The Royal Observer Corps (ROC) was a civil defence organisation intended for the visual detection, identification, tracking and reporting of aircraft over Great Britain. It operated 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.
Overview In 1925, following a Defence Committee initiative undertaken the previous year, the formation of an RAF command concerning the Air Defence of Great Britain led to the provision of a Raid Reporting System, itself delegated to a sub-committee consisting of representatives from the Air Ministry, Home Office and the General Post Office. This Raid Reporting System was to provide for the visual detection, identification, tracking and reporting of aircraft over Great Britain, and was eventually to become known as the Observer Corps. The Observer Corps was subsequently awarded the title Royal by His Majesty King George VI in April 1941, in recognition of the meritorious service carried out by Observer Corps personnel throughout the Battle of Britain.
Throughout the remainder of the Second World War, the ROC continued to complement and at times replace the Chain Home defensive radar system by undertaking an inland aircraft tracking and reporting function, while Chain Home provided a predominantly coastal, long-range tracking and reporting system. With the advent of the Cold War, the ROC continued in its primary role of aircraft recognition and reporting, and in 1955 was allocated the additional task of detecting and reporting nuclear explosions and associated fall-out. By 1965, thanks to advances in (radar) technology, most roles and responsibilities relating to aircraft recognition and raid reporting had been withdrawn and the ROC assumed the role of field force for the United Kingdom Warning and Monitoring Organisation (UKWMO); a role which the ROC continued until the early 1990s and the cessation of the Cold War.
By the late 1980s the ROC comprised approximately 10,500 civilian spare-time volunteers. At HQROC (RAF Bentley Priory), over a dozen full-time secretarial, clerical and other administrative staff were present. Each of the five Area HQs were staffed by a clerical officer and a typist, and each of the 25 Group HQs were staffed by a clerical officer, typist and handyperson. (Many MoD civilian support staff were also civilian spare-time volunteers.)
Following the UK Government's Options for Change armed forces defence spending review in 1990, the vast majority of the civilian spare-time volunteers were stood down on 30 September 1991, with the remainder being stood down on 31 December 1995. The closure of HQROC on 31 March 1996 and redeployment of those few remaining HQROC staff marked the disbandment of the ROC after over 70 years of service.
First World War
The Royal Observer Corps can trace its roots to the First World War and the requirement for a warning system to bolster UK defences, predominantly over south-east England, against bombing raids by Zeppelin airships of the German Luftstreitkräfte. A system of observation posts and observers was organised, with a network of approximately 200 posts established in strategic areas. Initially these posts were manned by British Army personnel, who were in turn replaced by Special (Police) Constables, and posts were coordinated on an area basis with telephone communications provided between themselves and their associated anti-aircraft defences.
In 1917 Germany began to deploy increasing numbers of fixed-wing bombers, with the result that the number of airship raids decreased rapidly in favour of raids by such aircraft. In response to this new threat, Major General Edward Bailey Ashmore, a Royal Flying Corps pilot who later commanded an artillery division in Belgium, was appointed to devise an improved system of detection, communication and control. The system, called the Metropolitan Observation Service, encompassed the London Air Defence Area and later extended eastwards towards the Kentish and Essex coasts of the English Channel.
The Metropolitan Observation Service met with some success towards the end of the First World War and, although not fully operational until late 1918, (the last German bombing raid having taken place on 19/20 May 1918, when 38 Gotha and 3 Giant aircraft bombed London and surrounding districts), the lessons learned were to prove invaluable for future developments in the fields of aircraft recognition and raid reporting.
Types of air raid undertaken by the Luftstreitkräfte over the UK during World War IYearAeroplanesAirshipsDeaths1914300191544218619162812630219173413065019185910178
Interwar period
By the end of 1920, the observation-post networks and their associated anti-aircraft hardware had been decommissioned, and in 1922 the responsibility for air defence was transferred from the War Office (responsible for the army) to the Air Ministry.
Following this transfer, Major General Ashmore, who had been responsible for air defence during the First World War, reported to a new Air Raid Precautions (ARP) committee, established in January 1924. In areas surrounding Romney Marsh and the Weald a series of trials were undertaken to develop a Raid Reporting System which would employ an optimum arrangement of observation posts and associated control-centres. During 1925 these trials were further extended to cover parts of the counties of Essex and Hampshire, and by October a proven modus operandi had been developed for a new organisation to be known as the Observer Corps, which was established on 29 October 1925.
