This after action report (AAR) shows great examples how radio intelligence provided indications and warning to task force commanders during WWII. Throughout the report designators 8600J, 5135J and 5715J are mentioned. These designators were used to identify discrete communications entities, such as links, nodes and networks to aid intercept operators to manage the tasking, collection and exploitation of Japanese radio communication circuits.  The end of this report list the Japanese language officers, their assignment to each of Task Force/Group and where they received the language training.  Although there were enlisted Japanese Kana Kata intercept operators on each ship, none are listed.

Strikes on FORMOSA and LUZON and
Landings at LINGAYEN GULF.

30 December 1944 – 25 January 1945

In this operation the 3rd Fleet was employed to support the operations of the 7th Fleet in landing occupation forces in LINGAYEN GULF. The enemy was expected to employ all his remaining air power in the PHILIPPINES, as well as the forces available in FORMOSA and such air power as might quickly be brought down from the EMPIRE or from CHINA. The presence of units of the Japanese Fleet at SINGAPORE was known and consideration had to be given to the possibility that these units- would sortie to support Tap forces on LUZON.

Task Force 38 sortied from ULITHI Atoll on 30 December, 1944, enroute to FORMOSA for strikes against air fields and shipping. Search for enemy planes was maintained by Radio Intelligence Units. Tactical air activity was followed on 5135J (note: network designator) , all of which concerned reconnaissance of Blue forces in the PHILIPPINES area.

The force arrived at position for the strike at dawn 3 January 1945. The run from ULITHI was uneventful with indications that tactical surprise was achieved. No searches had been noted airborne prior to the strike and the FORMOSA area was put under alert after the first Blue strikes had reached their targets. Pilots returning from the first strikes reported much shipping at or near TAKAO. Coverage on 8600J (a) enabled the radio intelligence units to supply the positions of many ships in the general area, which were attacked and sunk. At 1300 the strikes were cancelled for the rest-of the day due to bad weather. Although two enemy planes were shot down near the Task Force no radio reaction was noted.

The Task Force remained in the FORMOSA area to continue strikes on 4 January. Prior to dawn two planes made radar contacts with the force. One made contact in a grid message timed

0130.  The plane was not heard in communications but his despatch was intercepted on the SASEBO Broadcast. The other plane was heard in communication attempting to send a grid contact with the force shortly after 0100, but was unable to secure a response from his base until 0552. The strikes were conducted without enemy countermeasures until 1718 when an enemy reconnaissance plane on 5135J (a) sent a message containing a grid position on the carrier force.

On 5 January the Task Force replenished. Radio intercepts indicated that the enemy was concentrating his efforts against Blue forces at LINGAYEN GULF although the force was sighted at 0408 by a FORMOSA-based reconnaissance plane. Heavy assault on Blue forces at LINGAYEN GULF was followed on 5135J at about sundown.

T. F. 38 launched procedure attacks-on Northern LUZON on 6 January. At 0509 an enemy plane reported the position of the task force in a despatch. This plane had not been heard on circuit but the despatch was heard by all RI Units on the MANILA broadcast on 5715J (a). Again the enemy ignored T. F. 38 and hurled a heavy attack on Blue dispositions at LINGAYEN GULF in the early evening using 5135J for communications. Grids in this area and attack signals were copied during the development of this assault.

T. F. 38 struck LUZON again on 7 January. Again the enemy chose to ignore it and concentrated its attention on the 7th Fleet units at LINGAYEN GULF. 5135) was active throughout the day. Many attacks were made on the Blue invasion forces to the west of LUZON. Grids in this area and attack signals were copied. Nothing of importance to the Task Force was noted on 8 January as the force replenished. Air activity on 5135J declined somewhat. A search plane on that frequency transmitted a grid message at 1020 which was soon broadcast by MANILA, TAKAO, and TOKYO, and was apparently a contact with Blue forces west of LUZON.

The carrier force returned to FORMOSA on 9 January and was handicapped by bad weather. No planes were heard searching for the Task Force and only six were noted airborne on 5135J, the tactical channel for the area.

Raids in the SOUTH CHINA SEA

During the night T. F. 38 proceeded through LUZON Straits to prosecute the phase of this operation specifically called “GRATITUDE.” Prior to dawn two bogies were splashed without radio reaction. No indications were noted to indicate that the enemy suspected the presence of T. F. 38 in the SOUTH CHINA SEA. Despite the U. S. landings at LINGAYEN GULF on 10 January radio reaction was light. Activity on the air circuits was well below normal.

