Tizard Mission

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The Tizard Mission, officially the British Technical and Scientific Mission,[1] was a British delegation that visited the United States during World War II to share secret research and development (R&D) work completed in the United Kingdom that had potentially significant military applications. It received its popular name from the programme's instigator, Henry Tizard. Tizard was a British scientist and chairman of the Aeronautical Research Committee, which had orchestrated the development of radar.

The mission travelled to the U.S. in September 1940 during the Battle of Britain. They conveyed a number of technical and scientific secrets with the objective of securing U.S. assistance in maintaining the war effort and obtaining the industrial resources to exploit the military potential of these technologies, which Britain itself could not due to the immediate demands of war-related production.

The Tizzard mission catalyzed Allied technological cooperation during World War II. After the war, it became the foundation for future cooperation in scientific research at institutions within and across the United States, United Kingdom and Canada.

Preparation and objectives[edit]

Britain made significant scientific advances with potential military applications before World War II began in September 1939.[2][3][4] After the Fall of France in June 1940, which saw Germany overrun most of the countries of Western Europe, Germany's planned invasion of the United Kingdom, Operation Sea Lion, was preceded by its effort to establish air superiority in the Battle of Britain.

Henry Tizard was a British scientist and chairman of the Aeronautical Research Committee, which had orchestrated the development of radar before the war. He sought to initiate cooperation with the United States to further the research, development and production of radar and other technologies. The U.S. was neutral and, in many quarters, unwilling to become involved in the war, but had greater resources for development and production, which Britain wanted to use. The information provided by the British delegation was subject to carefully vetted security procedures, and contained some of the greatest scientific advances made at that time. The technology Britain possessed included the greatly-improved cavity magnetron, which the American historian James Phinney Baxter III later called "the most valuable cargo ever brought to our shores",[5] the design for the proximity VT fuse, details of Frank Whittle's jet engine and the Frisch–Peierls memorandum describing the feasibility of an atomic bomb. Though these may be considered the most significant, many other technologies had also been developed, including designs for rockets, superchargers, gyroscopic gunsights, submarine detection devices, self-sealing fuel tanks and plastic explosives.

The American Congress had many proponents of neutrality for the USA and so there were further barriers to co-operation. Tizard decided that the most productive approach would be simply to give the information and use America's productive capacity. Neither Winston Churchill nor the radar pioneer, Robert Watson-Watt, were initially in agreement with these tactics for the mission. Nevertheless, Tizard first arranged for Archibald Hill, another scientific member of the committee, to go to Washington to explore the possibilities. Hill's report to Tizard was optimistic.

Moving the secrets[edit]

After Churchill's approval of the project, the team began gathering all technical secrets which might have military use. At the end of August, Tizard went to the U.S. by air to make preliminary arrangements. The rest of the mission would follow by ship. They were:

All the documents were gathered in a small trunk: a lockable metal deed box, used for holding important valuable documents such as property deeds. Bowen was allowed to take 'Magnetron Number 12' with him. After spending the night under Bowen's hotel bed, the case was strapped to the roof of a taxi to the station. An over-eager railway porter whisked it from Bowen at Euston Station to take it to the train to Liverpool and Bowen almost lost sight of it. Inconsistently, in Liverpool, the magnetron was given a full Army escort.

The team arrived in Halifax, Canada, on 6 September on board the CPR Liner Duchess of Richmond (later known as the RMS Empress of Canada), and went on to Washington, D.C., a few days later. The team of six assembled in Washington on 12 September 1940.

Meetings and subsequent events[edit]

Tizard had met Vannevar Bush, the chairman of the National Defense Research Committee, on 31 August 1940, and arranged a series of meetings with each division of the NDRC. When the American and British teams met, there was initially some cautious probing by each side to avoid giving away too much without getting anything back in exchange. At a meeting hosted by NDRC's two-month-old "Microwave Committee" chairman Dr Alfred Loomis[8] at the Wardman Park Hotel on 19 September 1940 the British disclosed the technical details of the Chain Home early warning radar stations. The British thought the Americans did not have anything like this, but found it was virtually identical to the US Navy's longwave CXAM radar.

The Americans then described their microwave research done by Loomis and Karl Compton earlier in 1940. The British realised that Bell Telephone Laboratories and General Electric both could contribute a lot to receiver technology. The Americans had shown a Navy experimental shortwave 10-centimetre wavelength radar but had to admit that it had not enough transmitter power and they were at a dead end. Bowen and Cockcroft then revealed the cavity magnetron, with an amazing power output of about ten kilowatts at 10 centimetres.[8] This disclosure dispelled any tension left between the delegations, and the meeting then went smoothly. The magnetron would enable the production of radar units small enough to be installed in night fighters, allow aircraft to locate surfaced U-boats and provide great navigational assistance to bombers. It is considered to be a significant factor in the Allied victory in the Second World War.[9]

Britain was interested in the Norden bombsight. President Roosevelt apologised and said that it was not available to Britain unless it could be shown that the Germans had something similar. Tizard was not unduly dismayed as he thought there were other US technologies more useful to Britain than the bombsight, and he asked for the unit's external dimensions so that British bombers could be modified to take it, if it became available at some future date.[10]

Bowen stayed in America, and a few days later, at the General Electric labs in New Jersey, he showed the Americans that the magnetron worked. The Bell Telephone Company was given the job of making magnetrons, producing the first 30 in October 1940, and over a million by the end of the war. The Tizard mission caused the foundation of the MIT Radiation Lab, which became one of the largest wartime projects, employing nearly 4,000 people at its peak.

