Momentum was not lost, however. British wartime leader Winston Churchill, who was returned to power, was well onside with the idea of a British nuclear deterrent. When he learned, to his surprise, just how far advanced plans were, he was impressed and enthusiastic. A strong influence was his chief adviser Lord Cherwell, who barracked relentlessly for the UK to build its own A-bomb. To do this, Britain finally had to face facts and give up on the US. Plans for Hurricane were formally agreed between the UK and Australia on 27 December 1951.
Menzies kept much information about the British plans to himself and the small group of advisers and public servants such as Frederick Shedden who were closely involved. In the earliest stages, only Menzies, the minister for Defence Philip McBride and the treasurer Arthur Fadden knew. After striking the agreement to test the British bomb in Australia, Menzies constructed a formidable apparatus of secrecy. Most of his Cabinet still knew little or nothing, even after the Churchill ascendancy. The meetings were top-secret, and only limited information was shared outside the tight circle of insiders.
Meanwhile, much furtive activity was underway. The Monte Bello Islands had no infrastructure, so a massive operation began to deliver all the paraphernalia of a nuclear test and its associated scientific studies. The movement of navy vessels from Fremantle created some speculation though. As well as Karangi and Warrego, the navy deployed HMAS Mildura to assist with setting up the site. Karangi ferried heavy equipment, including a prefabricated hut, two 25-tonne bulldozers, a grader, a number of tip trucks, several electrical generating sets, twenty 1.8-kilolitre water tanks, a mobile transmitter and receiver, and the plant needed to establish refrigerators.
The whole thing took on the appearance of a major naval operation, which proceeded without any public acknowledgment. The grapevine along the Western Australian coast became progressively more active as sharp-eyed locals put two and two together, and the odd newspaper story also hinted at what was afoot. However, and remarkably, secrecy was maintained to the satisfaction of the authorities. When the Australian Government finally announced to the public that Operation Hurricane was about to begin, the media release congratulated all concerned: ‘Indeed, the degree to which secrecy about the really vital matters has been preserved is a splendid tribute not only to the security officials but also to the loyalty, integrity and sense of respect displayed by everyone concerned in the vast project’.
Soon after agreeing to provide Monte Bello to the British for atomic testing, the Australian Government realised they needed to formally exclude people from the test site. Although Monte Bello was remote and rarely visited, naval activity in the area could provoke curiosity. The odd nosy boatie might just turn his rudder in the general direction to have a bit of a look. To head off this possibility, the Defence (Special Undertakings) Act 1952 passed through federal parliament, making unauthorised entry illegal. At first, the Act embraced only Monte Bello, but it later covered Emu Field and Maralinga (and later still the US signals monitoring station at Pine Gap), effectively excluding citizens by law from portions of Australian territory. The prohibited area extended over all the Monte Bello Islands and their surrounding waters, and south to Barrow Island. The Act was passed quickly in June 1952 – so quickly, in fact, that it was alleged that Australia had accidentally prohibited areas outside the country’s territorial limit, over which it had no jurisdiction. Both the UK Foreign Office and the Commonwealth Relations Office (CRO) believed that it extended at least 32 kilometres outside Australia’s territory. The UK had been burned with disputes in the past over maritime boundaries and wanted the legislation amended to avoid future embarrassment. Despite their concern, it wasn’t.
So the inexorable process of turning Australia into a central player in the accelerating international nuclear weapons proliferation began with a combination of speed and a small but telling element of ineptness. The test location was an unassuming group of islands in a remote part of the nation, unknown to most Australians. Monte Bello is an archipelago of 174 small islands about 130 kilometres from the strikingly beautiful Pilbara coast, where the mining town of Karratha was established in the 1960s. The total land area of the islands is only 22 square kilometres, and they lie 20 kilometres north of Western Australia’s second largest island, Barrow Island, best known for its high conservation value and fossil fuel reserves. The limestone and sand Monte Bello Islands are mostly low in the water and covered with scrubby vegetation. The British chose Trimouille Island for the first test in 1952, then Alpha and Trimouille for the two Mosaic tests in 1956. Three atomic devices were tested at Monte Bello, one of which was so big that it sent a radioactive cloud over the entire Australian continent and created a cloud of suspicion about its true nature that took many years to clear.
Penney was happy enough with Monte Bello, under the circumstances. It was no better than third choice (after America and Canada), but it would do, and time was getting away. He selected the UK rocket scientist Dr LC Tyte as planning director for Hurricane, with the ballistics expert Charles Adams as his deputy. It was essentially a maritime operation, and Rear Admiral Arthur Torlesse from the Royal Navy was appointed to command the ships, while the Royal Australian Navy supplied patrol ships. Australia contributed extensively to the preparations. When the British scientific staff arrived at Monte Bello, they were amazed by the systems of roads on both Trimouille Island and nearby Hermite Island, where the field laboratories were built, as well as the network of buildings and laboratories.
Operation Hurricane was specifically designed to detonate a nuclear device from 2.7 metres below the waterline in the hold of a ship. Britain was a maritime nation with many ports. The British authorities were keen to find out what would happen if an atomic bomb was detonated in a port, a scenario that would radioactively contaminate a large volume of water. Not even the Americans had done this sort of test before. Highly contaminated water would rise up in a column upon detonation, and it would have to come down again. The British readied themselves to measure and analyse when, where and how this would happen. HMS Plym, a relatively new 1390-tonne frigate that was surplus to requirements after the war, steamed all the way from the UK carrying in its belly the framework for an atomic device. Plym was part of a Royal Navy flotilla that included four other vessels. She came the long way, around the Cape of Good Hope, because the narrow Suez Canal was deemed too risky. The plutonium heart of the device came separately, by seaplane, via the Mediterranean, the Middle East and Asia. At the end of her long voyage, the doomed Plym was anchored in 12 metres of water about a kilometre off the west coast of Trimouille Island.
The atomic device was detonated at 8 am on 3 October on Penney’s orders. Hurricane was a plutonium-based implosion weapon, using 7 kilograms of plutonium manufactured at Wind-scale in the UK. Penney had started to design it in 1947, when he joined the GEN.163 committee. The device was expected to have an explosive yield of 30 kilotonnes, although in the event its yield was 25 kilotonnes. Penney and Torlesse watched anxiously from the Operation Hurricane command ship aircraft carrier HMS Campania, anchored about 5 nautical miles to the southwest. The other ships were Narvik, Zeebrugge and Tracker. The Australian party was watching from Narvik.