A British nuclear submarine suffered £500,000 damage in a collision while tracking Russian vessels , The Mail on Sunday can reveal . A British nuclear submarine suffered £500,000 damage in a collision while tracking Russian vessels , The Mail on Sunday can reveal . The 5,300-ton HMS Talent limped back to port with a huge dent and will be out of action for several months . Royal Navy top brass are investigating the incident . Last night , defence officials refused to disclose exact details of the crash – including where or when it happened – but they were adamant that HMS Talent struck ‘ floating ice ’ rather than a Russian sub . But the collision , which ripped a 6ft hole at the top of the conning tower , comes at a time of heightened tension between Britain and Russia in the airspace over the North Sea and beneath the waves . Britain is understood to be mounting frequent patrols of the North Sea and areas as far north as the Arctic Circle , while the Russians have increased their submarine activity by half in the past 18 months . Navy sources say the damage to the nuclear-powered submarine , which will cost as estimated £500,000 to repair , is consistent with striking an object while trying to surface . Surfacing can be a risky manoeuvre because sonar equipment on a submarine tends to look ahead for threats rather than above . In addition , radar scanners do not work underwater . After the crash , engineers from HMS Talent ’ s 130-strong crew found that the impact had devastated the submarine ’ s outer layer of acoustic tiles . These square-shaped 2in-thick tiles minimise the vessel ’ s transmission of sound waves and other signals that could reveal her position . The Royal Navy ’ s explanation that HMS Talent struck ice was also used to explain damage to British submarines during the Cold War which was later found to have been caused by enemy vessels . In 1981 , the crew of HMS Sceptre were ordered to say they had hit an iceberg after their collision with the Russian submarine K-211 . HMS Talent , which was launched in 1988 , is a ‘ hunter-killer ’ submarine used to attack ships and other submarines , and also to perform a surveillance role . She is fitted with Tomahawk cruise missiles , cameras and thermal imaging periscopes . In 2009 , she suffered loss of primary and alternative power supplies to her nuclear reactors . Navy sources insist there was no such power problem on this occasion . Scroll down for video . The 5,300-ton HMS Talent limped back to port with a huge dent and will be out of action for several months . Above , the submarine is pictured before the crash off the Egyptian coastline . A Navy source said : ‘ Striking ice is a problem of the environment we work in . Some patches of ice show up on our scanners but not all , with the density of the ice also being a factor . On this occasion some damage was sustained by HMS Talent . ‘ A submarine is a very pressured environment and a lot can go wrong . You ’ re in a tin can under the sea tracking Russian subs and trying not to get found ourselves . HMS Talent ’ s captain , helmsman and her officers will have been making multiple calculations simultaneously and working in very testing conditions. ’ The activity of Britain ’ s fleet of nuclear submarines is strictly classified . Last night , the Royal Navy would say only that the incident happened last year . The submarine was photographed last month on her arrival at the Submarine Refit Complex at Devonport , where the repairs are taking place . A Royal Navy spokesman said : ‘ HMS Talent suffered minor superficial damage after striking some floating ice last year . She remained fully operational and continued with her deployment . ’
5,300-ton HMS Talent has a huge dent and will be out of action for weeks . Defence officials have refused to disclose exact details of the crash . Comment: The ship was carrying nuclear weapons, which is why it crashed in the first place.