scaling for vehicle damage proposed by Project 1.8, since this attached importance only
to dynamic pressure. Castle data was utilized in the preparation of a composite AFSWP
report (Reference 12), which showed that we scaling is the most-appropriate method
for predicting damage to military field equipment.
2.3.4 Effects of Rain. Ground zero of Shot 3 and most of the Tare complex to the east
were covered by heavy clouds with accompanying shower activity at zero time, a situation
well documented by radar, photography, and transmissivity measurements.
Although
the low yield of this shot failed to satisfy many of the program’s objectives, very inter-
ae
tt
Overpressure , psi
1
4
t
tooo
(
Uncie Biast Line
i
{
‘
|
Tare - Odos Bicet Line
1000
10,000
Range , Feet
80,000
Figure 2.3 Overpressure versus ground range, as measuredfor Shot 3.
esting data was obtained that appears to be directly associated with the presence of high
moisture content in the air.
Two instrumented blast lines had been established on bearings approximately 180
degrees apart—along the Tare complex eastward to Oboe Island and westward through
Uncle Island. When the data had been reduced and plotted, it became obvious that an
anomaly existed: pressures obtained from the Tare line were somewhat lower than those
recorded by the Uncle gages.
Possible correlation of this effect with low clouds or rain was suspected when the
radar-scope photography disclosed that Uncle and that area immediately to the west of
ground zero was relatively clear, while a solid return over the Tare complex indicated
heavy clouds and, possibly, actual rain.
Figure 2.3 shows a plot of pressure data from both lines.
Project 1.2b instrumented
the east and west lines with self-recording gages, while Project 1.2a covered only the
27