Two British sailors die and one hurt in submarine explosion

TWO British sailors were killed and another injured yesterday in an explosion on board a nuclear submarine during an exercise in the Arctic.

The accident occurred when a chlorate candle, used to produce oxygen, exploded during a training exercise.

The Ministry of Defence said the nuclear reactor on board HMS Tireless was unaffected by the accident, which happened at the front of the vessel.

The submarine, which carries only conventional weapons, "quickly surfaced and is completely safe", the MoD said.

The accident took place at 4:20am yesterday, while the submarine was under the Arctic icecap during a joint British-US exercise, about 170 miles north of Alaska.

The MoD said one sailor was killed instantly by the force of the blast, while the other died after inhaling poisonous fumes.

Chlorate candles have been used to create oxygen on submarines since the Second World War, usually as an emergency measure if the vessel's rises to dangerous levels. According to the navy source, one such candle was ignited yesterday on board HMS Tireless, as a part of training.

He added: "Something went wrong. It's not clear yet what happened, and whether the ratings [non-commissioned sailors] died from the force of the explosion or from burns. The boat had to breach the ice cap, which its crew are trained for, and it was able to do so without any problem."

The 23-year-old HMS Tireless is based in Devonport, Plymouth. The MoD did not release details of where the victims came from. However, it is understood at least one was from the north of England. The families of both dead sailors were informed of the accident last night, the MoD said.

The injured sailor, who was airlifted to a hospital in Alaska, was in a stable condition.

An MoD spokesman said the chlorate candles on board HMS Tireless had never failed before and, until then, had a 100 per cent safety record. Even so, their use on other boats had been restricted until safety checks could be carried out, he said.

A former sailor on British nuclear submarines insisted chlorate candles are known by crew to be dangerous. The mariner, who asked not to be named, said: "It's not a candle like you'd think - there's no open flame. It's ignited in a metal canister with a .22 bullet and they burn without any flame.

"Everyone on board will have been trained how to use them. They have definitely been known to explode before - high heat and oxygen is a combustible mix - but I couldn't imagine the force would have killed two men. Something else must have gone wrong.

"The candles line the entire sub and are used in an emergency. Next to each is a pair of asbestos gloves and a bucket of water. If you see the candle is starting to flame or burn, you simply put on the gloves and dump it into the water.

"Clean air is your primary concern on a sub and fire is the primary threat. It doesn't take a lot for things to go wrong. It's a very dangerous work environment."

Admiral Sir James Burnell- Nugent, the admiral of the fleet of the Royal Navy, offered his sympathy to the families of the men who died and paid tribute to the crew of HMS Tireless.

He said: "I very much regret that this incident has occurred, and my thoughts go out to the family and friends of the men who have lost their lives.

"I also wish to pay tribute to the crew of HMS Tireless that this incident has been dealt with and contained so professionally."

The accident is the latest in a series of incidents to affect HMS Tireless, which usually carries a crew of 130.

In 2000, all Britain's hunter-killer nuclear submarines were given intensive inspections following the discovery of a fault on board Tireless.

The vessel had limped into Gibraltar in May that year with a leak in pipework leading from the nuclear reactor system.

Then, in 2003 it suffered minor damage to its ballast tank during a collision with a submerged object.

The Tireless was testing operability in Arctic waters with the USS Alexandria. Since 1986, every Arctic tactical exercise has involved US Navy and Royal Navy submarines.

• A CHLORATE candle, or oxygen candle, is a cylindrical chemical oxygen generator containing a mix of sodium chlorate and iron powder. When ignited, the mixture smoulders at about 600C, and releases about 6.5 man-hours of oxygen per kilo of the mixture.

The candles have an indefinite shelf life if stored properly and have a good safety record. They are used in submarines, planes, and spacecraft. However, the candles have been involved in two high-profile incidents in the past 20 years.

On 11 May, 1996, an US airliner en route from Miami to Atlanta exploded when a case of the candles accidentally ignited.

The oxygen released by the candles led to a fire in the aircraft's hold. The hold's fire-protection system was limited to a no-oxygen environment, in which fires were expected to burn themselves out. All 110 on board ValuJet Flight 592 died.

On 23 February, 1997, during the exchange of an air filter on the Mir space station, a chlorate candle spewed a torch-like jet of a molten metal and sparks across one of the space station modules, burning for 14 minutes and blocking the escape route to one of the Soyuz spacecraft. There were no injuries.