Site Records

SiteName: Paddock (Alternative Cabinet War Room)

Brook Road
Dollis Hill
London, N.W.2.
OS Grid Ref: TQ223863

Sub Brit site visit: 19th April 2001 and various later dates

PADDOCK was built at the start of the 2nd World War on the site of the Post Office Research and Development Station in Dollis Hill. Its purpose was to act as an alternative underground control and command centre for Central Government should a devastating air attack on Whitehall force Government to evacuate central London. PADDOCK would provide protected accommodation for the War Cabinet and the Chief of Staff of the air, naval and land forces, acting as a stand-by to the Cabinet War Room that was, from 1938, located in the adapted basement of the Office of Works building in Storey's Gate, opposite St. James's Park.

As early as 1937 plans were drawn up to move Central Government out of London to the North West suburbs and if that became unusable a further withdrawal should be made to protected accommodation in the western counties.

After the Munich crisis, the suburban scheme received further consideration in the autumn of 1938 and despite some misgivings from the Committee of Imperial Defence who favoured a relocation to the western counties, construction of four underground citadels was authorised, one for each of the armed services and an Emergency War Headquarters at Dollis Hill on the site of the Post Office Research Station. The Admiralty Citadel (Oxgate) would be located at Oxgate Lane, Cricklewood beneath the Admiralty Chart Store with the Air Ministry Citadel (Station Z) at Harrow, beneath the Stationery Office annexe and the Army Citadel at Kneller Hall in Twickenham, the home of the Royal Military School of Music; the latter was never built.

The Post Office Research Station Photo by Nick Catford - click to enlarge

The Post Office Research Station at Dollis Hill was first established in 1921 with the main building being opened by the Prime Minister J. Ramsay MacDonald in 1933. Dollis Hill was at the forefront of telecommunications research and as such was considered a major enemy target.At the outbreak of war in 1939, the site was camouflaged, this included netting over important buildings. Colossus, the world's first electronic computer, was built at Dollis Hill by a team led by Tommy Flowers; it was later used at Bletchley Park for code breaking.

On 14th October 1938 the final plans were drawn up for the construction of the bombproof war headquarters deep underground at the Dollis Hill research station. The same team was employed on the plans as had been responsible for the adaptation of the Storeys Gate War Room. CWR2 as it became known would duplicate the facilities of CWR1 (Storeys Gate), the two major rooms being the map room with a usable wall surface of 1000 square feet and a cabinet room with seating for 30 people. All these would be located in a sub-basement 40 feet below ground.

The sub-basement would be protected by a roof of concrete five feet thick (probably in two layers with an intervening layer of gravel as a shock-absorber) while over it would be a first basement considerably larger in area, protected by another reinforced concrete roof
three and a half feet thick with similar protection on the sides. The entrance to this citadel would be concealed within a new three-storey building already planned by the Post Office to meet its own peace-time needs; only one storey was eventually built. The cost of the war HQ was put at nearly £250,000.

As built, the citadel was oblong in shape, running parallel with Brook Road under the north-east corner of the research station grounds. The two basements were longer and wider than the surface building with the first basement extending under the pavement of Brook Road.

Excavation started at the beginning of 1939 without attracting much attention although it involved earth-shifting on a massive scale. Construction work and fitting out were finished by June 1940 in line with the original 1938 plan and CWR2 was ready for use by the War Cabinet.

There was no dormitory accommodation at the research station; instead it was proposed to use 60 up-market flats for the purpose. Neville's Court is located 200 yards to the south east in Dollis Hill Lane, the war cabinet and senior staff and secretaries would have had rooms there while other personnel from the war headquarters would be billeted in local schools.

It was immediately manned by a skeleton staff to ensure that it was in a state of readiness. Should Whitehall be subjected to a devastating air attack Dollis Hill would be available at short notice. Although most Whitehall personnel were convinced that Dollis Hill would be required, Churchill found the thought of leaving central London unthinkable although he realised it might be necessary. Following the start of the London Blitz on 7th September 1940 he immediately visited Dollis Hill to see the new war headquarters for himself. He also approved the plan to knock together two adjoining flats in Neville's Court to form a double-flat for himself and his secretaries. One week later the Office of Works requisitioned the whole of Neville's Court for the Government.

Home Page