K-141 Kursk was an Oscar-II class nuclear cruise missile submarine of the Russian Navy, lost with all hands when it sank in the Barents Sea on August 12, 2000. Kursk, full name Атомная подводная лодка, which translated, means the nuclear powered submarine “Курск” [АПЛ "Курск"] in Russian, was a Project 949A Антей (Antey, Antaeus but was also known by its NATO reporting name of Oscar II). It was named after the Russian city Kursk, around which the largest tank battle in military history, the Battle of Kursk, took place in 1943. One of the first vessels completed after the fall of the Soviet Union, it was commissioned into the Russian Navy’s Northern Fleet.
Background
Work on building the Kursk began in 1990 at Severodvinsk, near Arkhangelsk. Launched in 1994, it was commissioned in December of that year. It was the penultimate of the large Oscar-II class submarines to be designed and approved in the Soviet era. At 154m long and four stories high it was the largest attack submarine ever built. The outer hull, made of high-nickel, high-chrome content stainless steel 8.5 mm thick, had exceptionally good resistance to corrosion and a weak magnetic signature which helped prevent detection by Magnetic Anomaly Detection (MAD) systems. There was a two-metre gap to the 50.8 mm thick steel inner hull.
The Kursk was part of Russia’s Northern Fleet, which had suffered funding cutbacks throughout the 1990s. Many of its submarines were anchored and rusting in Andreyeva Bay, 100 km from Murmansk.[1] Little work to maintain all but the most essential front-line equipment, including search and rescue equipment, had occurred. Northern Fleet sailors had gone unpaid in the mid-1990s. The end of the decade saw something of a renaissance for the fleet; in 1999, the Kursk carried out a successful reconnaissance mission in the Mediterranean, tracking the US Navy’s Sixth Fleet during the Kosovo War. August 2000′s training exercise was to have been the largest summer drill — nine years after the Soviet Union’s collapse — involving four attack submarines, the fleet’s flagship Pyotr Velikiy (“Peter the Great”) and a flotilla of smaller ships

Wreck of Russian submarine K-141 Kursk in a dock
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The explosion
On the morning of 12 August 2000, as part of a naval exercise, Kursk was to fire two dummy torpedoes at a Kirov-class battlecruiser, Pyotr Velikiy, the flagship of the Northern Fleet. At 11:29 local time (07:29:50 UTC),[1] high test peroxide (HTP), a form of highly concentrated hydrogen peroxide used as propellant for the torpedo, seeped through rust in the torpedo casing. The HTP reacted with copper and brass in the tube from which the torpedo was to be fired, causing a chain reaction leading to a chemical explosion. A similar incident was responsible for the loss of HMS Sidon in 1955.
The watertight door separating the torpedo room from the rest of the submarine was left open prior to firing. This was apparently common practice, due to the amount of compressed air released into the torpedo room when a torpedo was launched. The open door allowed the blast to rip back through the first two of nine compartments on the huge submarine, probably killing the seven men in the first compartment, and at least injuring or disorienting the thirty-six men in the second compartment.
After the first explosion, due to the fact the air conditioning duct was quite light, the blast wave traveled to more compartments, including the command post, filling them with smoke and flames. Additionally, an emergency buoy, designed to release from a submarine automatically when emergency conditions such as rapidly changing pressure or fire are detected and intended to help rescuers locate the stricken vessel, did not deploy. The previous summer, in a Mediterranean mission, fears of the buoy accidentally deploying, and thereby revealing the submarine’s position to the U.S. fleet, had led to the buoy being disabled.
Two minutes and fifteen seconds after the initial eruption, a much larger explosion ripped through the submarine. Seismic data from stations across Northern Europe show that the explosion occurred at the same depth as the sea bed, suggesting that the submarine had collided with the sea floor which, combined with rising temperatures due to the initial explosion, had caused other torpedoes to explode. The second explosion was equivalent to 2-3 tons of TNT, or about a half-dozen torpedo warheads and measured 4.2 on the Richter scale.
The second explosion ripped a 2-square-metre (22 sq ft) hole in the hull of the craft, which was designed to withstand depths of 1,000 metres (3,300 ft). The explosion also ripped open the third and fourth compartments. Water poured into these compartments at 90,000 litres (3,200 cu ft) per second – killing all those in the compartments, including five officers from 7th SSGN Division Headquarters. The fifth compartment contained the ship’s nuclear reactors, encased in a further 13 centimetres (5.1 in) of steel. The bulkheads of the fifth compartment withstood the explosion allowing the two nuclear reactors, which were resiliently mounted to absorb shock in excess of 50g, to automatically shut down preventing nuclear meltdown or contamination.
Later forensic examination of two of the recovered reactor control room casualties showed they had sustained shocks of just over 50g during the explosions. This shock would have temporarily disoriented the reactor control operators, and possibly the other sailors.
Twenty-three men working in the sixth through ninth compartments survived the two blasts. They gathered in the ninth compartment, which contained the secondary escape tunnel (the primary tunnel was in the destroyed second compartment). Captain-lieutenant Dmitri Kolesnikov (one of three officers of that rank surviving) appears to have taken charge, writing down the names of those who were in the ninth compartment. The air pressure in the compartment following the second explosion was still normal surface pressure. Thus it would be possible from a physiological point of view to use the escape hatch to leave the submarine one man at a time, swimming up through 100 metres (330 ft) of Arctic water in a survival suit, to await help floating at the surface. It is not known if the escape hatch was workable from the inside; opinions still differ about how badly the hatch was damaged. However it is likely that the men rejected using the perilous escape hatch even if it was operable. They may have preferred instead to take their chances waiting for a rescue vessel to clamp itself onto the escape hatch.
