Project 685 Plavnik (NATO Mike)

Nuclear attack submarine: Prototype K-278 Komsomolets completed 1983.

K-278 Komsomolets was the sole boat built in the Project-685 Plavnik (“fin”) class, NATO reporting “Mike”-class. This was a rather large nuclear-powered attack submarine of the Soviet Navy, unique for her record depth rating. She had been built to experiment dives deep enough to make classic torpedo crushed by pressure. A simple idea that led that boat to 1,020 metres (3,350 feet) in the Norwegian Sea on 4 August 1984. But when commissioned, this was also to evaluate technologies for 4th-generation nuclear submarines, notably for superior agility and fast deployment. Her career ended with a major incident, a serious fire while in the Arctic Ocean in 1989, ravaging two aft compartments while underway in the Barents Sea, off the coast of Norway. She surfaced and remained afloat for around five hours before sinking, with 42 dead and 27 survivors. Her wreck still lays there under 1.7 km (1 mile) deep, crushed, with her nuclear compartments and two nuclear warhead-armed torpedoes on board.

Development of the Project 685

Project 685 emerged from the Rubin Design Bureau. These renowned specialists, cumulating multiple awards for past designs, were challenged by the high command to develop an advanced submarine armed with torpedoes and cruise missiles, the latter with conventional or nuclear warheads, capable of greater dives and speeds in 1966. Work was quite long, with many changes in between and was eventually completed in 1974. The design specifications for this prototype were issued to TsKB-18 in 1966 but the design process indeed took nine years due to all the technological challenges that needed to be solved, and soon, the use of titanium was obvious (Project 705 Lira (NATO Alfa) proved this was feasible) allowed extra strength for greater dives and significant reduction in hull weight, thus, preserving speed. In fact that hull was calculated to be only 39% of the normal displacement, no more than that of other nuclear-powered submarines, while achieving significantly higher strength.

The experience gained in both the development of the Alfa, Mike was intended to be used to develop a design for deep-sea submarines suitable for serial production, which became the Sierra class, albeit their production was limited and development returned to non-titanium hull as they were a real pain to work with and manufacture. Chief Designer of Project 685 was N. A. Klimov (from 1977, Yu. N. Kormilitsyn), and Chief Observer of the Navy was Captain 2nd Rank A. Ya. Tomchin (later Captain 2nd Rank N. V. Shalonov). Project number 685 was codename “Plavnik”, so “fin” in English.

This deep-sea nuclear submarine was designed as a fully-fledged combat vessel, despite being a prototype: She was capable of performing a wide range of missions, searching for NATO subs, detecting and tracking US SSBNs, and destroying them, all for extended periods, as well as engaging enemy aircraft carrier groups with its cruise missiles, as well as isolated large surface ships or flotillas. One crucial aspect was the overall performance of the titanium alloy under high-stress conditions (meaning greater pressures) in the hull structure, as the main focus was clearly to give the project the ability to dive at greater depths. So it was decided to conduct a comprehensive series of studies and experiments, explaining how the development took nine years. Design methods and manufacturing technologies for various hull components were tested for all compartments, as well as tests of static, cyclic, and dynamic strength for the whole structure. Years of tedious, but necessary, experimental work.

For this, USSR financed the extra mile, by building three specialized pressure chambers in Severodvinsk. One was 5 meters in diameter and 20 meters long, another 12 meters and 27 meters in length, and the third 15 meters and 55 meters in length. The first generated a pressure of 400 kgf/cm² under a single load, and 200 kgf/cm² under cyclic loading. The second had an operating pressure of 200 kgf/cm², and the third 160 kgf/cm². These at the time were the world’s largest, to test from small scale to full-scale submarine compartments. This was not just theoretical. The ultimate goal was to provide a diving capability to almost a mile deep or 1100 m.

An aerial port quarter view of a Soviet Mike class nuclear-powered attack submarine underway.

