by Joan Smith
Penney described himself coyly as ‘a scientist who took part in the trial’. He said virtually nothing about the bomb. ‘Now for the weapon itself,’ he began promisingly, only to go on, ‘about which, of course, I can say little. You no doubt realize, if only from the cost of all large atomic energy projects, that the weapon is a complex affair involving specialists in many fields of science and engineering. The fissile material and all the equipment used at Monte Bello were made in Britain.’
The British government did not release figures showing the yields of the bombs detonated in Australia until 1984. Only then did it become clear that the very first bomb was one of the largest in the entire series of tests. At 25 kilotons, the equivalent of 25,000 tons of TNT, it was bigger than either of the bombs used against Japan, and among the British bombs it was the second biggest.
Penney commented in his broadcast that the explosion ‘had some resemblance to that of the atomic weapon exploded by the United States in the waters of the Bikini Lagoon’. In fact, the Hurricane explosion was designed to replicate a phenomenon first observed at this US test in 1946. It was called ‘base surge’.
The second Bikini test had shown that when a bomb exploded underwater, a huge quantity of water was thrown into the air, where it formed a column contaminated with the products of the explosion. When the column started to fall back to earth, it spread out rapidly and contaminated a wide area. Penney later described it as ‘for all the world like a thin pancake mixture spreading as it is poured into a frying pan’.
The Hurricane test, Penney said later, went according to plan. The cloud rose to just over two miles above the sea, the great weight of mud and water preventing its rising further. ‘We know what happened and we can give the Civil Defence authorities some accurate answers to some of their problems,’ he said.
The team which built the bomb had started off as the High Explosives Research Section of the Armaments Research Department at the Ministry of Supply. As Chief Superintendent, Penney was in charge of all the Department’s work - ships, bombs and high explosives, as well as atomic weapons. But in reality, the HER team was quite separate from the rest of the Department at its headquarters at Fort Halstead, in Kent. Effectively, Penney told the Australian Royal Commission, the completely new Atomic Weapons Research Establishment came into existence some time before he was officially made its first director in 1952.
‘AWRE was formed before then but with all the cloak and dagger stuff going on I was rather a strange person,’ he said. ‘I was Chief Superintendent, Armaments Research, but inside the establishments we had special compounds which were fenced off.’ Work started on the AWRE site at Aldermaston, in Berk shire, in April 1950, and it was ready for its first radioactive work by the end of 1951. But getting AWRE fully working in time was a close-run thing. The laboratory for processing plutonium manufactured at Windscale was ready only six months before the Hurricane test.
The overwhelming air of secrecy, combined with the hurried nature of a lot of the work - the date of the test had been imposed on the scientists by politicians, without much thought about whether the deadline was reasonable - meant that Operation Hurricane sometimes had the air of a Keystone cops movie. In the spring of 1952, the people of Gravesend had the British obsession with secrecy to thank for their blissful ignorance of the fact that a full-scale rehearsal of an atom bomb test was taking place on their doorsteps on the River Thames. It went smoothly, except for a communications problem, which was solved by buying radio-telephones designed for use in taxis.
The most vital component of the bomb, its plutonium core, made a surprisingly perilous journey from England to Australia. It was packed inside a container made of cork, with a bag of dye attached to it, and given into the care of an AWRE scientist, who was to look after it for the three-day flight on board a Sunderland flying boat. If the plane crashed in the sea, the theory went, the bag containing the dye would burst and mark the spot, so that the plutonium could be recovered. If it went down over land, the scientist’s instructions were simple: jump out, pull the parachute cord, and hang on to the plutonium for dear life. Luckily, the plane arrived without these plans being put to the test.
With hindsight, Australia was extraordinarily generous in its attitude to the conduct of the first three British tests. Operation Hurricane was carried out under British control, with virtually no say being given to the Australians. This arrangement continued for the Operation Totem tests a year later, in 1953. It was a situation which, in the end, disturbed even the hitherto complacent Australians - in 1955, they belatedly set up their own committee which was to be responsible for the health of the Australian people.
Australia’s nuclear watchdog, the Australian Ionising Radiation Advisory Council, known as AIRAC, took an optimistic view of the set-up for the early explosions when it reported in 1983 on the British tests and concluded: ‘Although Australian services and scientific personnel were present at all three tests, and meteorological services and consultants were provided for the tests, the decision when to fire rested solely with the British authority. However, it may reasonably be presumed that the authority would have taken into account the views of Australian meteorological officers in determining firing times.’
The question of whether conditions were safe enough to fire the weapon - based on predictions of where the wind would carry the radioactive cloud - was a crucial one. The consequences of a bomb being exploded in the most dangerous conditions possible, which happened at the first Totem explosion, will be discussed in a later chapter. For the moment, it is sufficient to note that the Australians did not insist on retaining a power of veto at Hurricane or the next two tests.
Penney’s original idea, in February 1952, was that two or three Australians might be invited to watch Operation Hurricane without having access to details of the weapon or its results. By contrast, he invited the chairman of the Canadian Research Policy Committee to attend the test, with full access.