Within a year four groups operated in South East England, covering much of Kent, Sussex, Hampshire and Essex, with the intention that a total of eighteen groups would cover the whole of Great Britain. The system required cooperation between and the participation of the RAF, the army, the British police forces and the General Post Office (GPO). (The GPO at that time operated Britain's national telecommunications system.) In January 1926 county police constabularies recruited observers as special constables, and each observation post was manned by a sergeant and six special constables. Recruits were spare-time volunteers who received neither pay, uniform, nor allowances. Individual volunteers purchased the only distinguishing insignia, Observer Corps lapel badges, at their own expense.
In 1929 the control of the Observer Corps passed from the county police forces to the Air Ministry, although Chief Constables retained responsibility for personnel and recruitment matters. 1 March 1929 saw the establishment of the new Headquarters of the Observer Corps at Hillingdon House, RAF Uxbridge in the west of London, and Air Commodore Edward A D Masterman was appointed as the first commandant of the Observer Corps. Masterman remained the commandant of the ROC until his retirement on 1 March 1936, and was succeeded by Air Commodore Alfred Warrington-Morris, who would lead the Observer Corps through the critical period during the Second World War which saw the RAF emerge bruised but victorious following the Battle of Britain of 1940.
During the 1930s the number of groups increased until by 1936, England had a full coverage of observation posts south-east of a line between Flamborough Head in Yorkshire and Poole Harbour in Dorset. In 1936 the Headquarters of the Observer Corps relocated from RAF Uxbridge to RAF Bentley Priory in north-west London. By 1939 a system of observation posts covering practically the whole of Great Britain was able to be integrated fully into the Dowding system of air defense, with the western parts of Wales and Scotland together with England's West Country being incorporated during 1940, (The final group, Portree in the Hebrides, forming in 1941).
Second World War
Preparation
At the end of September 1938 the political crisis which culminated in the Munich Agreement had led to the Observer Corps being mobilised for a week. This highlighted organisational and technical shortcomings, and provided the impetus for the development of solutions to resolve these. A series of exercises held throughout 1939 provided opportunities for the fine tuning of improvements made to command and control functions.
At this time the only uniform items issued to Observer Corps personnel were steel helmets bearing the stencilled letters 'O C', together with blue/white (vertically striped) armbands bearing the same. Both items of equipment were similar in style to those issued to members of the civil defence emergency services, including the Auxiliary Fire Service ('AFS') and Air Raid Precautions ('ARP'). The initial batch of helmets issued to Observer Corps members were the same as those issued to Police forces; black in colour with the word 'POLICE' stencilled in white. (This led some Observer Corps members to simply scratch off the stencilled letters P, L, I, and E, to leave letters O and C remaining as one can see in the photograph below).
High quality Royal Navy-issue binoculars were issued to observers, whose observation posts often consisted of a wooden garden shed located next to a telegraph pole, this arrangement enabling a telecommunications link to be established with a control centre, often via a manual switchboard at local telephone exchange. These 'garden shed' style observation posts were eventually replaced by more substantial brick structures, protected by sandbags, which due to their often having been constructed by Observer Corps personnel themselves resulting in no two observation posts being identical.
Observation posts were located in open playing fields, hilltops or cliff edges and, particularly in urban areas, on the rooftops of public buildings and factories. Purpose-built observation posts introduced later were usually two-storey structures, constructed of brick or concrete, with an open-topped observation platform situated above a small crew rest area.
Early days of the war
On 24 August 1939 Chief Constables issued Mobilisation Notices to all members of the Observer Corps, with war being declared just ten days afterwards. From 3 September 1939, observation posts and control centres would be manned continuously until 12 May 1945, four days after VE Day.
The first months of the Second World War were known as the Phoney War, with little significant enemy aircraft activity over Great Britain. The Battle of Dunkirk commenced at the end of May 1940, with Allied troops cut off in retreat by the German Army in north-east France, resulting in the evacuation of British troops in Operation Dynamo. During this time the RAF lost a total of 944 aircraft, with half of these being fighter aircraft. Observer Corps posts in Kent and around the Thames estuary were able to play some part in plotting aircraft while they were over south east England. This was a useful period of exposure to war-time operations for Observer Corps personnel, and one which would provide invaluable experience.