© conmneul,

G. W. Johnson

Page Two

COPAA-317

LSD would be the device loaded barge, two H&N I'M°s and an LOU loaded

with the barge moorings.

At slack high water the LSD would discharge

the LCU which would proceed through the Pokaakku Passage (widened to
70-100 yards) to the zero site at the north end of Taongi lagoon, and

commence the task of placing the moorings for the first barge.

The

crew of the LCU would be messed and housed aboard the LCU' during the
one to two day period required for placing the moorings. During this
time the LSD and experimental ship would lay te at sea in the leeward
ereacent of the atoll. Upon completion of the moorings, the LOU would

return to the LSD and with the assistance of the two LCM’s would proceed
to warp the shot barge through the passage, tow it to the zero site and

moor and position the barge in its final alignment.

Concurrent with the mooring and barge placement operations supported from the LSD, the experimental groups on the firing and diagnostic
ship would make final preparations and would prove out equipment ready
for dry runs. At this point the experimental equipment is in readiness

and the weapons group would start their final preparations, having been
transferred from the ship to the LSD by motor launch in order to board

the shot barge prior to flooding down.

The LCU and LOM's in turn would

have returned into the LSD with their boat crews. On this final day,
for purposes of final dry runs, the experimental ship would move to
the position chosen for the shot, complete the dry runs, return to the
passage entrance offshore, and receive the barge firing party from a
ship's launch, Hoisting this last boat aboard constitutes final
evacuation, leaving both the aforementioned ships free to move to their
final safe shot positions.
Assuming the shot 13 then detonated early the next morning, the

LSD would remain in her safe position while the experimental ship is

moved to a suitable safe distance off shore. From this point an aerial
rad-safe survey of the lagoon water would be made, both at small boat

moorings at the southern end of the lagoon and in the vicinity of the

crater. Upon determination that the radiation level at the small boat
moorings would permit a mooring operation there, the LSD would discharge

the LC0 (with a new set of moorings aboard) and the two LCM’s.

The LSD

would then sail for Nan to load and return the next shot barge, leaving
the experimental ship laying to at Taongi in support of the next mooring
placement operation. The radiation level in the crater proper probably
will not drop to a safe working level as rapidly as the level in the
southern lagoon. Thus the concept of the small craft being moored first
as described to await clearence into the crater is to allow the earliest
possible sailing time for the LSD.
In the above concept several points should be emphasized:
1. Deep water operations in the lee of the atoll can be delayed by
rough weather and the use of LCU's end LCM’s outside of the lagoon is

kept to an absolute minimum in the above plan.

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