role was seen as keeping the contact alive between the parties. He returned to the UK at the end of February 1947. Attlee's government decided that Britain required the atomic bomb to maintain its great power status. In the words of the Foreign Secretary, Ernest Bevin, "We've got to have this thing over here, whatever it costs ... We've got to have the bloody Union Jack flying on top of it." Officially, the decision to proceed with the British atomic bomb project was made in January 1947. The government also endorsed Portal's proposal to place Penney in charge of the bomb development effort. The project was based at the Royal Arsenal, Woolwich, and was code-named "High Explosive Research" (HER). In May 1947, Penney was officially named to head the HER project. The following month he began assembling teams of scientists and engineers to work on the new technologies that had to be developed. He gathered 34 senior members of his fledgling team in the library at the Royal Arsenal and gave a two-hour talk on the principles of how to build an atomic bomb. By mid-1948, it was clear that Penney's initial estimate that he would require 220 staff was wide of the mark, and that he would need nearly 500. This meant not only taking personnel from other projects, but scrapping some entirely. In October 1948, he submitted a request for developing a new, separate site for HER on grounds of safety, security and economy. This was approved, but it took another six months to locate a suitable site. A former airbase, RAF Aldermaston, was selected. At the same time, it was decided to separate HER from the Armaments Weapons Research Establishment (AWRE). This resulted in a painful bureaucratic battle over personnel whose expertise was wanted for research on both nuclear weapons and guided missiles. In the end, HER kept 25 of the 30 key personnel that AWRE wanted. The site was taken over on 1 April 1950. Penney became Chief Superintendent High Explosive Research (CSHER). The first stage of work at Aldermaston was completed in December 1951, but the plutonium processing building was only handed over in April 1952, the month that the first plutonium was due to arrive from Windscale. At the peak of construction in 1953, over 4,000 personnel were working on the site. On 3 October 1952, under the code-name "Operation Hurricane", the first British