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Fennessy, Sir Edward (1912–2009), radar pioneer and telecommunications executive, was born on 17 January 1912 at 26 Haldane Road, East Ham, London, the eldest of three children of Edward Patrick Fennessy (1884–1955), a schoolteacher of Irish descent, and his wife, Eleanor, née Arkwright (1882–1942), also a teacher. Practical rather than academic, Edward (often called Ned in later life) began making electrical circuits when he was ten. He attended St Bonaventure's Roman Catholic Grammar School in Forest Gate, London, but left at sixteen to join the British arm of the Swedish electrical firm ASEA as an apprentice. In 1931 he went to East London College (later Queen Mary, University of London), graduating in 1934 with a second-class degree in electrical engineering. He then followed his friend Geoffrey Roberts into the communications company Standard Telephones and Cables. On 28 August 1937, at the Roman Catholic church in Woodford Wells, Essex, he married Marion Banks (1903–1983), a schoolteacher and daughter of Albert Edwin Banks, mechanical engineer. They had a daughter and a son.

At Standard Telephones and Cables, Fennessy researched circuits for sound locators—‘passive’ devices used before the development of radar to locate aircraft by amplifying the noise of their engines. Radar, by contrast, is an ‘active’ technology which detects targets by bouncing far faster electromagnetic waves off their surface, and Fennessy would contribute decisively to its evolution and its successful use during the Second World War. Though radar was conceived in the nineteenth century, the first useful systems were built in America, France, Germany, Britain and elsewhere during the 1920s and 1930s. British work was led by the radio researcher Robert Watson Watt. While experiments at Orfordness, on the Suffolk coast, convinced him that radar worked, Watson Watt realized that a few stations, however effective, would only ‘see’ planes approaching a small part of the country's long coast, that there must be a reliable system for ensuring RAF fighters were sent to the right place in the right numbers to intercept them, and that radar would be of no value in the conflict many now saw as inevitable unless it was ready in time.

Watson Watt's answer was chain home, a network of stations guarding Britain's coast, and ‘filter rooms’ where information from these stations and other sources could be collated and forwarded to RAF fighter bases. To speed development, Watson Watt's small team moved in 1936 from Orfordness to nearby Bawdsey Manor where they were joined by some of Britain's ablest physicists, including Geoffrey Roberts. Roberts recommended Fennessy but his qualifications were not thought adequate and he was initially rejected. It quickly became clear, however, that practical engineering mattered as much as science and in 1938 Fennessy was summoned to Bawdsey. There he refined and integrated the first chain home stations, worked on the associated chain home low system that filled gaps in the coverage provided by chain home, and helped design high-speed calculators vital to the system's performance.

When the Munich crisis of 1938 showed that war was imminent, Fennessy and Roberts drove overnight to Fighter Command HQ at Bentley Priory near London where Roberts persuaded Air Chief Marshal Sir Hugh Dowding to extend the chain home network and install the first filter room (the latter being completed in thirty-six hours). Amid fears that Bawdsey might be attacked, Watson Watt's ‘boffins’ were moved to Dundee when war broke out. But Fennessy persuaded the RAF that radar operations must be tied to Fighter Command and, after an unsatisfactory spell in Harrogate setting up the enlarged chain home network—there were eventually over sixty stations—he helped establish 60 Group to supervise the whole radar system. To give him the necessary service rank Fennessy joined the RAF Volunteer Reserve. Initially a pilot officer (probationary), he later became a squadron leader. Based, at his suggestion, at Oxendon near Leighton Buzzard, Fennessy and 60 Group managed the coherent structure of radar stations, filter rooms, and communications links that helped bring victory in the battle of Britain by ensuring that the country's scarce planes and pilots stayed on the ground until required. The RAF then went on the offensive, targeting Hitler's ‘war machine’—the factories in the Ruhr valley that made his weapons and raw materials. But poor navigation meant that bombers often missed and the radar scientists were asked to find a solution. Their first response was Gee, a complex system devised by Fennessy's university colleague Robert Dippy. Fennessy led its introduction and Gee contributed to the famous dam-buster raids. Gee was followed by Oboe. Invented by Alec Reeves, Fennessy's contemporary at Standard Telephones and Cables, Oboe was the most accurate aiming device of the Second World War.

