we
Project 10.2 = Time-of~Arrival - J, F, Mullaney
The time-of-arrival method was employed to estimate the yield of
the gales:=) through use of hand-held stop watches at Station
1518, Parry Island,
The shock wave was heard clearly, and there was
almost exact agreement in time interval as measured by several obser=
vers.
The time of arrival at the microbarograph station of Project
31.1 at Eniwetok Island was also noted by Carter Broyles (Sandia).
The times of arrival and ranges of these stations are given in Table
10,21,
The weather conditions of interest, as observed at Eniwetok at shot
time are?
J
Pressure?
1,009.1
mb
Temperature?
80.3°F, relative humidity 80.2%
Winds
12 knots from 100°, with gusts to 15.
The sound velocity calculated using the expression
4s 1145 feet per second,
1.4 pressure/density
A wind of 12 knots from 100° adds 57 feet to
the air path between Ground Zero and the Eniwetok station, and 228 feet
to the path to Station 1518,
The shock wave speed (still slightly above
sound speed) in the last third of the path to Eniwetok is then:
(72,72
-
228) = 1147 fps
1.3 = 40.4
The sound speed 1145 fps is in good agreement with this figure, and is used
in getting the yield estimates in Table 10.2-1,
As was indicated in the report on
?
an empirical reflection
factor of 1.6 seems appropriate for a lahd-based surface shot.
(ERIE) was not a surface shot but was fired on a 300-ft. tower.
The fai]
Qa
D. F.
Seacord, Jr., and Carter Broyles point out that in the case of a tower
-_«
ti
shot, the reflection factor should not be applied in calculating the traverse