city was founded as...

 and converted to Project 644
("Whiskey Twin-Cylinder

Whiskey class submarine

Whiskey-class submarines are a class of naval submarines that the Soviet Union built in the early Cold War period.-Design:...

") guided missile submarine, by having launch tubes for two SS-N-3 Shaddock anti-ship missile

Anti-ship missile

Anti-ship missiles are guided missiles that are designed for use against ships and large boats. Most anti-ship missiles are of the sea-skimming type, many use a combination of inertial guidance and radar homing...

s fitted externally. She returned to sea in April 1959.

Sinking

During the night of 26 January 1961, S-80 was operating in the Barents Sea

Barents Sea

The Barents Sea is a marginal sea of the Arctic Ocean, located north of Norway and Russia. Known in the Middle Ages as the Murman Sea, the sea takes its current name from the Dutch navigator Willem Barents...

 at snorkel

Submarine snorkel

A submarine snorkel is a device which allows a submarine to operate submerged while still taking in air from above the surface. Navy personnel often refer to it as the snort.-History:...

 depth on her diesel engines. The ocean was at sea state

Sea state

In oceanography, a sea state is the general condition of the free surface on a large body of water—with respect to wind waves and swell—at a certain location and moment. A sea state is characterized by statistics, including the wave height, period, and power spectrum. The sea state varies with...

 6 and air temperature was -5°C (23°F). At 01:27 on 27 January, the boat dropped below snorkel depth, which should have caused the automatic snorkel valve to shut, preventing water from entering the snorkel system. However, the de-icing system that should have warmed the valve with hot water from the diesel engines had been switched off, and the valve had become jammed with ice.

The diesel engines failed immediately as seawater flooded their air intakes. The machinist in the fifth compartment who discovered the flooding became confused by the complex array of valves, and did not shut the ventilation flapper valve quickly enough. By the time he located the correct handwheel, the valve spindle had been bent by the force of the flooding water. As the compartment filled, the boat's trim became uncontrollable.

As her up-angle passed 45 degrees, the boat slowed, coming to a halt and then falling backward, gathering sternway and sinking until it grounded. The second, third, and fourth compartments were crushed, though 24 crewmen survived in the after compartments. Their attempts to escape the wrecked submarine using IDA-51 apparatuses

Rebreather

A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycled exhaled gas. This recycling reduces the volume of breathing gas used, making a rebreather lighter and more compact than an open-circuit breathing set for the same duration in environments where...

 failed, and all 68 officers and men of S-80 were lost. Their fate remained unknown for seven and a half years.

Recovery

On 23 June 1968, salvage vessel Altai discovered the wreck of a submarine at 70°01′23″N 36°35′22″E, at a depth of 196 m (643 ft). She inspected the wreck with her bathyscape and identified it as S-80.

A government commission studied the report and ordered Operation "Depth," the salvage of the wreck. The Nikolayevsk SSZ shipyard built Carpathia, a special salvage vessel equipped to raise the sunken submarine.

Operation "Depth" was carried out by a task force of the 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...

 consisting of groups of trawlers and a destroyer

Destroyer

In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

 under the command of Captain First Rank S. Minchenko. The wreck was lifted from the ocean floor on 9 June 1969 and transported to Mys Teriberskiy, suspended under Carpathia in slings. There, she was lowered to the bottom of Zavalishin Harbor at a depth of 51 m (167.3 ft) on 12 July.

On 24 July 1969, S-80 was raised to the surface. During August, a government commission began studying the wreck under the management of Hero of the Soviet Union

Hero of the Soviet Union

The title Hero of the Soviet Union was the highest distinction in the Soviet Union, awarded personally or collectively for heroic feats in service to the Soviet state and society.-Overview:...

Vice Admiral G. I. Schedrin. The commission determined not only the immediate causes of the boat's loss, but also that two further errors had compounded the accident: the crew never attempted to shift propulsion to the electric motors, and they never performed an emergency ballast tank blow.