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Gee, or AMES (Air Ministry Experimental Station) Type 7000, was a British radio navigation system used by the RAF and Bomber Command during World War II, which allowed bomber crews to navigate accurately at night across the blacked out countries of Europe to reach their targets in Germany.

Gee was a codename rather than an acronym, inspired by the virtual grid created by the interaction of the transmitted signals, and was later interchanged with Jay in messages in a move intended to confuse German intelligence.

In operation, a master station broadcast a series of reference pulses, while synchronised slave stations would broadcast similar pulses, delayed by a few milliseconds. By analysing the difference in the arrival time of these various pulses at the aircraft, the navigator could determine the position of the aircraft.

The Northern Gee chain operated from late 1942 until March 1946. The master and monitor stations were on Burifa Hill on Dunnet Head, Caithness, with slave stations at Scousburgh, Shetland Islands; Windyhead Hill, Pennan (Aberdeenshire); and Sango, Durness (Sutherland).


Gee was superseded by the later American LORAN (long range navigation) system, and the station was upgraded, receiving an AMES Type 23, also known as a Type 700 for security reasons. LORAN was used mainly by the United States Navy and Royal Navy, but the RAF employed the system when missions exceeded the operational range of Gee, which could typically reach up to 300 miles, while LORAN could reliably reach 400 miles, and much further in later developments. A number of Gee stations were upgraded to LORAN, and development of the system continued after the war, and the LORAN system developed into a world wide system used for coastal navigation.

Based entirely on terrestrial radio, LORAN remains a valuable alternative to the Global Positioning System (GPS) and its dependence on satellite technology. LORAN systems are currently maintained as a matter of public policy by government bodies, and the British government has undertaken to develop and maintain eLORAN (enhanced LORAN) fully until 2022.[1] The system is not only wholly independent of any of the GNSS (Global Navigation Satellite Systems), but offers technical capabilities which GPS cannot achieve, and the two can enhance one another's operation in future.

Scottish Gee chain

Shortly after the end of World War II the Scottish Gee chain was esstablished to provide navigational services to civil aviation. The master station was on Lowther Hill, and the slave stations on Craigowl Hill , Great Dun Fell, and Rhu Staffnish. The electronics were originally installed in transportable shelters, but permanent sites were constructed and became available shortly afterwards. The site at Rhu Staffnish included accommodation blocks immediately adjacent to the farm known as Feochaig, while a road was constructed to the top of an adjacent hill where the radio transmitters were installed. This accommodation was never in fact used, as staff were accommodated at farms in the vicinity and in Campbeltown.

The chain was closed in 1969 when more accurate methods of navigation had superseded Gee. No other Gee chains were set up for the benefit of civil aviation.

Closure of the Scottish Gee chain in 1969 was reported in FLIGHT International:

Scottish Gee chain closed, 1969, unknown
Scottish Gee chain closed in 1969

Gee chain closure

WHEN THE SCOTTISH GEE chain closed down earlier this year after 21 years of service to aviation, Mr E. L. T. Barton, lately retired chief of telecommunications NATCS, Board of Trade, performed the closing ceremony at Lowther Hill. He called up the slave stations in turn: Great Dun Fell in Cumberland (2,788ft), Craigowl Hill near Dundee (1,400ft), and Rhu Stafnish in Argyll (709ft) all came on the air to say farewell. The day began with an informal luncheon for a group of men who had been closely associated with Gee since its inception. Gee was the highly accurate navigational system first used by RAF Bomber Command over occupied Europe during the war.

The Scottish Gee chain was built immediately after the war to cover the aviation routes from Scotland to the south. It was the only civil chain built, and resulted from co-operation between industry, the airlines and Government through a committee chaired by Sir Robert Watson Watt.

The RAF system first got off the ground on June 26, 1941, and met two distinct requirements. It enabled a navigator, after penetrating deep into enemy-occupied Europe, to get his aircraft back to base or locate a safe alternative before his fuel supply ran out. Coverage was not limited to home territory and targets, particularly in such places as the Ruhr which had previously been so elusive, could be located. Effectiveness of the bombing offensive also improved since accurate navigation on the first stage of the journey improved the chances of locating the target at the far end. Other wartime aids such as G-H, Oboe, Rebecca/Eureka and H2S soon followed but Gee remained for many years the basic aid to navigation for the Mosquitoes, Wellingtons, Lancasters, Halifaxes and Stirlings of Bomber Command. During the 1950s the Scottish Gee chain proved invaluable to BEA on their Scottish services. In recent times civil aviation came to rely on other electronic devices, such as ADF, VOR and radar. The RAF continued to use the Gee system, including the Scottish chain, until this year but because they too are now) turning to other systems the Scottish chain has been closed down. Severe winters

Tributes were paid to the men who man the Lowther Hill station. They had a hard time in winter and were often cut off for several days at a time. Arctic conditions are common for seven or eight months of the year, only equalled in Greenland, the Canadian North and the Antarctic. It was pointed out that although they were saying goodbye to Gee this would not be the end of the four stations because over the years they have become the principal radio communications stations of the National Air Traffic Control Service in Scotland. NATCS at Prestwick exercises varying degrees of jurisdiction over all air movements in Scotland and it does so through these stations, which, because of their altitude, cover between them a substantial proportion of Scottish airspace. Now at Lowther Hill the BoT is building, not without great difficulty because of weather conditions, two large radar installations, both housed in huge radomes, to feed back to the Air Traffic Control Centre at Prestwick as a small part of the 200 million modernisation programme of the service.

- Gee Chain closure. FLIGHT International, 17 July 17, 1969.[2]


1 Trinity Housr press release about eLORAN

2 FLIGHT International, 17 July 17, 1969.


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