Office of Civil and Defense Mobilization
Over a period of six months in 1957, the United States conducted Operation Plumbob at the Nevada Test Site. From May through October, a series of twenty-nine nuclear devices of varying strengths and designs were detonated. In addition to the large number of bombs used, the test was notable for the amount of personnel involved. 18,000 servicemen were present to participate in the final stages of Exercise Desert Rock, a massive wargame meant to explore the viability of infantry tactics during an atomic campaign. They were joined by representatives from over twenty-one government agencies on hand to research nearly every aspect of the operation. Among them were a handful of specialists working for the Office of Civil and Defense Mobilization. This group was given the opportunity to train as radiological monitors under realistic conditions. Utilizing several types of monitoring instruments, they demonstrate how to chart fallout radiation patterns for both specific locations and broad areas. Footage from Operation Plumbob was edited into a film of the same name in 1957. Two years later, the O.C.D.M. released highlights of their own Operation Plumbob training exercises under the title Mission Fallout.
Although already considered experts in the field of radiological monitoring, the film explains how the O.C.D.M. crew spends several days prior to the test participating in classroom lectures. This additional instruction focuses primarily on how to properly calibrate and read their detection equipment in the shifting environment of an atomic attack. After being issued personal dosimeters (pen-sized devices which measure radiation on an individual) the men train with the CD-700 meter. Perhaps the most widely distributed piece of radiological detection equipment, the CD-700 was designed to measure radioactivity for specific areas, such as enclosed shelters, stocks of food and water, and on individual persons. Also featured is the CD-710 "survey" meter, designed to detect radiation on a much larger scale. Early civil defense plans called for CD-710 meters to be installed in aircraft for wide-range aerial monitoring. This concept is heavily featured in Mission Fallout, where volunteer pilots from local Civil Air Patrols fly O.C.D.M. specialists in criss-cross patterns downwind from the Nevada Test Site. By strapping several CD-710s into a plane and frequently recalibrating them, the monitors effectively chart the pattern of fallout. By 1963, a special instrument kit, the CD-781, had been specially designed for this purpose.
Using trucks and planes, the O.C.D.M. crew traverses the Nevada desert charting an ever-extending fallout cloud. Each measurement they take is relayed via radio back to a central headquarters, where meteorological experts compile data and predict future movements of the fallout threat. The many types of bombs detonated during the test, including tower based bombs, a missile designed for submarine launch, and a bomb suspended by a balloon, gave the O.C.D.M. the opportunity to track fallout in different conditions. In subsequent years, Operation Plumbob would become notorious for the amount of fallout it dispersed across the countryside. Many unsuspecting communities found themselves in the path of Plumbob's fallout. Additionally, medical studies have suggested much higher instances of cancer among the servicemen who participated in Exercise Desert Rock. Mission Fallout, on the other hand, would enjoy favorable longevity with the O.C.D.M. and its successor agencies. Unlike most civil defense films from the 1950's, it would not be declared obsolete in the following years.
Mission Fallout may be viewed in its entirety HERE.