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 registered charity number 1051994

 member of the British Aviation
 Preservation Council

  Friday 30th July 2010

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ROC Introduction

ROC History

Royal Observer Corps History

1920s

ROC Beginnings

The ROC had its beginnings during World War I. At the beginning of the war the need for an air raid warning system was not envisioned, but raids by Zeppelin airships starting in 1915 indicated that a warning system was needed.

A system of observers was soon organised with a series of some 200 posts established in strategic areas, initially these were manned by troops, but these were soon replaced by police, coordinated by area with telephone contact to anti-aircraft (AA) defences. This system proved to be reasonably successful in combating the Zeppelin.

In 1917 Germany started using fixed wing bombers and the number of airship raids diminished rapidly. To answer this new threat Major General E B Ashmore, who could fly and had been in command of an artillery division in Belgium, was appointed to devise improved systems of detection, communication and control.

General Ashmore devised a system which made use of all the various existing defence units which covered closely the London and South / South Eastern districts.

This system, known as the London Air Defence Area (L.A.D.A) and which was fully operational by September 1918; brought together these units comprising coastal and inland observation posts, searchlight and gun stations; balloon aprons, aerodromes and emergency landing grounds into coordinated groups of twos and threes and which were connected to 25 Sub-Controls.

Statistics of Air Raids on the UK during WW1

The system met with some success and although it was not fully working until late summer 1918 (the last air raid took place on 19 May) the lessons learnt were to provide valuable grounding for later developments.

The peace of the ending of World War 1 was followed by an era of strict economy and limited armament. In January 1924, an inquiry was held to investigate the aerial defence of the south east of England, south of a line drawn from Portland Bill to the Wash.

As a result from this inquiry, it was decided that an organised system was essential for the rapid collection and distribution of information on the movement of hostile and friendly aircraft. It was therefore in 1925 that the efforts of Major General Ashmore came to fruition in the formation of the Observer Corps.

Since its inception in 1925 as in integral part of the UK air defense system, the primary role of the Observer Corps (OC) was the recognition and identification of hostile aircraft.

ROC Crest depicting a Beacon Lighter of the Spanish Armada era

1930s & ‘40s

“The Nazi Threat”

Between 1939 and 1945 - the period of the Second World War - 32,000 men and women (observers) spotted, plotted and reported thousands of the aircraft attacking and approaching Britain. This was undertaken from a number of strategically placed overground posts which provided effective viewing of the sky by day and night, in anticipation of any potential attack. Their work enabled RAF fighters and anti-aircraft gunners to be prepared for any attacks.

Preparation

At the end of September 1938 the crisis which resulted in the “Munich Agreement” lead to the Corps being called out for a week. This exercise proved to be invaluable as it drew attention to organisational and technical problems and gave time for solutions to be sought. Exercises held throughout 1939 enabled necessary modifications to methods and structure. The Observer Corps would evolve over the coming years, a process aided by the keenness with which Corps members from every walk of life addressed the process.

World War 2

On 24 August 1939 Chief Constables issued mobilisation notices to all members of the Observer Corps. War was eventually declared on 3 September, posts and centres would be manned continuously until 12 May 1945, four days after VE Day on 8 May 1945.

The first months of World War II were known as the Phoney War. There was little significant enemy aircraft activity over Britain. The Battle of Dunkirk started at the end of May 1940, Allied troops were cut off by the German army in north-east France. This resulted in the evacuation of British troops in “Operation Dynamo” which ended on 4 June.

During this time the RAF lost 944 aircraft, half of these being fighters. Observer Corps posts in Kent and around the Thames estuary were able to play some part by plotting aircraft while they were over England. It was however an extremely useful period for training and practice which proved to be extremely valuable within a few months.

After the Fall of France, the German aim was air superiority over Britain to be achieved by destroying RAF fighters in the air and on the ground, and by bombing aircraft factories. Winning the “Battle of Britain”, as it was soon called, was Germany's prerequisite in preparation for the invasion of Britain … Operation Sealion.

The British Chain Home radar system was able to provide warning of enemy aircraft approaching the British coast, but once they had crossed the coastline the Observer Corps provided the only means of tracking them. During the period from July to October 1940 the Corps was fully stretched 24 hours a day plotting aircraft and passing this essential information to RAF groups and sectors.

The Battle of Britain saw the start of the Blitz, the shift of German bombing from airfields to cities, the Observer Corps provided the information which enabled air raid warnings to be issued. The Blitz itself continued until early in the summer of 1941 and bombing on a reduced scale continued until March 1945.

The Royal Warrant

After the successes of 1940 and early 1941 the Corps was retitled the Royal Observer Corps (the ROC); it was to continue as a civilian organisation and be administered by the Royal Air Force, and for the first time women members would be recruited.

