WWII aircraft factory, later the infamous RSG 6. Now used for archive storage.
This site is also discussed in the following issues of our members' magazine:
WWII aircraft factory, later the infamous RSG 6. Now used for archive storage.
The heavily wooded site is surrounded by a 10 foot chain link metal fence topped with barbed wire. Overhead power cables entered the site from the south. An aerial mast rises from its centre.
Two chalk mines originally occupied the site – the original ‘Star Mine’ entered from an addit off Star Lane (entrance now collapsed) and the ‘New Mine’ entered from a quarry on Warren Row Road.
The Star Mine is recorded by the Inspectorate of Mines as being owned by Warner and Company of Knowl Hill and to be employing 1 or 2 people above and below ground between 1899 and 1904. Described by Jukes-Browne and Osborne White in the “The Geology of the country around Henly-on-Thames and Wallingford” 1908 pp72-73 and by Osborne White in “Excursion to Twyford and the Wargrave outlier”. Proc.Geol Asscn. 17(4) pp l76-81. This records that the entrance to the workings is at the junction with the Reading Beds and Terebratulina chalk and flints were being worked both from a quarry and mines in 1889-90.
Brick and flints derived from the mine were used to construct the church and houses in Medmenham and the chalk was also used for whiting (or whitening). Warner’s also had a brickyard at Knowl Hill. A 1901 visit recorded that the entrance to the older galleries was blocked by a landslip a few years previously but the new and ‘less extensive workings’ were still readily accessible with a connection to the older workings.
In 1940 30,000 sq. ft. of the ‘new’ mine was adapted for the manufacture_of aircraft parts in World War II; it was Regional Seat of Government (RSG) No.6 from 1959 to 1964; CRC 61 (?) until 1971; and was re-opened for use as a Ministry of Defence signals centre in 1980; in May 1983 the Property Services Agency (PSA) applied for the erection of three 25m aerials and in December 1987 the PSA put it up for sale. Until recently the ‘new’ mine was a secure document store, and the ‘old’ mine, via a new re-opened entrance opposite the ‘new’ mine, was a wine store. The wine store may now (2021) have taken over the whole site.
The ‘new’ mine is entered from a sloping entrance big enough to take a car, with a modern flood gate. There is a second similar entrance (the ‘emergency exit’) in a separate fenced enclosure in woodland to the east and also a vertical exit up a ventilation shaft to a small surface brick structure in the main enclosure. The entire mine is filled with a brick structure which is the remains of a series of government uses from aircraft factory to Regional Seat of Government and finally a signals centre.
The structure is divided into numbered rooms, sometimes on one storey and sometimes on two, and the passage is large enough to enable a visitor to walk comfortably on the concrete roof beneath the original chalk ceiling. In 1987 beds, chairs, desks and water tanks testified to what must have been the equivalent of a self-contained underground village. In two places it was possible to crawl at roof level into the ‘old’ mine, a short ladder climb down led to a network of unspoiled chalk tunnels. This mine flooded to a depth of 5 ft. in wet weather, apparently by seepage, and cleared rapidly; in consequence the entire floor was covered with a layer of mud.
Compiled from Chelsea Speleological Society Records (the late Harry Pearman) 1983-8.
Warren Row was the site of a break in by ‘Spies For Peace’ in the spring of 1963 which revealed for the first time the existence of a network of secret government and military bunkers and their staffing. ‘Spies for Peace’ were a small (5 or 6 persons?) breakaway group from the Committee of 100, itself a breakaway group from the Campaign for Nuclear Disarmament, who had become disillusioned with its passive disobedience tactics and felt positive action must be taken.
Hearing rumours from telephone engineers of a secret facility near Reading, four members in a car explored the area fruitlessly until one noticed an overhead power line crossing the A4 at Knowl Hill. They followed it north to a wood with an aerial mast rising above it and discovered the Warren Row bunker. In subsequent visits they picked the boiler room door lock, which gave them access to the RSG, and photographed all the documentation they could find, collating it into a cyclostyled pamphlet ‘Beware Official Secret! RSG 6!’ which they posted anonymously to the press; influential people; politicians; the Prime Minister and distributed it on university campuses - causing an uproar. The stencils were burned, the typewriter thrown into the Thames, the negatives buried in Bertrand Russel’s garden, and no one was ever prosecuted. Three of them at least are now dead. Peter Laurie (‘Beneath the City Streets’)and Duncan Campbell (‘War Plan UK’) followed in their footsteps.
The site features in this 1942 Pathé newsreel on underground factories.
No videos are available for this site.