ROTOR
Encyclopedia
ROTOR was a huge and elaborate air defence radar
system built by the British Government in the early 1950s to counter possible attack by Soviet
bomber
s. The system was built up primarily of war-era radar systems, and was used only briefly before being replaced by more modern systems.
Thinking changed dramatically in 1949 with the Soviet test of their first atom bomb. It was known that the Soviets had made exact copies of the B-29 Superfortress
as the Tu-4 Bull, and these aircraft had the performance needed to reach the UK with a nuclear payload. Studying the problem, the Cherry Report of 1949 which suggested that the 170 existing Royal Air Force
radar stations be reduced to 66 sites and the electronics
extensively upgraded. East Coast sites were constructed in various 'hardened' designs in the 'R' series (R1, R2, R3 and R4 etc.), the original designs were not 'nuclear hardened' bunkers but very substantial structures protected against conventional attacks. West Coast sites were in semi-sunken hardened structures ( 'R6') or above ground 'Secco' type huts (Hartland Point etc.).
systems, while the rest were taken from the existing selection of Chain Home Low
, Chain Home Extra Low and the various Ground-controlled interception
(GCI) radars that had formerly served special purposes. This was, in part, a stop-gap measure anticipating the availability of the dramatically improved Type 80 Green Garlic radar which would replace the various early warning radars with a single system of much greater performance. Interception guidance would still be handled by existing systems in either case.
All of the radars were to be improved in terms of siting with the addition of hardened control bunkers to protect the operators from a conventional attack. On the east coast, the coast toward which a Soviet attack would be most likely, the bunkers were underground, while those on the western side of the UK were generally above ground as a cost-saving measure. The bunkers themselves were otherwise similar, featuring 10 feet (3 m) concrete walls with all equipment, operations generators and air conditioning located inside.
Additionally, ROTOR re-arranged the existing RAF Fighter Command
structure into six "Sector Operational Commands" (SOC) with their own command bunkers (three level 'R4' protected accommodation). Only four of these were built. Additional "Anti-Aircraft Operations Rooms" were built to coordinate the British Army
's AA defences in the same overall system. The entire network of bunkers, radars, fighter control and command centres used up 350,000 tons of concrete
, 20,000 tons of steel and thousands of miles of telephone and telex connections.
The work was mainly carried out by the Marconi Wireless and Telegraph Company
in several phases, called ROTOR 1, ROTOR 2 and ROTOR 3.
As a result of the introduction of the Type 80 (Green Garlic), many of the existing ROTOR sites were rationalized into Master Radar Stations (MRS), while the rest were made redundant, some only two years after opening, and all of the AAOR sites were closed. A few of these were re-used for government department ('RSG's) and local authority wartime headquarters. In the mid-1960s the MRS's themselves were replaced with a new system called Linesman/Mediator
.
Until the end of the Cold War many of the sites were retained by the government but now have been sold off to private buyers or converted into museums (for example 'RAF Hack Green') and some transferred to the National Air Traffic Control Centre
.
World War II
:
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
system built by the British Government in the early 1950s to counter possible attack by Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
bomber
Bomber
A bomber is a military aircraft designed to attack ground and sea targets, by dropping bombs on them, or – in recent years – by launching cruise missiles at them.-Classifications of bombers:...
s. The system was built up primarily of war-era radar systems, and was used only briefly before being replaced by more modern systems.
Post-war situation
UK radar operations were wound down late in the war, and by the time the war ended were already largely unused. It was assumed that another war was at least ten years away, and the need for any improvements in the cobbled-together system seemed remote.Thinking changed dramatically in 1949 with the Soviet test of their first atom bomb. It was known that the Soviets had made exact copies of the B-29 Superfortress
B-29 Superfortress
The B-29 Superfortress is a four-engine propeller-driven heavy bomber designed by Boeing that was flown primarily by the United States Air Forces in late-World War II and through the Korean War. The B-29 was one of the largest aircraft to see service during World War II...
as the Tu-4 Bull, and these aircraft had the performance needed to reach the UK with a nuclear payload. Studying the problem, the Cherry Report of 1949 which suggested that the 170 existing Royal Air Force
Royal Air Force
The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...
radar stations be reduced to 66 sites and the electronics
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
extensively upgraded. East Coast sites were constructed in various 'hardened' designs in the 'R' series (R1, R2, R3 and R4 etc.), the original designs were not 'nuclear hardened' bunkers but very substantial structures protected against conventional attacks. West Coast sites were in semi-sunken hardened structures ( 'R6') or above ground 'Secco' type huts (Hartland Point etc.).
ROTOR
Most of the new network would be made up of 28 re-built Chain HomeChain Home
Chain Home was the codename for the ring of coastal Early Warning radar stations built by the British before and during the Second World War. The system otherwise known as AMES Type 1 consisted of radar fixed on top of a radio tower mast, called a 'station' to provide long-range detection of...
systems, while the rest were taken from the existing selection of Chain Home Low
Chain Home Low
Chain Home Low was the name of a British radar early warning system, detecting enemy aircraft movement at lower altitudes than and summarily used with the fixed Chain Home system which was operated by the RAF during World War II...
, Chain Home Extra Low and the various Ground-controlled interception
Ground-controlled interception
Ground-controlled interception an air defense tactic whereby one or more radar stations are linked to a command communications centre which guides interceptor aircraft to an airborne target. This tactic was pioneered during World War II by the Royal Air Force with the Luftwaffe to follow closely...
(GCI) radars that had formerly served special purposes. This was, in part, a stop-gap measure anticipating the availability of the dramatically improved Type 80 Green Garlic radar which would replace the various early warning radars with a single system of much greater performance. Interception guidance would still be handled by existing systems in either case.