Members of both sexes were employed in two forms: Class A who were required to work for 56 hours a week, and Class B members who undertook up to 24 hours duty per week.

For the rest of the war the ROC provided an essential part of Britain's air defences. In 1944, during preparations for the invasion of France called Operation Overlord, a request for volunteers produced over 1,000, 800 of whom performed valuable aircraft recognition duties as seaborne volunteers.

During Operation 'Totter', the ROC fired ‘Snowflake’ illuminating rocket flares from the ground to identify V-1 flying bombs to RAF fighters.[1] On 12 May 1945, when it was certain that all Luftwaffe aircraft were grounded, the ROC temporarily stood down, to be quickly re-activated to meet post-war threats.

Corp’ Structure

The headquarters of each Group operated from a Centre and controlled about 30 to 40 Posts each of which would be some 10 km to 20 km from its neighbour. By 1945 there were 40 centres covering England, Wales and Scotland, controlling in total more than 1,000 posts, The ROC did not operate in Northern Ireland until 1954.

Overground Monitoring Posts

Posts were equipped with a mechanical sighting instrument mounted over a gridded map (See Display). If you know the height of an aircraft it is possible, from its horizontal bearing and vertical angle, to calculate a position. After setting the instrument with an estimate of the aeroplane's height, the observer would align a sighting bar with the aircraft. This bar was mechanically connected to a vertical pointer which would indicate the position of the aircraft on the post map.

Observers in posts reported the map coordinates; height and number of aircraft for each sighting to their Centre. At each Centre plotters sat around a large table map, they had head sets continuously connected to a Cluster of posts, usually three in number.

The plotting table consisted of a large map with grid squares and posts marked. Counters were placed on the map at the reported positions, each of which indicated the height and the number of aircraft represented, a colour coding system indicated the time of observation in 5 minute segments.

The table was surrounded by plotters, each communicating with a cluster of posts. Over time the tracks of aircraft could be traced, the colour coding enabled the extrapolation of tracks and the removal of stale ones. From 1942 long range boards were introduced to centre operations rooms, tellers in contact with neighbouring groups could handover incoming and outgoing tracks which were plotted on this map.

Operations Room (Centre)

Duties in the operations room included: plotters working on the plotting table and on the long range board; tellers communicating with neighbouring ROC groups, with fighter operations rooms, with anti-aircraft and searchlight units; alarm controllers in contact with the police, with the national alert system, with the Ministry of Home Security and with local factories; an interrogator liaising with the ground controlled interception (GCI) radar units; and the Duty Controller, his assistant and a post controller who supervised the plotters and posts.

Obviously it was essential that observers could correctly identify an aeroplane. In 1939 aircraft recognition was not yet the highly prized skill it was to become in the Observer Corps. The other services felt that accurate identification was impossible. Observers realised that this was a deficiency and the raised profile of aircraft recognition was driven from below. Identification literature with aircraft silhouettes and data, started almost entirely as a private initiative instigated by observers.

In September 1947, over a year after VE Day, the ROC held its first small scale exercise in southern England, which included for the first time substantial numbers of jet aircraft.

Another year later the first large scale exercise took place; in the last two of its four days of this radar only was used.

1950s

COLD WAR: The Nuclear Reporting Role

When the dust had settled in 1945 the incredible pace of development of fighting weaponry, had given, only too well, the clues to the future.

On the allied side, the Atom bomb had given them a weapon which had ensured the surrender of Japan; the Germans had developed the V2 rocket which was mobile and able to be fired from any site, and for which the allies were almost powerless.

U.K.W.M.O

By the mid-1950s the greater speed of aircraft and the improved performance of radar lead to a reduced need by the RAF for the ROC's services in tracking aircraft; another rôle in defence against nuclear weapons was announced in June 1955. The first significant exercise involving the ROC in handling nuclear data was in 1956.

In 1957 the British government's policy became clear and reliance would be placed on the nuclear weapons and within ten years any pretence that there was aircraft recognition and reporting role for the ROC had all but gone.

Later in ‘57 the United Kingdom Warning and Monitoring Organisation (UKWMO) was set up under Home Office control. It was intended that UKWMO would provide civil and military authorities in Britain with information during a nuclear attack.

The ROC would provide the first data on the positions and extent of the attack. This data would be used by UKWMO, in conjunction with weather information from the Meteorological Office, to produce a forecast of radioactive fallout.

As this fallout occurred, its strength and position would be mapped using data from posts, enabling further fallout forecasts to be given.

