Text 4. Submarines are a hidden threat to smaller craft

Collisions between submarines and surface vessels are an unfortunate inevitability given to the world's increasingly crowded oceans.

Submarines operate in many busy shipping lanes, and with their immensely strong hulls – built to withstand huge underwater pressure – will always come off the better in the event of a collision.

About 25% of all recorded collisions involving British and American submarines took place in coastal waters, either when a submarine was berthing or in the mouth of a harbour.

Even huge supertankers are not safe from the hidden threat.

In 1993, the French submarine Rubin collided with a supertanker in the Mediterranean. The ship was damaged and oil leaked into the sea.

But incidents involving smaller vessels – often fishing boats – are more common and far more likely to involve loss of life.

In 1989, the USS Houston snagged a towing cable and sank the commercial tugboat Barcona, 10 miles off Long Beach, California. One crewman drowned and two more were rescued.

By the nature of their work, fishing boats run the risk of making a far deadlier catch.

Every year, several instances are recorded of boats being dragged along the surface for miles after ensnaring submarines in their nets.

The results are sometimes fatal – in the Irish Sea from 1980 to 1989, at least 17 trawlers from various countries disappeared without trace claiming 37 lives, often in calm waters.

The levels of secrecy submarines operate under, and the fact that they spend 90% of their time under water, means that many accidents are never properly investigated.

But the US Navy alone receives claims for thousands of dollars of compensation from trawlermen who have had to cut their nets to escape being dragged under.

These accidents occur as the result of the way in which submarines operate. By using active sonar, they are able to accurately identify other vessels around them. However, active sonar gives away the submarine's position – so they often rely on passive sonar. This device provides information which is difficult to interpret, especially if the vessel is carrying out a series of manoeuvres.

The use of passive sonar at shallow depths can mean that submariners are as blind to the threat of collision as those on the surface.

Text 5. Fire aboard Russian submarine kills two

September 7, 2006

A fire on board a Russian nuclear submarine in the Barents Sea killed two crew members but there was no threat of a radiation leak, the Defence Ministry said.

The fire in an electrical equipment room late on Wednesday was away from the submarine's reactor and was put out by the crew, officials said. The vessel, the St Daniil Moskovsky, is being towed back to port.

The Russian navy's safety record has been under scrutiny since the Kursk atomic submarine sank in the Barents Sea six years ago, killing all 118 crew members.

"Our initial information is that the fire broke out in a power distribution panel in compartment No. 6", said a spokesman for Russia's Northern Fleet. "The crew did everything within their power to put out the fire. Two people suffered smoke inhalation from the thick smoke. They were evacuated from the submarine but it was not possible to save their lives".

The vessel is a Viktor class attack submarine which would likely have been carrying torpedoes but not nuclear weapons, said defence experts.

It entered service in 1990, making it one of the fleet's more modern submarines.

The vessel was north of the Rybachiy peninsula near Russia's border with Finland when it caught fire, Interfax news agency quoted navy sources as saying.

It was being taken to Vidyayevo, a Russian submarine base in the Barents Sea. Vidyayevo is about 50 km north of the Russian city of Murmansk, where just under one million people live.

Interfax quoted a navy source as saying: "The device protecting the nuclear reactor was activated. There is no radioactive contamination threat whatsoever".

Russia has the second largest submarine fleet in the world after the United States. Many of its atomic submarines date to the Soviet Union.

Environmental campaigners – and governments in some neighbouring states – worry about the condition of some of the vessels, especially decommissioned atomic submarines that are rusting in docks as they wait to be dismantled.

The same submarine had a fire in its torpedo compartment in 1994, said Nils Bohmer with the Norwegian environmental group Bellona, which tracks Russia's submarine fleet.

"It wouldn't surprise me if the reason for this fire is faulty equipment. The maintenance of the Northern Fleet is slightly neglected because of economic problems", said Bohmer.

Russia's navy has been dogged by accidents, of which the Kursk sinking was the worst in recent years.

Last year, the British navy helped rescue the crew of a Russian navy mini-submarine that was stranded 600 feet down in the Pacific with dwindling air supplies.

In July, the navy reported a spill of radioactive water on one of its submarines during repairs at Vidyayevo.

"This incident shows once again that we are faced with a very serious question: should we have these reactors at sea at all?" said Vladimir Tchouprov, head of the energy unit at Greenpeace Russia.

Bellona said its records showed the St Daniil Moskovsky had a crew of between 85 and 100 men.