BAE Systems has agreed a £1.2bn deal with the Ministry of Defence to design and manufacture the Royal Navy's new attack submarine HMS Audacious.

The vessel is the fourth of seven nuclear-powered submarines being built for the Royal Navy that will secure 3,000 jobs in Barrow-in-Furness in Cumbria. The MOD will commit a further £1.5bn to the remaining three astute class submarines being built.

The first two boats seen here, HMS Astute and HMS Ambush, are currently conducting sea trials. The third boat, Artful, is reaching the final stages of her construction at Barrow shipyard. It was reported last month that several faults had been found on Astute, a vessel BAE Systems described as, "the largest and most able attack submarine that the Royal Navy has operated, with a performance to rival any in the world".

The HMS Audacious contract is the first bumper deal BAE has signed since talks with EADS collapsed in October this year, in what would have been the world's largest defence and aviation merger.

Written and presented by Alfred Joyner