At the time of the detonation, the wind was calm at surface level. The device was detonated from a balloon located approximately above northeastern portions of the Yucca Flat at 4:40 am (
PT), setting bushes on fire and sending a thermal wave across the land which it was detonated over. Minutes after the detonation, the nuclear cloud reached in the atmosphere where the winds were from the southwest at 19 and 31
knots respectively. The residual radiation consisted primarily of neutron-induced activity around
ground zero.
Desert Rock VII and Project 52.1 Ground activity during shot
Hood included Exercise Desert Rock VII. As part of this exercise, the armed services fielded eight projects to evaluate military equipment and tactics. In the
Hood shot, the Marine Corps conducted a troop maneuver in the test area immediately after the detonation. This maneuver, which involved a Marine brigade and supporting units, included helicopter airlifts of assault troops, tactical air support, and air resupply. This was the largest single military activity in Operation Plumbbob. Observers were also issued gas masks to protect against a large non-radioactive dust cloud that was expected to occur as a result of the
Hood shot. The shot resulted in some trenches caving inward, although nobody inside sustained injuries. The largest group of participants were the 2,025 Marines who performed Project 52.1. This group consisted of the 4th Marine Corps Provisional Atomic Exercise Brigade and support units who were not present at the NTS. The project tested a task force assault following a nuclear detonation. Most of the participants in this exercise observed the detonation from trenches nearly five kilometers southwest of ground zero. Elements of one company watched from an area near the Control Point, more than south of ground zero. After the detonation, participants conducted a coordinated air-ground maneuver against the attack objective. When the maneuver was over, the Marines were transported to the equipment display area to view the effects of the detonation. In addition to the eight
Desert Rock exercises, the DOD conducted four operational training projects at
Hood. The
Federal Civil Defense Administration (FCDA) conducted another ten projects to assess the effects of nuclear detonations on civilian populations and to evaluate
Civil Defense emergency preparedness plans. Department of Defense participation in these projects was limited. The fourth project evaluated the accuracy of bomb damage assessment equipment on an aircraft. These projects, like those of the test groups, were approved and coordinated by the Test Director. == Aftermath ==