The Allied Victory in World War II was one of cooperation, not just on the battlefield, but in the laboratory. Microwave radar, jet propulsion, gyroscopic gunsights, and even penicillin were key innovations critical to American military success. All of them shared something in common—the United Kingdom had done much, if not all, of the initial work. The United States neither won World War II by itself, nor did it wholly invent its greatest weapons. The “war-winning” tools of victory had origins in many countries (especially when considering the birthplaces of the atomic scientists in the Manhattan Project, many of whom had fled fascist oppression). If there was a singular moment that defined the transfer of knowledge from abroad that enabled the Allied victory, it was a series of meetings in September and October 1940 that occurred at the Wardman Park Hotel in Washington, DC, between American military officials and a team of British scientists and technical leaders headed by Sir Henry Tizard, known as the Tizard Mission.

On August 14, 1940, Tizard and Royal Air Force (RAF) Group Captain F.L. Pearce departed England for Washington via Newfoundland on the Shorts Empire C-Class Clare flying boat (a film of the return of the Clare from the mission may be seen here). The previous day was Adler Tag, when the Battle of Britain began in earnest, but it was the rapid fall of France in May and June that resulted in the voyage. British scientists saw great value in establishing a technical exchange with the United States, both as a means of acquiring American advances, but also in the hopes of shoring up a potential ally. Churchill took some convincing, but the Battle of Dunkirk and the surrender of France encouraged him towards the realization that the risks of releasing Britain’s best technical secrets were worth the consequences of an America that would be more competitive in technical fields. Tizard was the ideal person to lead such an exchange. He had led the committee that recommended radar as the solution to Britain’s air defense concerns, which was arguably the primary reason that Germany failed to overcome the RAF during the Battle of Britain. In 1940, he was chairing Britain’s Aeronautical Research Committee and continued to provide leadership in the development of radar. While radar had developed largely simultaneously in Germany, Britain, and the United States, Britain was on the cusp of implementing a revolutionary new technology—microwave radar—made possible by the invention of the cavity magnetron. The enhanced resolution of microwave radar gave the western allies an enormous technical advantage. For all that has been written of German advantages in jet and rocket propulsion, British and American microwave radar had a far greater impact on the outcome of the war. Microwave radar guided bombers through clouds, located U-boats, pinpointed German aircraft, shot down Buzz Bombs, and guided paratroopers to their D-Day drop zones.


BC-929-A REBECCA Interrogator Indicating Unit

After extensive conversations with Canadian officials, Tizard rejoined the rest of the Mission’s team, who had traveled by ship from England with examples of critical pieces of technology. They revealed the secret of the cavity magnetron to the Americans on September 19, 1941. Over the following weeks, other technical secrets followed. Some of these dialogues resulted directly in amazing joint achievements. One of these was LORAN, which developed when British scientist Edward George Bowen revealed the Gee hyperbolic system to MIT Radiation Laboratory founder Alfred Loomis, who immediately set about developing a much longer range system, along with airborne intercept and gun-laying radars. The latter proved especially effective when married up with the radar proximity fuse. This combination did much to minimize the damage wrought by V-1 Buzz Bombs launched against England in 1944.


This was the first American device for making chaff, strips of aluminum foil used to create a countermeasure. It cut 8,000 strips of aluminum per minute. Harold Elliott constructed this demonstration prototype as part of a plan to manufacture millions of thin strands of aluminum chaff at military installations in Great Britain to avoid the security risks of industrial manufacturers. Industrial manufacture did become necessary as demand for chaff exceeded 3,000 tons. Until that time, over 500 cutters of this type made chaff at American air bases in England to jam German Wurzburg radars.


The Tizard Mission was not simply a delivery of documents and salesman’s samples of technology. Rather, it was beginning of a series of complex bureaucratic interchanges between Britain, its Commonwealth, and the United States that involved military personnel, research labs, academics, and industrialists. While Penicillin came to the U.S. outside of the Tizard Mission, other critical contributions included the basic concept of the atomic bomb, new rockets, plastic explosives, sonar, and gyroscopic gunsights were raised during Tizard’s visit. Not all went smoothly. Two areas of tension remained. One was the Norden bombsight, which Britain desperately wanted to purchase, and the other was jet propulsion, then under intensive development in Britain. Military commanders advised President Roosevelt to withhold the Norden bombsight out of concerns of it falling into German hands. Given that the sight had specifically been developed to target naval vessels, some felt it would be far more advantageous to the Germans trying to defeat the Royal Navy than it was to the Royal Air Force, who were bombing stationary targets that could theoretically be hit with other types of sights. It was also seen as a political liability with Congress if it were revealed that the United States had allowed its best technical secrets to fall into enemy hands even before the country was at war.


Norden bombsight stabilizing unit

Likewise, Britain was concerned that jet propulsion was of a longer-term significance and would not provide an immediate military advantage if the United States were to enter the war, but giving the secret away would eventually cost Britain competitive advantages in the postwar economy. Thus during the Tizard Mission, only general details were given to the United States, rather than specific engineering plans or actual components. Nonetheless, America’s entry into the war after the Japanese attack on Pearl Harbor erased nearly all remaining reluctance for technical exchange.


Model (1/24 scale) of the first Allied jet aircraft, the Gloster E.28/39 Pioneer.  

When British or American ships and planes went into combat after 1941, more than a few of the critical components aboard were often conceived, developed, or manufactured in the other’s country. To celebrate this all-too-often overlooked alliance that has persisted to the present day, the embassies of the United Kingdom, Canada, and the U.S. Navy’s Office of Naval Research (which had been a principal interface with the Tizard Mission in 1940) are hosting a day-long symposium to commemorate the exchange, the present state of Anglo-America-Canadian technical exchange, as well as its future. This symposium will be held at the Embassy of Canada on November 17, 2015, and is open to the public. The National Air and Space Museum will be supporting the event with a small artifact display depicting critical components associated with Tizard Mission technologies (seen in this blog), as well as participating in a panel discussion on the Tizard Mission’s World War II legacy.

Related Topics Aviation War and Conflict World War II
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