Radar Recollections - A Bournemouth University / CHiDE & HLF project


The prototype CH system - 1939... Chain, Home... Operational

Transmitter Receiver Towers
A set of TRansmitter and Receiver towers

Three principal companies were responsible for the manufacture of the Chain Home equipment; Metropolitan Vickers, A.C.Cosser and Marconi. The Type 1 CH stations typically involved 4 steel transmission towers and 4 slightly smaller wooden receiving towers.

Goniometer Control
A Radio operator using the Goniometer control

In the control room, trained Radar operators (often women) sat at the receiver / display consoles would carefully rotate the gonimeter (a device that determines the angle or bearing of an incoming radio signal) and searches for 'blips' on the screen. The work was skilled and required great concentration. The range and bearing of all 'blips' was noted and converted to a grid reference and then passed to the 'filter room'. It was the task of the filter room to pass accurate information (usually by telephone) to the squadrons on 'standby' for action. By 1940, it was possible to give up to 24 minutes notice to a squadron that an enemy formation was incoming. This was sufficient time to 'scramble' a squadron.


The system had some shortcomings… the beam produced at the 10 - 12 M wavelengths worked well in the horizontal plane but much of the energy was reflected off the surface of the land or sea and caused reflective problems. This meant that altitude estimations were possible only at intermediate flying heights.

There was a need to develop a system that could identify incoming low level aircraft. The solution was to use higher power and a much shorter wavelength of 1.5 M. The new system was known as 'Chain Home Low' (CHL). The new units were installed very quickly all along the south (and then east) coasts. Developments also included the construction of mobile CHL units that could be rapidly deployed depending upon varying enemy tactics.

By 1942 some 50 CH / CHL Stations had been constructed and encircled the whole of the British Isles and were the operational responsibility of (RAF) 60 Group.

Professor G. E. Bacon
Professor G. E. Bacon
Mr S. Ratcliffe
Dr G. L. Hutchinson(1)
Dr G. L. Hutchinson(2)
Dr G. L. Hutchinson(3)