| Operation Blowdown | |
|---|---|
 Detonation of 50 short tons (45 t) of TNT. | |
| Information | |
| Country | Australia |
| Test site | Iron Range Test Site, North Queensland |
| Coordinates | 12°44′56″S 143°16′46″E / 12.749°S 143.2795°E |
| Date | 18 July 1963 |
| Number of tests | 1 |
| Agency | Australian Army, DASA |
| Explosive | TNT |
| Configuration | Stacked Sphere, Tower |
| Yield | 50 tons of TNT (210 GJ) |
| Test chronology | |
Operation Blowdown was an explosives test carried out in the Kutini-Payamu jungle of Australia's Cape York Peninsula in 1963, to simulate the effects of a nuclear weapon on tropical rainforest. It was conducted by the Australian Army, the Department of Supply, and the Defence Standards Laboratory with participation from the United Kingdom, Canada and United States. In addition, blast effects on military material, field fortifications, supply points, and foot and vehicle movement were examined in a rainforest environment.[1]
A spherical charge of 50 short tons (45 t) of TNT was detonated on a tower 136 feet (41 m) above ground level and 69 feet (21 m) above the rainforest canopy. After the explosion, troops were moved through the area (which was now covered in up to a metre of leaf litter), to test their ability to transit across the debris. In addition, obsolete vehicles and equipment left near the centre of the explosion were destroyed.
Although never officially stated, there is speculation that the test intended to determine the feasibility of using nuclear weapons in clearing the jungles of Vietnam, at a time of Australia's increasing involvement in the Vietnam war starting in 1962.[2]
United States participation included the establishment of pressure measurement equipment and the loan of photographic and instrumentation equipment,[1][3] some of which had been used in the 1962 Project Plowshare.[2]