Military


K-141 Kursk Accident

On or about 12 August 2000, the tenth unit of the Oscar-II class, the K-141 Kursk, sank about 100 miles from the Russian port of Murmansk. At the time the boat was participating in the fleet's major summer exercises, involving about 30 other vessels. The Kursk apparently sank quickly, and did not launch distress buoys. The submarine was not carrying any nuclear weapons at the time, and there was apparently no immediate danger of radiation leaks. Considerable confusion surrounded initial reports, though apparently the Kursk shut down its two nuclear reactors after it was crippled. Although Russian Navy commander Adm. Vladimir Kuroyodev stated that there were "signs of a big and serious collision," subsequent reports cast doubt that the sub was damaged in a collision. The US Department of Defense stated that there was " no indication that a US vessel was involved in this accident." By 15 August it was generally believed that the Kursk had been damaged by an explosion on board, probably in the torpedo room.

Initial reports suggested that at least some of the crew were alive and communicating through rhythmic tapping on the hull. Rescue submarines that rushed to the Kursk reportedly found it damaged but resting upright on the seabed, at a depth variously reported as between 350 feet and 500 feet of water. Subsequent reports suggested that the submarine was listing, perhaps as much as sixty degrees. According to initial reports, as of Monday 14 August 2000 at least one rescue craft, the Kolokol, was said to be feeding power and oxygen to the Kursk. Communication links with the boat's captain, Gennady Lyachin, were reportedly restored after a day of radio silence. However, subsequent reports indicated that these initial reports were incorrect, and overly optimistic. Admiral Kuroyedov initially expressed doubts about the possiblity of rescuing the crew, stating "the chances for a positive outcome are not very high." The Russians had two India-class rescue submarines, each of which carried a pair of small rescue submarines which could reach a depth of 2,275 feet. However, these submarines and their rescue capabilities were apparently discarded by the Russians in 1995 as a cost-savings measure.

Rescue efforts centered on attempts to attach equipment to provide oxygen and restore electric power to the submarine. As of 15 August a first attempt to lower a diving bell to the submarine had failed, and a second attempt was launched soon thereafter. The two attempts on Tuesday to reach the Kursk were frustrated by of poor underwater visibility and 12-foot high waves. Rescue workers failed in efforts to maneuver a robotic remotedly operated vehicle onto an emergency hatch on the submarine.

By Wednesday, while Russian experts were still optimistic about the rescue operation, Russian President Putin termed the situation with wrecked sub "critical". The weather had worsened in the Barents Sea, while the Bester capsule with divers aboard was used for the first time Rrescue ships tried twice more to lower a diving bell to dock with the Kursk, but each time the operations had to be aborted because of rough seas, strong currents, and poor underwater visibility. Rescue efforts continued despite the fact that one of the three rescue capsules used to reach the stranded sub was damaged in the storm. The Russian military consulted NATO experts on submarine rescue, and Russia asked Britain and Norway to help the rescue effort. Britain sent three aircraft with crew and equipment, and the first plane loaded with a British rescue vessel landed in Norway late Wednesday [Moscow time]. The British mini-submarine may be transported to Russia by Saturday.

On Thursday 17 August it was reported that US surveillance ships in the area at the time of the accident heard two explosions on 12 August, the second much stronger than the first. The Russian navy was reported to be studying video footage showing massive damage to the first and second compartments in the submarine's bow. A Navy spokesman said the video showed extensive damage from the top to the back fin. The periscope was also still up, indicating the ship sank so fast the crew did not have time to react. Russia's Deputy Prime Minister Ilya Klebanov said films taken of the Kursk indicated extensive damage to the ship's bow that he said was caused by a collision with an unknown object.

By Friday it was reported that the submarine was lying at an angle of no more than 20 degrees from vertical, rather than the 60 degress previously reported, and at a depth of a little more than 100 meters. The depth and the angle are were said to be well within the operating limits of th British LR5 rescue craft.

