ations and would afford no risk of damage to Mike Shot installations, nor would it interfere
with vital Mike Shot preparations. King Shot had relatively little instrumentation, and Mike
Shot was not expected to cause a great amount of damageto these installations. Therefore it
was recommended to CJTF 132 that the shot sequence for Operation Ivy be changed to Mike
Shot followed by King Shot. This shot sequence was approved by CJTF 132.
At this time it was recommended that the planned date for the detonation of Mike Shot be
changed from 1 October 1952 to 1 November 1952, and it was decided that King Day would be
no later than M+3 weeks.
A tentative cab working schedule was drawn up in April 1952 in order that scientific personnel could properly schedule their work in the cab area (zero point for the Mike device, so
called by analogy to the cab on the top of a tower). This schedule was followed as planned with
only slight deviations. Initial Mike assembly schedules were laid out and were revised to agree
with changes in concept which occurred throughout the preoperational stages.
Ground zero for the King weapon was selected in April 1952 as the junction 6000 ft from
Station 6a and 2000 ft from the furthest point north on Runit Island. Runit was selected because
of its distance away from Mike Shot, thus lessening the possibility of damage to installations.
Runit was also far enough from Parry Island to avoid the risk of major damage on Parry.
This Task Group’s concept of operations was then disseminated for further operational
planning by other participating agencies in late May 1952, and in June an evacuation conference
was held at Los Alamos, during which time the effects of Mike Shot were predicted. It was
concluded that the structural damage on Parry and Eniwetok should be minor, that the thermal
effects at that distance should be negligible, that there was no danger from sea waves, and that
boats could be anchored safely in water of 50-{t depth.
t
The advanced echelon of this Headquarters was established on Parry in early August 1952,
and by the end of August the Mike device had been completed. It was then under the operational
control of TG 132.1 and was loaded aboard the USS Curtiss for transport overseas. The Cambridge Corporation (Camco) had completed eight Dewars (specialized equipment for the transportation of liquid hydrogen), had shipped them overseas, and was beginninginitial filling operations on the Dewars in the Forward Area. All major construction was essentially complete,
except for the construction of scientific stations. This Task Group’s Operations Plan 1-52 was
then issued.!
3.4.2
Basic Requirements
In early October 1951 the basic requirements for testing the thermonuclear device became
apparent; namely, a large cryogenics plant, Dewar transport facilities, a specialized cab in
which to build the device, and the use of the USS Curtiss as an assembly ship.
Upon the activation of TG 132.1 on 2 January 1952, staff studies were made which were
based on Greenhouse experience and on the best available estimates of the requirements peculiar to an accelerated thermonuclear program. In consideration of the Mike event many new
problems were introduced which had no precedents as criteria for establishing operational requirements.
By January 1952 the support requirements from the DOD were established and presented
to the Joint Chiefs of Staff JCS). The requirements dictated the use of certain types of ships,
numbers of small boats, various aircraft, and much other military support.
In February 1952 the cryogenics plant design was finalized, and construction began in
March. The shot-isiand camp was started and was completed in late April.
By Apri] 1952 the project aircraft requirements becamefirm, and TG 132.4 was in the
process of obtaining modifications for most of these aircraft. The requirements for modifications to TG 132.3 ships became firm, and the operational dates for ships to be in the Forward Area were determined.
The various modifications required for aircraft were coordinated with CTG 132.4, and
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