This article is based on a chronological listing of theories and presented in Russian media and at the different stages of the rescue operation.

The accident occurred during tactical military exercise of the Russian Northern Fleet on August 12, 2000. The submarine, powered by two 190 MW reactors, was capable of carrying 24 supersonic anti-vessels cruise missiles and 24 torpedoes. The tactical military exercises of the Northern Fleet in August were a part of the preparation for autumn mission to the Mediterranean Sea that would include vessels of the Baltic Fleet and the Black Sea Fleet. The mission was to be performed in consent with the order of President Vladimir Putin dated April 4, 2000, which outlined Fundamentals of Naval Policy of Russian Federation for the period until 2010. 118 submarine crewmembers perished in the accident.

Cruise missile Oscar-II class submarine Kursk (K-141)

Displacement-17 000 tons

Length – 153 meters

Reactor – Two 190 MW of the type OK 650 b

Max Speed – 30 knots

The following theories of the accident have been suggested so far.

Theories

The theories are set up by the dates they were presented in media or by experts and are supplied with comments.

AUGUST 15, 2000

1. One of the versions of the disaster suggests that a fire broke out in the submarine and as a result some compartments were flooded. Therefore, the boat had to go down to the seabed. There is no official confirmation of this version.

Source: Russian daily Komsomolskaya Pravda

2. According to the official version, given by the Commander-in-Chief of the Russian Navy, Vladimir Kuroedov, the submarine’s bow part was damaged as a result of collision with a rock or other barrier. On August 14, the version of collision with another submarine, perhaps NATO’s, was not excluded by the HQ of the Russian Navy.

The reason of the accident could be an explosion inside the submarine. The President of the Submariners Committee in St. Petersburg, Captain of the 1st rank Igor Kudrin, referring to unofficial information from the Northern Fleet, said that a hydraulic shock resembling an underwater explosion was detected by the cruiser Peter the Great and another submarine, which participated in the exercises, on Saturday at 11.38 am. Malfunctioning batteries located in the first compartment of the submarine could cause the explosion.

Source: Russian daily Kommersant

3. Submarine design flaws, malfunctioning equipment and lack of proper professional training of the crew (pilot mistake, turbine halt, weight increase of the boat etc.). Therefore, the boat got a trim and went down to the seabed what led to damages in the bow part of the submarine, opening of torpedo tube lid, followed by seawater flooding the submarine.

Source: Russian daily Rossiyskaya Gazeta

AUGUST 16, 2000

The following accident theories outlined:

1. Collision with a NATO submarine.

2. Explosion of hydrogen in batteries located in the first compartment. (Then, further developing of the accident, leading to mechanical hull damages and flooding of the compartments).

3. Explosion of a World War II mine. (The area of the military exercises is always carefully examined before they start. That makes a ‘sudden’ appearance of an old mine impossible. Secondly, the hull of the boat is designed to withstand a direct impact with a modern torpedo).

4. Torpedo tube lid remained open after firing of a torpedo (experts consider it improbable).

5. Torpedo stuck inside torpedo tube and exploded.

Source: Severodvinsk daily Severny Rabochy

AUGUST 17, 2000

1. The main version of the Northern Fleet HQ announced is collision with a foreign submarine.

Pro arguments: The surface vessels and submarines of NATO countries monitor regularly military exercises of the Northern Fleet. In particular, the Norwegian intelligence vessel Marjata was observed several times during the present and past exercises. American officials confirm that a U.S. Navy electronic intelligence ship was tracking Kursk during the exercises in the Barents Sea. The vessel was four hundred kilometres away.

Contra arguments: The Western countries and the Pentagon denied the possibility of collision. Their main argument was that a NATO submarine would not have survived damages should it have collided with Kursk.

2. During the second part of the day the Russian Deputy Prime Minister, Ilya Klebanov, said that the collision with a World War II mine was now an official theory.

Pro arguments: It is possible to believe that strong sea currents drifted a World War II mine to the area of the military exercises in the Barents Sea. But it is unlikely that the mine could bring such sever damages.

Contra arguments: It is unlikely that the area of exercises had not been checked before they started. Experts believe that the submarine could withstand a direct impact with a modern torpedo.

3. Kursk could collide with a Northern Fleet submarine or a surface vessel (for example, trawler).

AGAINST: Should such collision have taken place, it would have been reported to the Northern Fleet HQ by the second naval ship.

4. An accidental explosion in Kursk torpedo section could sink the submarine. Submarine’s compartments were flooded after the explosion.

Pro arguments: An expert from one of the defence establishments, who works with marine engineering, said that visual inspection of the submarine’s hull suggested that an explosion in torpedo section took place. The explosion was apparently triggered by collision with an unidentified object.

Contra arguments: Rear-Admiral Ilya Kozlov, chief of the Naval Rescue Service, said that the torpedo explosion theory is unreal since during an exercise ships shoot torpedoes that are not armed with warhead. An explosion in battery compartment could take place only in case of seawater flooding the submarine.

