The Defence Secretary has revealed a £2.5 billion investment in the UK's nuclear submarine programme.
Gavin Williamson has also signed a contract to build a seventh Astute-class hunter-killer submarine and announced contracts worth £960 million for the second phase of construction of the UK's four new nuclear-armed Dreadnought submarines.
He was in Cumbria to officially open a new £100 million sub-construction building at BAE Systems' shipyard in Barrow-in-Furness.
"What you see is the submarine building hall busy as it's actually been in decades," said Mr Williamson.
"You see the new Astute boat being produced - they're going to be produced incredibly rapidly."
"They're all part of our effort to make sure Britain continues to remain safe going forward.
"You're seeing a Russia that wants to assert itself more and more - that's why it's absolutely essential for us to be able to have the ability to match that threat.
"The hunter-killer submarines are essential in terms of dealing with that threat that Russia poses to the nation."
"This is a huge investment in submarines" - Professor Peter Roberts, Director of Military Sciences at the Royal United Services Institute.
Under this new investment, the seventh Astute-class submarine, HMS Agincourt, will complete the hunter-killer fleet.
As many as 8,000 jobs will also be supported at BAE Systems.