Kursk submarine disaster
The Russian nuclear submarine sank in an accident on 12 August 2000 in the Barents Sea, with the death of all 118 personnel on board. The submarine, which was of the Project 949A-class, was taking part in the first major Russian naval exercise in more than 10 years. The crews of nearby ships felt an initial explosion and a second, much larger explosion, but the Russian Navy did not realise that an accident had occurred and did not initiate a search for the vessel for over six hours. The submarine's emergency rescue buoy had been intentionally disabled during an earlier mission and it took more than 16 hours to locate the submarine, which rested on the ocean floor at a depth of.
Over four days, the Russian Navy repeatedly failed in its attempts to attach four different diving bells and submersibles to the escape hatch of the submarine. Its response was criticised as slow and inept. Officials misled and manipulated the public and news media, and refused help from other countries' ships nearby. President Vladimir Putin initially continued his vacation at a seaside resort in Sochi and authorised the Russian Navy to accept British and Norwegian assistance only after five days had passed. Two days later, British and Norwegian divers finally opened a hatch to the escape trunk in the boat's flooded ninth compartment, but found no survivors.
An official investigation concluded that when the crew loaded a dummy 65-76 "Kit" torpedo, a faulty weld in its casing leaked high-test peroxide inside the torpedo tube, initiating a catalytic explosion. The torpedo manufacturer challenged this hypothesis, insisting that its design would prevent the kind of event described. The explosion blew off both the inner and outer tube doors, ignited a fire, destroyed the bulkhead between the first and second compartments, damaged the control room in the second compartment, and incapacitated or killed the torpedo room and control-room crew. Two minutes and fifteen seconds after the first explosion, another five to seven torpedo warheads exploded. They tore a large hole in the hull, collapsed bulkheads between the first three compartments and all the decks, destroyed compartment four, and killed everyone still alive forward of the sixth compartment. The nuclear reactors shut down safely. Analysts concluded that 23 sailors took refuge in the small ninth compartment and survived for more than six hours. When oxygen ran low, they attempted to replace a potassium superoxide chemical oxygen cartridge, but it fell into the oily seawater and exploded on contact. The resulting fire killed several crew members and triggered a flash fire that consumed the remaining oxygen, asphyxiating the remaining survivors.
The Dutch company Mammoet was awarded a salvage contract in May 2001. Within a three-month period, the company and its subcontractors designed, fabricated, installed, and commissioned over of custom-made equipment. A barge was modified and loaded with the equipment, arriving in the Barents Sea in August. On 3 October 2001, some 14 months after the accident, the hull was raised from the seabed floor and hauled to a dry dock. The salvage team recovered all but the bow, including the remains of 115 sailors, who were later buried in Russia. The government of Russia and the Russian Navy were intensely criticised over the incident and their responses. A four-page summary of a 133-volume investigation stated "stunning breaches of discipline, shoddy, obsolete and poorly maintained equipment", and "negligence, incompetence, and mismanagement". It stated that the rescue operation was unjustifiably delayed and that the Russian Navy was completely unprepared to respond to the disaster.
Naval exercise
On the morning of 12 August 2000, Kursk was in the Barents Sea, participating in the "Summer-X" exercise, the first large-scale naval exercise planned by the Russian Navy in more than a decade, and also its first since the dissolution of the Soviet Union. According to the Russian press, the exercise involved more than 50 ships and submarines, 40 support vessels, and around 80 airplanes and helicopters.Kursk had recently won a citation for its excellent performance and been recognised as having the best submarine crew in the Northern Fleet. Although this was an exercise, Kursk loaded a full complement of conventional combat weapons. It was one of the few submarines authorised to carry a combat load at all times. The Oscar II Class submarines are equipped with 24 P-700 Granit cruise missiles. In addition, since the torpedo tubes can fire both torpedoes and anti-ship missiles, it also carried two dozen other weapons, including the RPK-6 Vodopad/RPK-7 Veter missiles.
Kursk had an almost mythical standing. It was reputedly unsinkable and, it was claimed, could withstand a direct hit from a torpedo. The outer hull was constructed using steel plate covered by up to of rubber, which minimised other submarines' or surface
vessels' ability to detect the submarine. The inner pressure hull was made of high-quality steel plate. The two hulls were separated by a gap. The inner hull was divided into nine water-tight compartments. The boat was, about as long as two jumbo jets.
