Approximately 18,000 members of the U.S. Air Force, Army, Navy and Marines participated in exercises Desert Rock VII and VIII during Operation Plumbbob.

[2] Other pigs were placed in pens behind large sheets of glass at measured distances from the hypocenter to test the effects of flying debris on living targets.

Studies were conducted of radioactive contamination and fallout from a simulated accidental detonation of a weapon, and projects concerning earth motion, blast loading and neutron output were carried out.

The Rainier shot, conducted September 19, 1957, was the first fully contained underground nuclear test, meaning that no fission products were vented into the atmosphere.

[7] In 1956, Robert Brownlee, from Los Alamos National Laboratory in New Mexico, was asked to examine whether nuclear detonations could be conducted underground.

However, the detonated yield turned out to be 50,000 times greater than anticipated, creating a jet of fire that shot hundreds of meters into the sky.

Regarding its speed Brownlee reckoned that "a lower limit could be calculated by considering the time between frames (and I don't remember what that was)", and joked that the best estimate was it was "going like a bat!".

[10] Brownlee estimated that the explosion, combined with the specific design of the shaft, could accelerate the plate to approximately six times Earth's escape velocity.