5. An explosion took place not outside the submarine, as it was suggested earlier, but inside. Speculations about possible act of terrorism start circulating.

Neither officials of the Northern Fleet nor the Navy HQ can sensibly explain what caused such damages to the hull of the submarine. The Commander-in-Chief of the Russian Navy, Admiral Kuroedov, said that the preliminary visual inspection of the submarine’s hull conducted by rescue capsules showed that the submarine’s bridge was damaged and lids were torn off two missile tubes. The submarine rests on the seabed with its periscope extended.

Military daily Red Start placed an article where it stands that Kursk was refitted in 1998 to carry torpedoes of new design. The Russian Navy went against the upgrade, but the industry managed to lobby it through. The article said that the new torpedoes were difficult to store and dangerous to handle. The reason for the replacement was that they were cheaper. The older type torpedoes Oscar-II was equipped with used batteries containing silver for propulsion system. The torpedoes were launched from the submarine using high-pressure air. The propulsion of the new torpedoes used liquid fuel. The torpedoes were launched with a help of a trigger that produces gas shooting the torpedo out.



Source: Murmansk daily Vecherny Murmansk and Russian daily Red Star



AUGUST 19, 2000

Kursk received a powerful impact blow as a result of a collision with an ‘external object’ of large displacement, Ilya Klebanov, Deputy Premier Minister and Chairman of the Governmental Kursk Inquiry Commission, said at a press conference in Murmansk.

AUGUST 21, 2000

Ilya Klebanov speaks with a certain degree of confidence about the reasons to Kursk accident. He said that it was a collision with an underwater object that had displacement not less than 8,000 tons. This implies that a British or an American attack submarine was involved. The hole in the hull as a result of the collision led to water intake followed by explosion in battery section and simultaneous detonation of ammunition in the first compartment.

AUGUST 22, 2000

Ilya Klebanov keeps sticking to the version of strong external impact blow with an underwater object or collision with a World War II mine.

AUGUST 23, 2000

1. U.S. Secretary of Defence William Cohen said that the reason to the Russian submarine accident is unclear. Cohen added that a part of Russian officials still believe that a collision took place. Cohen strongly denied any involvement of American submarines into the accident.

Source: Russian daily Kommersant

2. New list of Kursk accident theories.

1. Kursk collided with a foreign submarine, probably, the British one. This version is more accepted by the Russian Defence Ministry. Officials claimed that signal buoys of white and green colour were found at the place of K-141 accident. Such buoys are not used in the Russian Navy. Also some unidentified underwater object was said to be detected in the area of accident, but then it disappeared from radar screens promptly. None of these statements was proved in any way.

2. The second version follows from the first one. As a result of a collision with “an object”, water flooded inside the submarine through the damaged bow part. That led to an explosion in the battery section and detonation of ammunition. Some experts said that the ammunition onboard could not detonate.

3. The boat was rammed by a large ship (trawler, cargo ship, tanker, ice-breaker etc.). Such ship could send Kursk down. But officials claimed that there were no civil vessels in the area of exercise. The Navy HQ was denying a possible collision with a military surface ship.

4. Explosion of a torpedo in torpedo tube. An experimental torpedo with liquid fuel propulsion could detonate.

5. World War II mine explosion. Experts said the explosive force of such mine would not bring so serious damages to the submarine.

6. Detonation of a depth mine in the area where Kursk was. Depth mines detonation was said to be a part of the exercise. But the military exercises were completed on Friday while the boat sunk on Saturday, August 12.

7. Emergency during manoeuvring. The submarine could hit the seabed at the depth of 80 meters and then slide down to the depth of 108 meters.

8. Chechen terror act. A Chechen web site placed information that this was a planned action.

9. Design flaws. A minor malfunction, shot circuit etc. could trigger a serious of events that resulted into the accident.



Source: Russian daily Izvestiya

AUGUST 30, 2000

A representative from the Pentagon said to The New York Times that a preliminary data analysis of acoustic records obtained in the Barents Sea by American submarine Memphis confirms the version that the cause of the Kursk accident was an explosion of one of the torpedoes in the bow compartment of the submarine with subsequent detonation of the ammunition onboard.

The Americans assert that at attempt to fire a prototype torpedo from Kursk, torpedo’s propulsion system exploded for some reason and the fire broke out onboard. The submarine started urgent surfacing, but the rest of torpedo stock blew up in 2 minutes and 15 seconds. Almost all the crew died immediately.



SEPTEMBER 5, 2000

The reason to the submarine accident could be a fire, Norwegian divers, who took part in the rescue operation, suggested. They said they found melted parts in the boat’s 9th compartment. Thus there could be a fire there before the compartment was flooded.

SEPTEMBER 13, 2000

The Chief Military Prosecutor Office stated that the crew of the submarine was not to blame for the accident. The Office said it was “the fault of the officials from the unidentified vessel who must be held responsible for the collision with Kursk.”

However, the Office had no evidence of the stated fact.