To enable the ROC's centre and post structure would need to undergo physical and organisational change. The Groups were reorganised the number being reduced from 40 to 31, the Corps now covered Northern Ireland for the first time.

Nuclear fallout monitoring within ROC Sector Control

1960s, ‘70s & ‘80s

COLD WAR: Underground Nuclear Monitoring

“Going Underground”

With the start of the cold war and the increasing threat of nuclear attack in the 1950's, the ROC added responsibility of reporting nuclear bursts and monitoring fall-out necessitated the construction of 1563 underground monitoring posts throughout Great Britain & Northern Ireland. (The posts were later reduced in number to approximately 850 from 1968).

It would now be necessary for these posts (as well as centres) to be occupied for at least seven days after any nuclear event: centres were expanded with increased accommodation, emergency power generation and air handling and filtration, and underground posts were constructed with concrete under a 200 mm slab, they were 4.75 metres long and 2.25 metres in length and height.

Power would be supplied from a 12 volt car battery. Conditions in these posts cramped, cold and damp, it was fortunate for observers that long occupation was never necessary.

Altogether more sophisticated than its WW2 role; the ROC formed part of the United Kingdom Warning and Monitoring Organisation (UKWMO) which was the only organisation in Britain equipped and trained to report on radioactive fall-out on a national basis.

The fact that the Corps was trained to obtain and disseminate this information might have well meant the difference between life and death for many of us.

Initially communications were by telephone, replaced in 1964 by Tele-talk units; these used landlines with transistorisation to boost power. The vulnerability of land lines lead to VHF radio being installed with one post in each cluster; clusters had local arrangements for communication between themselves.

“The Science Bit”

If nuclear weapons are used on a large scale, those of us living in the country areas might be exposed to as great a risk as those in the towns.

Following a nuclear bomb-burst, dust and debris are sucked up into the atmosphere by the explosion. After being dispersed by any subsequent wind, it falls across the country as radioactive particles or commonly known as fall-out.

The radioactive dust, falling where the wind blows it, will bring the most widespread dangers. No part of the United Kingdom could be considered safe from both the direct effects of the weapons and the resultant fall-out.

Thanks to the array of instruments and apparatus embodied in the 25 reinforced Group Controls and the underground monitoring posts, the Corps would have been able to supply essential data on the arrival and intensity of the fall-out. This would enable officers of the United Kingdom Warning and Monitoring Organisation to advise people in the path of radioactive dust to take cover.

The ROC was ideally suited for its role of reporting fall-out. The strategically placed network extended from the Orkneys to the far south-west. Each Group Control was in contact with a network of about 30 small monitoring posts spaced some 10 to 15 miles apart. However, although the role of the Corps had changed completely during the late 1960’s / Early 1970’s, the traditional links with the Royal Air Force remained and the skill of visual aircraft recognition was still maintained by post observers up until stand-down in 1991.

ROC Underground Monitoring Post

1990s

“The Big Thaw”

Stand-Down

Following the stand-down of the main field force of the ROC in September 1991, and the disestablishment of the UKWMO following what was described by HM Queen Elizabeth II at the ROC Royal Review as "the end of the Cold War", the remnant elements of the Corps entered a new and highly-uncertain phase.

Reduced to less than 300 members in total over the whole UK, the original retained Nuclear Reporting Cells (NRCs) found themselves tasked with the challenge of providing a comprehensive Nuclear, Biological and Chemical (NBC) warfare analysis and warning service for the Military Home Commands, on a reserve-manned basis as NBCCs.

The removal of any Home Office involvement in the ROC from 1991 onwards resulted in the "Remnant Elements" becoming effectively a single reserve Directly Administered Unit within RAF Strike Command (RAFSTC), commanded by Group Captain (GND).

All still-serving members were required to remove their original ROC Group designations from their air force uniforms, and to accept moves towards a change in conditions of service during any Transition-To-War (TTW) that would make them effectively members of the Royal Auxiliary Air Force (RAuxAF), with protected rights, and closer links were made with the war-appointable flights of the Royal Air Force Volunteer Reserve (RAFVR).

Despite having successfully built upon the extensive NBC reporting trials carried out earlier with the RAF Regiment, meeting full NATO standards and evalutions (STANAGs and OPEVALs), and the total support of the RAF for keeping the ROC in the orbat, the conclusion reached by the UK MoD was that retention of the Corps in its NBC Cell role was "desirable but not essential in the existing format".

As a consequence, the remaining part-time members of the ROC were stood-down in a Corps Banner laying-up ceremony at RAF College Cranwell on 8 Dec 1995. The ROC Banner hangs in the Rotunda at RAFC Cranwell alongside other stood-down Air Force units and squadrons that are subject to liability for reactivation in the future.