A DOCUMENTARY is due to lift the lid on life onboard a Barrow-built nuclear submarine.

Submarine: Life Beneath the Waves spends time with crew on HMS Trenchant during a four month tour of duty to the mid-Atlantic.

The two-part series will start on Channel 5 tonight at 9pm.

It promises to reveal the realities of life spent on a 'claustrophobic' submarine travelling for moths submerged under the water.

In trailers for the series, one crew member says: "Our job is dangerous. We're in a tin can that can go bang at any time."

A description of the programme said: "For the first time British cameras have been given access on board a hunter-killer submarine on live operations.

"Submarine: Life Under the Sea goes on board HMS Trenchant, a nuclear submarine, on its four month tour of duty to the mid-Atlantic to uncover the reality of life at sea.

"Living in extremely close quarters the crew are tasked with helping guard the UK’s Trident missiles and keeping British waters safe."

The Trafalgar-class nuclear-powered submarine was launched by war hero Vice Admiral Sir Arthur Hezlet – commander of the original HMS Trenchant submarine during the Second World War.

The boat sailed home for the final time earlier this year ahead of being decommissioned.

The documentary comes following the BBC thriller Vigil, set on a Vanguard-class Trident submarine, which has been criticised for its inaccuracies.