No military submarine at the time, apart prototypes tailored for this such as the Trieste and others, were able to blow this record up by a long stretch. Let’s recall the Marianna deep is c10,984 (36,037 ft or 6,000 fathoms/6.825 miles). But the submarines that did it had a very small compartment, essentially an armoured spherical capsule for two or three occupants. In the case of an attack submarine, which was essentially a combat vessel with many compartments, the pressure hull measured around 100 meters. It was thus far less resistant, being a cylinder, than a sphere. One solution would have been to muster the whole crew inside a large sphere and the remainder of the hull being entirely automated and under nonhabitable mixed pressure compartments, but in 1966 this clearly was science fiction, albeit early concepts for the Alfa class looked that way. In the case of Project 685 the main goal was to out-run acoustic torpedoes to such depths the hull of the latter would just crush out under pressure. A simple idea. But the operating depths needed to be kept top secret.

K-278 keel was laid down on 22 April 1978 at Severodvinsk and she was launched at Sevmash, as Yard number 510 on 3 June 1983, commissioned on 28 December 1983.

Design of the class

Hull and general design

K-278 had a double hull, an inner hull composed of titanium, and an outer hull. There was also a single shaft. For the first time, a titanium alloy 48-T with a yield strength of approximately 720 MPa was chosen for the pressure hull. This light outer hull consisted of 10 main ballast tanks with bow and stern ends and permeable superstructures, plus wells for retractable systems, radars and periscopes. The carefully crafted external shape of the outer hull reduced hydrodynamic drag, and it was lined with a rubber coating, enhancing stealth.
The pressure hull however was carefully designed to avoid any pressure point in its shape, and it was cylindrical amidships, 8 meters in diameter then was thinned up as cones at the bow and stern ends, ending with extra-string spherical bulkheads. The angle between the cylinder and the cones did not exceed 5 degrees, again to equalize pressure. This forced to headaches and compromises to managed the interior components. The torpedo tube bays and cutouts for the forward hydroplanes as well scuppers were all equipped with protective shields.

The pressure hull was divided into seven compartments over 2-3 decks:
1- Torpedo compartment, separated by two decks. Upper deck torpedo tube breech, torpedo racks, communications equipment. Lower deck: 112-cell battery.
2- Living quarters, over two decks. Upper: wardroom, galley, sanitary facilities. Lower crew’s quarters. Hold: provisions storeroom, fresh water tanks, electrolysis unit.
3- Control room, over two decks. Upper: control panels, main control room/computer system. Lower, emergency diesel generator.
4- Reactor compartment. Steam generator, with all equipment and piping, primary circuit.
5- Auxiliary machinery compartment and cooling system for the PWR
6- Steam turbine compartment. Centreline main turbo-gear unit and two independent turbogenerators, two main condensers.
7— Tail compartment, with the main shaft and rudder drives.

The second and third compartments were separated by transverse bulkheads designed to withstand pressures up to 40 kgf/cm² and were called the “refuge compartments” or “rescue zones”. There was also, in case of a fire, air-foam and chemical fire extinguishing system, something that apparently failed in 1989.
The ballast tanks were located inside the pressure hull and to create immediate positive buoyancy within 20-30 seconds at great depths when seawater entered the submarine at great pressures, a ballast blowing system was installed in one of the mid-tanks using propellant gas generators. The forward horizontal rudders were retractable to make the hull flush if needed. It was decided to eliminate the torpedo loading hatch and strong conning tower entirely. So no helms post. Entry to the submarine was through a floating rescue chamber (FRC) also used for exiting the sub in case of hazard. This minimized the number of openings in the pressure hull, and thus, made for greater strength overall.

According to Norman Polmar and Kenneth J. Moore, two Western experts on Soviet submarine design and operations, this advanced design included many automated systems allowing for fewer crew members than usual (like the Alfa class). The manning table approved by the Soviet Ministry of Defence in 1982 specified 57 men, almost all officers. This was later increased to 64, with 30 officers, 22 warrant officers, and 12 petty officers and seamen. But when she was lost, 69 were aboard, likely engineers from Rubin as well or staff members.