In April that year, the United Kingdom High Commission formally invited Australia to provide two junior scientists to work on the test; one would work with the health monitoring team after the test, the other would examine its effects on concrete structures. The High Commission also passed on a personal request from Penney to use the scientific services of an old colleague, Ernest Titterton. Titterton, who had been sent from Birmingham University to Los Alamos during the war and worked there at the same time as Penney, had emigrated to Australia in the post-war period.
Britain also asked at this time for the use of laboratory space in Australia. This was provided at the University of Melbourne. As the limited extent of the involvement the Australians were being offered became clear, the Australian Defence Committee became rather uneasy: after a correspondence between Britain and Australia which lasted from the end of April to the end of September, Professor Leslie Martin, Professor of Physics at Melbourne University, was officially given an invitation to attend.
Nine days before the test took place at Monte Bello, the Daily Graphic’s Sydney correspondent reported that Menzies had confirmed that he did not even know the date on which the test was due to take place. ‘I cannot assist the tests - except by keeping quiet,’ he said cryptically. No wonder that the Daily Graphic went on to report that ‘highest government quarters in Canberra’ were criticizing Britain for ‘excessive secrecy’. An unnamed member of the Australian cabinet is reported to have told the Daily Graphic that ‘Britain is treating us like colonials’ by withholding almost all information. ‘Several ministers are openly piqued that Australia should be asked “to do the spade and shovel work at Monte Bello and then be asked to quit the site,”’ the report concludes.
These murmurings from unnamed sources did not improve Australia’s position. In August 1954, nearly two years after Operation Hurricane, Professor Martin met officials from the British Ministry of Defence to complain that Australia had not yet been given any information about the Monte Bello test or, for that matter, the two tests which
had been carried out in 1953 at Emu Field. The Australian armed forces were unhappy about spending money on a project which brought them no advantage, he said. He also pointed out that the siting of the tests in Australia had become a matter of public controversy in the country itself - if the government was to be able to give assurances that it was keeping a close eye on the safety of its people, it had to be in a position to say it was getting the information it wanted about the tests.
The British officials at the meeting were very sympathetic. The difficulty was a technical one, they said reassuringly. Unfortunately, the relevant reports were just being sent to the printer, and happened to be unavailable for the moment. They would be provided soon. Three weeks later, a committee drawn from several Australian government departments met to consider the demands placed on Australian resources by a decision to allow Britain to construct a permanent weapon-testing site in Australia. Inter alia, the committee noted that Britain still had not provided information from Operations Hurricane and Totem. Clearly, strong action was called for. The committee decided to recommend that ‘a firm request’ be sent to Britain seeking the results of the first three tests.
As it happened, the British themselves had less information about Operation Hurricane than they were to have about any other test in the Australian series. The bomb was the very first tested by the British on their own; it was one of the biggest bombs tested in or close to Australia; it was an underwater burst which was known, from the American experience at Bikini in 1946, to produce heavy contamination. In spite of all these factors, only the most desultory atempt was made to check for contamination on the mainland.
In fact, the conduct of the first British test was far from something to be proud of, in spite of the fawning and uncritical press it got at the time. Air crew were not given protective clothing, nor were they monitored to check their exposure to radiation while engaged on the dangerous job of taking samples of the radioactive cloud; estimates of their exposure are really little more than guesses. Radioactive waste was simply dumped in the sea. The permitted levels of exposure to radiation for personnel at the test were much too lax, while no one even gave thought to limits for the exposure of the Australian public. The four main British ships taking part in the exercise became contaminated and were still radioactive when they arrived back in Britain months later; the naval dockyards had no experience at all in how to decontaminate them. The Monte Bello Islands were not properly guarded after the test to prevent chance visitors being exposed to radiation.
Safety measures at the test consisted largely of keeping unauthorized people out of the area and laying down permitted levels of exposure for the people actually involved in the test. The issue of levels of exposure is discussed later in the book; for the time being it is enough to mention two features of the conditions in which Operation Hurricane was carried out. First, no recommendation at all was made about the maximum amount of radiation members of the public should be exposed to. Second, the standards adopted permitted personnel involved in the test to be exposed to six times the maximum dose laid down for workers in the nuclear industry at home.
The exclusion of unauthorized people from the islands was ensured by a rather cavalier piece of Australian legislation which was enacted in June 1952. The Monte Bellos lie about fifty miles from the north-west coast of Australia. A prohibited zone was declared, extending for a radius of forty miles from one of the islands in the group.
This legislation conveniently ignored the fact that part of the prohibited area was not in Australian waters at all but counted as the high seas. The Australians were subsequently infuriated by an article in the Daily Mail in London which queried Australia’s legal right to ban foreign vessels from a piece of water it did not control.
Nevertheless, such minor considerations were not allowed to interfere with planning for the test. Sea and air traffic were excluded from the area, and an officer on board HMS Zeebrugge was given the power to have people removed from the islands until Rear-Admiral Torlesse arrived and took over. At the same time, a large part of the mainland in Western Australia was declared a restricted area for flying.
