Communication Intelligence Summary, 15
General.-Traffic volume normal, with a number of general address messages originated by Communication
Division, Tokyo, to Radio Officers, Ominato,
U. E. 9 (D. F. Station in Marshalls), Jaluit, Palao, Truk, Saipan, Takao and Sama Radios, Staff
Communication Officers All Major Flagships,
Staff Communication Officer South Expeditionary Force and two apparent collective shore addresses. Traffic
from all stations mentioned except Sama
and Ominato to D. F. Control and Plotting Room Tokyo information to Staff Communication Officer Combined Fleet was
exchanged. No messages of the D. F.
type were detected so it is presumed that the interchange had to do with arrangements for drill or organization
of the net. The Minister of the Navy
originated one Alnav and one to all Major Commands and collective shore. Tokyo Personnel and Tokyo
Communication Division originated
several to collective fleet and shore. Significance is not determined though it is believed possible that a further
partial change of shore and air calls
may be in prospect. The Empire air station net was normally active using tactical calls. Secretary First
Fleet I originated one Urgent Code to
unidentified (MINI 55), Staff Communication
Officer Carrier Division Four (at Sasebo) and Commanding Officer of Batdiv Three flagship.
Combined Fleet.-Same as yesterday, same units (Batdiv Three, Desrons
One and Three) associated through
traffic with South Expeditionary Force. CinC Second Fleet was the most active originator and appeared to
be arranging operations of units
involving First, Second, Carrier and Air Units.
Fourth Fleet.-Apparent movement of Fourth Fleet units in prospect or underway with continued emphasis on the
Marshalls Area. CinC. Fourth traffic
still being handled from the Truk area, with Airron Twenty-four (Kamoi) and associated Yokohama and Chitose
air units involved in some movement
direction undetermined. All Marshall Island activities, including unidentified Army Forces,
exchanging traffic freely.
Submarine Force.-Little activity detected. It is believed that some submarine activity is operating or preparing
to operate in the Marshall area, from
communication arrangements underway between Staff Communication Officer
Submarine Force and same Fourth Fleet, information to Jaluit. Jaluit
has been heard working on various
frequencies, using tactical calls and procedure
associated with submarine operations, but no identifications of calls used have been made.
air traffic to and from Takao area, with unidentified Airron formerly YOME 7) including South
Expeditionary Force and Sama addressees
n traffic. Composition of this force and purpose still speculative but believed o be preparing to
move southward to work with the South
The large number of alternate calls used by major forces renders analysis of traffic headings very slow and
difficult, but identifications and
recoveries of alternates are improving as a greater volume of November traffic becomes available for research.
(FROM: U.S. CONGRESS JOINT COMMITTEE ON PEARL
HARBOR ATTACK HEARINGS; PT. 35, THE
CLAUSEN INVESTIGATION, PP. 62-81. EXHIBIT "A" DAILY COMMUNICATION