It was initially estimated that the air on the K-141 Kursk submarine would run out by Friday 18 August 2000. As of Friday it was officially estimated it could last another five days. Contrary to most news reports, the problem was not a lack of oxygen for the crew to breath in, but rather the buildup of the carbon dioxide that they would breath out. Over time, this carbon dioxide would build up to a level that would kill any crew members who survived the initial accident. The oxygen limit is about 0.1 atm and the Carbon dioxide limit is time dependent, but somewhere between 0.03 and 0.06 atm. Respiration produces (roughly) 1 molecule of carbon dioxide for each molecule of oxygen consumed. This suggests that, starting with 0.21 atm of oxygen, the oxygen partial pressure will still be 0.15 atm even when 0.06 atm of carbon dioxide is present. [see the NOAA Diving Manual for details].

While some Russian Navy officials maintained that some crew members remained alive and were sending an SOS message by banging against the submarine's hull, other officials said there had been no communication and that the crew might already be dead.

On 21 August Chief of staff of the Russian Northern Fleet Mikhail Motsak pronounced the Kursk flooded and its whole crew dead. Admiral Motsak said a Norwegian-led team of divers was videotaping the interior of the rear compartment after successfully breaking in through damaged escape hatches.

On 01 September 2000 an agreement was reached on the technical and organizational aspects of the international effort to lift to the surface the bodies of the crewmen of the Kursk. The Norwegian Stolt Offshore company received blueprints representatives of the naval design center which designed the sunken submarine that showed where deep water frogmen may enter the boat. A team of international and Russian divers planned to cut holes in the Kursk's hull to pull out the remains of the 118 seamen who died. The operation was scheduled to begin in October 2000.

There was no chance of quickly salvaging the Kursk submarine, since September is the month when storms start raging in the Barents Sea, which would make such impossible. At best the salvaging operation could be carried in 2001. Neither the Russian submarine base at Vidyaevo, nor any western base have hoists capable of salvaging such a large vessel the Kursk submarine, or even moving it to a shallow place closer to the coast. It would take several months only to build such a device. Another priority on the agenda is the salvaging of the submarine and taking it to shallow waters. The Norwegian Stalled Offshore Company has given its consent to participate in the salvage effort.

On 06 September 2000 Russian President Vladimir Putin was reported to have said that the 118 sailors aboard the submarine Kursk probably died quickly after it sank, and that they never sent any signals from the distressed sub after it went down. At the time of the accident, conflicting reports from some Russian naval officials indicated that survivors were tapping on the ship's hull. But Putin said that the signals came from "a mechanical device on board" that went off automatically.

There are several versions of the reasons for the disaster. According to Vice-premier Ilya Klebanov, the first version is that of an underwater collision with a foreign vessel. Ilya Klebanov who heads the commission to investigate the case described as the second version a possibility that the submarine hit a German mine left over from the time of the Second World War. The third version, the Vice-premier believed, could be an emergency situation in the submarine's torpedo compartment. According to Ilya Klebanov, the majority of the crew died during the first seconds of the disaster.

By July 2002 Russia's prosecutor-general, Vladimir Ustinov, said an investigation had established that an exploding fuel from a blank torpedo caused the other blasts that destroyed the submarine. Ustinov said the blast was triggered by a complex chemical reaction with hydrogen peroxide - used as its fuel in the torpedo exploded because of a complex chemical reaction. "The initial impulse which triggered an explosion of the torpedo was the result of an unusual process of events inside the oxidising agent reserve of the torpedo," Mr Ustinov said. This triggered a massive explosion of other, combat-ready torpedoes, and just over a minute after the initial blast the front section of the submarine was completely destroyed.

In May 2001 Russian Deputy Prime Minister Ilya Klebanov said that the Kursk would be raised in a three-month operation, tentatively set to begin in late July 2001. The Dutch company Mammoet in cooperation with Smit International salvaged the Kursk. Mammoet carried out the lifting work and Smit International all underwater work, which was completed in October 2001.




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