Deputy Prime Minister Ilya Klebanov keeps insisting on the following versions:

· An accident in the torpedo section;

· Explosion of the Second World War mine;

· Collision with an unidentified underwater object.

SEPTEMBER 17, 2000

Valeriy I. Alexin, retired Rear-Admiral, former head of Navigation Department of the USSR/Russian Federation Navy, can. sc., professor of the Military Academy, gives the following version.

The first version – The cause of the accident was an explosion of the torpedo in the bow part of the submarine, possibly, in the first torpedo room. There are two versions explaining what had led to the explosion. Firstly, an explosion of flawed torpedo propulsion during test fire, that resulted the water intake in the first compartment, short circuit, loss of control over the boat and emergency diving with bow trim, and finally collision with seabed. But during the 20-year operation period of project 949 (there were two of them and both are now retired) and project 949? (there are 11 of them in the Russian Navy, including Kursk) submarines, there were no similar accidents during torpedo launch.

The second version – Kursk collided with an underwater object. The other object did not have to be of the same displacement as Kursk. It is enough with dynamic force and one to two thousand tons to smash the lid of a torpedo tube casing detonation of the warhead the torpedo is tipped with.

The U.S., Britain and Norway sent their extra naval forces of intelligence to the region to monitor the military exercise of the Russian Northern Fleet. The force included American nuclear submarines Memphis and Toledo, Britain sent nuclear powered submarine Splendid.

The planned fire training with anti-vessel missiles was conducted on August 10 and 11. Kursk successfully fired Granite class missile at a sea target.

On August 12, submarines taking part in the training were to carry out a torpedo attack against a squad of combat ships, which acted as the ‘opponent’. The squad was under command of the nuclear cruiser Peter the Great, which was also the main target. The squad was assigned to follow a south-east course. The attacking submarines were in ‘ambush’ along the course. Kursk was one of the submarines to attack the squad being at alert in its designated area (15×20 miles in size).

What happened to Kursk?

The further events are described according to the model developed by decades of experience in similar battle exercises and tactics involving cruise missile submarines. Having assumed the region assigned and having reported the readiness to fire torpedoes, the captain of Kursk searched the area including its southern edge. Then the submarine turned back to the north-west and went up to the periscope depth of 19 meters to conduct radio surveillance of the surface forces of the ‘opponent’. Except for the periscope, the submarine extended its antennas and radar, as well as, most probably, the device for air intake to fill the high-pressure air tanks. To improve the ability to steer the submarine at the periscope depth in unquiet sea, one of the ballast tank started to take water in. The speed set was about 3 knots. In the midday, August 12, the ‘opponent’ squad of ships was manoeuvring approximately 30 miles to north-west from the area where Kursk was on guard.

The author describes further in a truth worthy way that a foreign submarine sliced Kursk’s bow part where torpedo (type USET-80) with warhead was located. The author says that Kursk had six torpedoes in tubes but only four of them were tipped with warheads (two USET-80 ad two 65-76 mm). In addition, 18 armed torpedoes were in the torpedo room.

After the collision, Kursk torpedoes detonated and the foreign submarine grounded itself, but its captain managed to resume control over the submarine and flee the area later.

20 September 2000

In Murmansk the dominating theory among officers and those involved in the rescue operation is that a missile launched from Peter the Great hit Kursk leading to the accident. Below are two modifications of this theory:

First

A squad of nuclear powered submarines, including Kursk, was to carry out a torpedo attack against the ‘opponent’, i.e. Peter the Great, on August 12. Peter the Great for its part was to ‘defend’ itself and to fire back missiles. One of the missiles malfunctioned and after reaching low altitude suddenly went down. It went down approximately to the same area where Kursk was at the periscope depth. It is believed that the missile, although it was not armed, hit the torpedo section of Kursk on high speed. One of the torpedoes, likely the one of the new design, detonated. Kursk was testing high-speed top secret torpedoes equipped with hydrogen accelerator. Should something happen to the submarine, the captain in consent with the existing regulations must give order to surface. Being unaware the first seconds after the hit what was going on, the captain commanded emergency surfacing, powering up the turbines, but water intake in the first compartment trimmed submarine forward steering it down to hit the seabed. The other torpedoes onboard detonated.

Second

On August 12, Peter the Great was to perform firing of self-guided missiles at sea targets. The missiles are designed first to penetrate the given target and then to detonate, creating a so-called ‘volume explosion’. At the time of firing the missiles all the vessels in the area are obliged to keep radio silence. By unknown reasons, Peter the Great delayed the missiles launch for one hour. In the meantime, Kursk had its schedule, namely to go up at the periscope depth and to fire its own torpedoes. At the moment when Peter the Great launched the last missile, Kursk was at the periscope depth asking for permission to start firing torpedoes. The self-guided missile was in the air at that moment and received the radio signal from Kursk. The missile then changed its target destination and started descending towards Kursk. Fifteen minutes later, the Commander-in-Chief of the Northern Fleet, Vyacheslav Popov, departed from Peter the Great on helicopter to Severomorsk.