[176] Communication Intelligence Summary, 4
December 1941
General.-Traffic volume normal with fair receiving conditions. Takao Radio today instituted a fleet broadcast system
using the prefix UTU in heading so that
there are now two fleet broadcasts in operation. So far only a few messages have been placed on the
Takao broadcast. There were a large
number of urgent messages, today, most of these from Tokyo to the major commanders. Among others Tokyo
Intelligence originated a seven part
message to Chiefs of Staff China Fleet, Combined Fleet, Third Fleet, South China Fleet, French Indo-China
Force and Sama. In all, this activity
sent twelve messages to the major commanders.
Combined Fleet.-The outstanding item of today's traffic is the lack of messages from the CinC. Second Fleet and
CinC. Third Fleet. These previously
very talkative commanders are now very quiet. While the Fleet calls are not yet well identified, the lack
of traffic from these commands cannot
be ascribed to that. These two commands are still prominent as addressees. It is now believed that the CinC. Second
Fleet is in the vicinity of Takao and
that the apparently conflicting evidence is due to traffic destined for the Tokyo UTU broadcast which CinC.
Second Fleet is still copying. The
CinC. Combined Fleet sent one message to
an unidentified unit for information to Third Base Force Palao, CinC. Second Fleet and CinC. Third Fleet.
Fourth Fleet.-The CinC. Fourth Fleet sent a message to Chief of Staff Combined Air Force, information to Eleventh
Air Corps, Chitose Air, Air Squadron
Twenty-four, Third Base Force at Palao and Fourth Base Force at Truk. No further check could be made today on
the presence of Fourth Fleet units in
the Marshalls. Jaluit appeared many times in today's traffic being associated with Commander Submarine Force, Tokyo
Radio and MUSI 88 (which is believed to
be an oil tanker).
South China.-Bako continues as an active originator addressing many messages to Sama and Saigon. Except for
traffic between South China Commanders,
all units in that area quiet.
(FROM: U.S. CONGRESS JOINT COMMITTEE ON PEARL HARBOR
ATTACK HEARINGS; PT. 35, THE CLAUSEN
INVESTIGATION, PP. 62-81. EXHIBIT "A" DAILY COMMUNICATION
INTELLIGENCE SUMMARIES)