storage, so a firm in Melbourne was asked to make some. An order was placed on a Friday evening, and the pipe was shipped the following Thursday morning, making its way to the Fortescue River by road and rail. The system delivered up to per hour to a jetty on the Fortescue estuary, from which it was taken to the islands by the 120ft Motor Lighter MWL 251. The British assembled a small fleet for Operation Hurricane that included the escort carrier , which served as the flagship, and the LSTs Narvik, Zeebrugge and Tracker, under the command of Rear Admiral A. D. Torlesse. Leonard Tyte from the AERE was appointed the technical director. Campania had five aircraft embarked, three Westland WS-51 Dragonfly helicopters and two Supermarine Sea Otter amphibians. Between them, the LSTs carried five LCMs and twelve LCAs. The bomb, less its radioactive components, was assembled at Foulness, and then taken to the River-class frigate on 5 June 1952 for transport to Australia. It took Campania and Plym eight weeks to make the voyage, as they sailed around the Cape of Good Hope instead of traversing the Suez Canal, because there was unrest in Egypt at the time. The Montebello Islands were reached on 8 August. Plym was anchored in of water, off Trimouille Island. The radioactive components, the plutonium core and polonium-beryllium neutron initiator, went by air, flying from RAF Lyneham to Singapore in Handley Page Hastings aircraft via Cyprus, Sharjah and Ceylon. From Singapore they made the final leg of their journey in a Short Sunderland flying boat. The British bomb design was similar to that of the American Fat Man, but for reasons of safety and efficiency the British design incorporated a levitated pit, in which there was an air gap between the uranium tamper and the plutonium core. This gave the explosion time to build up momentum, similar in principle to a hammer hitting a nail, enabling less plutonium to be used. The British fleet was joined by eleven RAN ships, including the aircraft carrier with 805 and 817 Squadrons embarked, and its four escorts, the destroyer , and frigates , and . The Defence (Special Undertakings) Act (1952) was passed through the Parliament of Australia between 4 and 6 June 1952, and received assent on 10 June. Under this act, the area within a radius of Flag Island was declared a prohibited area