His Majesty's Naval Base, Devonport (HMNB Devonport) is the largest naval base in Western Europe, and one of three operating bases in the United Kingdom for the Royal Navy. It is the sole nuclear repair and refuelling facility for the Royal Navy. HMNB Devonport is located in Devonport, in the west of the city of Plymouth, England.

The base began as a Royal Navy Dockyard in the late 17th century, designed and built on open ground by Edmund Dummer as an integrated facility for the repair and maintenance of warships, centred on his pioneering stone dry dock (one of the earliest stepped docks in the world). Over the next two centuries it expanded, reaching its present extent in the 20th century. Historically, the yard was also used for shipbuilding: over 300 naval vessels were built there, the last being HMS Scylla (launched in 1968).

The yard was known as HM Dockyard, Plymouth until 1843, when it was renamed HM Dockyard, Devonport. (In the late 20th century, here as elsewhere, the term 'Naval Base' replaced 'Dockyard' in the official naval designation.)

HMNB Devonport served as the home port of the Devonport Flotilla until it was merged into the Surface Flotilla. Commander Fleet Operational Sea Training, the training hub of the front-line Fleet, is also based there, as is the Royal Navy's Amphibious Centre of Excellence (at RM Tamar). Although shipbuilding ceased at Devonport in the late 1960s, ship repair and maintenance work has continued; the now privatised maintenance facilities are operated under the name Devonport Royal Dockyard by Babcock International Group, which took over the previous owner Devonport Management Limited (DML) in 2007 (DML had been running the Dockyard since privatisation in 1987). Babcock owns around a third of the overall area of the base (having been sold the freehold in 2011).

Accommodation and support services are provided within the base for naval personnel. The Royal Naval Barracks, dating from 1889, were first commissioned as HMS Vivid, before being renamed HMS Drake in 1934. Since the early 21st century the name HMS Drake (and its command structure) has been extended to cover the entire Naval Base, while HMS Vivid is Plymouth's Royal Naval Reserve unit (which has its headquarters within the base).

The Naval Base today

The Naval Base as a whole covers an area of with four miles (6 km) of waterfront; it has twenty-five tidal berths, five basins and fourteen dry docks (docks numbered 1 to 15, but there is no 13 Dock). The base employs 2,500 service personnel and civilians, supports circa 400 local firms and contributes approximately 10% to the income of Plymouth. The Naval Base commander has in recent years been a Commodore (RN), but in 2022 Brigadier Mike Tanner took command (the first Royal Marine officer to be appointed to the role).

Ships based at Devonport In 2009 the Ministry of Defence announced the conclusion of a long-running review of the long-term role of three naval bases. It was decided that Devonport would no longer be used as a base for attack submarines (a move completed with the retirement of HMS Triumph in early 2025), and that the Type 45 destroyers would be based at Portsmouth. In November 2024, it was also decided to retire the Albion-class assault ships which were based at Devonport. However, Devonport continues to host most of the fleet's Type 23 class frigates. In 2018 the Secretary of State for Defence announced that the proposed new Type 26 frigates would all be based at Devonport when delivered starting in the latter 2020s.

Ships based at the port include:

Type 23 frigates

In changes to base porting arrangements announced in November 2017, HM Ships Argyll, Monmouth and Montrose were all to join the Portsmouth Flotilla (however, Monmouth retired in 2021, Montrose decommissioned in 2023 and Argyll in 2024); HM Ships Richmond, and St Albans moved in the opposite direction, to Devonport. Richmond also became a Devonport ship on completion of her refit. St Albans moved to Devonport in July 2019 in preparation for her major refit. HMS Westminster retired in 2024 followed by HMS Northumberland in 2025. In 2025, it was confirmed that (since retired) would relocate from Portsmouth to the Devonport naval base. Devonport became the sole base for Type 23 frigates with the retirement of HMS Lancaster in December 2025.

Survey ships

Antarctic patrol ship

Other units based at Devonport Fleet Operational Standards and Training (FOST) Hydrographic, Meteorological & Oceanographic Training Group 2 × Sea-class 15 m survey/hydrography vessels (Merlin and Fantome) HQ Amphibious Task Group RNR (relocated to the South Yard from Mount Wise in 2004) RM Tamar/47 Commando (Raiding Group) Royal Marines 10 Landing Craft Training Squadron 4 Assault Squadron 6 Assault Squadron 9 Assault Squadron 539 Assault Squadron Hasler NSRC (Naval Service Recovery Centre) & Hasler Company Royal Marines Southern Diving Group RN 1 × Sea-class 15 m diving support boat (DSB Vulcan) Defence Estates South West Ministry of Defence Police

Dockyard facilities

Babcock's privatised Devonport Royal Dockyard facility is co-located with HM Naval Base Devonport, providing 'through-life support for submarines, surface ships and associated systems and equipment'. Operational vessels are provided with 'in-service engineering maintenance support' from the yard, dry docks are available to 'maintain, refit, convert and modernise sophisticated modern surface warships' and specialised workshops enable complex systems to be 'removed, overhauled, tested and installed'.

In the early 1970s it was announced that Devonport would join Chatham and Rosyth in serving as a refit base for nuclear submarines; the Submarine Refit Centre duly opened in 1981. Since 2002, Devonport has been the sole refitting base for all Royal Navy nuclear submarines.

