OPERATION CASTLE -
DAVE:
TIME:
PPG Time
1 Mar 1954
O6h5
TOTAL YIELD:
~
Bravo
GM?
Sponsor:
28 Feb 195)
1845
SITE:
15 Mt
FIREBALL DATA:
LASL
PPG - Bikini - on reef between
Burner and Charlie
Ve hat
165° 36"
Site elevation:
Timetolst minimum:
313 to 250 msec
Time to 2nd maximum:
3.54 to 3.95 sec
Radius at 2nd maximum
9,512 ft
TYPE OF BURST AND PIACEMENT:
Surface burst from platform on
HEIGHT OF BURST:
eo"
ON
is
Sca level
7 ft
CLOUD TOV HEIGHT:
114,000 ft
CLOUD BOTTOM WEIGH:
55,300 ft
CRATER DITA:
Coral soil
a7"
Diameter:
Depth:
Lip:
6,000 {t
240 ft.
Apparently
washed away
REMARKS:
The on-site fallout pattern was constructed from survey measurements on
Bikini Atoll, and from samples obtained with the total collectors and
gummed paper collectors.
The free-floating sea stations were not in the
correct location to receive primary fallout.
The data were cxlrapolated
to Htl hour by the composite gamma-ionization=decay curve obtained from
samples measured in the laboratory.
This is the only megateon shot where some downwind land areas were unexpectedly contaminated; thus, partial documentation of fallout effects
was possible,
However, the major portion of the fallout occurred over
the open oces;: and was not documented.
Eccause this chot is one of those
used as the Lasis of fallout predicticr fcr megaton yield weapons, three
off-site fallout patterns arc presented.
The mosu widely known pattern
is shown in Figure 40.
It was construcced immediately after the event
from the preliminary data available at Fus, #J*SWe.
The second pattern
was constructed by NRDL by establishing an coxperimental model; the field
data plus a thorough analysis of the wind structure existing at and after
shot time was used.
The third pattcrn was consiructed by RAND Corp., by
supplementing, field observations with mode] calevlationc.
63