Supporting submarine maintenance infrastructure at Devonport Royal Dockyard

Supporting submarine maintenance infrastructure at Devonport Royal Dockyard

AtkinsRéalis has been providing engineering support to international defence, aerospace and security company, Babcock International, in its work at Devonport Royal Dockyard, Plymouth. Under the watchful gaze of an iconic red and white lighthouse at Plymouth Hoe, the UK’s silent and unseen defenders resurface after months of hidden service.

It is here, at Devonport Royal Dockyard, where the Royal Navy’s nuclear-powered submarines are maintained, refuelled and overhauled. The facility, the largest naval base in Western Europe, has berths and dry docks for submarines, which are critical to their effective maintenance. Devonport contains a nuclear-licensed site, owned and operated by Babcock, which is delivering a series of major upgrades to the dockyard’s critical infrastructure so it can maintain the Astute Class fleet, continue to support the Vanguard Class fleet, and defuel decommissioned submarines.

AtkinsRéalis has been supporting Babcock on this key defence site since 2010, providing engineering design, nuclear safety and project management services. More than 800 AtkinsRéalis experts worked on various major dock and facility upgrades during 2024. This has included approximately 100 early careers apprentices and graduates, developing the next generation of skills to support the submarine enterprise into the future.

Supplying skills and expertise

AtkinsRéalis has provided a range of engineering skills – including nuclear safety, civil, structural, mechanical handling, nuclear process, electrical, mechanical services, and human factors – as well as support across project and programme management, radiological protection and waste management, cyber security, and environmental management. We have used the breadth of our experience and expertise across other defence nuclear programmes to share best practice, enabling multidisciplinary coordination across a highly regulated and complex environment.

Examples of our work include seismic strengthening design for both a new flood wall at 15 Dock and concrete reinforcements to lift shafts at 14 Dock. At 10 Dock, we supported Babcock to define requirements for new cranes and lead the nuclear safety case for the refurbished facility. Additionally, we are supporting the design review at 5 Basin Berth East Wall and are revalidating submarine maintenance equipment in 9 Dock. Our teams are playing a part in ensuring the reliability, availability and continued safe and secure operation of the submarine enterprise. Positive and cooperative collaboration with the supply chain has been critical to the delivery of our work at Devonport. We offer the critical capabilities needed to enable submarine platform and infrastructure success; and as a trusted supplier, we support resilience – across infrastructure, cyber security, the supply chain and equipment.

Operational readiness

In February 2025, Babcock marked the critical milestone of successfully docking an Astute Class submarine for the first time in 15 Dock, allowing it to undergo maintenance before returning to active duty. This achievement reflects how key suppliers like AtkinsRéalis contribute to the work Babcock deliver to the UK’s Royal Navy that allow these steel leviathans to continue to play their role in protecting the UK’s national security.