First dive for Astute

First in class Royal Navy nuclear submarine, Astute, built by BAE Systems, has successfully completed two days of underwater tests of her systems at Devonshire Dock, Barrow.

The 'Trim and Basin Dive' took place over 30-31 October, and involved submerging Astute in a dive hole large enough for the 100m long, 7,400 tonne boat. The dive was the first time that the submarine has been fully submerged.

A Royal Navy crew of 60 worked alongside BAE Systems technicians to carry out the tests. These involved trials of various boat systems and equipment, including the mechanism that releases an emergency buoy, the emergency escape tower, and various hydraulics and electrical systems.

One of the main tools used to assess her performance was a simple plumb line, suspended on up to 8m of wire running through three decks, with a large pendulum ‘bob’ immersed in a bath of oil to dampen its swing. As the boat was rolled, measurements were taken to prove that the submarine can perform according to its design specifications.

Defence Secretary Lord Drayson said: ‘This is an important step on the road to preparing Astute for service. These submarines are hugely impressive vessels, and will provide the Royal Navy with a world class capability.’

After completing the dive, Astute will be docked and taken back into Devonshire Dock Hall. The next stage will be to calculate her stability, weight and buoyancy. She is due to be handed over to the Royal Navy next autumn and enter service in 2009.

Murray Easton, managing director BAE Systems Submarine Solutions, said: ‘The workforce at Barrow continues to demonstrate that although the production of nuclear powered submarines requires a specialist subset of skills, in line with the government’s Defence Industrial Strategy, we have the ability to deliver the intellectual resource and technologies required.

‘Astute class submarines will play a key role in the defence of the

for decades to come. The boats demonstrate a step change in capability when compared to those they will replace.’