Powerplant

The main propulsion system consisted of an OK-650B-3 pressurized water reactor with a thermal output of 190 MW, four steam generators, a main turbo-gear unit with a shaft output of 43,000 horsepower, and two independent turbogenerators with a capacity of 2 MW each. To prevent accidental ingress of radioactive coolant into the pressure hull, there was a dual-circuit heat exchanger system installed between the main propulsion plant and onboard equipment. The primary cooling circuit used High-purity distilled water to carry heat to two overboard water-to-water coolers. There was of course a backup propulsion system with a DG-500 emergency diesel generator with a capacity of 500 kW and battery bank in the first compartment. The tips of the horizontal stabilizers even had two watertight capsules with a 300 kW electric motor in each to drive small propellers and lift these in case of the main drive failure. But they could also propel the submarine up to 5 knots for some time.

Armament

The Project 685 had six 533 mm torpedo tubes in the bow with a quick-loading system. Each torpedo tube had an independent pneumatic-hydraulic firing system. Firing was possible at all diving depths as it was entirely remotely operated, a first in 1974. The ammunition comprised a total of 22 torpedoes and missile-powered torpedoes.

Torpedo Tubes

The Torpedo armament was solely of 533 mm, and all models could be fired under 100 m. There were also two extra 400 mm tubes capable of launching decoy under 250 m for a total of 16 in store. The combat suite was essentially the same as for the Project 659 (ECHO). Six rocket-assisted torpedoes and ten torpedoes were stored on racks.

SET-65 torpedoes “Yenot-2”

533 mm Guided Electrical Torpedo with active acoustic guidance, homing range 880 yards (800 m). 3,836 lbs. (1,740 kg), 307 in (7.800 m), WH 452 lbs. (205 kg), RA 17,500 yards (16,000 m)/40 knots, Silver-zinc battery. Although not attributed, they could had been issued in case of war, as they were much cheaper than the SAET-60M. Western sources pointed them out anyway.

SAET-60M torpedoes:

Entering service in 1969, these models developed by Gidropribor and built at Dagizel plant were Heavyweight torpedoes 533 mm, 7.80 m long for a Weight of 1.855 kg.
The 300 kg Warhead used a Contact and proximity fuse, guided by Passive acoustic homing.
Propulsion relied on a silver zinc battery with 46 cells, twin propeller wakeless propulsion for a main setting at 42 knots at short distances (13 km), but 15 km at 35 kt.
It could reach 400 m in depth as well.

VA-111 Shkval rocket-assisted torpedoes:

Famous super cavitation torpedo, which does not need any more introduction.
Mass 2,700 kg (6,000 lb), length 8,200 mm (26 ft 11 in) for 533 mm (21 in)
Effective firing range 7 km (4.3 mi), warhead 210 kg (460 lb) conventional explosive or nuclear*
Solid-fuel rocket for 50 knots (93 km/h; 58 mph) or in excess of 200 knots (370 km/h; 230 mph)
GOLIS autonomous inertial guidance. It was a straight line weapon, no homing.
Latr models M-5 warhead with a 150 kt yield. Early models 1969: Variable yeld.

S-10 Granat 3M10 cruise missiles:

NATO SS-N-21 ‘Sampson’.
1,700 kg (3,750 lb), 809 cm (26 ft 7 in) for 51 cm (20.1 in) diameter, wingspan 310 cm (122 in).
Warhead Conventional or Nuclear 200kt
Solid-propellant rocket booster R-95-300 or 36MT-37 turbofan 450 kgf
Range 3,000 km (1,600 nmi) at max 720 km/h (447.4 mph), sea-skimming for the final approach.
Some sources also points out the use of the URPK-6 Vodopad-PL SSM/ASuM (83R, 84R), comparable to ASROC.

Sensors

-MRK-55 Chibis radar: No more info.
–MGK-500 Skat-Plavnik sonar suite: The Skat-KS sonar system uses analogue signal processing. Its antennas and instrumentation were housed in a strength capsule in the forward end of the outer hull.
-Bukhta ECM suite, radio signal detection system.
-MG-74 Korund-2 decoys, with sixteen 400 mm of these in store.
–MVU-132 Omnibus CCS: Centralized combat control with the motion control system providing automated control over the flow of seawater into the pressure hull and generating recommendations for the submarine’s resurfacing.
-Medveditsa-685 all-latitude navigation system.
-Communication: Molniya-L communications suite, R-750 Tsunami satcom, Sintez antenna, R-655 HF transmitter, Kora, Anis HF antennas, R625 VHF station.

