Tube Alloys - Tube Alloys and The United States

Tube Alloys and The United States

The American effort increased rapidly and soon outstripped the British as the American authorities were reluctant to share details with their British counterparts. However, separate research continued in each country with some exchange of information. Several of the key British scientists visited the United States early in 1942 and were given full access to all of the information available. They were astounded at the momentum that the American atomic bomb project had then assumed. The British and American exchange of information and efforts continued but the nations did not combine their efforts, leading their programmes separately. Furthermore, the British Government rebuff and vetoed attempts and proposals by U.S. Science Adviser Vannevar Bush and highly regarded U.S. government official James Bryant Conant in 1941 to strengthen cooperation between Great Britain and America. This had the disastrous impact on British efforts as they lacked the manpower, facilities, equipment and materials needed, therefore Tube Alloys fell behind in a race with Manhattan Project. On 30 July 1942, the British civil servant Sir John Anderson advised Prime Minister Winston Churchill, quoting that: "Sir... We must face the fact that ... pioneering work ... is a dwindling asset and that, unless we capitalise it quickly, we shall be outstripped. We now have a real contribution to make to a 'merger.' Soon we shall have little or none" By the time Great Britain realized, its position had worsened, Bush decided that outside help for the Manhattan Project was no longer needed while the U.S. government increasingly convinced to the fact that prevented Great Britain from being able to build a postwar atomic weapon. The Military Policy Committee (MPC) supported Bush's arguments and restricted the classified information to what Britain could succeed to develop its atomic weapons program even if it slows down the American efforts for nuclear weapons.

In June 1942, the U.S. Army took over process of development, engineering design, procurement of materials and site selection for pilot plants and facilities for which the research was engaging. Lieutenant-General Leslie Groves of Corps of Engineers tightened the security of the American atomic bomb programme that dried up the information flow to Britain.

The Americans stopped sharing any information on heavy water production, the manufacture of uranium hexafluoride, the method of electromagnetic separation, the physical or chemical properties of plutonium, the details of bomb design, or the facts about fast neutron reactions. This was a major disappointment which hindered the British and the Canadians, who were collaborating on heavy water production and several other aspects of the research programme. By 1943, Britain stopped sending its scientists to United States which slowed down the pace of work that was being done in the United States. The British boycott had a deep impact on American project which had relied on the efforts led by the British scientists. On March 1943, Conant approached the bomb policy committee and decided that Britain's help would benefit some areas of the project. James Chadwick, William Penney and one or two other British scientists were important enough that the bomb design team at Los Alamos Laboratory needed them, despite the risk of revealing weapon design secret.