Former Aaor And County Emergency Hq

FORMER AAOR AND COUNTY EMERGENCY HQ, MISTLEY

Cold War bunker and Anti-Aircraft Operations Room, built in 1951. Reinforced concrete construction.

The building is a square, two-storey semi-sunken structure with a central operations and plotting room surrounded by a circulating passage, offices, plant room and control cabins. The plain exterior elevations feature a flat roof with a protruding ventilation and exhaust structure above the plant rooms. An associated tall aerial stands immediately to the south-west of the bunker. The two entrances are protected by heavy blast walls with twin double outer blast doors of steel.

The interior centres on a double-height semi-sunken planning room overlooked by first-floor viewing galleries, which retain their characteristic curving perspex fronts and are supported on columns. These galleries connect to a suite of surrounding rooms, chiefly offices, latrines and rest rooms. Ground-floor rooms were designed primarily for ancillary equipment, plant, batteries and communications. The original and ancillary stairs remain in position. Most rooms leading off the main corridor retain their original wooden doors, and most interior spaces preserve original fittings including floor tiles over concrete floors and period light switches. The original box ducting for the ventilation system remains intact throughout. The air conditioning and filtration systems are intact and operational. The RN diesel engine and Crompton Parkinson generator system, installed in 1951, remains virtually intact, as does a hoist for mechanical goods.

Anti-Aircraft Operations Rooms formed an integral part of United Kingdom anti-aircraft defences during the early 1950s and embodied early Cold War defence strategy drawing on Second World War experience. The system was designed to counter the perceived contemporary Soviet nuclear threat from manned turboprop bombers carrying atomic bombs targeting major conurbations and airfields. By the mid-1950s, advancing technology—fast jet bombers, hydrogen bomb development, and long-range rockets—rendered the system obsolete.

The bunker at Furze Hill was constructed in 1951 for the Royal Artillery under the command of 1 Group, 6 Brigade. The AAOR network comprised 32 gun-defended areas across the United Kingdom, of which 23 were in England, typically positioned around major conurbations and centres of armament production. They received information of hostile aircraft approach from Master Radar Stations and allocated targets to gun batteries within their area. The Furze Hill bunker controlled Anti-Aircraft Batteries in the Harwich Defended Area, though this role proved short-lived. Anti-Aircraft Command was abolished in 1956, and the bunker was sold to Essex County Council in 1963. It later became one of four sub-controls reporting to the County Control at Chelmsford, and by 1966 served as County Emergency Headquarters for Essex County Council. From 1968 until the early 1980s it was placed on care and maintenance. In 1984 it became the county standby following the opening of a new control centre in County Hall. The bunker remained operational until 1993 when it was decommissioned. In 1995 it was leased to the Bunker Preservation Trust and opened to the public as a museum in 1996 until closure in 2002.

This Anti-Aircraft Operations Room is a rare surviving example of its type and one of the best-preserved remaining examples in England. Its intact exterior is complemented by a relatively unaltered interior, which retains its original room configuration, notably the central operations room with its first-floor viewing platforms, as well as the original air filtration plant and numerous original fittings.