In 1943 Fennessy initiated plans to integrate radar into the landing on continental Europe which he saw as the next step, prompting alarm (and his brief arrest) when senior officers realized he was not ‘bigoted’—the code for those officially involved with operation Overlord. Radar duly played a vital role, and soon after D-day Fennessy himself landed in Normandy. Surviving attack by US troops who failed to recognize RAF uniforms, he supervised the deployment of mobile radar stations that eventually took the war to Berlin itself. He was mentioned in dispatches and was appointed OBE in 1944. Promoted to group captain, Fennessy now became responsible for all RAF radar and radio navigation systems in Britain and Europe.

Soon after the Second World War Fennessy met his German opposite number, Wolfgang Martini, who told him that, though a German airship crew had detected signals from chain home, they did not realize it was a radar because its low frequencies showed it was old-fashioned by German standards. Fennessy accepted this implicit criticism at a technical level but felt Britain's real achievements were to develop an integrated, radar-based defence system—something the Germans did not have, though they had excellent equipment—and to ensure it was up and running when war began in 1939. As well as his vital contribution to that success, Fennessy has a more bizarre claim to fame. From the earliest days of chain home, radar operators had spotted large echoes which they could not explain. It later emerged that most of these were flocks of birds. In a speech soon after the war Fennessy joked that they were actually ‘guardian angels … the souls of British soldiers killed in France over the centuries returning to defend their country’ and the term ‘angels’ came to be used to describe unexplained echoes.

Among those Fennessy recruited during the Second World War was Arthur C. Clarke, who wrote his seminal 1945 article on communications satellites while working on ground-controlled approach radar and wrote later of the job that ‘it would not have been possible to design a more stimulating environment for a would-be science fiction writer’ (A. C. Clarke, Astounding Days, 1989, 188). Fennessy's own life was also changed by his wartime experiences, for he was now a radar expert and a formidable manager of people and projects. Combining these skills, he became joint managing director of the Decca Navigator Company on demobilization, recruiting many former RAF engineers to develop navigation equipment and a simple but effective marine radar. By 1950 Decca Radar had been established and, with Fennessy as its managing director, was an industry leader whose products included air traffic control. In 1952 Fennessy won a major contract from the Ministry of Defence for type 80 air defence radars after competitors like Marconi thought the ministry's timescale impossible.

When Decca's non-marine radar business was sold to the much bigger Plessey, Fennessy went too, returning to his roots in telecommunications and heading both the firm's research unit and a joint venture with GEC building ground stations for the satellites proposed by Clarke. In 1969 Fennessy was recruited by Plessey's biggest customer, the Post Office, as managing director of its telecommunications business and, from 1975 to 1977, deputy chairman. He helped cut the massive waiting list for new phones by introducing portable exchanges not unlike the radars he had sent to Germany; and he presented the country's twenty millionth phone to the Revd Chad Varah and the Samaritans. But he and the Post Office were criticized for slowness and Margaret Thatcher later privatized the telecommunications side of the organization.

Fennessy left the Post Office in 1977 but held various consultancies and chairmanships, retiring fully in 1991. He wrote and broadcast frequently, partly because he felt the work of radar pioneers was not fully appreciated. At university Fennessy rowed, ran and cycled. Later he took up golf and landscape gardening—his home near Guildford included a large ‘wild’ area—and was active in family history. He was a founder member and fellow of the Royal Institute of Navigation and its president from 1975 to 1978. He received an OBE in 1944 and a CBE in 1957 and was knighted in 1975 for services to telecommunications. Fennessy received an honorary doctorate from the University of Surrey in 1971 and an honorary fellowship from Queen Mary College in 1998.

His wife Marion died in 1983 and on 16 June 1984, at Surrey South-Western register office, he married (Leonora) Patricia Birkett (b. 1920), daughter of Albert George Kneeshaw, tax inspector, and widow of Trevor Birkett. Fennessy died at home in Shamley Green, near Guildford, on 21 November 2009 of bronchopneumonia and was survived by his wife Patricia and the two children of his first marriage.

David Robertson

Sources  

Daily Telegraph (16 Dec 2009) · The Times (18 Dec 2009) · The Guardian (21 Jan 2010); (27 Jan 2010) · Burke, Peerage · WW (2009) · personal knowledge (2013) · private information (2013) [Patrick Fennessy, son] · b. cert. · m. certs. · d. cert.

Likenesses  

obituary photographs

Wealth at death  

£1,958,591.37: probate, 18 Aug 2010, CGPLA Eng. & Wales