All of the radars were to be improved in terms of siting with the addition of hardened control bunkers to protect the operators from a conventional attack. On the east coast, the coast toward which a Soviet attack would be most likely, the bunkers were underground, while those on the western side of the UK were generally above ground as a cost-saving measure. The bunkers themselves were otherwise similar, featuring 10 feet (3 m) concrete walls with all equipment, operations generators and air conditioning located inside.
Additionally, ROTOR re-arranged the existing RAF Fighter Command
RAF Fighter Command
RAF Fighter Command was one of three functional commands of the Royal Air Force. It was formed in 1936 to allow more specialised control of fighter aircraft. It served throughout the Second World War, gaining recognition in the Battle of Britain. The Command continued until 17 November 1943, when...
structure into six "Sector Operational Commands" (SOC) with their own command bunkers (three level 'R4' protected accommodation). Only four of these were built. Additional "Anti-Aircraft Operations Rooms" were built to coordinate the British Army
British Army
The British Army is the land warfare branch of Her Majesty's Armed Forces in the United Kingdom. It came into being with the unification of the Kingdom of England and Scotland into the Kingdom of Great Britain in 1707. The new British Army incorporated Regiments that had already existed in England...
's AA defences in the same overall system. The entire network of bunkers, radars, fighter control and command centres used up 350,000 tons of concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
, 20,000 tons of steel and thousands of miles of telephone and telex connections.
The work was mainly carried out by the Marconi Wireless and Telegraph Company
Marconi Company
The Marconi Company Ltd. was founded by Guglielmo Marconi in 1897 as The Wireless Telegraph & Signal Company...
in several phases, called ROTOR 1, ROTOR 2 and ROTOR 3.
Post-ROTOR
As the anticipated Type 80 "Green Garlic" radar started testing shortly after ROTOR came online, it became clear that it could fill both early warning and interception guidance from a single site. This dramatically decreased the complexity of the ROTOR system, which otherwise required sightings from the early warning radars to be telephoned to the fighter control GCI stations for local plotting. By concentrating all of this complexity at a single site the total number of operators was greatly reduced.As a result of the introduction of the Type 80 (Green Garlic), many of the existing ROTOR sites were rationalized into Master Radar Stations (MRS), while the rest were made redundant, some only two years after opening, and all of the AAOR sites were closed. A few of these were re-used for government department ('RSG's) and local authority wartime headquarters. In the mid-1960s the MRS's themselves were replaced with a new system called Linesman/Mediator
Linesman/Mediator
Linesman/Mediator was the dual-purpose civil and military radar network in the United Kingdom. Against a background of the Russian H-bomb and supersonic bombers Linesman was the answer to the Cold War defence policies, replacing the earlier ROTOR and Type 80 Master Radar Stations that were the...
.
Until the end of the Cold War many of the sites were retained by the government but now have been sold off to private buyers or converted into museums (for example 'RAF Hack Green') and some transferred to the National Air Traffic Control Centre
National Air Traffic Services
NATS Ltd. is the main air navigation service provider in the United Kingdom. It provides en-route air traffic control services to flights within the UK Flight Information Regions and the Shanwick Oceanic Control Area, and provides air traffic control services to fifteen UK airports and Gibraltar...
.
Sector Operation Control centres
Custom Built:- BawburghBawburghBawburgh is a village and civil parish in the South Norfolk district of Norfolk, England, lying in the valley of the River Yare about west of Norwich city centre. According to the 2001 census it had a population of 466...
- Kelvedon HatchKelvedon HatchKelvedon Hatch is a village and civil parish in the Borough of Brentwood in south Essex, England. It is situated just north of Pilgrims Hatch, approximately to the north of Brentwood and is surrounded by Metropolitan Green Belt. The village today is no longer a rural backwater with a large...
- Barnton QuarryBarnton QuarryBarnton Quarry is a ROTOR bunker of the R4 type in Clermiston, Edinburgh. It was built in 1952 as the SOC for correlating information from ROTOR radar stations throughout Scotland...
World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
:
- Box, WiltshireBox, WiltshireBox is a village located in Wiltshire, England, about east of Bath and west of Chippenham. It is quite a large parish with several settlements, apart from the village of Box, within its boundaries....
- GoosnarghGoosnarghGoosnargh is a village and civil parish on the north side of Preston, Lancashire, England. The village lies between Broughton and Longridge, and mostly lies in the civil parish of Whittingham, although the ancient centre lies in the civil parish of Goosnargh...
See also
- Faraid HeadFaraid HeadFaraid Head is a small peninsula on the northern coast of Sutherland, Highland, Scotland, located two miles to the north of the village Balnakeil and three miles north of Durness....
- Hack Green Secret Nuclear BunkerHack Green Secret Nuclear BunkerThe Hack Green Secret Nuclear Bunker is a former government-owned nuclear bunker located at Hack Green, Cheshire, England.- History :The first military use of the area was in World War II, when a Starfish site was established at Hack Green...
- RAF WartlingRAF WartlingRAF Wartling was a Royal Air Force station located near the village of Wartling in East Sussex. It was an a Second World War and later Cold War Ground Controlled Interception station built to complement the nearby Chain Home station at RAF Pevensey....
- RAF BemptonRAF BemptonRAF Bempton was an RAF base situated at Bempton in the East Riding of Yorkshire, England, 6 miles north of Bridlington.-Operational history:*The site was established in February 1940 as RAF Flamborough Head, but was renamed by the end of that year...