Leaking torpedo could cause “Kursk” disaster

A study submitted to the commander of the Russian Navy, Admiral Vladimir Kuroedov, says a torpedo explosion was the most likely scenario for the Kursk disaster. The study concludes the explosion could be caused by various factors, rather than only by collision with another submarine, as the Russian officials are prone to believe.

As Bellona Web reported earlier the Kursk accident timeline is now shaping up.

From August 9th to August 12th, the Northern Fleet was engaged in a military exercise. On August 12th, submarines, taking part in the training, were to carry out a torpedo attack against a group of combat ships, which acted as the ‘opponent’. The ships had orders to follow the south-east course. The attacking submarines were in ‘ambush’ along the course. Kursk was one of the submarines to attack the group being on the alert in its designated area (15×20 miles in size).

According to the training schedule, the Kursk was to attack the ‘opponent’ firing two practice torpedoes from 11:30 to 18:00 Moscow time.

Kursk went up to the periscope depth of 19 meters to find the ‘opponent’ ships at around 11:00. The submarine slowed down to about 8 knots, extended its periscope and antennas. The available data say that at that time the ‘opponent’ was manoeuvring approximately 30 miles to north-west from the area where the Kursk was on guard. Kursk, playing the rules of this hypothetical combat mission, could not attack the ‘opponent’ before they entered the area the submarine was responsible for.

Data from the Norwegian seismological station Norsar say that two detonations were detected on August 12th. The first blast, recorded at 07:28:27 GMT (11:28:27 Moscow time), equalled 100kg TNT. The most powerful explosion documented at 07:30:42 GMT (11:30:42 Moscow time) had 3,5 points on Richter scale, ranging between one tonne to two tonnes TNT detonated underwater.

Russian officials suggest that it could be a collision with a foreign submarine, a mine from the second world war, or an emergency situation in the submarine’s torpedo compartment. The version, which says the disaster could be triggered by an emergency inside the submarine, was not prioritised, however. Both the head of the governmental Kursk inquiry commission, Ilya Klebanov, and head of the Russian Navy, Vladimir Kuroedov, said the chances of this theory to be true were slim. Their main argument was that it was technically hardly possible.

But in the study made in Explosion Resistance research centre, a branch of the Moscow State Construction University, it is proved that the emergency could in fact develop in the torpedo section. The blame is put on 65-76-type torpedo.

“Oscar-II” class submarines have four 533mm torpedo tubes and two 650mm torpedo tubes. The two 650mm torpedo tubes were reportedly loaded with 65-76-type torpedoes armed with conventional warheads. Two of the four 533mm torpedo tubes had USET-80 torpedoes with electric propulsion inside also armed with conventional warheads. The two remaining tubes were loaded with practice torpedoes. In addition, 18 torpedoes and tube-launched missiles with conventional warheads were in the torpedo room.

65-76 torpedo (65cm / 11m) designed in 1976. The 65-76-torpedo propulsion is based on reaction of concentrated hydrogen peroxide with water. The reaction’s output, hydrogen, is pushed under pressure to turbine. Hydrogen peroxide is contained in a metal tank inside the torpedo.

The study says that uncontrolled process in hydrogen peroxide can lead to pressure growing inside the tank it is contained in. If the pressure relieve valve is broken, it can lead to an explosion. The pressure inside the torpedo fuel tank can also grow if the torpedo is exposed to fire.

Another option is leakage of hydrogen peroxide and its contact with a combustible material as well as a presence of an ignition source.

The last option is the collision with an underwater object what could lead to leakage of hydrogen peroxide. But the ignition source is necessary for a fire to start.

The study also says that given 200kg of hydrogen peroxide leaked out and fire started, then the pressure created could be high enough to destroy the wall separating the first and the second compartments as well as the hull of the submarine.

The growing pressure in the torpedo compartment and the temperature rise of up to several thousands Celsius degrees could trigger off the warhead explosions of other torpedoes.

The study does not make any final conclusions regarding the cause of the Kursk disaster, but explains the events onboard the submarine that fit in the overall picture rather neatly.

In the meantime, Ilya Klebanov said at the press conference presenting the Kursk Foundation that the true cause of the Kursk disaster may never be found, even if the submarine is lifted. The Kursk Foundation was created a couple of weeks ago to collect funding for raising of the submarine.