The Tizard delegation also visited Enrico Fermi at Columbia University and told Fermi of the Frisch–Peierls concept for an atomic bomb. Fermi was highly sceptical, mainly because his research was geared towards using nuclear power to produce steam, not atomic bombs. In Ottawa, the delegation also met a Canadian, George Laurence, who had secretly built his own slow neutron experiment. Laurence had anticipated Fermi's work by several months.

When they returned to the UK in November 1940, the delegation reported that the slow neutron research conducted by French exiles in Cambridge, Columbia (by Fermi) and Canada (by Laurence) was probably irrelevant to the war effort. But since nuclear boilers could have some post-war value, they arranged for some financial support for the Canadian fission experiments. George Laurence later became involved in the secret exchanges of nuclear information between the British and the Americans. The British did not realise the atomic bomb was a serious possibility until Franz Simon reported in December 1940 to the MAUD Committee that it was feasible to separate the isotope uranium-235.

Tizard met with both Vannevar Bush and George W. Lewis and told them about jet propulsion, but he revealed very little except the seriousness of British efforts. Bush later recalled: "The interesting parts of the subject, namely the explicit way in which the investigation was being carried out, were apparently not known to Tizard, and at least he did not give me any indication that he knew such details".[11][12] Later, Bush realised that the development of the Whittle engine was far ahead of the NACA project. In July 1941 he wrote to General "Hap" Arnold, commander of the USAAF, "It becomes evident that the Whittle engine is a satisfactory development and that it is approaching production, although we yet do not know just how satisfactory it is. Certainly, if it is now in such state that the British plans call for large production in five months, it is extraordinarily advanced and no time should be lost on the matter".[12] Bush recommended that arrangements should be made to produce the British engine in the United States by finding a suitable company.[12] This company turned out to be General Electric and the US Whittle engine would emerge as the General Electric I-A and subsequent production General Electric J31.


The Tizard mission was hailed as a success, especially for its impact on the subsequent development and deployment of radar as well as wider Allied technological cooperation during World War II. Although the German bombing of the UK was largely over by the time that the new radar systems were in production, technology such as aircraft radar and LORAN navigation greatly helped the Allied war effort in Europe and the Pacific. According to James Phinney Baxter III, Official Historian of the Office of Scientific Research and Development: "When the members of the Tizard Mission brought one cavity magnetron to America in 1940, they carried the most valuable cargo ever brought to our shores."[13]

The mission also opened up channels of communication for jet engine and atomic-bomb development and is seen as one of the key events in forging the wartime Anglo-American alliance.


The Tizard Mission was the foundation for cooperation in scientific research at institutions within and across the United States, the United Kingdom and Canada. Its legacy was marked on its 75th anniversary in 2015 by various groups including: the Massachusetts Institute of Technology, Imperial College London, Office of Naval Research, British Embassy in Washington, Canadian Embassy in Washington, National Air and Space Museum, and the Defense Visual Information Distribution Service.[14][15][16][17][18][19][20]

See also[edit]


  1. ^ Robert C Stem (3 April 2012). US Navy and the War in Europe. Pen and Sword. pp. 20–. ISBN 978-1-4738-2020-3.
  2. ^ "Work Done by 1,500,000 Horses in France during the War". Scientific American. 87 (2250supp): 105. 15 February 1919. doi:10.1038/scientificamerican02151919-105bsupp. ISSN 0036-8733.
  3. ^ Paul Kennedy, Engineers of Victory: The Problem Solvers Who Turned The Tide in the Second World War (2013)
  4. ^ Roberts, Eric (16 March 2004). "British Technology and the Second World War". Stanford University. Retrieved 26 April 2015. British science and technology was instrumental in winning the Second World War. This course looks at several different technological innovations undertaken in Britain in the context of the wartime period: the breaking of the German Enigma code at Bletchley Park (which Winston Churchill credited with having won the Battle of the Atlantic), the development of radar, the advances in wartime medicine and pharmacology (most notably, the first practical uses of penicillin), and the participation by British scientists in the Manhattan Project.
  5. ^ "Radar". Newsweek. 2 December 1997.
  6. ^ John Cockcroft would receive a Nobel prize in 1951
  7. ^ Brown, Minnett & White 1992.
  8. ^ a b Conant 2002, pp. 168–169, 182.
  9. ^ Hind 2007.
  10. ^ Zimmerman 1996, p. 99.
  11. ^ Zimmerman 1996, p. 120.
  12. ^ a b c Dawson 1988, Chapter 3.
  13. ^ Baxter III 1946, p. 142.
  14. ^ "How the Tizard Mission paved the way for research at MIT". MIT News | Massachusetts Institute of Technology. Retrieved 14 January 2023.
  15. ^ "The Tizard Mission: 75 years on | Imperial News | Imperial College London". Imperial News. Retrieved 14 January 2023.
  16. ^ "Tizard Mission75th Anniversary Commemoration" (PDF). www.secnav.navy.mil. Office of Naval Research, the British Embassy Washington, and the Embassy of Canada in Washington. Retrieved 14 January 2023.
  17. ^ "'Desperate act of trust': US, allies recall and renew scientific ties". EurekAlert!. Retrieved 14 January 2023.
  18. ^ "The Tizard Mission – 75 Years of Anglo-American Technical Alliance". National Air And Space Museum. Smithsonian. Retrieved 14 January 2023.{{cite web}}: CS1 maint: others (link)
  19. ^ "The Tizard Mission: 75 Years of Transatlantic Partnership on Science and Technology". GOV.UK. Retrieved 14 January 2023.
  20. ^ "Tizard Mission 75th Anniversary Commemoration". DVIDS. Retrieved 14 January 2023.



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