Profile by Mike1979 Russia released un CC.

⚙ Sierra Pr.685 specs.
Displacement	4,400–5,750 tons surfaced, 6,400–8,000 tons submerged
Dimensions	117.5 x 10.7 x 8-9 m (385 x 35 x 26-30 ft)
Propulsion	1 shaft 190 MW OK-650 b-3 PWR, 2x 45000 shp steam turbines
Speed	14 knots (26 km/h; 16 mph) surfaced, 30 knots (56 km/h; 35 mph) submerged
Range	Unlimited (less food)
Armament	6x 533 mm (21-in) TTs 53-65, VA-111 Shkval, SS-N-15 Starfish SSM
Sensors	MRK-55 Chibis, MGK-500 Skat-Plavnik sonar, Bukhta ECM, MG-74 Korund-2 decoys, MVU-132 Omnibus CCS
Test depth	1,000 m safe, 1,250 m design, 1,500 m crush
Crew	64 (30 officers, 22 warrant officers, 12 petty officers+ enlisted)

K-278 Komsomolets’ Career

Construction and earl service

Project 685 “Plavnik” large nuclear submarine K-278, yard number 510, was laid down on April 22, 1978, on the slipway of Workshop No. 42, Sevmash, in Severodvinsk. To gain time in construction, she was built using the block method, each completed block undergoing extensive testing in dry-dock chambers built during the design process before final assembly. On May 30, 1983, she was ceremoniously launched. On June 3 she was launched a second time with all top brass present. From July to August, she underwent mooring trials and in August, the naval ensign was ceremoniously raised, to start a campaign of sea trials. On December 28, 1983, the acceptance certificate was signed, and she officially entered service.

K-278 “Komsomolets”, January 1, 1986. An American artist’s rendering of the Komsomolets submarine. Illustration from Soviet Military Power magazine, 1984

Her existence, when revealed, was a problem for NATO as she was rumoured as an improved version of the Alfa class with conventional PWR (metal-liquid on the Alfa) but with a stronger hull. In her early years, K-278 was not deployed immediately for patrols however, but became the base for deep-diving experiments, and soon intensively used for fleet exercises and combat missions, including antisubmarine protection of SSBNs against US SSNs. She was officially part of the 6th Submarine Division, Northern Fleet, together with the Project 705 Alfa class and Project 945 and 945A Sierra “multipurpose” submarines, all made of Titanium. K-278 however, only completed three combat missions.
-On January 18, 1984, she was assigned to the 6th Submarine Division, 1st Submarine Flotilla, Red Banner Northern Fleet and on December 14, she arrived at her permanent homeport in Zapadnaya Litsa for trial operation under supervision of the flotilla Commander.

Operational Sorties

On June 29, 1985, she was declared ready for permanently combat-ready submarines and on August 4, 1985, under command of Captain 1st Rank Yuriy Zelensky, while deployed off Norway she set an absolute world record for diving depth at 1,027 meters. Upon surfacing at 800 meters, her torpedo tubes fired dummy models. At this depth, she was inaccessible to US submarines and their standard acoustic torpedoes, virtually undetectable by hydroacoustic detection systems as well. In 1986, K-278 successfully tested her powder-based emergency surfacing system, from 800 meters.
From November 30, 1986, to February 28, 1987, she completed her first regular combat patrol. In June 1987, her trial run completed, she was no longer considered a test submarine, but regulat combat submarine and from August to October she performed a second combat patrol.
On January 31, 1989, she was renamed “Komsomolets”. On February 28, 1989, K-278 “Komsomolets” started her third combat patrol with the 604th replacement crew, under command of Captain 1st Rank E. A. Vanin. Her regular crew remained ashore. She was set up to the standard 2-crew patrol operations.

