The work will employ 850 contractors at its peak and include both new build facilities and the refurbishment of existing infrastructure in preparation for the construction of a successor to the Vanguard class submarines.

Tony Johns, Managing Director of BAE Systems Maritime – Submarines, said: “Redevelopment of the site is fundamental to the future of our business and will ensure we stay at the forefront of submarine design, build, test and commissioning.

“This investment will provide a modern, 21st century environment for our employees to apply the unique skills and expertise that have delivered complex submarines to the UK Royal Navy for over a century.”

Demolition of some existing buildings will start in April. This will be the first major activity of a programme that will include:

• an extension to the Devonshire Dock Hall construction facility to include a new state-of-the-art manufacturing and installation facility
• two new major buildings that will house pressure hull units ready for shot blast and paint and the integration of submarine equipment modules
• the refurbishment of the site’s main fabrication facility, together with its existing plant and machinery
• an intention to build a 28,000m2 off-site logistics facility to store submarine parts and materials within the local area

Defence Secretary Philip Hammond said  “The next generation nuclear-deterrent submarines that will be built in Barrow will be the largest and most advanced submarines ever operated by the Royal Navy.

“The £300m of infrastructure work that will take place over the coming years will not only protect 6,000 highly skilled jobs at the site, but also provide hundreds of additional construction jobs.”