Operation Plumbbob - Weapons Development Report. Nevada 1957: 30 shots were fired April-October. New techniques were developed to lesson the effects of fallout. On Plumbbob the basic methods were tired: Higher towers for given yields, balloon suspended devices and under ground detonation. 30 bombs were set off to further the advance of the weapons development program. Smaller size and weight, nuclear material economy, nuclear material balance, one-point safety & pre-pacific information. Military Effects Studies.