Robert Watson-Watt’s contribution to radar began with a different problem: how to locate thunderstorms. Working with radio signals at the Meteorological Office, he developed techniques for finding the direction of lightning. The experience helped prepare him for a new challenge in the 1930s, when he and his colleagues investigated whether radio waves could reveal the position of aircraft. Their work led to Chain Home, the British radar network that supplied important warning during the Battle of Britain.
From Brechin to radio research
Watson-Watt was born in Brechin, Angus, on 13 April 1892. He attended Damacre Primary School and Brechin High School before entering University College, Dundee, then part of the University of St Andrews. He graduated in engineering in 1912 and stayed on as an assistant in the college’s Engineering Department. The physicist William Peddie encouraged him to study radio, then commonly called wireless telegraphy, and taught him about radio-frequency oscillators and the propagation of waves.
At the beginning of the First World War, Watson-Watt was working at the college. In 1916 he sought a position with the War Office, but instead joined the Meteorological Office, which was interested in his ideas about using radio to detect thunderstorms. Lightning produces radio signals. Watson-Watt’s aim was to detect them so that pilots could be warned of approaching storms.
His experiments showed that the signals could be detected over long distances. To estimate a storm’s direction, an operator turned a loop antenna until the signal was strongest or weakest. Because lightning flashes were brief, a single reading was difficult; operators instead combined observations from many strikes to estimate a location. Later, at Ditton Park near Slough, a system using Adcock antennas and an oscilloscope made it possible to display the direction of a strike on the screen. Watson-Watt’s system was in use by 1926.
The Met and National Physical Laboratory radio teams joined together in 1927 to form the Radio Research Station, with Watson-Watt as its director. Work on radio signals and their behaviour also brought researchers to investigate reflections from the upper atmosphere. After a further reorganisation in 1933, Watson-Watt became superintendent of the Radio Department at the National Physical Laboratory in Teddington.
Turning radio research towards aircraft
In the mid-1930s, the prospect of aerial attack presented a serious problem for British air defences. Aircraft could approach from across the Channel, and relying on fighters to patrol continuously would demand a very large force. The Air Ministry’s Committee for the Scientific Survey of Air Defence, chaired by Sir Henry Tizard, considered possible ways to improve protection.
In January 1935, the Air Ministry asked Watson-Watt whether radio waves could be used as a destructive “death ray”. A calculation by his assistant Arnold Wilkins showed that such a weapon was not practicable. Wilkins also proposed a more promising use: detecting aircraft through reflected radio waves. Watson-Watt developed the proposal and sent a secret memorandum to the Air Ministry on 12 February 1935. The ministry asked for a demonstration before committing funding.
On 26 February, Watson-Watt and Wilkins tested the idea near Daventry. Two receiving antennas were placed about six miles from a BBC short-wave transmitter. Signals travelling directly from the transmitter were arranged to cancel each other; signals arriving from another direction could register on a cathode-ray-tube display. When a Handley Page Heyford bomber flew nearby, the receiver showed returns from the aircraft. The demonstration established that aircraft could be detected in this way. Watson-Watt received a patent for a radio device for detecting and locating aircraft on 2 April 1935.
The achievement belonged to a developing team effort, not to a single demonstration alone. Wilkins and Edward Bowen were among those who continued the research. At Orford Ness in Suffolk, tests detected aircraft at 16 miles by June 1935 and reached 60 miles by the end of the year. The researchers used available components to get workable equipment into service quickly. By 1937 the first three stations were ready, and encouraging tests led the government to commission 17 more.
Chain Home and the Battle of Britain
Chain Home was a network of fixed radar stations, initially positioned to watch the eastern and southern approaches to England. Nineteen stations were ready by the start of the Second World War; more than 50 had been built by its end. The system entered service in 1938, before the Battle of Britain. It provided advance information about approaching aircraft, helping the Royal Air Force direct fighters where they were needed.
Radar did not by itself deliver that information to pilots. Early full-scale tests showed that tracking reports could take too long to pass through the system. Henry Tizard, Patrick Blackett and Hugh Dowding worked on the reporting and command arrangements that brought information together for assessment and communication to fighter units. Chain Home’s value therefore depended on both the equipment and the organisation built around it.
Watson-Watt left Bawdsey Manor in 1938 to become Director of Communications Development at the Royal Aircraft Establishment. In 1939 he became scientific adviser on telecommunications to the Ministry of Aircraft Production. He travelled to the United States in 1941 to advise on air defence after the attack on Pearl Harbor, then continued to lead radar development for the War Office and Ministry of Supply.
Radar development also included work beyond the coastal stations. Watson-Watt put Bowen in charge of developing radar that could be carried by a fighter. Airborne interception radar was perfected by 1940 and later helped end the Blitz. Watson-Watt’s approach has been associated with a preference for a usable, imperfect design over an ideal system that arrived too late. His often-quoted formulation was: “Give them the third-best to go on with; the second-best comes too late; the best never comes.”
Honours and later life
Watson-Watt was elected a Fellow of the Royal Society in 1941 and knighted by George VI in 1942. The United States awarded him the Medal for Merit in 1946. Ten years after his knighthood, the British government awarded him £50,000 for his contribution to radar development. In 1945 he delivered the Royal Institution Christmas Lecture on wireless.
After the war, he worked as a consulting engineer. He moved to Canada in the 1950s and later lived in the United States; his book Three Steps to Victory appeared in 1958. He returned to Scotland in the 1960s. His work on radio direction finding had also produced high-frequency direction finding, known as “huff-duff”, which could locate an enemy radio transmitter quickly and was used against German U-boats during the Second World War.
Watson-Watt died in Inverness on 5 December 1973, aged 81. He was married three times. His third wife was Dame Katherine Trefusis Forbes, who had led the Women’s Auxiliary Air Force and whose personnel supplied radar-room operators. The couple lived in London during the winter and at her home in Pitlochry during warmer months.
Why Robert Watson-Watt deserves a place in British Legacy
Watson-Watt deserves a place in British Legacy because his work helped turn radio physics into a practical part of Britain’s air defence. His career linked sustained investigation to an urgent public need: research into radio signals that began with locating thunderstorms ultimately contributed to a system capable of detecting aircraft at a distance. Chain Home was not simply a set of towers. Its usefulness depended on rapid development, working equipment and a reporting structure that could get information to those directing fighters. The history gives due weight to Watson-Watt’s leadership while recognising the contributions of colleagues including Wilkins, Bowen, Tizard, Blackett and Dowding.
The consequences reached beyond one wartime network. Watson-Watt’s earlier work on high-frequency direction finding helped locate hostile radio transmitters, and radar carried aboard aircraft became another part of the wartime effort. These developments show how engineering advances can grow through successive problems and applications. His British legacy is therefore not just the familiar association between radar and the Battle of Britain. It is also the example of scientific and engineering teams adapting ideas, equipment and systems to meet practical demands. The continuing memorials to him in Brechin and the naming of a radar briefing facility in his honour reflect the place his work holds in Britain’s engineering history.
Sources
Robert Watson-Watt — Wikipedia, revision 1379216830
Adapted in part from Robert Watson-Watt by Wikipedia contributors, under CC BY-SA 4.0. Text has been edited and combined with the existing article; this adapted text is shared under the same licence. Contributor history.