Exploring Kent's Past

It should not be assumed that this site is publicly accessible and it may be on private property. Do not trespass.

Monument details

Summary

This underground headquarters bunker, with a surface element, was built in 1960 for No. 1 Group of the Royal Observer Corps. The role of the Group HQ was to receive and process reports of the location and strength of nuclear bursts and the spread of radioactive fallout from such posts across its area of responsibility (Kent and the eastern parts of Surrey and Sussex). Scientific advisers in the bunker examined information about nuclear bursts and predicted the spread of fallout. This information was communicated to the controls of armed services, and other recipients in a communications chain. Local communities could be warned of approaching radiation through the use of air raid sirens or maroons. The safest routes for the traffic of military vehicles and of the emergency services could be established as well as information collected about which airfields were at risk or, at the time, unusable from the spread of fallout.

Monument Types

• ROYAL OBSERVER CORPS HEADQUARTERS (Modern - 1960 AD to 1991 AD)

Full description

If you do not understand anything on this page please contact us.

This underground headquarters bunker, with a surface element, was built in 1960 for No. 1 Group of the Royal Observer Corps.

It succeeded earlier use of the adjacent brick ‘Fairlawns’ (later called Ashmore House) as a centre for the plotting of aeroplanes spotted visually by an outlying network of ground observers. The house was a group HQ from 1942 but its function was transferred to a site in Beckenham in 1945 and became training accommodation. The HQ returned to Maidstone on the construction of the new bunker and in reciprocation Beckenham became the training facility.

The construction of the new bunker reflected the changing role of the Corps from aircraft spotting to detecting nuclear explosions and monitoring radioactive fallout in the event of a nuclear war. This new role was undertaken from the 3-man underground posts across the countryside, which were being built to replace the above-ground observation posts used hitherto.

The role of the Group HQ was to receive and process reports of the location and strength of nuclear bursts and the spread of radioactive fallout from such posts across its area of responsibility (Kent and the eastern parts of Surrey and Sussex). Scientific advisers in the bunker examined information about nuclear bursts and predicted the spread of fallout. This information was communicated to the controls of armed services, and other recipients in a communications chain. Local communities could be warned of approaching radiation through the use of air raid sirens or maroons. The safest routes for the traffic of military vehicles and of the emergency services could be established as well as information collected about which airfields were at risk or, at the time, unusable from the spread of fallout.

Several shifts of ROC personnel would have lived in the bunker and have utilised the ‘hot bed’ system of sleeping rotation. Information received by telephone or radio from individual posts was marked by plotters on translucent maps, as controllers looked down from a raised balcony.

The bunker was intended to be self-sustaining, with its own power plant, water and food supplies and could be sealed against radioactive contamination for a lengthy period.

The Royal Observer Corps was stood down in 1991 and the bunker was sold into private ownership.


Externally, the concrete bunker presents as a flat-topped rectangular and turf-covered mound, with a blockhouse-like entrance structure at its north-eastern corner. Diagonally opposite, at its south-western corner, there is a small emergency exit. Internally the bunker consists of 16 rooms split between 3 levels.

The entrance is surmounted by louvered air in and out takes. Next to this a retractable radio mast remains in place. The entrance is secured by a steel blast door leading into an airlock, on the left of which is a decontamination room with shower heads and, on the right, a filter room for cleaning air admitted from the outside. Behind the airlock, a staircase leads down to the middle level of the bunker.

The middle level is a sequence of rooms either side of a corridor. These include a plant room, complete with working generator, air extractor room, toilets, dormitories, administration, and canteen as well as the door to the emergency exit.

A second staircase gives access to the lower level. This contains the map plotting room, complete with its fixed furniture and translucent maps. This is overlooked by the controller’s balcony, which is entered from the middle level. Two other rooms, of uncertain purpose, are adjacent at the lower level.(1)

<1> Victor Smith and Andrew Saunders, 2001, Kent's Defence Heritage (Unpublished document). SKE6956.

Sources and further reading

Related records

Related thematic articles

• The Defence of Kent (Thematic Essay)