The UK Chancellor George Osborne has committed £500m of funding for the Royal Navy's flagship submarine base HM Naval Base Clyde at Faslane.
Due to begin in 2017, the new developments will take ten years to complete and are expected to secure 6,700 jobs and create thousands more.
The new investment will be spent on ship lifts, sea walls and jetties, as well as other major projects.
Osborne said: "Today's announcement of more than £500m demonstrates the UK Government's commitment to investing in the infrastructure and capability to ensure that Faslane remains the centre of UK submarine operations for the next generation.
"I'm proud to say that this government continues to recognise that our brave Armed Forces across Britain have always been resolute in defence of liberty and the promotion of stability around the world."
Faslane is the largest military establishment in Scotland and is home to Astute submarines. The UK also expects to base Successor-class submarines at Faslane when they come into service from 2028.
The base will be the Royal Navy's 'Submarine Centre of Specialisation' from 2020, accommodating all of the UK's underwater capability.
Currently, the base houses around 6,700 military and civilian staff and contractors with plans to increase this to approximately 8,200 by 2022.
The latest development follows the country's decision to spend 2% of national income in defence sector.
This investment in defence will also support the UK's defence and security exports industry.
Image: Royal Navy's flagship submarine base, HM Naval Base Clyde, Faslane. Photo: © Crown copyright.