Babcock has awarded a contract worth approximately £600M to KierBAM as the redevelopment of 10 Dock at Devonport enters its main construction phase. The project is intended to provide essential deep maintenance capacity for the RN submarines, but the originally stated aim of completion by 2027 now appears to be unachievable.
The full £750M contract awarded to Babcock covers construction of the dock’s water-retaining boundary and associated buildings and infrastructure. Preliminary work has already been completed, including demolition of legacy buildings and the commissioning of an on-site concrete batching plant, allowing major civil engineering activity to begin. The wider programme is expected to support around 1,500 jobs across the supply chain, including approximately 300 Babcock positions at Devonport, alongside opportunities for local businesses and apprentices.
The redevelopment is part of a much wider programme to modernise the ageing nuclear submarine support infrastructure at Devonport. The naval base must sustain the existing Vanguard-class ballistic missile submarines and Astute-class attack submarines while preparing for the introduction of the Dreadnought and eventually SSN-AUKUS classes. These increasingly complex vessels require highly specialised facilities, and the ability to dock and maintain them is just as important as building new submarines.
£750M is going into this hole in the ground. When complete, 10 Dock will be capable of accommodating Vanguard and Dreadnought-class SSBNs or Astute / and SSN AUKUS boats.
In November 2023, the MoD stated that the Submarine Waterfront Infrastructure Future (SWIF) programme, including 10 Dock, would be completed in 2027. The latest contract announcement provides no timetable. With the main construction phase only now beginning, completion within about a year appears unlikely, adding further pressure to the submarine support enterprise. The major reconstruction of the adjacent 9 Dock took approximately three years, from 1999 to January 2002 and went around £283M over budget.
In September, Defence Minister Luke Pollard told Parliament that opportunities to accelerate work on 10 and 14 Dock were being explored following the lifting of enhanced nuclear regulatory oversight at Devonport. The dockyard operator was returned to routine regulatory attention in March 2026 after 12 years of additional scrutiny by the Office for Nuclear Regulation. However, the minister did not provide a revised completion date, and the latest announcement gives no indication whether acceleration has been agreed.
The work involves considerably more than conventional dock refurbishment. The existing structure must be substantially strengthened to meet stringent modern nuclear safety requirements, including resistance to extreme weather, tidal surges and seismic events. The dock will be narrowed and shortened by new reinforced walls, with extensive electrical, cooling water and other services incorporated into the structure. Unlike the adjacent 9 Dock, it will not be equipped for nuclear refuelling or defuelling operations.
CGI showing preliminary design proposal for the refurbishment of 10 Dock and the new support building to be constructed on the west side. The white areas are the new reinforced walls, which will comprise the main part of the work to be undertaken by KierBAM (Image: Arcadis Consulting UK ).
The shortage of suitable dry docks has been a major contributor to poor RN submarine availability. At present, the UK has just three facilities capable of taking nuclear submarines out of the water: the shiplift at Faslane and 9 and 15 Docks at Devonport. Number 9 Dock is occupied by HMS Victorious undergoing a lengthy deep maintenance period, while 15 Dock provides essential support for the Astute-class SSNs. The completion of 10 Dock would provide much-needed additional flexibility, reducing the risk that maintenance delays to one submarine affect the wider fleet.
The programme forms part of Project Royal Oak, which will see £7.1 billion invested in Devonport over the next decade. Separate work is under way to recommission 14 Dock for defuelling decommissioned nuclear submarines, an activity that has been suspended at Devonport since 2004. Taken together, the projects are intended to address decades of underinvestment in infrastructure that has become a critical constraint on the RN’s ability to sustain its submarine force but progress is painfully slow.
Main image: mock-up of completed 10 Dock renovations