The tragedy

K-278 Komsomolets was lost on April 7, 1989, while returning from her third patrol. Perhaps the use of an unexperimented crew was one of the main reasons, but here it is: A fire in two adjacent compartments broke out, destroying the main ballast tank systems, and causing a massive flooding. Subsequent assessments of the cause vary significantly across various sources, with Navy leadership blaming designers, the latter blaming the crew’s incompetence.

On April 7, 1989, she was travelling under 380 meters at 8 knots on her 39th day of patrol. At 11:02, a fire broke out in the 7th compartment (true cause remained unknown, fire in electrical equipment and oil separators being the most probable). The first casualty was intoxicated by fumes, Nodari Bukhnikashvili, watchman in the 7th compartment.
At 11:12, an emergency alarm sounded and the procedure for emergency surface to 50 meters was activated. However, the fire could not be extinguished using the critical chemical fire extinguishing system (LOH). The fire spread and engulfed electrical power systems, causing multiple issues. The steam turbine plant’s emergency protection system was activated at 150 meters, and she lost propulsion. Captain Vanin ordered to purge a group of main ballast tanks, but this contributed largely to the tragedy.

Objective evidence indicates that a high-pressure air line ruptured in main ballast tank No. 10 in compartment 7, resulting in compressed air entering the compartment under high pressure, and causing a localized fire, to rapidly grew as a full-scale fire. The sudden increase in pressure, with air mixed with combustion products flew into the main engine oil drain tank in the adjacent compartment 6, and this excess pressure forced oil back into the compartment, sprayed across the equipment. Warrant Officer Vladimir Kolotilin on watch in compartment 6, was killed in the outburst. No order was given to shut off the high-pressure water and hydraulic lines leading to the 7th compartment, and the bulkheads were not sealed at the time.

At 11:16, K-278 surfaced at last. Initially, she had a flat list and trim, but it degraded in 1-2 minutes after surfacing, with hot gases from compartment 7 blowing out through the starboard main ballast tank, through a ruptured pipeline, causing her to list 4-6°. Compartments 6 and 7 were already ablaze, smoke filled compartments 2, 3, and 5. A control panel in compartment 3 caught fire and flammable gases ignited in compartment 5. The reactor’s emergency protection system was activated, shutting down main electrical circuits, transferring power to the battery. It was then ordered to start the emergency diesel generator, bu it took two hours.

At 11:23, the list to port reached 8° and at 11:37, an emergency signal to base was transmitted. However, due to the failure of the hydraulic systems, the retractable systems started to lower under their own weight. The emergency signal transmission was only received and deciphered on shore after an eighth attempt at 12:19. Hot air from compartment 7 continued to flow into main ballast tank No. 10 starboard side, blowing through it, causing the list to increase. Without determining its cause, there was an attempt to correct it by blowing through the opposite tanks, a terrible decision as it introduced more fresh air under pressure into the burning compartments.

The crew was then wearing hose-type breathing apparatus, but combustion products entered it anyway, causing further fatal intoxications. Most of the crew inside started to lose consciousness due to poisoning, and emergency teams were organized to evacuate injured men from the compartments. The command to switch to self-contained breathing apparatus (SCBA) was apparently done too late as well, and further casualties were reported.

Rescue Effort

At 11:54, pilot Major Gennady Petrogradsky was alerted of the SOS, and orders to assist were given to all air and naval rescue forces. The command post knew a fire has broken out on K-278 near Bear Island and that she was surfaced, with the crew fighting for its survival. To reach the area and establish contact, continuously report the situation to fleet headquarters, rescue aviators with helicopters capable of floating on water, and seaplanes were prepared. But it was decided to send an ASW patrol aircraft Il-38, the first capable of reaching her.
The helicopters in between ran out of fuel, and one crashed at 980 kilometres from the Soviet border. A seaplane was on its way, but much slower than the patrol plane. The early reporting of the situation on board however was not particularly alarming.