A full rehearsal of the test took place on 19 and 20 September; on 1 October, the standby period started. The weapon was detonated by remote control at 9.30 in the morning, Australian time, on 3 October. HMS Plym, within whose bowels the weapon had been placed, was vaporized in the blast. Penney watched the test from the flight deck of HMS Campania, along with Torlesse and most of the ship’s company. They faced away from the explosion as they listened to the last seconds of the countdown being relayed over the ship’s loudspeakers.
In a radio broadcast given a few weeks after the test, Penney recalled: ‘Suddenly there was an intense flash, visible all around the horizon. We turned to look. The sight before our eyes was terrifying - a great, greyish black cloud being hurled thousands of feet into the air with astonishing rapidity. A great sandstorm suddenly sprang up over the islands. It seemed ages before we heard the bang but, in fact, it was only a minute. Somewhat to our surprise, a second bang - at least as loud as the first - followed a few seconds later. At the same time we felt a peculiar sensation in our ears such as one has in an aircraft losing height rapidly. We were feeling the suction, or reduced pressure, which always follows a blast wave. All the time the cloud was getting higher and higher and assuming fantastic shapes as it was pulled about by the strong winds at different altitudes.
‘The explanation of the two bangs heard on the ships and also heard on the mainland is actually quite simple. The first bang was the direct sound wave, and the second was a reflection from a layer of warm air some two miles up.
‘Many comments have been made about the shape of the cloud and how different it was from the mushroom cloud with the very high stalk shown in most American pictures of atomic explosions. The great weight of the mud and water in the cloud at Monte Bello kept the cloud from rising very far.’
In fact, the shape of the cloud was a warning of just how unpredictably atomic clouds can behave. Clouds would get lost or they would be blown in unexpected directions, either because the wind changed or because winds were blowing in different directions at various levels. The cloud from Hurricane encountered exactly this phenomenon, as Penney explained in his broadcast: ‘The peculiar Z-shape of the cloud ten minutes or so after the explosion was due to the strong winds blowing in quite different directions at different heights. The cloud was pulled into a gigantic spiral shape which, when seen from the ships and from the mainland, appeared rather like a letter “Z”, rapidly moving northwards away from the islands and the mainland.’
Penney went on to say that ‘the experiment went according to plan’. But the key secret report on Hurricane, compiled by Rear-Admiral Torlesse and released only in 1985, during the Australian Royal Commission hearings, tells a more complicated story. As planned, the early fallout fell into the sea to the north of the islands, and on the northernmost section of the islands themselves. Torlesse records the results of a helicopter survey on the day of the explosion, which showed the area to the north of where Plym had been moored to be ‘heavily contaminated’. Instruments placed on the northern islands, including Trimouille, confirmed that they must be considered ‘dirty’ when monitoring teams were being sent out. But Torlesse’s report shows that the cloud then behaved so erratically that, by the next morning, most of it was lost; it also shows that part of the cloud broke away and drifted over the mainland not at the expected height of 25,000 feet, but at 10,000, while another piece of it was detected on its way to Fiji.
The operation of tracking the cloud was initially put in jeopardy by what Torlesse calls a ‘signal mishap’. As the cloud moved out to sea, he says, ‘it was obvious that within a few hours large and increasingly rapid errors in its estimated position were inevitable. In addition, there was an alarmingly large wind sheer in the layers just below 10,000 feet, so that different parts of the cloud travelled in different directions.’ Because of these problems, i
t was decided to start the search for the cloud sooner than planned. A message was sent to Broome, on the mainland, where RAAF planes were waiting to take off. But it took six hours for the secret message to arrive at Broome in ‘intelligible form’. It was a stroke of luck that the planes were still able to find part of the cloud, over the sea about 500 miles from the mainland, and collect samples.
A section of the cloud had been expected to travel south-east across the centre of Australia at between 25,000 and 30,000 feet. But on the day of the explosion, weak contamination was detected by an RAAF Lincoln at 10,000 feet near Port Hedland, on the mainland, to the east of the Monte Bellos. The following day, a Dakota aircraft detected a strong signal on radiation measuring equipment at 10,000 feet in the same area over the mainland. A quantity of radioactive dust was drifting inland over the coast.
No attempt was made to track this section of the cloud further inland or to see if any other parts of the cloud had crossed to the mainland. Only one attempt was made to check for contamination on the ground: two Dakotas flew along the coast at five hundred feet the day after the test but reported no evidence of fallout on the ground. This result is not as impressive as it looks; it was revealed during the London hearings in 1985 that it was realized after the Totem tests in 1953 that an aircraft flying at this height registered only a tenth of the contamination lying on the ground.
None of the aircrew who took part in this sampling and tracking operation wore film badges or protective clothing. The safety measures adopted for the Hurricane test specified that anyone who might be exposed had to have special clothing and be supplied with devices to monitor their exposure to radiation, but an exception to this rule was made for aircrew. Back in 1950, the Air Ministry in Britain had sought the advice of scientists at Harwell on whether there was any risk to aircrew flying through the atomic cloud after the explosion. The answer was that aircrew must avoid flying through the visible cloud after the explosion but once the cloud could no longer be seen, there would be no danger.