FIRE SAFETY: The Kursk

Not every dream that comes true is a good thing.

It’s been said that a submariner’s worst nightmare is to be trapped on the ocean floor. The nightmare became a reality for Russian sailors during the worst submarine disaster in recent history.

On August 9, 2000, the Kursk, a Russian nuclear powered submarine, left Severomorsk Naval Base in the Barents Sea. The next day, it joined the rest of Russia’s Northern Fleet for a series of war games. At 9 a.m., August 12, the Kursk made its final radio contact. It received orders to carry out a mock attack on the Russian ships. The fleet waited. The attack never came.

The Kursk was described by Norman Polmar, a U.S. naval analyst, as being “one of the most potent, anti-ship weapons ever developed.” It was six stories tall, 500 feet long, made use of a double hull design and was separated into nine watertight compartments. The Kursk was built to take a direct hit and still survive. But on August 14 the Russians admitted that for two days the Kursk had been lying at the bottom of the Barents Sea, unreachable by radio. Russia confirmed that a powerful blast of an unknown origin destroyed the Kursk. On a television documentary, “Kursk: Disaster at Sea,” Commander Viktor Rozhkov, captain of the Kursk from 1991 to 1997, said: “You can’t take the Kursk out; even with a torpedo.”

The U.K., U.S., and other countries immediately offered their assistance in rescuing any possible survivors. The Russians first attempted their own rescue operation; but after two days of failure, they asked the U.K. and Norway for help. The British rescue submersible, the LR5, arrived at the scene on August 19. For reasons unknown, however, the Russians did not permit the British to descend to the Kursk. The Americans, who operate the Avalon, a rescue submersible capable of transporting 24 survivors, were not contacted.

It was later discovered that of the 118 crew members, 23 had survived for at least 100 minutes after the blasts by locking themselves in the ninth compartment. There, the survivors waited, trapped on the bottom, hoping for a rescue that would never come — at least not in time. Even if the Russians had allowed the British or the Americans to help in the rescue operation it does not seem likely that the Kursk crew would have survived. Still, this is the kind of uncertainty that keeps the families of the deceased awake at night, wondering what might have been.

The Russians held two theories as to what caused the disaster. The first theory was that a Kursk torpedo had exploded in the hull — a theory that has found international support. The second theory was that a submarine collided with the Kursk. Video footage from the disaster showed the hull had been ripped open and the Russians claimed this was evidence of an American submarine collision with the Kursk. The collision theory seemed plausible. According to retired Admiral Valery Aleksin of the Russian Navy, “a total of 25 collisions have been recorded since 1967. And many of these, 11, occurred near the naval base in the Barents Sea.” The Russians provided a military satellite photograph showing an American sub docked at a Norwegian port six days after the Kursk sank, where the Russians claimed it was being repaired after the collision. The Americans denied the claim and it appeared that the answer to what happened on the Kursk disaster would remain a secret.

The Kursk investigation turned a new corner when seismologists at the Blacknest Seismic Research Centre in Berkshire, England, made a breakthrough discovery. The seismic monitoring station is capable of detecting nuclear and other explosions any where in the world, and on August 12, 2000 it recorded an event equivalent to a measurement of four on the Richter scale. Blacknest concluded this event was the explosion of the torpedo warheads, which resulted in the hull being ripped open. But they soon found something even more interesting. Dr. Peter Marshall of Blacknest said,”two minutes and 15 seconds before the large event arrived, there was indeed another much smaller event from the same area.” This first event turned out to be only one per cent of the size of the second event (the warhead explosion) and it provided a clue as to what happened on that fateful day.

The Russians assumed the first event was the collision with an American sub and that the second event was the resulting explosion of the warheads. Dr. Marshall’s team enlarged the seismic signal of the first event and superimposed it with the signal of the second –and larger — event. If the two signals were different it might show that the Russians were correct that the first event was not an explosion and was, possibly, a signal of a collision with an American vessel. But what Dr. Marshall’s team noticed was that the signals matched extremely well. This discovery was remarkable because seismic signals are rarely the same size and shape. The two seismic signals proved that the first event was not a collision. It, too, was an explosion.

The investigation now needed to determine what could have caused the initial, smaller blast in the front compartment of the Kursk. Theories that there was an explosion of the reactor core or the warheads were dismissed because they would have created an explosion greater than the signal from the seismic graphs.

An incident on a British submarine almost half a century earlier, on June 16, 1955, gave a clue as to the most likely cause of the Kursk disaster.

On that day, the British submarine HMS Sidon loaded an experimental torpedo carrying hydrogen peroxide (HTP) while docked in England. The torpedo exploded, killing 13 people. In researching this earlier catastrophe, the investigators of the Kursk learned that when HTP comes into contact with metal it breaks down and produces water and oxygen. When it changes to a gas phase it expands in volume by a factor of 5,000. The connecting point was that the Kursk had torpedoes that also used HTP.

Torpedo designer Maurice Stradling told the British Broadcasting Corporation, “If the torpedo was accidentally started [before launching], then because the propellers were not in the water there would be nothing to control the speed of the engine. The engine would have over-revved and the HTP pipe would have burst. HTP would have sprayed into the hull of the torpedo.” He went on to explain that the HTP would then have reacted with the metal. The resulting gas build-up would have created an enormous pressure within the casing of the torpedo. The casing would have exploded and a fireball of torpedo fuel and oxygen would have raged around the warheads. The first seismic signal was likely from an explosion of a burst torpedo casing. The second seismic signal came two minutes and 15 seconds later when the fire set off the warheads.

After the explosion, Lieutenant Kolesnikov and 22 other sailors barricaded themselves in the ninth compartment. Kolesnikov wrote a note to his new bride. He recorded his final thoughts about the incident. “None of us can get to the surface,” he wrote. “It seems as though we’ve got little chance. No more than 10 or 20 per cent.”

Most of the Kursk has already been raised, and plans were under way to lift the bow by mid-summer 2002. But on June 19, 2002, CNN reported that Russia, without having raised the bow, confirmed that a faulty torpedo, and not a collision or a mine, was to blame for the accident. The investigation of the Kursk disaster has been officially closed by Russian Prosecutor General Vladimir Ustinov. Loved ones of the victims, however, are not accepting the report issued by the Russian Navy, claiming that it implies the crew is to blame for the disaster.

What we are left with is a plausible theory about what happened to Russia’s nuclear submarine, but not a definitive answer. We may never know with absolute certainty the answer to what went wrong on the Kursk. But it’s a question that 23 sailors, trapped at the bottom of the Barents Sea with their air running out, probably thought about during their last 100 minutes.

Paul H. Boge, P. Eng. is an engineer with Boge & Boge in Winnipeg
. He also writes technical articles, film reviews, and novels.

Resources

The Learning Channel: “Kursk: Disaster at Sea,” and “Extreme Machines: Submarines”

BBC News online, August 30, 2000, August 7, 2001, July 31, 2002.

CNN.com, November 16, 2001, June 19, 2002