After discussions with JIF SEVEN operations planners, it was
decided that a secure voice facility between the ESTES and the
firing bunker on Enyu wovnld be of benefit.
NSA agreed to provide
four sets of AFSAY 804 (x) if the Task Force would send four well
qualified radio technicians for ciphony maintenance training and
the operation of a test circuit in the Washington, D. C., area.
This was accomplisned and the test circuit was successful.
NSA
approved the facility for operation through TOP SECRET.
B.
On-Site Phase.
The cen-site period proved the extensiveness and the flex-
ibility of the communications planning.
The significant difficul-
ties were successfully overcome and in ne case did communications
inadequacies or failures delay the completion of the cverall CASTLE
mission.
Detonaticn of the first device had an effect on the comm~
nications plan but a swift adjustment to the altered concept was
accomplished.
The following narrative treats these difficulties
which were of the greatest concern, communications-wise, during the
CASTLE on-site phase.
During the early operational period the Eniwetok-Los Alamos
radio-teletype circuit was placed in operation twenty-four hours
a day, in contrast to the ten-hour a day operation previously
employed.
Contimious operation of this circuit soon revealed the
unreliability of circuit operation during periods of propagation
instability.
The unstable conditions most generally existed during
critical operational periods, resulting in high precedence traffic