Low

wo
At

wise to 90° asxiam distanse 35 MM. For H plus 6 hours,

pmaltiply distances by six.

wwe

in om effort to saseist the jelein permanent garrison, the

monitor staticn for the period H to H plus 36 houre. (No contamination vas
subsequently detocetod on ako.)
At the 1S00M Command Briefing, the wind pattems observed and forecast
being completely favorable, the decision to shoot the following acrning we
confirmed. At approximately 230G@M a dircstive wae passed te CTG 7.4 relae
tive to the cloud tracing flights for the first twelve-hour period on shot
day. Inasmehas it had been desided during tue interia period following
BRAVO to attempt a better evaluation of the effeet of the depth of trids=

wind on the rosultant fall-out aoving toward Iniwetok, two "5-29 cloud

trackers were planned to operate in the rneetresk holding pattern west
of GZ, one at 10,000 feet, the cther approxiaately alduay between the sur
face and 10,000 feet. The dircetive consequently speeified a flight by
Wilsen 2 from H plas 2 to H plus 14 hours from base to a three-hour holding pattern 50 NM west of GZ at 10,000 feet, thence to a 500 NK seator, liniting true bearings frem GZ of 60% and 90° 38 10,000 feet. “Llson 3 wae
Girested to search from H plus 2 hours until released, in the holding pate
tern specified above, and at an altitude selsctod by the pilct to clear
natural clouds, but not in excess of 5,000 feet.

3

A comph ee Command Briefing wee hold at aidnight, at which all pre=
vious. factore, advisories and decisions were confirmed. It was decided
however, to re-check the winds at 04300 and just prior to shot tine.
forecast fall-out plot by elliptical approximation is included in Inclod=
ure 4.

-

,

The British Unit was again advised at H minus 6 hours relative to the

latest changes in the forecast winds,

Due to a small shift in the low leve

el winds, the Control DDS was moved to 230° True, 90 NU from GZ. Mo change

was recommended ralative to the Task Force fleet location southeast of GZ
at a minima distance of 30 NK.

The lata cheeks of the weather/radsafe conditions indicated a sore
favorable shot time wind pattern than forecast (i.e. decpor southorlies
in the levels botween tho trades and 55,000 fect). Transient shipping con=
tacts being favorable, ROMEO was detonated on a barge in approximtcly 110

feat of water in the BRAVO crater at 270630M March 1954, the first water

surface shot in the history of U. S. atumis testing. No undue ineident
oceurred to the embarked task force personnel and ships. Post-shot advis-

ories were issued prior to H plus 30 minutes to the Chairman, AEC, C/S Aray
and CINCFACFLT as on BRAVO, indicating time of detonation and a general
statement of safety of personnel.

IH-4

Select target paragraph3