It is not known with certainty how long the remaining men survived in the compartment. As the nuclear reactors had automatically shut down, emergency power soon ran out, plunging the crew into complete blackness and falling temperatures. Kolesnikov wrote two further messages, much less tidily than before. In the last, he wrote:
“It’s dark here to write, but I’ll try by feel. It seems like there are no chances, 10-20%. Let’s hope that at least someone will read this. Here’s the list of personnel from the other sections, who are now in the ninth and will attempt to get out. Regards to everybody, no need to be desperate. Kolesnikov.”
There has been much debate over how long the sailors might have survived. Some, particularly on the Russian side, say that they would have died very quickly. Water is known to leak into a stationary Oscar-II craft through the propeller shafts, and at 100 metres (330 ft) depth it would have been impossible to plug these. Others point out that the many superoxide chemical cartridges, used to absorb carbon dioxide and chemically release oxygen to enable survival, were found used when the craft was recovered, suggesting that they had survived for several days. Ironically, the cartridges appear to have been the cause of death; a sailor appears to have accidentally brought a cartridge in contact with oily sea water, causing a chemical reaction and a flash fire. The official investigation into the disaster showed that some men appeared to have survived the fire by plunging under the water (the fire marks on the walls indicate the water was at waist level in the lower area at this time). However the fire rapidly used up the remaining oxygen in the air, causing death by asphyxiation
Rescue attempts
Initially the other ships in the exercise, all of which had detected an explosion, did not report it. Each only knew about its own part in the exercise, and ostensibly assumed that the explosion was that of a depth charge, and part of the exercise. It was not until the evening that commanders stated that they became concerned that they had heard nothing from Kursk. Later in the evening, and after repeated attempts to contact Kursk had failed, a search and rescue operation was launched. The rescue ship Rudnitsky carrying two submersible rescue vessels, AS-32 and the Priz (AS-34) reached the disaster area at around 8:40 AM the following morning.
Priz reached Kursk’s ninth compartment the day after the accident, but failed to dock with it. Bad weather prevented further attempts on Tuesday and Wednesday. A further attempt on Thursday again made contact but failed to create a vacuum seal required to dock.
The United States offered the use of one of its two Deep Submergence Rescue Vehicles, as did the British government, but all offers were refused by the Russian government. Four days after the accident on 16 August 2000, the Russian government accepted the British and Norwegian governments’ assistance and a rescue ship was dispatched from Norway on 17 August and reached the site on 19 August. British and Norwegian deep-sea divers reached the ninth compartment escape hatch on Sunday, 20 August. They were able to determine that the compartment was flooded, and all hope of finding survivors was lost

Size and mass comparison of Kursk (top) and Toledo (bottom). Toledo is less than half of the Kursk's displacement.
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Russian government response
The first fax sent from the Russian Navy to the various Press offices said the submarine had “minor technical difficulties”. The government downplayed the incident and then claimed bad weather was making it impossible to rescue the people on board.
On 18 August Nadezhda Tylik, mother of Kursk submariner Lt. Sergei Tylik, produced an intense emotional outburst in the middle of an in-progress news briefing about Kursk’s fate. After attempts to quiet her failed, a nurse injected her with a sedative by force from the back, and she was removed from the room, incapacitated. The event, caught on film, caused further criticism of the government’s response to both the disaster, and how the government handled public criticism of said response.
For President Vladimir Putin, the Kursk crisis was not merely a human tragedy, it was a personal PR catastrophe. Twenty-four hours after the submarine’s disappearance, as Russian naval officials made bleak calculations about the chances of the 118 men on board, Putin was filmed enjoying himself, shirtsleeves rolled up, hosting a barbecue at his holiday villa on the Black Sea.
—Amelia Gentleman,
At first, Russian naval sources expressed suspicion that Kursk had been struck by an American submarine.[5] In its 2002 review of two books on this topic, “Kursk, Russia’s Lost Pride” and “A Time to Die: The Kursk Disaster” The Guardian says: “The hopelessly flawed rescue attempt, hampered by badly designed and decrepit equipment, illustrated the fatal decline of Russia’s military power. The navy’s callous approach to the families of the missing men was reminiscent of an earlier Soviet insensitivity to individual misery. The lies and incompetent cover-up attempts launched by both the navy and the government were resurrected from a pre-Glasnost era. The wildly contradictory conspiracy theories about what caused the catastrophe said more about a naval high command in turmoil, fumbling for a scapegoat, than about the accident itself.”
After Kursk sank, the exercise was canceled and two American Los Angeles-class submarines — USS Memphis (SSN-691) and USS Toledo (SSN-769) — put in at European ports. These two vessels, plus the Royal Navy submarine HMS Splendid, were monitoring the activities of the war games.[6]
French filmmaker Jean-Michel Carré, in Kursk: a Submarine in Troubled Waters,[7][8][9] which aired on 7 January 2005 on French TV channel France 2, alleged that Kursk sank because of a sequence of events triggered by a collision with the US submarine USS Toledo. According to Carré, Kursk was performing tests with Shkval torpedoes and the tests were being observed by two US submarines on duty in the region, USS Toledo and USS Memphis.
Salvage
Most of the submarine’s hull, except the bow, was raised from the ocean floor by the Dutch salvage companies Smit International and Mammoet in late 2001 and towed back to the Russian Navy’s Roslyakovo Shipyard.[1] The bodies of its dead crew were removed from the wreck and buried in Russia – three of them were unidentifiable because they were so badly burned. Russian President Vladimir Putin signed a decree awarding the Order of Courage to all the crew and title Hero of the Russian Federation to the submarine’s captain, Gennady Lyachin
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