T. F. 38 proceeded during the 11th toward CAMRANH BAY. It was regarded as possible that units of the Jap Fleet would be found at that anchorage. Planes on 5135J came close to the force. Signals at 1600 were strong. The CAP was sent out and splashed three planes without radio reaction noted. Radio intelligence units checked for FRENCH INDO-CHINA frequencies which might come up during the strike.

Tactical surprise was achieved in the attack on Jap shipping and installations on the coast of FRENCH INDO-CHINA. The alerts for the area came out on circuit well after the first strikes had arrived over the targets. Although the fleet units which we hoped to find at CAMRANH BAY were not there, much Jap shipping was located. By coverage of the ship-shore local frequency the RI Units were able to provide the commands with the positions of many vessels in the area and so aided in their destruction. Japanese air activity was unheard throughout the day.

T. F. 38 refueled on the 13th and 14th. No intercepts of importance were made on the 13th. Activity continued light on all air circuits on the 14th until about 1520, at which time a plane on 5135J sent a grid contact with the Task Force. Apparently three planes were involved in the search. Another sent a grid at 1530 which appeared to be a contact with the replenishment force. The third plane which was heard on this circuit apparently failed to make contact.

The Force launched strikes against FORMOSA on 15 January. Tactical surprise was achieved. Enemy reconnaissance on 5135J was successful at 0850 and 0910 when two planes reported the position of the task force. This was the second day in a row that the enemy had the task force well located and the RI Units tightened up their search efforts in anticipation of an attack. However, again the force was unmolested.

On 16 January T. F. 38 struck the HONGKONG area. Again tactical surprise was achieved. Radio interception during the day revealed nothing in the way of enemy countermeasures. No searches were sent and all air frequencies were below normal.

T. F. 38 replenished on the 17th, 18th and 19th of January. The operation was complicated by heavy weather. Interception provided nothing pertinent as the enemy was apparently also hampered by weather.

The Task Force retired through BALINTANG CHANNEL late on the 20th. Interception on 5135J revealed one plane with a strong signal at 0844. Radar was alerted and at 0929 the plane was located on the screen. At 0950 the plane was splashed without getting off a message. As the force passed through the straits at 1800 a ferry flight from FORMOSA was intercepted. Most of the planes were destroyed. The activity on 5135J which was relatively heavy throughout the day appeared to be, in part, search for T. F. 38; but despite the effort no genuine report of the position of T. F. 38 was intercepted and no indications were noted of the development of a mission against the force when its presence in the straits became known at 1800.

At dawn on 21 January T. F. 38 launched strikes against FORMOSA. Enemy planes were in communications on 5135J soon after dawn and at 0812 a plane reported contact with the task force. He followed with a grid message at 0832. During the morning several other planes were up on 5135J apparently operating from FORMOSA bases. Several reported sighting Blue aircraft end the CAP reported splashing several enemy planes singly. Between 1200 and 1315 one task group was attacked. No attack signal was heard when the USS TICONDEROGA was first hit but planes were heard in the vicinity of the Task Force on 5135J. An attack signal was heard at 1253 when the enemy prosecuted the second successful attack on the TICONDEROGA. The attack was signaled again at 1301. Activity died down during the afternoon on 5135J, but by 1850 several planes were again active on the circuit. The signal “Enemy sighted” was heard at 1927 and at 1931 one plane was shot down, but ship’s gunfire. No grid was intercepted. No further activity was noted on the 21st.

Tactical surprise was achieved in the attack on OKINAWA on 22 January. Blue planes were over their targets at 0635. The alert for the area was set at 0642. One despatch originated by the OKINAWA Base Force Commander and addressed for action to Base One Torpedo Beat Unit #27 and Base One OKINAWA Midget Sub Unit was intercepted carrying a high precedence indicator. It was regarded as indicative of offensive possibilities. However, no attack resulted. 5135J became active about 1700. Two search units were heard airborne but no signals became loud and no grid contacts were heard.

On 23 January the Task Force refueled. Interception on 5135J was heavy with planes heard up from FORMOSA bases between 0300 and 0800 and again between 1600 and 2400. No planes came near the task force, although the activity was believed to be search and patrol.

The Force retired toward ULITHI on the 24th of January, arrived on the 25th without incident.

End of AAR

Following are the Japanese language officers supporting these missions:

Comdr. G. M. Slonim – Japanese language officer, received his training in Japan, 1939-41

Lt. E. B. Beath – Japanese language officer, received his training at University of California at Berkeley, Class 1942

Lt.(jg) W. M. Kluss – Japanese language officer, received his training at University of Colorado at Boulder, Class 1944

Lt.(jg) R. A. Wilson – Japanese language officer, unknown where and when he language.

Lt.(jg) R. B. Palmer Japanese language officer, received his training at University of Colorado at Boulder, Class 1944