Site Records

Site Name: Plymouth Maritime Headquarters
                    (Mount Wise)

Richmond Walk
Mount Wise
Plymouth, Devon
OS Grid Ref: SX458540

Sub Brit site visit 13th December 2004

[Source: Bob Jenner]

The area of Devonport, south of the dockyard known as Mount Wise is rich in history and military remains. Very briefly, the founding of the dockyard in the 1690's dictated the areas history from then on. During the early 18th century defensive works, known as 'Dock Lines' were built outside the dockyard walls, encircling them and enclosing an area of housing to the north and Mount Wise to the south. The lines consisted in the main of a wide deep dry ditch that ran from Stonehouse creek in the south to the Hamoaze in the north.

A redoubt was built at the summit of the ridge that ran across Mount Wise and a series of gun batteries were laid out to protect the dockyard and to prevent access to the Hamoaze from Plymouth Sound. This redoubt later became a naval signal station, equipped with a shutter telegraph connecting to the Admiralty in London. A military barracks and a laboratory were built behind the redoubt.

Until the late 18th century, Military control of the Plymouth Garrison was vested in the Military Governor, who resided, with his deputy, in the 'Citadel' to the east of Plymouth Hoe.

Naval control was exercised by the senior Admiral present in the Hamoaze anchorage from his Flagship. The dockyard was under the supervision of an Admiral Superintendent who resided in the dockyard.

This changed, with the building at Mount Wise of a new Government House for the Military Governor and at the beginning of the 19th century Admiralty House, for the Port Admiral who had moved ashore from his Flagship.

Admiralty House (formerly Government House)

The post of Military Governor was abolished in 1842. Government House was then occupied by the army GOC, Western District. By 1915, the military presence on Mount Wise was diminishing with the removal of the Western District (by now Wessex District) to Salisbury, Wilts and the transfer of the whole of Mount Wise, including the redoubt, to the Admiralty. Government House now became Admiralty House, residence of the naval Commander in Chief (C in C), Plymouth and the old Admiralty House became Hamoaze House, later HQ of the Major General, Royal Marines until 1993. On 8th November 1943 the Americans set up the United States Advanced Amphibious Base at Queen Anne's Battery, Plymouth. The Commanding Officer, Captain C F M S Quimby USN occupied Hamoaze House together with Admiral Moon,USN until September 1945 when the base was decommissioned.

Photo:The main entrance to the Maritime Headquarters at Mount Wise - the side walls of the dry ditch are clearly visible.
Photo by Nick Catford

Prior to the outbreak of World War 2 in 1937, proposals were made for a protected joint service HQ in the dry ditch near to Hamoaze House consisting of a single storey structure with a 20 ft concrete and shingle overburden.

By 1939, this plan had been widened to provide an Area Combined HQ (RN & RAF) at the following locations:

  C in C Plymouth at Mount Wise  
  C in C Portsmouth at Fort Southwick  
  Flag Officer Rosyth at Pitreavie Castle  
  C in C Nore at HMS Pembroke (post war HMS Wildfire)  

These HQ's, built to withstand a direct hit by a 500lb bomb, would house the Naval and Air Force commanders together with an army representative. Also accommodated, would be the Fortress Defence HQ (Coastal Artillery) and Air Defence HQ (Anti Aircraft Artillery)

Construction began in 1939 at Mount Wise on the previously chosen site in the dry ditch, but the plan was now for a two storey structure. As an interim measure, a temporary combined HQ was set up in Eggbuckland Keep, an early fortification in northeast Plymouth, together with the Fortress Defence HQ.

Photo:The roof of the Maritime HQ in the dry ditch - the dark building in the middle distance is the now disused WW2 generator block. The two lighter coloured buildings to the left of the MHQ are protected air inlets added during the 1990/91 refit.
Photo by Nick Catford

The naval command at this stage was C in C Plymouth and Western Approaches. A decision had already been made to re-locate Western Approaches HQ to a safer and more central location, initially to be on the Clyde the final choice was Liverpool where Derby House had been taken over and strengthened , opening on 17th February 1941,with the appointment of Admiral Sir Percy Noble as the first C in C Western Approaches and following the decision to split the command, the transfer to Derby House of No 15 Group, RAF Coastal Command from Lee on Solent under the command of Air Marshal Sir L H Slatter

This transfer of function resulted in work at Mount Wise being halted at the half-way stage, however, in view of the large costs already made and in anticipation of the return to Plymouth of Western Approaches HQ post war, it was decided to complete the project as a protected HQ for C in C Plymouth and Fortress Defence HQ. It was fully complete by early 1941and contained the following:

  C in C Plymouth  
  Fortress Defence HQ  
  AA Gun Operations Room (GOR)  

The Fortress Defence, Fire Control moved, in 1943, to Wembury Battery where it remained until the end of the war. The GOR moved to Eggbuckland Keep at the same time, moving on to Crownhill Fort in 1948.

Plan of the WW2 Maritime Headquarters - with post 1985 refit annotation. (Note: the air conditioning plant shown at the bottom of the upper floot plan is part of the 1985 refit and did not exist prior to this.
Drawn by Nick Catford

By 1942 planning for D Day was well underway. An outcome of this was the requirement for a series of protected tactical communications facilities at a number of strategic locations to serve all allied commitments.

For further information and pictures of Mount Wise click here

[Source: Bob Jenner]

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