At 12:43 PM. Petrogradsky flew off his Il-38. It had been prepared not for 1 hour and 20 minutes, loaded notably by life rafts, but in 49 minutes. This included removing weapons and installing the droppable emergency rescue containers. At 1:20 PM. the Northern Fleet Command transmitted the coordinates of K-278 to rescue barge “Alexey Khlobystov,” heading to the accident site.
At 2:20 PM, the Ll.38 established radio contact with the submarine commander, the latter reporting the “fire was under control” and that her prevented it from spreading. Petrogradsky reported that he had been tasked with directing the barge ship.

At 2:40 PM, after breaking through clouds, the IL-38 aircraft established visual contact with K-278, stationary, heading due north to south, with a list to starboard. Heavy foaming of water was observed near the sixth and seventh compartments, port side. A tail of light smoke was emanating from the conning tower. A report was sent to shore that visibility 5-6 kilometres, cloud base 400 meters, wave force 3 in swell with intermittent snow reducing visibility to 1.5 kilometres. Back on the sub, attempts to correct the list and reconnoitre the damaged compartments went on, but water started to enter the pressure hull of compartment 7, and the list shifted to starboard, with a trim to 2 degrees by the stern. K-278 just run out of LOH coolant.
14:50 saw three aircraft in the air, one commanded by Vladimir Votintsev and the other, Anatoly Malyshev, between Medvezhye and Murmansk, to relay communications between the submarine commander and fleet headquarters.

Major Petrogradsky helped organize communications and flew around to guide surface vessels to the area, with an arrival time estimated at 6 p.m.
At 3:20 PM. firefighting went on and commander Vanin maintaining constant contact with the shore. He learned a tugboat was on its way, and at 4:00 PM. the commander unexpectedly requested freon. Petrogradsky contacted the vessels which prepared their reserves. However at 4:35 PM. pilots reported the submarine was settling by the stern and from there on, events unfolded rapidly.
At 4:38 PM the stern trim and list starboard increased, and two minutes later, the order was given to evacuate the crew and prepare the floating rescue chamber (FRC), abandon all compartments. The crew released life rafts, but only one was launched. Her bow still emerged from the water but the stern trim was increasing rapidly.

At 16:44, water approached the base of the conning tower and three minutes later it was half submerged. At 16:50 the commander transmitted “Preparing 69 people for evacuation”.
At 17:00. Two deployed life rafts for 20 appeared next to the submarine and sailors started to evacuate in a continuous stream. The IL-38 dropped an air rescue container, making for another life raft. Eight minutes later, K-278, had a stern trip of 80 degrees and sank under 1,658 meters. There were 60 men in the water, and 5 sailors including commander E. A. Vanin managed to climb into the pressure chamber, but after the chamber surfaced, the pressure difference blew the hatch off, throwing Warrant Officer Sergei Chernikov into the sea. The chamber then flooded rapidly and only Warrant Officer Viktor Slyusarenko could escape through the open hatch. Captain 3rd Rank A. M. Ispenkov remained inside the submarine, maintaining the diesel generator until the last minute. At 17:10. Major Alexander Volkov’s crew arrived in the disaster area. His plane was prepared in 50 minutes, and he deployed another rescue container at an altitude of 30 meters. All aircraft left the area as darkness fell and running low on fuel. By 6:20 PM the tug Alexey Khlobystov arrived and started rescuing men, but most had already died from exposure.
17 drowned, 30 survived, but also 16 bodies were rescued by the tug.

Public reception and Tragedy

On April 9, 1989, the Soviet press published a release from the Central Committee, Presidium of the Supreme Soviet and Council of Ministers:

“On April 7, a fire broke out on a nuclear-powered torpedo submarine in neutral waters in the Norwegian Sea. The crew’s efforts were unsuccessful in extinguishing the fire. The submarine sank. There were casualties. The Central Committee of the CPSU, the Presidium of the Supreme Soviet of the USSR, and the Council of Ministers of the USSR express their deepest condolences to the families, relatives, and loved ones of the victims.
During the third voyage, the 604th crew of the Project 685 submarine, consisting of 69 people, was aboard the K-278. As a result of the disaster and the sinking of the ship, 42 people died, and 27 survived.
The bodies of 16 of the dead were recovered aboard the arriving ships a day later. Three more of the 30 rescued died on board on April 8. The bodies of the deceased were buried. The remaining 23 victims remained at sea: Captain 3rd Rank A. M. Ispenkov, as well as the watchmen of the 6th and 7th compartments, Warrant Officer Vladimir Kolotilin and Senior Seaman N. O. Bukhnikashvili, were on board the ship. The bodies of three crew members, including the ship’s commander, E. A. Vanin, remained on the bottom of the VSK, but the majority drowned in the icy waters before rescuers could arrive.”

