[173] Communication Intelligence Summary, 2
December 1941
General.-The most prominent factor in today's traffic is the apparent confusion in the routing of traffic for
certain major parts of the Japanese
Fleet. There were instances where the same dispatch was repeated several times after it appeared on
the Tokyo broadcast and also where
Takao Radio received the same dispatch that it had previously sent. ComSixteen reported Second and Third
Fleets in Takao area and that Takao
Radio was broadcasting traffic to these fleets. This broadcast was not uncovered here and contrary to location
reports, there was one indication that
these two fleets were not close to Takao. In several instances Takao Radio forwarded traffic to Tokyo for these fleets.
Summing up all reports and indications,
it is believed that the large fleet
made up of Second, Third and First Fleet units has left Empire waters but is either not close enough to
Takao for good communication or is
proceeding on a course not close to Takao. The change of calls on December first has prevented this office from
making definite statements at this date
of the units now in the Southern area. To further complicate the situation, Shanghai Radio handled a considerable
mount of traffic which obviously was
originated by and destined for units in the Takao area. The Chief of Staff, South China area continues to
appear in Shanghai ComSixteen reported
nine submarines proceeding south by Camranh Bay. This group is believed to comprise both Submarine Squadrons
five and six, which units normally
operate with the First Fleet but have been included repeatedly in the Second Fleet Task Force for Southern operations.
There was a very high percentage of high precedence traffic originated both by major forces afloat and Tokyo. Hainan
continues as a prominent address. Palao
and Third Base Force is holding the same relative importance.
First Fleet.-Despite the lack of positive identification, the First Fleet appears relatively quiet. From
inconclusive evidence, it appears as if
there may have been a split in the original or normal Combined Fleet Staff and that these may be two supreme
commanders with staffs. As an example,
traffic routing indicates one Combined Fleet call associated with the Second and Third Fleets and
apparently in company while another Combined
Fleet call appears not associated with the Second and Third Fleets.
Second Fleet.-No units have stood out prominently the last two or three
days.
This is partly due to lack of new identifications but contributes somewhat to the belief that a large part of
the Second Fleet is underway in
company. Cruiser Division Seven and Destroyer Squadron Three are unlocated and unobserved since change of
calls.
[174] Third Fleet.-Nothing to report. Shanghai
appeared in an indirect way in some of
the Third Fleet traffic.
Mandates.-Association of Submarine Force and Fourth Fleet continues. Some traffic for Fourth Fleet units still
going through Truk.
Carriers.-Almost a complete blank of information on the Carriers today Lack of identifications has somewhat promoted
this lack of information- however,
since over two hundred service calls have been partially identified since the change on the first of
December and not one carrier call has
been recovered, it is evident that carrier traffic is at a low ebb.
Combined Air Force.-This force continues to be associated closely with Second, Third and Indo-China Fleets. Some
units of the Combined Air Force have
undoubtedly left the Takao area.
(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)