The Monte Bello 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.