AN INVESTIGATION is under way into how the UK's most sophisticated nuclear submarine managed to run aground off the Isle of Skye. At high tide last night, the £1.2 billion HMS Astute finally left the shale and silt seabed where the 7,800-tonne vessel had been marooned for about 11 hours.
• HMS Astute sits almost in the shadow of the Skye Bridge yesterday, after running aground while transferring crew to shore Picture: Ken MacPherson
The grounding of Astute, stranded within full view of the Skye Bridge yesterday morning, also led to fears that the accident could have compromised the security of the brand new hunter-killer ship, which has been hailed as the most powerful attack submarine in the fleet when it was officially commissioned just two months ago.
The Royal Navy has launched a service inquiry into why a 100-metre long submarine that is supposed to be able to circumnavigate the globe undetected suddenly came to grief in the narrow channel between Skye and Kyle of Lochalsh.
Interested onlookers gathered on the nearby shore throughout the day and watched as the Royal Navy spent futile hours trying to wrest the stricken vessel from its cradle of shale.
Ross McKerlich, who runs a guest house in Kyleakin and is operations manager for the Kyle lifeboat, said: "When I woke up this morning and looked out my bedroom window I could see the submarine.
"It is certainly not something you see every day out of your window."
Although it is not yet known whether the accident was caused by a technological failure or human error, military prosecutors are expected to consider whether HMS Astute's skipper Andy Coles or any of his crew was negligent and ought to face a court martial.
Navy spokesman Captain Karl Evans said: "There will clearly be a full investigation in due course into the incidents leading up to this untoward event."
A defence source said it was likely that Cmdr Coles, as the officer in ultimate charge of the advanced nuclear-powered submarine, would face a court-martial.
The service inquiry, to be carried out by specialists in navigation and naval engineering, will look in painstaking detail at the incident.
Royal Navy police could also carry out a criminal investigation into whether any offences were committed under the Armed Forces Act 2006.
The Service Prosecuting Authority, the military equivalent of the Crown Prosecution Service, would then decide whether there is enough evidence to bring anyone before a court-martial.
The submarine, which was commissioned by the Duchess of Cornwall only in August at a ceremony on the banks of the Clyde, had travelled north from her base at Faslane and was taking part in the sea trials she has to undergo before going into service next year.
The ship was patrolling in a narrow channel, which is commonly used for such trials, and had drifted outside marker buoys that are in place to indicate when boats are at risk of running aground.
She became stuck on a shingle bank at about eight o'clock yesterday morning when the tide went out, as the submarine was transferring crew to shore.
There were no reports of any injuries and the Ministry of Defence said it was not a "nuclear incident".
Mike Critchley, a former naval officer and the editor of Warship World magazine, said the accident was likely to have been caused by a navigation error or technical failure of the steering gear.
"She was a long way out of where she should have been to do this transfer. It was 800 yards away from where it should have been and grounded in shale and silt and not jagged rocks.
"There will certainly be a board of inquiry into what went wrong. The MoD will have to speak to the captain on board. You don't put one of the world's best submarines aground without there being inquiries into what happened."
Defence experts last night also expressed concern that the submarine's unique design was exposed for such a long time. Normally, the shape and make-up of such important vessels are kept a closely guarded secret, as such information can help foreign powers to detect them when they are underwater.
Tim Ripley, a defence analyst for Jane's Defence Weekly, said: "This is so embarrassing, because this is the Royal Navy's newest, most expensive and best submarine that's ever been built. For whoever was in charge of HMS Astute, this will be an extremely testing time.
"There is an issue with security. A large part of it is above water, and it is the shape of the submarine that determines its underwater acoustics. It is the bumps and shapes of the hull and the shape of any propellers, if that is seen above water, then someone can work out what it sounds like under water - that is the bit that's really sensitive. You have to be extremely careful."
Although HMS Astute is nuclear-powered, it does not carry nuclear weapons.
Nevertheless, there was concern about the vessel itself, with reports suggesting that the rudder could have been damaged on the shingle. It is thought that the hull escaped harm.
"At some point, she touched the rudder on the bottom and they weren't able to get her off immediately," a navy spokesman said.
"There are no nuclear issues, no environmental impact, no injuries to people - potential damage to the rudder, that's about it," the spokesman said.
An inspection of the submarine will be carried out today now that she has been towed into deeper waters. The journey back to its base at Faslane on the Clyde could take several days.
Rescuers had to wait until high tide at 7pm last night before the submarine became dislodged.
Two tugs attached lines to her and pulled her free. It was second rescue attempt of the day.
As Britain's most advanced submarine, the new class of vessel escaped the severe defence cuts announced by the government this week, which saw the Royal Navy's surface fleet reduced from 23 destroyers and frigates to 19. There are plans to go ahead with a total of seven Astute-class submarines to be built by BAE systems.
HMS Astute was one of the first three ships in its class to be built to replace the Trafalgar class submarines.
According to the Royal Navy's website, HMS Astute is supposed to be able to sit off the coast undetected, delivering the UK's special forces where needed or even listening to mobile phone conversations.
The 39,000 acoustic panels which cover its surface mask its sonar signature, meaning it can sneak up on enemy warships and submarines alike, or lurk unseen and unheard at depth.
The submarine can carry a mix of up to 38 Spearfish heavyweight torpedoes and Tomahawk Land Attack cruise missiles, which are able to target enemy submarines, surface ships and land targets from 1,240 miles with conventional weapons.
The submarine's nuclear reactor means that it will not need refuelling once in its entire 25-year life, and it makes its own air and water, enabling it to circumnavigate the globe without needing to surface.
Yesterday was not the first time a British nuclear submarine has run aground off north-west Scotland.
In 2002, HMS Trafalgar got into trouble off Skye during a military exercise. Two years later, two crew members were reprimanded for negligence at a court martial.
HMS Astute has been based since last November at HM Naval Base Clyde, at Faslane on the Gare Loch, around 25 miles north-west of Glasgow.
The vessel was built amid unprecedented security measures at the BAE Systems yard in Barrow, Cumbria, over the previous eight years.
Ministry of Defence bosses would not even say in advance when Astute was due to sail from Barrow's giant dock before she made the journey in November.
Even inside the yard, parts of its hull and sonar systems were concealed behind sheeting to keep the top-secret features secure from prying eyes.
It has been specially designed to carry out anti-ship and anti-sub operations, as well as surveillance, intelligence gathering and support for land forces.
Its 39,000 acoustic panels which cover its surface mask its sonar signature, meaning it can sneak up on enemy warships and submarines alike, or lurk unseen and unheard at depth.
A COURT martial was ordered after more than 5 million worth of damage was caused when the nuclear-powered submarine HMS Trafalgar ran aground off Skye in November 2002.
Three crew members were injured when the vessel hit a small island 500 metres off north-west Skye.
A hearing in 2004 heard how the submarine ploughed into the seabed while trying to change direction.
The navigation was being carried out by Lieutenant Commander Tim Green, who was training to become the commander. The two officers were reprimanded after pleading guilty to a charge of negligence over the incident.