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HMS Artful: Time-lapse video shows submarine entering water

21 May 2014 Last updated at 11:55 BST

Time-lapse footage has been released of HMS Artful being lowered into the water in Cumbria.

The third Astute Class submarine is one of seven nuclear-powered vessels being built by BAE Systems in Barrow.

The 97m-long 7,400-tonne attack submarine, which was officially named at a ceremony in September, will now undergo tests to prove its systems work properly before sea trials in 2015.

BAE Systems said it was a significant step forward in the Astute programme.