Royal Observer Corps

In this section we give an overview of the role of the ROC during the Cold War period, as the field staff of the United Kingdom Warning and Monitoring Organisation (U.K.W.M.O.). Please use the navigation menu details tab to view expanded descriptions of the various elements of the warning system.

ROC Function

A body known as The United Kingdom Warning and Monitoring Organisation (U.K.W.M.O.) was set up in 1957 to warn the population of any impending air attack. The Royal Observer Corps (ROC) set up in WW2 as part of the Royal Air Force (RAF) to spot enemy aircraft, became the eyes and ears of the UKWMO during the cold war. In the nuclear era the job of the Royal Observer Corps (ROC) was to report the positions of the bomb strikes and monitor resulting fallout areas and relay these back to UKWMO Group Headquarters. Fallout warnings issued by the UKWMO would be relayed to the public via the HANDEL network. The structure of the organisation was such that the destruction of an observer post or headquarters would have limited effect on the ability of the organisation to function as a whole.

Brief History of the ROC in Nuclear Warning and Monitoring

Throughout the Cold War the UKWMO staff and the ROC were separate organisations. The U.K.W.M.O. was run by the 'Home Office' in England and the 'Scottish Department of Home and Health' in Scotland through part time civil servants. The ROC continued to be part of the RAF and administered by the Ministry of Defence. The ROC at this stage were a uniformed organisation who were seconded to UKWMO to be its field force. Command of all sections resided with the non-uniformed UKWMO staff. The attack warning and subsequent fallout warnings were assessed by the scientific members of the UKWMO. ROC members played no part in any assessment or decision making within controls.

At the time of the creation of the UKWMO in 1957 the ROC consisted of 40 Observer groups with 1563 observation posts. In 1968 the Labour Government spending cuts saw the disbanding of the Auxiliary Fire Service, the Civil Defence Corps and some elements of the Territorial Army and Volunteer Reserve. The ROC was reduced in size to 873 underground posts and the staff halved. A further rearrangement of boundaries occurred in 1973 which reduced the organisation to twenty five groups. This left each ROC Group with thirty to forty observation posts within its control. Each post making frequent observations and forwarding them to Group for processing.

The ROC data was processed to generate bomb detonation locations then estimated yield (bomb size) were calculated. Taking into account factors like bomb size and wind direction, the UKWMO would make fallout predictions. Live radiation readings from ROC posts were used confirm the path of fallout and amend the prediction if necessary.

Each of the five Sectors consisted of five Groups, the Sector Headquarters was collocated with one of the Groups. Groups forwarded their observations to Sector who would collate this to create a national picture. Sectors had links to our European neighbours Civil Protection authorities to exchange information about fallout that may affect other counties.

Following a Home Defence review, government spending on the UKWMO increased during the 1980's, resulting in many improvements to equipment and especially communications. The structure set in 1973 remained fairly static until stand down in 1991.

Sector and Group Locations

UKWMO Group Areas

UKWMO Group Areas

The UK was divided into twenty five areas each served by a Group Headquarter. Five of these acted as Sector Headquarters too. Preston Sector headquarters also served as the UKWMO headquarters had the facility to issue the country wide HANDEL Attack Warning message should the RAF strike command be disabled.

The UKWMO Group locations were not a secret, as almost all were listed in their local telephone directory under Royal Observer Corp quoting an address and phone number. On the whole most members of the public knew nothing about the existence of the U.K.W.M.O.

A list of the all UKWMO Group Headquarters bunker locations in use at stand-down may be found in the part of this website concentrating on the details of the UKWMO organisation linked at the bottom of this page. Some have now been demolished and other bunkers have found new uses.


York ROC Group HQ

ROC Museum in York (former York UKWMO Group HQ)

During the period 1960-62 small underground chambers were constructed to protect the observers from blast and fallout. At this time Group and Sector Headquarters had purpose built bunkers constructed. These were usually semi-sunken to afford protection against minor blast damage and increase the fallout protection factor. The picture shows the York Group HQ, now a museum operated by English Heritage. The HQ originally stood in the grounds of a Government building the external fence around the museum was added when that property was sold off for housing development.

Typical ROC Post

This photograph is typical of the exterior view of a ROC observer post. A 20 ft vertical ladder leads to an underground chamber only 7ft x 16ft x 7ft high. This houses the observers and their instruments and welfare facilities. Conditions were very primitive, as there was no running water, gas or mains electric.


The ROC had an extensive communications network of its own. Other topics on this web site explore the communication network in great detail, use the tabs at the top of the page to navigate. To summarise:-

Stand Down

On the 10 July 1991, the current Home Secretary Mr Kenneth Baker, announced to parliament that the services of the United Kingdom Warning and Monitoring Organisation were no longer required. Its field force, the Royal Observer Corps would be 'Stood-Down' on 30 September 1991.

Former members meet socially via the Royal Observer Corp Association, (ROCA). Many of the monitoring posts have been left derelict but a small number survive thanks to the dedication of a few individuals who have lovingly restored them. Many of the Group controls have found other uses and some have been demolished for housing. In Bedford, for example, Observer Close MK40 4EU is all that remains of the former ROC Group Headquarters.