It is fortunate that the committee for the scientific survey of air defence, chaired by Sir Henry Tizard, had foreseen the need for an air detection device several years in advance of the outbreak of war. A member of this committee wrote to Sir Robert Watson-Watt about the possibility of developing a radio “death ray” which would have enough energy to incapacitate aircraft. Watson-Watt’s assistant, Arnold Wilkins, calculated that this would not be feasible with the current technology, but a way of detecting reflected energy from aircraft could be possible.
Further investigations led to Watson-Watt’s memorandum, “Detection and Location of Aircraft by Radio Methods”. Experiments took place on 26th February 1935 and the results so impressed Watson-Watt that he said, “Britain has become an island again!” Watson-Watt was born in Brechin in 1892 and educated at Damacre School and Brechin High School. In 1912 he graduated with a Bsc in engineering from UCD. By 1935 he had made it possible to follow an aeroplane by the radio-wave reflections it sent back. The directions of such an object is discovered by transmitting a beam of short-wavelength, short pulse radio waves, and picking up the reflected beam. Distance is determined by timing the radio waves, which travel at the speed of light, to the object and back. This is known as radar which is an acronym for radio direction and ranging.
On 1st September 1936 Watson-Watt became superintendent of a new establishment under the Air Ministry at Bawdsey Manor near Felixstowe. Due to his work there radar was first put to practical use for aircraft detection by the British who had a complete coastal chain of radar sets installed in time for the war. Researchers at Bawdsey were concerned that it would be a prime target for the German bombers, so Watson-Watt renewed old contacts at Dundee University. He arranged with the Vice-Chancellor emergency accommodation at Dundee University. However, when the Bawdsey team arrived the Vice-Chancellor appeared to have forgotten the visit and the arrangement he made with Watson-Watt! He provided two rooms, which was all he could spare for the several hundred people arriving in Dundee. Flying facilities were provided at the airfield in Scone where two aircraft hangars were used for laboratory work. The main work at Dundee was on the Chain Home Low System to enable ground controlled interception, (GCI), so night fighters could be directed close to the enemy aircraft to overcome range limitations. Experience and training in the use of GCI led significantly to the cessation of night bombing in 1941 as the RAF were so successful the German losses couldn’t be sustained.
Radar made it possible for the British to detect oncoming German aircraft as easily by night as by day and in all weathers, including fog. Professor C Susskind wrote, “Watson-Watt’s able reasoning, his grasp of what was feasible, his clear conception of the operational requirements and organisation were all brilliantly vindicated by the success of the British radar network during the Battle of Britain”.

Return to Index