Soviet submarine K-278 Komsomolets

K-278 Komsomolets was the only Project 685 Plavnik (Плавник, meaning "fin", also known by its NATO reporting name of "Mike"-class) nuclear-powered attack submarine of the Soviet Navy. On August 4, 1984 K-278  reached a record submergence depth of 1,020 meters, in Norwegian Sea. The boat sank in 1989 and is currently resting on the floor of the Barents Sea, one mile deep, with its nuclear reactor and two nuclear warheads still on board. The single Project 685 was developed to test technologies for Soviet 4th generation nuclear submarines. Although primarily intended as a developmental model, it was fully combat capable, but sank after a fire broke out in the aft engineering compartment on its first operational patrol.

The Komsomolets was able to surface after the fire started and remained afloat for approximately 5 hours before sinking. Of the 42 crewmembers who died, only 4 were killed by the fire and smoke, while 34 died of hypothermia and drowning in the frigid waters while awaiting rescue that did not arrive in time. Because of this shocking loss of life a very public enquiry was conducted and, as a result, many formerly classified details were revealed by the Soviet news media.

Design
The Project 685 was designed by the Rubin Design Bureau in response to a challenge to develop an advanced submarine that could carry a mix of torpedoes and cruise missiles with conventional or nuclear warheads. The order to design the submarine was issued in 1966 and design was completed in 1974. The first (and only) keel was laid down on 22 April 1978 at Severodvinsk. K-278 was launched on 3 June 1983 and commissioned on 28 December 1983.

K-278 had a double hull, the inner one being composed of titanium, which gave her an operating depth far greater than that of the best American submarines. The pressure hull was composed of seven compartments with the second and third protected by stronger forward and aft bulkheads creating a "safety zone" in case of an emergency. An escape capsule was fitted in the sail above these compartments to enable the crew to abandon ship in the event of an underwater emergency. Initial Western intelligence estimates of K-278’s speed were based on the assumption that it was powered by a pair of liquid-metal lead-bismuth reactors. When the Soviet Union revealed that the submarine used a single OK-650b-3 conventional pressurized-water reactor, these speed estimates were lowered.

Crew
According to Norman Polmar and Kenneth J. Moore - two Western experts on Soviet submarine design and operations - the Project 685's advanced design included many automated systems which, in turn, allowed for fewer crewmembers than would be expected for a submarine of its size. The manning table approved by the Ministry of Defense in 1982 called for a crew of just 57 men. This was later increased to 64: 30 officers, 22 warrant officers, and 12 petty officers and seamen. While automation allows for smaller crews in many cases, US Navy policy for nuclear-powered ships has been to maintain higher crew levels in order to operate with battle damage, when automated systems may fail. The current 688-class, for example, has a crew of 129.

Submarine K-278 gets a name
In October 1988, K-278 was honored by becoming one of the few Soviet submarines to be given an actual name: Komsomolets (Комсомолец, meaning "a member of the Young Communist League"), and her commanding officer, Captain 1st Rank Yuriy Zelenskiy was honored for diving to a depth of 1020 meters (3,345 feet).

Sinking
On 7 April 1989, while under the command of Captain 1st Rank Evgeny Vanin and running submerged at a depth of 335 m about 180 km southwest of Bear Island (Norway), fire broke out in the aft compartment, and even though watertight doors were shut, the resulting fire spread through bulkhead cable penetrations. The reactor scrammed and propulsion was lost. Electrical problems spread as cables burned through, and control of the boat was threatened. An emergency ballast tank blow was performed and the submarine surfaced eleven minutes after the fire began. Distress calls were made, and most of the crew abandoned ship.

The fire continued to burn, fed by the compressed air system. Several hours after the boat surfaced, it sank again in 1680 m of water. The commanding officer and four others who were still on board entered the escape capsule and ejected it. Only one of the five to reach the surface was able to leave the capsule and survive before it sank again in the rough seas.

Rescue aircraft arrived quickly and dropped small rafts, but many men had already died from hypothermia in the 2 °C water of the Barents Sea. The floating fish factory B-64/10 Aleksey Khlobystov (Алексей Хлобыстов) arrived 81 minutes after K-278 sank, and took aboard 25 survivors and 5 fatalities. In total, 42 men died in the accident.

Environmental threat
In addition to her eight standard torpedoes K-278 was carrying two torpedoes armed with nuclear warheads. Under pressure from Norway, the Soviet Union used deep sea submersibles operated from the oceanographic research ship Akademik Mstislav Keldysh to search for K-278. In June 1989, two months after the sinking, the wreck was located. Soviet officials stated that any possible leaks were insignificant and pose no threat to the environment.

Examination of the wreck in May 1992 revealed cracks along the entire length of the titanium hull, some of which were of 30-40 centimetres (12-16 inches) wide, as well as possible breaches in the reactor coolant pipes. An oceanographic survey of the area in August 1993 did suggest that waters at the site were not mixing vertically, and thus the sea life in the area was not being rapidly contaminated. That survey also revealed a hole over six metres (20 feet) wide in the forward torpedo compartment.

An expedition in mid-1994 revealed some plutonium leakage from one of the two nuclear torpedoes. On 24 June 1995, Keldysh set out again from St. Petersburg to the Mike datum to seal the hull fractures in Compartment 1 and cover the nuclear warheads, and declared success at the end of subsequent expedition in July 1996. The Russian government has declared the risk of radioactive contamination of the environment negligible until 2015 or 2025.

Norwegian authorities from the Marine Environmental Agency and Radiation Agency took several samples in August 2008 and no radioactive radition was found. They checked for traces after ammaemittere, plutonium, americium and strontium.

In 1993, Vice Admiral (ret.) Chernov, commander of the submarine group of which the Komsomolets was part, founded the Komsomolets Nuclear Submarine Memorial Society, a charity to support the widows and orphans of his former command. Since then, the Society's charter has expanded to provide assistance to the families of all Soviet and Russian submariners lost at sea. Also, 7 April has become a day of commemoration for all submariners lost at sea.