The Royal Observer Corps (ROC) was a civil defence organisation operating in the United Kingdom between 29 October 1925 and 31 December 1995, when the Corps' civilian volunteers were stood down. (ROC headquarters staff at RAF Bentley Priory stood down on 31 March 1996). Composed mainly of civilian spare-time volunteers, ROC personnel wore a Royal Air Force (RAF) style uniform and latterly came under the administrative control of RAF Strike Command and the operational control of the Home Office. Civilian volunteers were trained and administered by a small cadre of professional full-time officers under the command of the Commandant Royal Observer Corps; latterly a serving RAF Air Commodore.
In 1957, the United Kingdom Warning and Monitoring Organisation (UKWMO) was established under Home Office control. It was intended that the UKWMO would provide both civil and military authorities in the UK with essential information during a nuclear attack, with the ROC providing primary data on the position and magnitude of atomic weapons detonated during any such attack. This data would be used by the UKWMO, in conjunction with weather information provided by the Meteorological Office, to produce a forecast of radioactive fallout. Fallout would be monitored as and where it occurred, with its actual location and strength mapped using data obtained from instrumentation at ROC posts. Such information when combined withROCMet, (data concerning actual wind speed and direction obtained from cluster Master Posts equipped with wind anemometers and other basic meteorological instruments), would permit the dissemination of accurate forecasts predicting the distribution and strength of nuclear fallout.
These underground bunkers are dotted throughout the UK but not many survive in great condition.