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Operations:
To measure sea waves generated by MIKE, instruments
were set out at 19 locations:
the Enewetak Lagoon near Runit and
Enewetak Island, Sea Mounts 265 and 72 north of ground zero, two
locations on Bikini Atoll, Kwajalein, Wake, Truk, Guam, Canton
Island, Yap, Midway, four locations in Hawaii, and two locations
in California.
The Horizon recovered the instruments from the two
sea mounts.
Radiation Exposure Potential:
The Horizon placed instruments on
the two sea mounts before the MIKE shot.
At shot time the ship
“was standing by Sea Mount 72. At 0745 the ship was ordered-to get
underway on a course 045°T at 11.5 knots for 4 hours and then
started circling on new station approximately 100 miles
north-northeast of ground zero.
At 1240 radioactive fallout was
detected and the ship was closed up, ventilation secured, and the
washdown system started.
Upon receipt of a message from the
Horizon that fallout was being encountered, the ship was ordered
to proceed southward.
After 25 hours steaming at 11.5 knots, the
ship reported clear of the fallout area and that the peak
radiation intensity encountered was an average of 0.008 R/hr
(gamma only) and a maximum of 0.035 R/hr (gamma only).
After
Ola) o4¢,.
from the washdown system were hosed down and the ship's decks were
washed down.
Then the radiation levels decreased to an average of
0.003 R/hr, with a maximum of 0.020 R/hr.
When the ship the
returned to Enewetak on 6 November, the radiation intensity had
lar
f\
Ihe Ob Ve.
py
leaving the areas of highest activity, the masts above the spray
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