On May 12, 1989, the Presidium issued a decree awarding all members of the crew the Order of the Red Banner.

Investigation

On April 9, 1989, the Northern Fleet’s military prosecutor opened a case for K-278 under paragraph “c” of Article 260.1 of the Navy Criminal Code for, “Negligence of a superior or official in service, resulting in grave consequences.”
The investigation was conducted amidst clashes between navy, and Rubin’s design bureau designers as well as the builders. There were three years of investigation and a joint expert commission, helped by hearing all survivors, which concluded that the 604th crew was not sufficiently prepared for the mission. The break since the previous deployment exceeded the maximum permitted period of eight months, and five crew members were not authorized to perform their duties. In other words, operational competence was not present in this mission. Sending them to sea without additional training was unacceptable and by January 1998, the head of the investigative team sent his report to the CiC of the new Russian Navy, regarding the elimination of the causes and conditions contributing to the disaster, urging a reform of combat training. Admiral O. A. Yerofeyev (Northern Fleet) and Rear Admiral O. T. Shkiryatov (24th Research Institute, MoD) were blamed for their lax approach to guidelines during the preparation of the 1989 mission of K-278. It was apparent the 1990 version of the nuclear submarine combat training course introduced numerous simplifications, reducing crew training drastically. However, it was objected by the Navy’s Military-Technical Council and subsequent investigations led in 2002, after the retirement of the officers conducting the investigation, to be suspended. No criminal charge was retained.

The wreck

Seven expeditions were conducted from 1989 to 1998 in the area in the Norwegian Sea. The first was by the Mir deep-sea submersible, measuring and recording equipment and checking torpedo tubes, confirming nuclear warheads were on board and managed to seal them to ensure radiation safety. In 1998, it was discovered that the recording stations were missing, leaving only carefully undocked anchors. On July 7, 2019 it was surveyed by an Ægir 6000 ROV from Norwegian Institute of Marine Research, which published a video.
The depth makes it unreachable by most conventional systems, only suitable for modern deep-sea submersibles, enabling the removal of nuclear weapons and other materials. Still, there is a constant risk of a radiation due to the release of nuclear materials into the water, after the natural decomposition of the nuclear munitions and reactor casings. The idea of raising Komsomolets entirely or at least part of it was repeatedly mooted.

Back in August 1993, Rubin attempted to raise the floating chamber and found it the seabed under 1,650 m. It was secured with a special grapple, raised 200 m, but the cable snapped, and the camera fell back. Anatoly Zakharchev, project manager for the Integrated Submarine Decommissioning Project Office at Rosatom studied any question and concluded that raising the Komsomolets was feasible, but not earlier than the early 2020s. The first step was the lifting and dismantling of K-27 sunk in the Kara Sea in 1982 instead.
Surveys of 1991-1993, sensed high levels of cesium-137 in the bottom sediments and by March 2007, a Russian expedition detected a radionuclide leak. In 2019, the Norwegian ‘Barents Observer’ conducted a survey with its Ægir 6000 frop the G. O. Sars and Hilda Elise Heldal, reported radiation levels exceeding background radiation by 100,000 times at 100 Bq/liter after a water sample from the ventilation pipe was taken revealed 800 Bq/liter. This was however alleviated by the great depth in which she sank. Admiral Vyacheslav Popov refuted the results.
Still, the submarine was injected with a composite polymer containing chitin and chitosan to stop these emissions. The date of the Komsomolets sinking was proclaimed in the Russian Federation “Submariner Remembrance Day”. A dedicated stele was erected in St. Petersburg.