At 08:51 local time, Kursk requested permission to conduct a torpedo training launch and received the response "Dobro". After considerable delay, the submarine was set to fire two dummy torpedoes at the . At 11:29 local time, the torpedo room crew loaded the first practice Type 65 "Kit" torpedo,, without a warhead, into Kursks number-4 torpedo tube on the starboard side. It was long and weighed.
Initial seismic event detected
At 11:29:34, seismic detectors at the Norwegian seismic array and in other locations around the world recorded a seismic event of magnitude 1.5 on the Richter scale. The location was fixed at coordinates, north-east of Murmansk, approximately from Norway, and from the Kola Peninsula.Secondary event
At 11:31:48, 2 minutes and 14 seconds after the first, a second event, measuring 4.2 on the Richter scale, or 250 times larger than the first, was registered on seismographs across northern Europe and was detected as far away as Alaska. The second explosion was equivalent to 2–3 tons of TNT.The seismic data showed that the explosion occurred at the same depth as the sea bed. The seismic event, triangulated at, showed that in a little over 2 minutes the boat had moved about from the site of the initial explosion. It was enough time for the submarine to sink to a depth of and remain on the sea floor for a short period.
Rescue response
The crew of the submarine Karelia detected the explosion, but the captain assumed that it was part of the exercise. Aboard Pyotr Velikiy, the target of the practice launch, the crew detected a hydroacoustic signal characteristic of an underwater explosion and felt their hull shudder. They reported the phenomenon to fleet headquarters but their report was ignored.The schedule for Kursk to complete the practice torpedo firing expired at 13:30 without any contact from the sub. Accustomed to the frequent failure of communications equipment, Fleet Commander Admiral Vyacheslav Alekseyevich Popov, aboard Pyotr Velikiy, was not initially alarmed. The ship dispatched a helicopter to look for Kursk, but it did not find the sub on the surface; this was reported to Popov.
File:AS-28 Priz.png|thumb|Russian sailors on the surface aboard the DSRV AS-28 Priz
The Northern Fleet duty officer notified the head of the fleet's search and rescue forces, Captain Alexander Teslenko, to stand by for orders. Teslenko's primary rescue ship was a 20-year-old former lumber carrier, Mikhail Rudnitsky, which had been converted to support submersible rescue operations. Teslenko notified the ship's captain to be ready to depart on one hour's notice. Berthed at the primary Northern Fleet base at Severomorsk, the ship was equipped with two AS-34 and AS-32 Priz-class deep-submergence rescue vehicles, a diving bell, underwater video cameras, lifting cranes, and other specialised gear, but it was not equipped with stabilisers that could keep the vessel in position during stormy weather, so it could lower its rescue vessels only in calm seas. The Russian Navy had previously operated two s, each of which carried a pair of Poseidon-class DSRVs that could reach a depth of, but due to a lack of funds, the vessels had been held since 1994 in a Saint Petersburg yard for pending repairs.
At 17:00, an Ilyushin Il-38 aircraft was dispatched. The crew spent three hours searching for Kursk, without success. At 18:00, more than six hours after the initial explosion, Kursk failed to complete a scheduled communication check. The Northern Fleet command became concerned and tried to contact the boat. After repeated failures, at 18:30, they began a search-and-rescue operation, dispatching additional aircraft to locate the submarine, which again failed to locate the boat on the surface. At 22:30, the Northern Fleet declared an emergency, and the exercise was stopped. Between 15 and 22 vessels of the Northern Fleet, including about 3,000 sailors, began searching for the submarine. The Mikhail Rudnitsky left port at 00:30.
Official government response
The Russian Navy initially downplayed the incident. Late on Saturday night, nine hours after the boat sank, Northern Fleet commander Admiral Popov ordered the first search for the submarine. Twelve hours after it sank, Popov informed the Kremlin, but Minister of Defence Igor Sergeyev did not notify Putin until 07:00 Sunday morning. Sergeyev "did not recommend" that Putin visit the disaster site.On Sunday, after Popov already knew that Kursk was missing and presumed sunk, he briefed reporters on the progress of the naval exercise. He said the exercise had been a resounding success and spoke highly of the entire operation.