By 1954 my father was promoted to manager of the construction division at Eniwetok Island, in the South Pacific Proving Grounds.
Operation Castle in 1954 was a six-detonation test series in the South Pacific Proving Grounds. The Castle series released nuclear explosion products into the atmosphere, causing hundreds of radiation injuries and deaths while contaminating much of the Marshall Islands in the South Pacific.
The six explosions named Bravo, Romeo, Koon, Union, Yankee, and Nectar were shot between February 25, 1954 and May 13, 1954.
“The Bravo crater in the atoll reef had a diameter of 6510 ft, with a depth of 250 ft. Within one minute the mushroom cloud had reached 50,000 feet (15 km), breaking 100,000 feet (30 km) two minutes later. The cloud top rose and peaked at 130,000 feet (almost 40 km) after only six minutes. Eight minutes after the test, the cloud had reached its full dimensions with a diameter of 100 km, a stem 7 km thick, and a cloud bottom rising above 55,000 feet (16.5 km).
The Bravo test created the worst radiological disaster in US history. Due to failures in forecasting and analyzing weather patterns, failure to postpone the test following unfavorable changes in the weather, and combined with the unexpectedly high yield and the failure to conduct pre-test evacuations as a precaution, the Marshallese Islanders on Rongelap, Ailinginae, and Utirik atolls were blanketed with the fallout plume, as were U.S. servicemen stationed on Rongerik.”
For more certificates, see Operation Ivy Bomb Certificate, Part 1