The Russian nuclear submarine K-141 Kursk 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 (Oscar II 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; it took more than 16 hours to locate the submarine, which rested on the ocean floor at a depth of 108 metres (354 ft).
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 (HTP) 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 the 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 without melting down. 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 3,000 t (3,000 long tons; 3,300 short tons) 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 undertaken 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 aircraft.
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 (SS-N-19 "Shipwreck") 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 (SS-N-16 "Stallion") 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 8 mm (0.3 in) steel plate covered by up to 80 mm (3 in) of rubber, which minimised other submarines' or surface
vessels' ability to detect the submarine. The inner pressure hull was made of high-quality 50 mm (2 in) steel plate. The two hulls were separated by a 1-to-2 m (3-to-7 ft) gap. The inner hull was divided into nine water-tight compartments. The boat was 155 m (509 ft), 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" ("Good"). After considerable delay, the submarine was set to fire two dummy torpedoes at the Kirov-class battlecruiser Pyotr Velikiy. At 11:29 local time, the torpedo room crew loaded the first practice Type 65 "Kit" torpedo, (Russian: tolstushka, or "fat girl", because of its size), without a warhead, into Kursk's number-4 torpedo tube on the starboard side. It was 10.7 m (35 ft) long and weighed 5 t (4.9 long tons; 5.5 short tons).
Initial seismic event detected
At 11:29:34 (07:29:34 GMT), seismic detectors at the Norwegian seismic array (NORSAR) 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 69°38′N 37°19′E / 69.633°N 37.317°E, north-east of Murmansk, approximately 250 km (160 mi) from Norway, and 80 km (50 mi) 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 69°36.99′N 37°34.50′E / 69.61650°N 37.57500°E, showed that in a little over 2 minutes the boat had moved about 400 m (1,300 ft) from the site of the initial explosion. It was enough time for the submarine to sink to a depth of 108 m (354 ft) 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.
The Northern Fleet duty officer notified the head of the fleet's search and rescue forces, Captain Alexander Teslenko, to stand by for orders. The primary rescue ship under Teslenko's command 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 India-class submarines, each of which carried a pair of Poseidon-class DSRVs that could reach a depth of 693 m (2,270 ft), 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.
Rumours among family members
Early on Sunday morning, 13 August, at the Vidyaevo Naval Base, rumours began to circulate among family members of Kursk's crew that something was wrong. A telephone operator handled an unusual volume of calls and overheard that a submarine was in trouble and the boat's name. As the base was very small, news spread quickly. Wives and family members exchanged news, but information was scarce. The deputy base commander assured the women that the headquarters office was half empty and that the officers present were just "passing the time."
Foreign assistance refused
On the afternoon of the explosion, before the Kremlin had been informed of the submarine's sinking, U.S. National Security Adviser Sandy Berger and Defense Secretary William Cohen were told that Kursk had sunk. Once officially informed, the British government, along with France, Germany, Israel, Italy, and Norway, offered help, and the United States offered the use of one of its two DSRVs, but the Russian government refused all foreign assistance. Minister of Defence Igor Sergeyev told the American Embassy that the rescue was well under way. The Russian Navy told reporters that a rescue was imminent.
Russian rescue efforts falter
At 04:50 on Sunday, 13 August, personnel aboard Pyotr Velikiy detected two anomalies on the seabed that might be the boat. At 09:00, Mikhail Rudnitsky arrived at the location. While setting anchor, its crew interpreted an acoustic sound as an SOS from the submarine, but soon concluded the noise had been produced by the anchor chain striking the anchor hole. At 11:30, Mikhail Rudnitsky prepared to lower the AS-34, which entered the water at 17:30. At 18:30, at a depth of 100 m (300 ft) and at a speed of 2 kn (3.7 km/h), the AS-34 reported colliding with an object, and through a porthole, the crew saw the Kursk's propeller and stern stabiliser. With the AS-34 damaged by the collision and forced to surface, the crew of Mikhail Rudnitsky began preparing the AS-32 for operation.
At 22:40, the AS-32 entered the water and began searching for Kursk. It failed to locate the submarine because it had been given an incorrect heading by personnel aboard Pyotr Velikiy. Crew aboard Mikhail Rudnitsky tried to contact Kursk and briefly thought they heard an acoustic SOS signal, but this was determined to be of natural origin. They reported the sounds to Pyotr Velikiy. The AS-32 returned to the surface at 01:00 on Monday morning, 14 August.
The salvage tug Nikolay Chiker (SB 131) arrived early in the rescue operation. Using deep-water camera equipment, it obtained the first images of the wrecked submarine, which showed severe damage from the sub's bow to its sail. Kursk was listing at a 25-degree angle and down 5–7 degrees by the bow. The bow had ploughed about 22 m (72 ft) deep into the clay seabed, at a depth of 108 m (354 ft). The periscope was raised, indicating that the accident occurred when the submarine was at a depth of less than 20 m (66 ft).
The AS-34 was repaired and was launched at 05:00 on Monday. At 06:50, the AS-34 located Kursk and tried but failed to attach to the aft escape trunk over Kursk's ninth compartment. Unable to create the vacuum seal necessary to attach to the escape trunk, its batteries were quickly depleted and the crew was forced to surface. No spare batteries were available, so the crew was forced to wait while the batteries were recharged. Meanwhile, winds increased, blowing 10–12 m/s (19–23 kn) to 15–27 m/s (29–52 kn), and the waves rose to 3–4 points (4–8 ft; 1.2–2.4 m), forcing the Russians to suspend rescue operations.
First official announcement
The first official announcement of the accident was made by the Russian government on Monday, 14 August. They told the media that Kursk had had "minor technical difficulties" on Sunday. They stated that the submarine had "descended to the ocean floor", that they had established contact with the crew and were pumping air and power to the boat, and that "everyone on board is alive." The BBC reported that the Kursk crew "had been forced to ground" the submarine because it "[had] broken down during exercises," but rescue crews were "in radio contact with surface vessels."
Collision initially blamed
Senior officers in the Russian Navy offered a variety of explanations for the accident. Four days after Kursk sank, Russian Navy Commander-in-Chief and Fleet Admiral Vladimir Kuroyedov stated the accident had been caused by a serious collision. Vice-premier Ilya Klebanov said the submarine might have hit an old World War II mine. He also said that almost all of the sailors had died before the vessel hit bottom.
The Russian government convened a commission, chaired by Vice-Premier Ilya Klebanov, on 14 August, two days after Kursk sank. Nearly half of the commission members were officials with a stake in the outcome of the investigation. Independent investigators were not invited to take part, giving the appearance that the commission's findings might not be impartial.
Weather delays efforts
Bad weather, 3.7 m (12 ft) waves, strong undersea currents, and limited visibility impaired the rescue crews' ability to conduct operations on Tuesday and Wednesday. On Tuesday Mikhail Rudnitsky lowered a diving bell twice, but could not connect to the sub. They also tried and failed to manoeuvre a remotely operated vehicle onto the rescue hatch.