Australian
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Teacher’s notes

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This clip shows silent footage of a nuclear fission bomb test at ground level at Maralinga in South Australia in 1956. The clip begins with the intertitle ‘“MARCOO” GROUND BURST’, and features footage taken with two sets of cameras (the high-speed Vinten HS 300 and a normal-speed Cameflex) at two sites known as North Base and Eagle. The footage records the detonation of the bomb and shows a flash of light, followed by a fireball and the distinctive 'mushroom’ cloud.

Educational value points

• Maralinga was the site of a joint British and Australian nuclear testing facility in SA that operated between 1956 and 1963. In 1954 the British Government secured agreement from Prime Minister Robert Menzies, who agreed without consulting his Cabinet, to develop a permanent testing range at Maralinga. After its completion, tests carried out at Maralinga included two major trials, Operation Buffalo (1956) and Operation Antler (1957), and a number of small trials. Britain had earlier conducted nuclear tests at Emu Field in SA in 1953 and the Monte Bello Islands, Western Australia, between October 1952 and June 1956.

• After the development and deployment of nuclear weapons by the USA during the Second World War and the subsequent escalation of the Cold War between the western powers and communist countries such as the Soviet Union and China, an arms race ensued. The Soviet Union became a nuclear power in 1949, followed by Britain in 1952, France in 1960, China in 1964 and, although not confirmed, Israel in the late 1960s. India and Pakistan followed, detonating their own nuclear weapons in the late 1990s. The office of the Director of National Intelligence in the USA confirmed that North Korea had detonated a nuclear device on 9 October 2006.

• Marcoo was the second nuclear fission bomb detonated as part of Operation Buffalo, a series of nuclear tests carried out by the British Government (with the agreement and support of the Australian Government) at Maralinga between September and October 1956. Operation Buffalo included four tests, codenamed 'One Tree’, 'Marcoo’, 'Kite’ and 'Breakaway’. They were part of Britain’s nuclear weapons program and involved testing fission weapons and monitoring the effects of these weapons.

• Nuclear fission bombs use either uranium 235, uranium 233 or plutonium 239. Unlike other atoms, the atoms of uranium and plutonium are relatively easy to split. When these atoms split they give off a lethal form of radiation, called gamma radiation. Maralinga in western SA was selected as a test site because of its remoteness from population centres; however, it was inhabited by the Maralinga Tjarutja people, most of whom were relocated to the Yalata mission prior to testing. Those who remained in the area were exposed to radiation.

• In a nuclear bomb, the process from detonation to explosion takes place within a millionth of a second and the explosion can range from 1 kiloton (equal to about 1,000 sticks of trinitrotoluene (TNT)) to 50 megatons (about 50,000 sticks of TNT) in size. Marcoo was a 1.5-kiloton (about 1,500 sticks of TNT) bomb. It was placed in a shallow pit and exploded on the ground so that scientists could collect data about ground shocks and the cratering effects produced by a nuclear explosion. It produced a crater that was about 49 m wide and about 12 m deep. Tracer rockets were fired prior to the explosion to create a 'grid’ in the atmosphere and so provide a visible record of air disturbance caused by the explosion.

• When a nuclear fission bomb is detonated it creates a blinding flash of light, a fireball and a 'mushroom’ cloud. The intense heat of the fireball vaporises everything within it and creates an updraft or mushroom cloud. Vaporised material is drawn upwards within the cloud, where it mixes with radioactive particles from the bomb. As the combined material cools, it condenses and drops to earth as dust particles known as radioactive fallout. Fallout contaminates the immediate area, but may also be carried long distances by wind currents.

• The Australian Government agreed to host Britain’s nuclear weapons tests in the interests of national security. The Australian Government was concerned about communist expansion, particularly in parts of Asia. Prime Minister Robert Menzies felt that Australia needed to cultivate its 'great and powerful friends’, such as Britain and the USA, who would come to the nation’s defence. It supported the tests until 1957, when scientist Hedley Marston revealed the extent of radioactive fallout. The tests were then moved to Christmas Island (then a British territory) in the Line Islands south of Hawaii in the Pacific Ocean.

• Following the recommendations made by the 1984 Royal Commission into the British nuclear tests at Maralinga, the Australian and British Governments spent $108 million in 1999 to decontaminate the site, and in 1995 the British Government paid the Maralinga Tjarutja people $13.5 million in compensation for being displaced from their land. Both Governments also agreed to compensate veterans who became ill through exposure to radiation at Maralinga; however, the onus of proof is on the veterans and few of these cases have so far been resolved.