Tizard Mission - Meetings

Meetings

Tizard had met Vannevar Bush the chairman of 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 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. This disclosure dispelled any tension left between the delegations and things then went smoothly. The magnetron would enable the production radar units small enough to be installed in night-fighters, allow aircraft to locate U-boats and would provide great navigational assistance to bombers. It is considered to be a significant factor in the Allied victory in the Second World War.

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 thirty 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 researches being conducted by French exiles in Cambridge, Columbia (by Fermi) and Canada (by Laurence), were 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".

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". Bush recommended that arrangements should be made to produce the British engine in the United States by finding a suitable company.