In general, the principal objectives of the military-effect programs
were realized. The numerous changes in shot schedules together with the
repeated delays due to unfavorable weather forced many revisions and lastminute improvisations in many projects’ plans. For some-notably those
concerned with documenting fallout-much information was thereby lost; for
other projects, such as those involving effects on aircraft, the repeated

delays allowed completion of necessary maintenance between shots and resulted
in almost 100-percent participation.
Despite uncertain yields and delays, the blast program obtained a

considerable amount of worthwhile data and achieved its objectives. Wave
forms from the surface gages were nonideal in shape for both overpressure

and dynamic pressure and demonstrated that water is not an ideal surface-

it sometimes had been presumed to be ideal.

detected.

Precursors as such were not

The uncertainly of the free-air data did not permit any definite

conclusions regarding the effects of a nonhomogeneous atmosphere on the blast
wave. Data from a megaton burst over a shallow water layer indicated that
except for theclosein region, underwater pressures are of comparable
magnitude to the direct air-blast overpressures at the same range.
In

contrast to results from Operation Ivy, studies at Castle indicated that surface

water waves do emanate from the central region of the detonation and that

refraction and reflection against reefs and shores can significantly affect
their destructive capability.

In the nuclear-radiation and fallout program, the unexpectedly high yield

of Shot 1 caused destruction of much of the spare equipment on Site Tare,
curtailing instrumentation on future shots; however, the important military
significance of fallout over large areas beyond the blast- and thermal-damage
envelopes was demonstrated dramatically.

The realization that activity

dissolved in sea water could be a measure of the fallout intensity provided
the impetus for the water and aerial surveys that provided valuable data

after Shots 5 and 6.
In the blast-effect program, the instrumented, rigid concrete cubicle
was exposed to a blast intensity from Shot 3 of only about a tenth of that
predicted. Although the specific objective of that particular project was
not accomplished, an evaluation of the blast-loading data therefrom made by
Sandia Corporation showed that two loading-prediction procedures were
reasonably good.

The documentation of air-blast effects on miscellaneous

structures was an unplanned project of opportunity-one initiated because of
the damaging, unexpectedly high yield of Shot 1.
Crater size data was obtained as planned, increasing considerably the

reliability in predictions of craters produced by megaton weapons.
Despite unexpected deviations from predicted yields for Shots 1 and 3,
breakage data and other results on damage to natural tree stands were obtained.
The underwater minefield-121 mines of various types set 180 feet deep
and exposed to a 7.0 Mt surface detonation-gave data on the extent of
neutralization of these mines by the detonation.
Extensive data was obtained in the biomedical study of the individuals

acciently exposed to significant amounts of fallout radiation. Total gamma
dosages up to 182 r were received and produced the physical effects expected.
The actual yield of Shot 1 was approximately 25 percent greater than the
positioning yield used for the effects studies on aircraft in flight.

An

overpressure of 0.81 psi was recorded on the B-36; damage to the B-36
necessitated replacement of the bomb-bay doors, aft lower Plexiglas blisters,
and the radar-antenna radome.

Select target paragraph3