In 2022 Babcock began a ten-year programme of work to upgrade its Devonport Dockyard facilities. The project is described as 'a major infrastructure refurbishment of the nuclear licensed docking and berthing facilities at the dockyard' to meet the evolving requirements of the Royal Navy. The work is focused around No. 5 Basin, with Dry Docks 9, 10, 14 and 15 being upgraded (along with their surrounding buildings and infrastructure) to support the maintenance programme for 'new and existing classes of submarine', along with Dry Docks 8, 11 and 12 which will be used for new classes of frigate (some of which are likely to be too large for the covered docks of the current refit complex).

Nuclear submarine decommissioning Thirteen out of service nuclear submarines were stored at Devonport in 2018.

(preserved in North Yard as a museum ship)

In 2018, the UK Parliament's Public Accounts Committee criticised the slow rate of decommissioning of these submarines, with the Ministry of Defence admitting that it had put off decommissioning due to the cost. The National Audit Office in 2019 stated that the costs of laid up storage of all nuclear submarines had reached £500 million, and they represent a liability of £7.5 billion.

South Yard (Freeport)

Several sections of the South Yard (the oldest part of the Naval Base) are no longer used by the Ministry of Defence. Its historic slips were formerly the shipbuilding centre of the Royal Dockyard. In 2012 the southernmost part of the site was sold to a private company and in 2014 the northernmost section was leased to Plymouth City Council as part of a City Deal regeneration project; other areas are leased to Babcock. In 2022 the whole of the South Yard (except for the north-east corner of the site) became part of Plymouth's Freeport.

Princess Yachts In 2012 Princess Yachts acquired the freehold to at the southern end of the site, which now houses its construction facility for 'superyachts'. The company sees itself as continuing the boat building tradition within the dockyard, and 'adding drama to the site' with yachts being moved around the quayside, launched on No. 3 Slip, tested in No. 2 Slip and moored alongside the quay wall. Alongside the modern yachts, classic vessels are repaired and restored by Stirling & Son, on and around the 18th-century covered No. 1 Slip.

Oceansgate In 2014 it was announced, as part of a 'City Deal' regeneration agreement, that more of the South Yard would be 'unlocked' with a view to it becoming a 'marine industries hub'. By 2016 the northern section of the South Yard was being redeveloped in phases, from east to west, with a marketing strategy focused on 'the development of marine industries and the high growth area of marine science and technology'. The area has been renamed Oceansgate.

Phase 1 (east of the 18th-century dockyard wall) was completed in 2018; Phase 2 (immediately to the west) was completed in 2021. These areas, containing new-build offices and business units, have been designated an Enterprise Zone (and are not part of the Freeport). Phase 3, the westernmost area extending to the waterfront, encompasses three 18th-century dry docks and several listed buildings; it was being offered for sale on a lease of up to 295 years. As of 2022 this area has been incorporated into the Freeport plan.

Devonport Naval Heritage Centre, a volunteer-run maritime museum, is currently housed within two listed buildings in the Oceansgate area of the yard.

MOD

The majority of the South Yard site remains in Ministry of Defence (MOD) ownership. All land to the south of 'Oceansgate' (with the exception of the area which is owned by Princess Yachts) is currently retained by the MOD, with No. 4 Slip having been recently refurbished for use with landing craft. Largely used by MOD contractors, it remains a closed site and subject to security restrictions.

Freeport As approved by the government in December 2022, the South Yard is now one of the three 'freezones' of the Plymouth and South Devon Freeport. Freeport status provides certain tax advantages for businesses based there. The South Yard Freeport zone includes all the land owned by the MOD and Princess Yachts, and most of the land leased to Plymouth City Council as 'Oceansgate'.

The Freeport's business plan envisages the South Yard being focused on marine and defence sector development, and at the same time 'forming the centrepiece of the Freeport’s Innovation Hotbed'. Proposed developments include expansion of Oceansgate beyond its current footprint, construction of a new factory for Princess Yachts and the building of a new Innovation Centre and 'Mobility Hub' (described elsewhere as a 'huge multi-storey car park'). (Development of the Innovation Centre will require 'relocating' the Naval Heritage Centre.) Eventually it is hoped that the Freeport with its tax advantages will enable 'defence and other contractors to invest and bring back into productive and sustainable use dormant waterfront spaces [...] which, for the time being, must remain "behind the wire" [i.e. within the MOD restricted area]'.

History Overview

From its original 17th-century site, around No.1 Dock in what is now called the South Yard, the dockyard expanded in stages (first to the south and then progressively northwards) over the next two-and-a-half centuries. Key periods in the geographical development of the yard included: The building of Plymouth Dock and Yard (1692–1698). The building of Morice Ordnance Yard (1719–1720) alongside the dockyard to the north (this became part of the dockyard during the Second World War). The Great Rebuilding (1760–1790) which saw the dockyard expand to the south. The building of Keyham Steam Yard (1844–1865) to the north of the Morice Yard. The building of the Keyham Extension (1896–1907) which more than doubled the size of the Keyham yard. Post-war appropriation of adjacent land (1950s) with bomb-damaged streets were brought within the dockyard perimeter to allow for future expansion. The reclamation of Weston Mill Lake (1972–1979), now the northernmost part of the base.

Origins