Neither the Montebello Islands nor Emu Field were considered suitable as permanent test sites, although Montebello was used again in 1956 for Operation Mosaic. Montebello could be accessed only by sea, and Emu Field had problems with its water supply and dust storms. The British Government's preferred permanent test site remained the Nevada Test Site in the United States, but by 1953 it was no closer to securing access to it than it had been in 1950. When William Penney, the Chief Superintendent Armament Research, visited South Australia in October 1952, he gave the Australian Government a summary of the requirements of a permanent test site. In May 1953, the UK Chiefs of Staff Committee were advised that one was needed. They delegated the task of finding one to Air Marshal Sir Thomas Elmhirst, the chairman of the Totem Executive (Totex), which had been formed in the UK to coordinate the Operation Totem tests. He wrote to J. E. S. Stevens, the permanent secretary of the Australian Department of Supply, and the chairman of the Totem Panel that coordinated the Australian contribution to Operation Totem, and outlined the requirements of a permanent test site, which were: