JAPANESE MONOGRAPH No. 90
JAPANESE MONOGRAPH No. 91 included.
The "A-GO" Operations
May - Jun. 1944
Through Instruction No. 126 to Japanese Government, 12 Oct 45, entitled "Institution for War Records Investigation", steps were initiated to exploit military historical records and official reports of the Japanese War Ministry and the Japanese General staff.* Upon the dissolution of the Mar Ministry and the General staff, and the transfer of their former functions to the Demobilization Bureau, the general research job continued and resulted in the development of a series of historical monographs. Detailed instructions covering the preparation of these monographs were included in Memoranda 15 December 1945 and 21 November 1946, subject "Japanese Operational Histories."
The basic material contained in this operational record was developed by former officers, on duty in command and staff units within major units during the period of operations. It should be noted at once, that the enormous destruction by aerial bombardment and fire has practically wiped out the Tokyo records; much of this material was reconstructed from memory.
The paucity of original orders, plans and unit journals, which are normally essential in the preparation of this type of record, most of which were lost or destroyed during field operations or bombing raids rendered the task of compilation most difficult; particularly distressing has been the complete lack of official strength reports, normal in AG or G-3 records, however, while many of the important orders, plans and estimates have been reconstructed from memory and therefore are not textually identical with the originals, they are believed to be generally accurate and reliable. Further data as a result of continuing research and the occasional recovery of hitherto unavailable original documents will be covered in the subsequent publication of "supplements" by the demobilization bureau.
* The action under this memorandum and incidental detailed instructions, which followed, were initiated by the Assistant Chief of Staff, G-2, GHQ, charges with responsibility for execution of the program under G.O. No. 9, SCAP, 2 October 1945.
In order to protect the interest of the United states, in the exploitation of Japanese Military Information, sub-paragraph 4 of G.O. No. 9 further provided for the screening of enemy documents and established inventories in Japanese Governmental archives. Careful examination of the first records submitted by the Japanese Government in the summer of 1946 detected a misconception on the part of the Japanese as to what should be included in comparative histories; in a memorandum issued by Assistant Chief of Staff, G-2, on 21 November 1946, the Imperial Japanese Government was directed to record the operations of the Japanese forces more extensively. The G-2 Section thereafter assumed coordination of the entire program, including the establishment of a small historical research section within the ATIS (Allied Translator and Interpreter Section.)
GENERAL HEADQUARTERS
FAR EAST COMMAND
MILITARY INTELLIGENCE SECTION, GENERAL STAFF
Allied Translator and Interpreter Section
Translation Requested by G-2 Historical Section
Date Rec'd ATIS 10 Oct 47
Description of Contents: Full translation of Operation "A", as directed by Imperial Naval General Headquarters.
(TN * indicates on exact ROMAJI transliteration of the original KANA.)
Operation A
Operation A |
|
Part One. |
The Situation. |
Part Two. |
The Progress of the Plan of Operation. |
Part Three. |
Operations Directed by Imperial General Headquarters. |
Part Four. |
Operations Directed by the Combined Fleet. |
Part Five. |
The Plans of the Task Force. |
Part Six. |
Base. Air Unit Plans. |
Part Seven. |
Outline of Developments. |
Chapter I. |
General Developments. |
Chapter II. |
Task Fores. |
Chapter III |
Base Air Units. |
Chapter IV. |
Submarine Force. |
Operation A
Operation A was planned and executed, during the middle part of 1944, to discourage the enemy's plans for a counterattack by concentrating and deploying the greater part of the Combined Fleet's decisive strength along the main counterattack front and annihilating the enemy fleet with one blow.
Part One. The Situation.
After the enemy began their counterattack, on August 1942, from the Solomon Front, a fight to the death was continued for a year and a half.
Although our navy, with the main strength of the Combined Fleet relatively dominated the enemy one inflicted great losses upon him, we also incurred many losses from among the elite of our air force and naval units.
In November of 1943 the difference between our air strength and that of the enemy became greater. As soon as the situation in that area become favorable to the enemy, they increasingly strengthened their offensive and also launched an attack on the GILBERT Islands.
We defied all risks in planning the destruction of the enemy force in the Solomon Area. Not only did we provide for the strengthening of base air units but, also, we increased the carrier-based sir strength of the combined fleet in that area. For this reason, it was possible to slow down, to a certain degree, the speed of the enemy's assaults is this region. However, as for other areas, the enemy strengthened their counterattacks in the Marshall and New Guinea areas. Finally, on 1 Feb 45, (TN Feb 44?) they quickly launched an attack on KWAJALEIN Island, the central base of the MARSHALL Islands. Along with occupying this island, they furthermore attacked the BROWN Islands.
On 17 February, for the first time, we suffered a carrier-based raid on TRUK and the enemy threatened our rear line of operations in the Southeastern Area. Therefore, the Imperial Navy, in view of the overall situation, transferred the entire mobile air strength in the RABAUL area to the rear during the latter part of February 1944, and the necessity for meeting the enemy's counterattack with a new plan was recognised.
During this period, an enemy task force carried out initial air raids on the islands of SAIPAN and TINIAN, on 23 February. They concurrently swarmed over the eastern portion of NEW GUINEA and occupied the ADMIRALTY Islands. The speed of the offensive from the two enemy fronts gradually increased and
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the invasion of the inner South Pacific, defensively important to national pretention, was merely a matter of days.
In accordance with the foregoing, from the middle part of February 1944, Imperial General Headquarters had the main force of the First Air Fleet, which had undergone organizational training as a unit directly supervised by Imperial General Headquarters since 1 July 43, successively proceed and wait at the inner South Pacific and PHILIPPINE Islands. Concurrently, they were made to co-operate with Combined Fleet operations, and this same fleet was integrated with the Combined Fleet on 15 March. The strength of base air units which were caused to retreat from RABAUL were reorganised and stationed in the inner South Pacific Area. The main strength of the sea units of the Combined Fleet transferred its advanced bases from TRUK to PALAU the first part of February (prior to the air raid on TRUK by the enemy task force). Combined Fleet Headquarters was also in the process of directing operations at PALAU.
In accordance with the critical conditions in the inner South Pacific Area and in order to fortify defensive conditions in the area, the 14 Air Fleet was newly formed on 4 April, with the majority of the air units of the 11 Air Fleet, then in the inner South Pacific Area, as its nucleus. On the same day this air fleet and the 4 Air Fleet formed the Central Pacific Area Fleet and was stationed on SAIPAN. Together with the army unit (32 Army) newly stationed in the same area under the operational command of the Commander-in-Chief of the Combined Fleet, they were entrusted with the defense of the inner South Pacific Area. Daring the period from 30 March to 1 April an enemy task force raided the PALAU Area, as well as TRUK, on 1 April, with one element of its strength. They again raided the HOLLANDIA Area on 3 April and finally began to land on HOLLANDIA, on 22 April.
During the period from 30 April to 1 May the enemy task force made a third raid on TRUK. In May, the enemy proceeded westward along the northern coast of NEW GUINEA and finally landed on BIAK Island on 27 May. Whether the Marianas Area, the Western Caroline Area, or the northwestern part of NEW GUINEA was to be the next invasion objective of the enemy was difficult to predict. Since the greater part of the sea units of the Combined Fleet, which had been laying in at PALAU from February 1944, suffered some damage at the time of the raid on
--2--
PALAU by the enemy task force, the majority were moved to SINGAPORE and the Lingayen Area, while one element of damaged ships was sent back to JAPAN (While attempting to evade the air raid of 29 March, the MUSASHI, flagship of the Combined fleet was anchored north of PALAU, at which point she was attacked and damaged by enemy submarines. She was sent back to Japan for repairs.)
As of April 1944 the Imperial Army and Navy were resisting the enemy in the inner South Pacific north of AUSTRALIA and in the South East Area, with units already in those areas. In general, they were equally matched with the enemy on the other fronts. During this time, the main force of the Imperial Navy surface units, in the Lingayen Anchorage of the Southeast Area, and one element in the western area of the Inland Sea were engaged in training and preparing for the next operation.
Part Two. The Progress of the Plan of Operation.
In view of the situation previously described and in order to safeguard the nation's defense by stopping the enemy's counterattack, Imperial General Headquarters, taking advantage of the reorganization of our surface task forces and base air units, made its prerequisite the destruction of the enemy task force which was the nucleus of the counterattack, and whose main strength consisted of aircraft carriers. They had been awaiting a good opportunity for this and they saw their chance when the enemy launched its attacks in the Central Pacific - Philippines Area and the area north of AUSTRALIA (particularly the PALAU Area). By co-operating with the army and strengthening land defenses in those areas and by assembling the major part of the decisive strength of the Combined Fleet from other areas, they thought to force the enemy to a fight to the finish in these areas. On 3 May 44, the following orders were issued by Imperial General Headquarters, Navy Section, Order No 373.
Imperial General Headquarters, Navy Section, Order No 373, 3 May 44
By Commander-in-Chief of the Naval General Staff, SHIMADA, Shigetaro Directed to TOYODA, Commander-in-Chief of the Combined Fleet.
As for immediate operations, the Commander-in-Chief of the Combined Fleet
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will, aside from following Imperial General Headquarters, Navy Section, Order No 209, "Operational policies to be followed by the Combined Fleet", take action according to "Policies to be taken by the Combined Fleet in the Immediate Operation", as per separate sheet.
Imperial General Headquarters, Navy Section, Order No 373, Separate Sheet.
Policies to be followed by the Combined fleet in the Immediate operation.
1. By assembling the major part of our decisive strength and placing it along the enemy's main counterattack front, you will annihilate him with one blow and destroy his plan of counterattack. To this end, the following measures shall be taken:
a. You will immediately organise our decisive strength and plan to engage and annihilate the main strength of the enemy fleet contained in the area from the Central Pacific Area to the North Philippines and area north of AUSTRALIA, approximately after the latter part of May.
b. Before the aforementioned decisive strength in organised, the main object, aside from special cases, is to avoid a decisive battle.
2. The outline of operations is the area for the decisive battle is as follows:
a. You will await the preparations of the 1 Task Force and of the 1 Air Fleet, to be completed by the latter part of May, and instruct the 1 Task Force to wait in the south central area of the PHILIPPINES. By deploying the 1 Air Fleet is the Central Pacific Area, the Philippine Area and the area north of AUSTRALIA, you will be in a state of readiness and, taking advantage of a good opportunity, will employ your entire strength, making particular use of the forces to their best advantage, to engage and annihilate the main force of the enemy.
b. The area for the decisive battle shall be selected as close as possible to the area in which our task forces are deployed.
3. The following operations shall be taken in the event the enemy attacks us before our decisive bottle strength is readied.
--4--
a. Securing of strategic points and conditions:
Except when the situation is especially advantageous, decisive battles using surface forces shall be avoided. In the main, the enemy shall be diverted and annihilated by base-air forces and local-area defense forces. Specified strategic points will be separately indicated.
b. As pertains to the utilisation of base-air strength in this event, you must foresee the changes in the general battle situation. In particular, except when our advantages are such that success is inevitable, us must plan our future decisive battles so as not to deplete our strength any more than necessary in order to be able to properly carry out the following decisive sea battle.
4. Operations in other areas during the period of the decisive battle will be as follows:
a. Maintaining close army-navy co-operation, the enemy offensive shall be diverted in general by forces on hand and they will ensure designated strategic points according to previously-set policies, to the best of their abilities.
b. Surprise operations will be conducted as much as possible and steps will be taken to destroy the enemy's offensive spirit.
5. In preparing for decisive battle, the following points shall be especially observed:
a. A combined land and sea operation shall be planned to annihilate the enemy at one blow, with the objective of completing operational preparations around the latter part of May, the operational preparations in the area extending from the Central Pacific Area to the PHILIPPINES and the ares north of AUSTRALIA, and especially in the West CAROLINE Islands, South-Central PHILIPPINES, the Halmahera Area and West New Guinea Area shall be hastened. At the same time, the defenses of the strategic points located in these areas shall be strengthened. In this manner an attempt shall be made to establish strategically advantageous positions in the area in which the battle is to be fought.
b. Priority must be given to preparations for air operations. Utmost
--5--
effort must be put forth in the construction of bases and in defense preparations in the accumulating of required fuel and ammunition. In particular, emphasis must be placed on the construction of an impregnable air base.
a. Disregarding existing regulations concerning the use of air bases, the Army and Navy must utilize all its bases to a maximum degree in order to fully execute combined Navy and Army air operations.
6. This operation will be called Operation A.
Although the basic orders issued by Imperial General Headquarters concerning Operation A are as per the foregoing paragraphs. Imperial General Headquarters, in anticipation of enemy moves, has been steadily working beforehand, since the latter part of 1943, in organizing those units which were to be the foundation for the previously described operational policies. That is, the 1 Air Fleet, 1 Task Force, Central Pacific Area Fleet, and 14 Air Fleet were newly organized and previously existing surface units were strengthened.
Furthermore, in March 1944, and prior to Operation A, Imperial General Headquarters planned a surprise attack, Operation U, on MAJURO, the advance base of the main strength of the enemy's task force. This operation was unavoidably called to a halt, due to the disaster which befell the staff of the Combined fleet while negotiations with Combined Fleet Headquarters were in progress.
The plan of Operation U was as follows:
1. Time: The first or middle part of May.
2. Strength Employed: Task Force and about 1,000 planes, the majority of base-air units, and an element of the advanced naval units.
3. Outline of the Operation:
a. The task force will attack MAJURO from northeast of the MARSHALL Islands, departing MUTSUKAI Wan and passing OTASAWARA to the northeast, MARCUS Island, and north of WAKE Island.
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b. Base Air Unit bombers will operate with the MARCUS Islands and WAKE Island as their bases.
c. Advanced forces: Five or six submarines will land four special tanks each, which will cross coral reefs and attack.
Chapter I. Organisation of the 1 Air Fleet
In July 1943 the 11 Air Fleet was putting up a strong defense in the important battle area of the Solomons Front and was being used to bolster the front lines. At this time, with disregard for all difficulties, the 1 Air Fleet was being organised with the 11 Air Fleet as its nucleus, in anticipation of the coming decisive surface battle.
The 1 Air Fleet, (Commander, Vice Adm SUMIDA) was directly under the command of Imperial General Headquarters. The commander, staff officers, senior officers, and senior flight personnel were all highly skilled veterans of battle. The equipment of the fleet was modernized as much so possible.
Although, at first, the training period for this fleet was scheduled to be approximately one year, the enemy counterattack came sooner than was expected. Consequently, there was no alternative but to successively advance to the Inner South Pacific Area bases, beginning in the middle part of February 1944.
From the time of its organization, the 1 Air Float steadily became stronger. On 1 May 44, there were the 61 Air Flotilla (10 air groups, about 670 planes) and the 62 Air Flotilla (10 Air Groups, about 670 planes), but the 62 Air Flotilla, lacking sufficient training for Operation A, was excluded from the organization and was left behind in the homeland.
An attempt was made to increase strength by adding the air groups under the command of the superbly trained 13 and 14 Air Fleets. For this reason, the 14 Air Fleet did not possess the essential operational air strength.
On 5 June 44 the organization of the 1 Air Fleet just prior to the commencement of Operation A was as follows:
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DISTRIBUTION |
TYPE OF AIRCRAFT |
NUMBER OF AIRCRAFT (FIXED NUMBER) |
TOTAL |
|||
FLEET |
AIR FLOTILLA |
AIR GROUPS |
FLYING UNIT |
|||
121 AIR GROUP |
LAND RECONNAISSANCE |
48 |
672 |
|||
261 AIR GROUP |
"A" FIGHTER |
72 |
||||
263 AIR GROUP |
"A" FIGHTER |
72 |
||||
265 AIX GROUP |
"A" FIGHTER |
72 |
||||
321 AIR GROUP |
"C" FIGHTER |
72 |
||||
343 AIR GROUP |
FIGHTER-BOMBER |
72 |
||||
321 AIR GROUP |
LAND BOMBER |
96 |
||||
523 AIX GROUP |
CARRIER-BOMBER |
96 |
--8--
AIR FLEET |
22 AIR FLOTILLA |
761 AIR GROUP |
LAND ATTACK |
72 |
552 |
||
151 AIR GROUP |
T |
LAND RECONNAISSANCE |
24 |
||||
101 |
|||||||
202 AIR GROUP |
S |
S |
"A" FIGHTER |
96 |
|||
301 |
603 |
||||||
251 AIR GROUP |
S |
"C" FIGHTER |
48 |
||||
901 |
|||||||
253 AIR GROUP |
S |
S |
"A" FIGHTER |
94 |
|||
309 |
310 |
||||||
301 AIR GROUP |
S |
S |
"A" FIGHTER FIGHTER BOMBER |
48 |
|||
316 |
6011 |
48 |
|||||
503 AIR GROUP |
K |
CARRIER-BOMBER |
48 |
||||
107 |
|||||||
551 AIR GROUP |
K |
LAND ATTACK |
48 |
||||
251 |
|||||||
755 AIR GROUP |
K |
K |
LAND ATTACK |
96 |
|||
701 |
706 |
--9--
23 AIR FLOTILLA |
153 |
T |
S |
LAND RECONNAISSANCE |
24 |
552 |
|
102 |
311 |
"A" FIGHTER |
48 |
||||
732 |
K |
LAND ATTACK |
48 |
||||
707 |
|||||||
755 |
K |
LAND ATTACK |
48 |
||||
705 |
|||||||
26 AIR FLOTILLA. |
201 |
S |
S |
"A" FIGHTER |
96 |
240 |
|
305 |
305 |
||||||
501 |
S |
K |
"A" FIGHTER CARRIER-BOMBER |
48 |
|||
351 |
105 |
48 |
|||||
751 |
K |
LAND ATTACK |
48 |
||||
704 |
|||||||
Attached |
1021 |
TRANSPORT |
12 |
12 |
--10--
TOTAL |
LAND RECONNAISSANCE |
96 |
1644 |
|||
"A" FIGHTER |
648 |
|||||
FIGHTER BOMBER |
120 |
|||||
FIGHTER |
120 |
|||||
CARRIER BOMBER |
192 |
|||||
LAND BOMBER |
96 |
|||||
CARRIER ATTACK |
48 |
|||||
LAND ATTACK |
312 |
|||||
TRANSPORT |
12 |
--11--
Distribution |
Surface Units |
Chain of Command |
Commander |
|||
Central Pacific Area Fleet |
4 Fleet |
4 Base Force |
Commander-in-Chief of the Central Pacific Area Fleet |
Commander-in-Chief of the 4 Fleet |
Commander of 4 Base Force |
|
6 Base Force |
Commander of 6 Base Force |
|||||
Attached |
NAGO |
|||||
Others omitted |
||||||
22 Air Flotilla |
202 Naval Air Group |
Commander of the 22 Air Flotilla |
||||
301 " " " |
||||||
503 " " " |
||||||
551 " " " |
||||||
755 " " " |
||||||
14 Air Fleet |
26 Air Flotilla |
201 Naval Air Group |
Commander-in-Chief of the 14 Air Fleet (Also Commander-in-Chief of the Central Pacific Area Fleet) |
Commander of 26 Air Flotilla |
||
501 " " " |
||||||
751 " " " |
||||||
Attached |
802 Naval Air Group AKITSUO |
Commander of 5 Base Force |
||||
5 Base Force |
||||||
39 Base Force |
Commander of 30 Base Force |
|||||
Attached |
ISUZU Others omitted |
|||||
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ORGANIZATION OF THE 1 TASK FORCE
Distribution |
Surface Craft Units |
Chain of Command |
Commander |
|||
1 Task Force |
2 Fleet |
4 Squadron |
ATAGO, TAKAO, MAYA CHOKAI |
Commander-in-Chief of the 1 Task Force |
Commander-in-Chief of 3 Fleet (Also Commander-in-Chief of 1 Task Force) Commander-in-Chief of 2 Fleet |
Under direct jurisdiction of the 2 Fleet Commander-in-Chief |
1 Squadron |
NAGATO, YAMATO, MUSASHI |
Commander of 1 Squadron |
||||
3 Squadron |
KONGO, HARUNA |
Commander of 3 Squadron |
||||
5 Squadron |
MYOTAKA, HAGURO |
Commander of 5 Squadron |
||||
7 Squadron |
KUMANO, SUZUTANI TONE, CHIKUMA |
Commander of 7 Squadron |
||||
2 Destroyer Flotilla |
NOSHIRO |
Commander of 2 Destroyer Flotilla |
||||
24 Destroyer Division |
||||||
27 " " |
||||||
31 " " |
||||||
32 " " |
||||||
SHIMAKAZE |
||||||
3 Fleet |
1 Air Flotilla |
TAIHO, ZUIKAKU SHOKAKU 601 Naval Air Group |
Under the direct jurisdiction of 3 Fleet Commander-in-Chief |
|||
2 Air Flotilla |
HAYATAKA, HIYO, RYUHO 652 Naval Air Group |
Commander of 2 Air Flotilla |
||||
3 Air Flotilla |
CHITOSE, CHIYODA, ZUIHO, 653 Naval Air Group |
Commander of 3 Air Flotilla |
||||
10 Squadron |
AGANO, YAHAGI |
Commander of 10 Squadron |
||||
4 Destroyer Division |
||||||
10 " " |
||||||
16 " " |
||||||
17 " " |
||||||
61 " " |
||||||
MOGAMI |
Note: 4 Air Flotilla omitted.
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Furthermore, the fixed number of airplanes of each Air Group is as follows: | |||||
Air Group |
Carrier Reconnaissance Plane |
Carrier Fighter |
Carrier Bomber |
Carrier Attack Plane |
Total |
601 Air Group |
9 |
81 |
81 |
54 |
225 |
652 Air Group |
81 |
36 |
18 |
135 | |
653 Air Group |
63 |
27 |
90 | ||
Total |
9 |
225 |
117 |
99 |
450 |
Each of the foregoing Air Groups was put aboard the aircraft carrier of the Air Flotilla to which it was assigned.
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Chapter II. Organisation of 1 Task Force and Reinforcement of Air Strength
1. Because of the lack of base-air unit strength in the Solomon Area, the carrier-air strength of the 3 Fleet was first increased by the air strength of the 1 Air Flotilla in November 1943. Alternating with the 1 Air Flotilla, the 2 Air Flotilla, which had finally completed its training in the Singapore Area, was dispatched to the Rabaul Area in the latter part of January 1944. Both Air Flotillas lost the major part of their joint air strength in this area. In any case, surface operations for them as carrier units was impossible.
Because of this, the 1 Air Fleet was re-enforced with new planes and was sent to the Singapore Area for training. Taking advantage of the enemy's task force raid on TRUK on 17 Feb 44, the 2 Air Flotilla was ordered to retreat on the basis of the grave decision that the air battle in the Rabaul Area was to be totally abandoned. After quickly replenishing them with personnel and planes, they were sent to the homeland for training. The result was that, although the 2 Air Flotilla had many veteran crew members, their planes were old-type Model 99 Carrier Bombers.
Although the planes in the 1 Air Flotilla were of a newer model (JUDY), the crewmen were inexperienced. From the standpoint of displaying all-around strength, on extremely unorthodox organisation was inevitable.
Moreover, the 3 Air Flotilla was organized with only small-type, carriers. As an initial test, flying units equipped ZERO—Type fighter planes with bombs. (Each carried one 250 kg bomb). These flying units consisted of a total of 45 fighter-bombers (15 planes to a carrier).
2. Although the 3 Fleet, with carriers as its main strength, was organised in June 1942 after the MIDWAY Operation, the organisation of the 2 Fleet, which did not possess any carrier unit, remained the same. Therefore, taking advantage of a decisive surface battle, the 1 Task Force was organised on 1 March 1944 with the 2 and 3 fleets (Vice Admiral OZAWA, Jisaburo, Commander-in-Chief) for the
--15--
purpose of exploiting the all-around strength of the surface units in the Combined Fleet. The 3 Fleet, a carrier unit, was put under the direct control of the Commander-in-Chief of the 1 Task Force.
The organization of the 1 Task Force, as of 1 March 1944, is as follows: (TN See charts on following pages).
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Chapter III. The Organizations of the Central Pacific Fleet and the 14 Air Fleet
In order to defend the Inner South Pacific Area, the 14 Air Fleet was organized on 4 April 1944. Later, The Central Pacific Area Fleet was organized with this fleet and the 4 Fleet, (Commander-in-chief, Vice Admiral NAGUMO, Tadaichi. The 14 Air Fleet was put under the direct control of the Central Pacific Area Fleet Commander.
The organizations of both fleets are as follows. However, along with the strength increase of the 1 Air Fleet on 5 May, the 14 Air Fleet became an air fleet without any attacking power. (TH See chart on following page.)
--17--
Chapter IV. Preparation of Land Plane Bases
The rapid preparation of land plane bases in the MARIANAS and CAROLINE Areas was begun after the middle part of 1943. The air bases which could possibly be used at the time of Operation A were as follows: (the figures in the parenthesis show the number of bases before 1943).
IWO JIMA |
1 |
(1) |
SAIPAN |
2 |
(1) |
GUAM |
2 |
(0) |
TINIAN |
3 |
(1) |
ROTA |
1 |
(0) |
TAP |
1 |
(0) |
PALAU |
2 |
(1) |
Chapter V. Preparation of Surface Craft
After the South Pacific sea battle of 26 Oct 42, carrier-based air units were frequently employed; they were dispersed to the various areas. Consequently there were no opportunities to give combined operations training to elements to be used as task forces, and the result was that efficiency decreased conspicuously as compared to the time of the first stage of the operations. As the scarcity in the number of aircraft carriers with operational potentials was also one of the reasons for this, the utmost efforts wars devoted to preparations and now construction. As a result, Operation A saw the construction of the TAIHO, a large-type aircraft carrier, and small-type converted aircraft carriers, the CHITOSE mad the CHIYODA. Finally, after October 1943, as well as having one newly-built light cruiser and ten newly-built destroyers participate, we succeeded in having all ships of the Imperial Navy above the cruiser class participating in the front lines.
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Part Four. Operations Directed by the Combined Fleet
In March 1944, Admiral KOGA, Mineichi, the Commander-in-chief of the Combined Fleet, moved his headquarters onto land when an enemy task force attacked PALAU on 29 March while he was conducting the overall operations from the MUSASHI, the flag-ship of the combined fleet, which was anchored in PALAU. On 31 March, while the command station was being moved to DAVAO, most of the key personnel (including the commander-in-chief and his subordinates) of the combined fleet headquarters were killed, except Vice Admiral FUKUDOME, the chief of staff, when the transport planes met with disaster in the foul weather; therefore Vice Admiral TAKASU, Shiro (vice commander-in-chief of the combined fleet), the commander-in-chief of the Southwest Area Fleet, took command of the Combined Fleet for about a month at SURABAYA.
On 2 May a new commander-in-chief, Admiral TOYOTA, Soemu, was appointed and he raised his flag on the OEDO in Tokyo Bay.
When the enemy landed on HOLLANDIA, on 22 Apr 44, the 23 Air Flotilla was placed under the command of the 1 Air Fleet and was ordered to attack in that area. Simultaneously, the air unit stationed in the MARIANA - CAROLINE Area was assigned to guard and reconnoiter the main part of the enemy task force in the Majuro area of the Marshall Archipelago. (The existence of the enemy in this area which was indicated in the communications and intelligence reports.)
An imperial General Headquarters, Navy Section order concerning operation A, dated 3 May, was issued; the strength of the combined fleet was stationed according to the said operational plans, which were as follows:
1. The 1 Task Fores was ordered to assemble in the TAWITAWI Anchorage.
At that time, the main element of the 1 Task Force was in training and awaiting orders at the Singapore and Lingayen Anchorage Areas and one portion of the force was in the zone of interior, also in training
--19--
and awaiting orders. Then it was ordered that the entire 1 Task Force assemble at the TAWITAWI Anchorage in the Southwestern Philippines and complete its operational preparations.
The 1 Task Farce moved to a point west of the inland waters on 16 May. There it joined with the 3 Fleet, which assembled at that point on 15 May, and the 2 Fleet, which assembled on 14 May. The 2 and 3 Fleets formed the nuclei of their respective units. With the arrival to this anchorage on the 16th of the unit which had as its main elements the 2 and 3 Air Flotillas, the assembling of the 1 Task Force was completed.
2. On 17 May 44, the enemy began landing operations in the Wakde and Sarmi area in Northwestern NEW GUINEA, so the Air Force stationed in the area to the north of AUSTRALIA was ordered to attack this enemy.
3. Deployment order of the Navy Base Air Force.
In view of the imminence of this phase of combat, an order was issued on 18 May to execute the deployment according to Operation A of the Air unit of the 1 Air Flotilla. On the 26th, this unit completed, in general, its prearranged deployment.
4. The order to begin Operation A.
On 20 May, the enemy task force attacked the MARCUS islands. From the communications, intelligence reports etc., it was concluded that an all-out attack by the enemy was imminent; at 0000 hours on 20 May, an order was issued to "execute Operation A."
5. The transfer of the Combined Fleet Headquarters to the western part of the inner sea.
Since his appointment, Admiral Toyota, the Commander-in-Chief of the Combined Fleet, was directing the operations from his flagship, OEDO, in Tokyo Bay, but on 22 May he left Tokyo Bay and moved this headquarters to the Hashirajima Anchorage, because of the completion of liaison with the central area and because of the communication with the Southern Area (at that time, the Tokyo Bay reception of the radio telephone from the southern area was poor).
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6. Tactical command at the time the enemy landed on BIAK.
On 26 May the enemy occupational forces attacked BIAK so an order, dated 27 May, was issued for a portion of the Navy Base Air Force which was stationed in the Mariana - Caroline Area and for a part of the forces which were to be stationed in that same area (a combined force of 70 carrier-based fighter planes, four land-based reconnaissance planes, and 16 carrier-based bombers) to advance to the western New Guinea Area. Simultaneously, the enemy on BIAK was attacked by our air force, stationed in the SORONG area.
7. A suicide reconnaissance of the enemy strategic area.
a. On 27 May, reconnaissance planes of the 1 Air Fleet, which were on TRUK, reconnoitered the Tulagi area via the Buin* air field and discovered, anchored in the various harbors of the FLORIDA Islands and off LUNGA, the following:
Aircraft carrier - one (SARATOGA Class); escort carriers - two; battleships- four; cruisers- five; destroyers- three; unknown - one; small ships and beats - 50; transports, large -seven; transports, medium - 16; transports, small - 23; sea trucks - 40.
b. On 29 May, through a reconnaissance made by an Army plane, it was discovered that there ware four Cruisers, two Submarines, three Destroyers, nine medium transports and 10 small transports anchored in Humboldt Harbor, and that five Destroyers, and nine transports were cruising outside the harbor.
c. On 30 May, MAJURO island (via NAURU island) and Finschhafen Bay were reconnoitered by the reconnaissance planes of the 22 Air Flotilla stationed on TRUK.
(1) Fire carriers (certain), two Flying boats, three battleships, three Cruisers, 10 Destroyers, two Transports and six Tankers, a total of 31 vessels, were anchored in Majuro Harbor.
Too Carriers (certain), three battle-cruisers, eight destroyers, a total of 13 vessels, were outside the harbor.
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(2) Five large transports, six medium transports, five small transports, three destroyers, a total of 19 vessels, were anchored in Finschhafen Harbor.
d. On 31 May, KWAJALEIN and the Admiralty Archipelago were reconnoitred by the reconnaissance planes based on TRUK.
(1) KWAJALEIN Island: The following were in the Kwajalein Anchorage - eight destroyers, also small type ships, one ship tender, 18 transports, one tanker and 20 others. One B24, seven medium aircraft, three small aircraft, one transport aircraft were at the Kwajalein Air Base. Two destroyers and two transports were at the Ruot Anchorage.
Five medium aircraft, 84 small aircraft, two destroyers and two transports were at the Ruot Airfield.
(2) ADMIRALTY Archipelago: one aircraft carrier (SARATOGA Class), one battleship, one cruiser, 40 small type ships, and one transport anchored in this anchorage. Approximately 150 large and small planes were on this airfield.
e. On 2 June, BROWN island was reconnoitered by the reconnaissance planes based on TRUK.
There were two cruisers, one destroyer, 17 transports, one coaler, 20 small aircraft, 10 medium aircraft and 30 large aircraft in the Eniwetok Area. There were three large transports, 10 small aircraft and 10 medium aircraft in the ENCHABI* Area.
f. On 5 June, MAJURO Island was again reconnoitered.
There were five carriers (certain) - all were either of the "ESSEX" or •"ENTERPRISE" Class. There were eight escort carriers, (among these, two were of the "INDEPENDENCE" class), six battleships, eight cruisers, 16 destroyers, 10 coalers and many others.
On the same day, the Admiralty Archipelago was reconnoitered and one carrier, two battleships or battle cruisers sad five destroyers were
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discovered in the ADORA* Harbor.
Through the above information, it was confirmed that the main elements of the enemy task force were anchored at MAJURO.
8. Plan and execution of operation KON.
As for the battle situation on BIAK island, the combined Fleet, with one portion of its force, hastily transported the 2 Amphibious Brigade, which was in ZAMBOANGA, to BIAK Island to ensure the security of this Island. The enemy task force was lured out by this operation and plans were made to commence operation A. This operation was called the KON Operation and this unit was called the KON Unit.
The gist of operation No 102, ordered by the Combined Fleet, which was based on wireless Report No 292342 Secret, of the Combined Fleet, concerning this operation, is as follows:
a. The day (X day) to attack BIAK was 3 June, (to assemble in DAVAO by 31 May).
b. The Commander of the 16 Division became the commanding officer for the Transport Division (AOBA, KIDO, URANAMI, SHIKINAMI and ITSUKUSHIMA), the patrol unit (5 Division, four cruisers) and the Escort unit (FUSO and two cruisers).
e. The 3 Air Force is to give neutralising support to the northern shares of NEW GUINEA.
d. The Southwestern Area Fleet is to quickly transport the Army Unit stationed on SORONG to the Manokwari area.
e. The Units in Operation A must give necessary co-operation to the KON Operation and, at the same time, must closely observe the progress of the KON operation.
f. For the "preparation of the decisive battle", the patrol unit and the escort unit will return to their original unit.
The KON Operation was executed according to this plan on 8 June. However, during the operation, we encountered both the enemy fleet and her planes, with the resultant loss of one cruiser and inability of realizing our objective.
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9. The third reconnaissance of the Majuro anchorage.
On 9 June, the second Suicide Reconnaissance of MAJURO was made, but there was no sign of a powerful enemy fleet, as it had already left the harbor, so it was concluded that the enemy attack was imminent.
10. An order to prepare Operation A for decisive battle.
In view of the foregoing situation and in line with the communications and intelligence reports, an order was issued, on 10 June, for Operation A to make preparations for a decisive battle, simultaneously, an order to prepare for a decisive battle was issued to the 1 and 2 Attack Groups (units based in the Mariana and Caroline Archipelagos) of the Base Air Force.
11. The Second KON operation was planned.
With the aim of attacking enemy ships in the Biak Waters, shelling the land, and transporting land troops to BIAK if an opportunity presented itself, the Second KON Operation was planned by adding the 1 Division and others to the initial force. Orders for this were issued early on the morning of 10 June.
The gist of this order is as follows:
"Dispatch operational order No 127 of the Combined Fleet" (Summary)
a. 1S (YAMATO, MUSASHI) and the 2 sd (NOSHIRO, two destroyers) will be included in the KON unit and the Commanding Officer of this unit will be designated as the 1S Commander.
b. The KON Unit will continue the KON Operation, according to the following:
(1) The annihilation of the enemy reinforcements in the Biak Area and the enemy task force; and the bombardment and annihilation of the enemy landing force on BIAK and MAUI* islands.
(2) If there is an opportunity, transport the 2 Mobile Brigade to BIAK Island. Although there is an order to make preparations for a decisive battle of Operation A, continue the KON operation as long as there are no special orders. According to the enemy situation, carry
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on such activities as will lure the enemy KdS into the decisive battlefield (100013).
According to the shows, the Commanding officer of the KON Unit selected BACHAN* Anchorage on HALMAHERA island as the assembly point for this unit and, at 1600 hours 10 June, he left TAWITAWI leading the 1s and 2sd. At 0800 hours 12 June, he arrived at the BACHAN* Anchorage. Assembling the greater part of the KON unit, he made operational preparations, according to the new plan.
12. Operations at the time the enemy task force attacked MARIANA.
At 1215 hours 15 June, the enemy task force appeared at a point 90 degress, i.e. 170 nautical miles from GUAM, and at 1530 hours of the same day, it commenced an air attack on SAIPAN, TINIAN, ROTA, and GUAM. The great air attack was resumed in that same area again on the following day, the 16th (TN presumably the 16th, although the document says the 12th).
At that time, the Combined Fleet estimated that the main force of the enemy strength was based on 10 or 15 carriers, but according to the plan of Operation A, it tried to reconnoiter the enemy situation. Except for the surprise attacks made with planes on hand, no positive attacks were made until the enemy intentions became clear.
On the 13th, the enemy was still carrying on his full-fledged air attack in the MARIANA Area so his intentions were, on the whole, clarified; consequently, on that same day, "alert order for a decisive battle of Operation A" was ordered and, at the same time, "temporary cessation of the KON Operation" was ordered. In the other areas, the 2 and 3 Attack Groups of the Base Air Force, which were in the midst of deploying in and reinforcing the Halmahera area, were ordered to move up to the area to the west of the CAROLINES and to take the disposition for a decisive battle. The remaining force of the 23 Air Flotilla was assigned to the Southwestern Area Unit and, with this Southwestern Area unit, the operations in the western New Guinea Area was continued.
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13. The operation at the time the enemy landed on SAIPAN.
On 15 June, the enemy occupational forces appeared off shore of SAIPAN so, on this same day, an order to "commence the decisive battle of Operation "A" was issued and, at the same time, an order to begin the attack was issued to the 5 Base Air Force (centered around the 1 Air Fleet).
At that time, the Commander-in-Chief of the Combined Fleet, while making suicidal attacks with the Base Air Force, awaited the appearance of the task forces. Except for those forces disposed in HOKKAIDO and CHISHIMA, he combined the 7 Base Air Force (centered around the 3 Air Fleet) with the YOKOSUKA Air Force; thus with the entire strength of the task forces and the Base Air Force, he planned for an all-out decisive battle against the enemy task force. During this period, approximately 20 submarines were assembled in the Mariana Area. Then, on 19 May, he ordered the Base Air Force to send all available planes to GUAM by the 20th, in order to co-operate with the 1 Task Force in carrying the battle against the enemy task force.
Instead of inflicting great damages on the enemy in the air and sea battle of the 19th and 20th, we lost three large type carriers. The remaining carrier force and supply force were ordered to retire to Nakagusuku Harbor and the diversion attack force was ordered to retire to the Philippines Ares. Simultaneously, the enemy task force was attacked with the YAWATA Unit (approximately 120 planes) based on IWO JIMA, but instead of any great accomplishments, this unit lost the greater portion of its planes. Thus, Operation A was a failure, so there was no alternative but to retreat. On 25 June, the Task Force, which had entered Nakagusuku Harbor, was sent back to the home waters. Then the 2 Fleet was sent to the Singapore Area and the 3 Fleet was ordered to train and equip in the home waters and to get into readiness for future operations.
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Part Five. The Plans of the Task Force
1. The operational policies of the task force.
With the close co-operation of the friendly forces, especially the Base Air Forces, the forces will maneuver to take advantage of all opportunities and engage in a fierce attack, utilising all forces by co-operating with the attacks of our Base Air Force and annihilating the enemy attack power, that is, the enemy task force, with one blow, thus shattering the enemy counter-attack plans.
a. The Task Force is to complete its preparations for a decisive battle on 20 May at the alert anchorage in the southern PHILIPPINES.
The Decoy Force will move up to the Ululssi or the Palau area according to orders, and, in co-operation with friendly forces, will endeavor to induce the enemy to come out into the sea in which the decisive battle will be fought.
b. The Task Force will, according to orders, sortie, sad while endeavoring as much as possible to conceal our plans, more ap to the waters to the east of the PHILIPPINES, and at the opportune time absorb the Decoy Force.
c. Make all enemy situations clear with the close observation of such units as the Base Air Forces and the Spearhead unit, and at the same time, advance while observing strict security, to the desired waters at the opportune time. Make this into a decisive battle and annihilate the enemy by making neutralising attacks against his task force, in co-operation with the Base Air Forces operations.
In the air battle, the pattern will be strong daytime attacks and the primary objective will be to attack the enemy from the flank.
d. When the task force advances and engages the enemy in battle, strict caution must be paid to the enemy's tactic of a flank attack or trap. In the event base-air strength cannot afford close escort and our carrier strength is small, one element of the attack force (generally 2sf) any be reserved until the moves of the enemy become more definite.
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c. As the battle moves into the stage of close-range fighting, overcome all difficulties; approach and annihilate the enemy by means of repeated attacks.
In the event that surface battle is advantageous, the operation will be continued. According to the situation, the air forces will be deployed to the land bases or the carrier-fighters be launched to bring about favorable battle results.
2. Distribution of 1 Fleet
After 15 May. the distribution of the 1 Fleet without orders will be as follows: Note.
Strategy Number One
This carrier unit will be divided into a main force and a vanguard force and deployed in "defense in depth" order.
Strategy Number Two
This carrier force will break up into three groups and form in dispersal in depth order.
Strategy Number Three
Concentrate the carrier units. (TN See charts on following pages)
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Remarks:
1. Organisations listed under Supply are on shown in Distribution 2 1 Carrier Unit.
2. Will be need mainly for Strategy Number Two.
c. (3) Distribution of 3 Carrier Unit Omitted
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a. Distribution of 1 Carrier Unit
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Remarks:
1. To be used mainly in Strategy Number One.
2. Assignment of destroyers subject to change.
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b. (2) Distribution of 2 Carrier Unit
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Part Seven Outline of Developments
Chapter I. General Progress.
Anticipating that Operation "A", which employs the entire surface and air strength of the Imperial Navy Combined Fleet, would be the final decisive surface battle of this war, the preparations for the operation were carried out with the maximum effort and full use of the nation's resources. However, the objectives of Operation "A" were not accomplished, for the following reasons:
1. Because the enemy attack came sooner than expected.
2. While preparing for this vital Operation "A" was necessary to appoint a new Commander-in-Chief, to take the place of the former, who had died in line of duty.
3. Training of air forces was insufficient, and especially was impossible to train and prepare carrier-based air units. Moreover, at the advanced bases, the various forces were alerted, which necessitated an almost complete suspension of training for about one month.
4. Surface craft were insufficiently trained because of the shortage of supply ships and the lack of anchorages for alerted surface craft.
5. On the first day of the decisive battle, the 1 Task Force committed the blunder of planning a long-range attack.
Moreover: a. The base air forces lost approximately half of the 2nd and 3rd attack groups during the BIAK Island Area Operation in the latter part of May and in several air engagements in the BIAK Area while advancing to the North of AUSTRALIA and the western Carolina area, and while returning to the Operation "A" decisive battle deployment area. In addition, just before the decisive battle with the enemy task force, the 1st attack group suffered heavy losses in the attack made by the enemy on the Mariana, Caroline, and Iwo island Area bases. Beside this, the operation became impossible due to malaria suffered by a great number of air crew members. Poor facilities at the West CAROLINE Area bases was the cause for the heavy toll taken by malaria.
Because of the above and various other factors, only shout 20 percent of the 1 Air Fleet's 1644 planes actually participated in Operation "A".
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b. The carrier-based air units of the 1 Task Force were equipped with up-to-date aircraft (Model 52 Zero Fighter, JUDY for carrier-bombers, JILL for carrier-attack planes, and ZERO-type Fighters used as fighter-bombers). However, the carriers were obsolete and thus unable to efficiently accomodate late-type aircraft (HAYATAKA and HITAKA - maximum speed 25 knots); also, the crews lacked sufficient training. Not only were the opportunities for carrying out training extremely limited, due to the shortage of fuel for the vessels and planes, but on the other hand, losses were heavy and replenishments from the homeland were not able to meet replacement demands. As a result, just prior to the decisive battle, only about 80 percent of the designated 450 planes were in readiness for combat.
c. In the beginning, there were, among the combat vessels, a minimum number of required destroyers; but seven of them were lost during the training and alert periods and skirmishes prior to the decisive battle. As a result, plans of Operation "A" were upset by the above losses.
On May 29, while our Combined Fleet was in the aforementioned condition, the enemy carried out reconnaissance attacks on all strategic points in the Central Pacific. Concurrently, on 11 June, the main elements of the enemy's task force started their raids on the Mariana area. Since an attack by the enemy's landing force was imminent, the Commander-in-Chief of the Combined Fleet alerted Operation "A" on 13 June and, on 15 June, ordered Operation "A" to commence the decisive battle.
Each Unit acted in accordance with the Pre-arranged Plan of operation. However, because of an attack by the enemy task force, the main elements of the base air force, which was to have been employed in the Mariana Area, was lost. For this reason, the base air force was not even able to carry out reconnaissance which should have been conducted in co-operation with the task force by taking advantage of the opportune battle conditions. As a result, the task force had no alternative but to dispatch its own reconnaissance. Consequently, the enemy discovered the reconnaissance planes and perceived the existence of our task force. The base air force sent its entire mobile strength, which was stationed in the Truk Area, to the Mariana area.
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In conjunction with the mobile strength despatched from TRUK and with the aid of the YAWATA Unit stationed at (TN Place name illegible), the task force planned to attack the enemy. However, on the 19th when the all-out attack was made by the task farce, it ended by each Unit making its on attack.
The air units, which should have been the nucleus of the task force attacking the enemy task farce, ware all inexperienced. Ac a result, the first attacking wave of the 1 Air Flotilla lost several planes in friendly fire when passing heedlessly over the advanced guard on their attack mission against the enemy. The greater part of the 2 Air Flotilla and the second attacking wave of the 1 Air Flotilla did not find their objectives. Those who accomplished their missions were only the 1 Air Flotilla and the first attacking wave of the 3 Air Flotilla. During this time the TAIHO and SHOKAKU were sunk by enemy submarines, which necessitated a change of flagships by the task force commander. Consequently, the aims of the decisive battle were completely disrupted.
The reason for the success of our attack is that the enemy ceased his attack because of the great distance between his and our forces. Also, it lies in the fact that he utilised the greater part of his fighter planes for interception.
On the 20th, our task force reorganised and replenished its strength, and at the time a second attempt to engage the enemy was being planned the enemy task force attacked. As a result the HIDAKA was sunk, and the greater part of the Air Unit was lost. Thus, abandonment of this operation was inevitable.
The general progress of Operation "A" is as indicated in the separate Chart, Development of Operation "A", and in the separate volume, The Daily War Record of Operation "A". The details of each Unit are as follows:
Chapter II. Task Force
1. From the time it was concentrated at the advance base to the time the attack was launched.
On 16 May the Task Force, based upon the order of Operation "A" of the Combined Fleet, completed its concentration at the Tawitawi anchorage, southwest of the Philippine Islands. On 20 May, it completed battle preparations.
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On 22 May, the 1 Supply unit was ordered to advance to DAVAO, and on 24 May one part of the 3 Supply Unit was ordered to advance on PALAU.
With the above situations, the deployment of strength to be carried out prior to the pre-arranged attack, was completed.
On 27 May, the enemy launched attacks on the western parts of NEW GUINEA and BIAK. Therefore, the FUSO of the 5 Squadron and also the 27 destroyer division and the 10 destroyer division were ordered, on 29 May by the Combined Fleet, to participate in the KON Operation (to insure the strength of BIAK island). However, because of the KON Operation was ordered to be suspended on 8 June, the 5 Squadron and other units were ordered to wait in readiness at DAVAO.
In conjunction with the commencement of the "KON" Operation on 2 June, it was recognised that there existed on opportunity to decoy the enemy carrier Unit, located north of HOLLANDIA, and to capture it. Thus, on 3 June, the 2 Supply Unit was ordered to advance to the east of the PHILIPPINE Islands. However, because of the events which followed, it was ordered to sail to GUIMARAS And wait in readiness.
During this period through the use of various intelligence reports and resorting to suicide reconnaissance over the Marshall Area, an attempt was made by the 5 Air Force to ascertain the enemy's movements, but conditions were such that it was difficult to detect the main course of the enemy attack.
It seemed that the enemy had detected our task force at TAWITAWI and, since the latter part of May, enemy submarines swarmed the seas southwest of the PHILIPPINE Islands. Although mopping-up operations were conducted against enemy submarines with the aid of combat vessels and aircraft, and in co-operation with the Southeast Area Fleet, four destroyers were damaged in succession by the enemy submarines during the period from 6 June to 9 June. Thus, the destroyer strength was reduced to the extent that it barely met the minimum strength requirement for the decisive battle. As a result, it was deemed necessary to move the fleet anchorages and to temporarily neutralize the effects of enemy submarine activities.
On the other hand, due to the inadequacy of the nearby anchorages and air bases, along with delays in schedules from the time the units advanced from the southern part of the Philippine Islands, it was extremely difficult to
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execute training of the air units. As a result, each air flotilla was able to conduct attack training but once or twice. Consequently, because the standard of proficiency of crews dropped, it became necessary to undergo training by utilizing the airfield in the Central part of the PHILIPPINE Islands.
Thus, suffering from deficiencies in intelligence reports and in defense, the Task Force moved into the Control PHILIPPINES, and, with due consideration to the line of supplies, it was decided on the 13th that the Task Force would move its anchorage to GUIMARAS.
During this period, the Biak Area battle did not develop to our advantage and, as a result, it greatly affected our subsequent operations. It was feared that the increasing and strengthening of our forces in this area would tend to draw the enemy into the open and the decisive battle would take piece prematurely, instead of on schedule with plans of Operation "A". In consideration of these facts, it was recommended to higher echelons that it would be all right to send the 2 Air Flotilla to reinforce that area, as long as this would not hamper the decisive battle of the Task Force.
On 20 June there was an order to revive the KON Operation with the commander of the 1 Division as its commanding officer. According to the orders the 1 Division (less NAGATO), the 5 Division, the 2 Destroyer Squadron (less one portion) and a portion of the destroyers of the 10 Division were dispatched from the Task Force to take part in the Operation.
On 11 and 12 June, the enemy launched an attack in the Mariana Archipelago Area with a task force which had, as its core, the entire strength of the regular aircraft carriers and converted cruiser carriers.
The enemy air attack was on an especially large scale on the 12th, so there were some who thought that the enemy might invade the Saipan Area; however, at 0900 on the 13th, the Task Force left Tawitawi for GUIMARAS as planned, because it was necessary to train the air units and to assemble the reserve planes which were already in DAVAO at that time and, furthermore, because our advance to GUIMARAS would be advantageous from the standpoint of immediate tactical counteraction, even if the enemy operations in the MARIANAS were to develop into an operation of invasion.
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Part Six Base Air Unit Plans
The base air force devised a plan for Operation "A", based upon the following assumption:
1. Operational Plan
a. At least one-third of the enemy task force carrier unit must be destroyed by our base air force prior to the decisive battle. Then the remainder of the enemy fleet shall be destroyed in co-operation with our task forces and other friendly units.
b. Suicide reconnaissance of the enemy advanced base must be carried out in order to secure accurate information of enemy movements.
e. Strength of the base sir force will be organised into three attack groups and various type of planes will be assigned to each group, thus facilitating the movement and concentration of forces.
d. When the main elements of the enemy force launches its attack, each attack group will be deployed as follows, in order to intensify concentration of attacking poser.
1 Attack Group
Saipan, Tinian, Guam, and Truk Areas
2 Attack Group
Palau, Yap, and Davao Areas
3 Attack Group
North Australia, and Celebes Areas
In the event the objective of the enemy attack is perceived, the attack forces deployed in that area shall leave a force of reconnaissance planes and withdraw to bases where other attack groups are deployed. In this manner, the enemy attack shall be avoided, enabling us to carry out a concentrated attack against the enemy from the base to which we have withdrawn.
2. Distribution of respective Units is as shown in the following map. (TN No map).
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2. Accounts of the Move from TAWITAWI to GUIMARAS
After the task force left TAWITAWI there were reports that the enemy invasion of SAIPAN became imminent, so at 1614 on the 13th, the 1 and 2 Supply Units were ordered to be alternatively on the alert for 30 minute intervals and, at 1704, the 1 Supply Unit was ordered to advance to point A and there be on the alert.
At 1724, an alert order for Operation "A" was issued through operations order No 146 of the Combined Fleet. Through operation order No 147 of the Combined Fleet, the KON Operation was temporarily suspended and the 1 Division (less NAGATO), the 5 Division, the 2 Destroyer Squadron (KOSHIRO, SHIMAKAZE OKINAMI), and the 10 Destroyer Division (YAMAGUMO, NOWAKE) were sent back to their original unit.
At 1744, the 3 Supply Unit was ordered to advance to Point J and there alerted. The plans for the tactical command, while enroute to GUIMARAS, were as follows: a. Following plans GF and FdB of Operation A, bombard the enemy regular carrier group with day planes by closely co-operating with the friendly Base Air Force and the Advance Forces. Then the entire force is to close in on the enemy and destroy its task force. The 19th was tentatively set as the day to commerce the daylight air battle. However, it was decided that if the arrival of the YAWATA unit (the unit composed of the YOKOSUKA Air Force, which was to proceed to IWO Island) were delayed, the plans for the tentative day for the decisive battle would be made accordingly.
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b. The problem was whether or not to have a great portion of the task force stop at GUIMARAS to replenish supplies, prior to engaging in the decisive battle. It was decided that it would be beneficial to anchor at GUIMARAS, even though we should run the risk (While we were anchored at TAWITAWI, our location and general plans were probably known to the enemy.) of having our full strength discovered by the enemy, because we considered it more important that our supply lines function easily and dependably.
The task force arrived at GUIMARAS on the afternoon of 14 June. From 1700 hours on that day until 0700 hours on the fifteenth the entire task force took on supplies. The amount supplied came to 10,800 tons.
It was reported that early on the morning of 15 June, thirty enemy transports began to appear in the seas off the west coast of SAIPAN and that the enemy's landings had begun. Further word was received that one group of a large task force attacked the BONIN Islands and IWO JIMA. Thereafter, it seemed that they continued to carry on operations in this same area.
At 0717 hours on the fifteenth came the order for Operation A, which was to set out for the decisive battle. At 0800 hours the main body of the task force (excluding those units which had engaged in Operation KON) put out from GUIMARAS.
3. From the time of the departure from GUIMARAS until the meeting with the enemy.
At 1730 hours on 15 June our task force passed through San Bernardino Straits in the central part, of the PHILIPPINE Islands. At 2038 hours, while we were advancing, we found out by Intercepting enemy signals that an enemy submarine had discovered the movements of our task force and had sent back a radio message to that effect.
a. The determination of battle conditions on the evening of 15 June:
(1) The strength of the enemy:
(a) In the area of the MARIANA Islands:
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The enemy is divided into approximately five groups, centered around fifteen aircraft carriers, seven of which are the regular type and eight of which are the type converted from cruisers. It is believed that practically all of the American task force strength has come to make an attack.
At present a group of supply ships are located in an area four hundred nautical miles east of the Archipelago and one group of LST's has been observed to be commencing landing operations in the vicinity of the Archipelago. The arrival of a large-scale invasion fleet within the near future is almost inevitable. We have only observed part of the CVE's or escort carriers which are east of the Archipelago, but there is a very good possibility that they will come in extremely large numbers to attack, both before and after the decisive battle in the vicinity of the Archipelago.
(b) In the area around the ADMIRALTY Islands:
We cannot rely too heavily on this report because it was made by a fighter plane, but approximately eight carriers and all other types of ships, including battleships and transports, are said to be lying in wait in this area.
(2) Our calculations of the strategy of the enemy:
The objective of the strategy of the enemy is to accomplish one or more of the following:
(a) The invasion and occupation of strategic bases in the MARIANA Archipelago.
(b) Together with the above operation, to strengthen invasion operations in western NEW GUINEA and to invade and occupy strategic areas in the western CAROLINE Islands.
(c) To draw out our task force strength for a decisive battle.
(3) An estimated study of the distribution of enemy forces in the region around the Mariana Archipelago both before and after the decisive battle between task forces:
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(a) It was quite possible that the enemy knew the plans of our task force. (Reason: Because of the interception of signals by enemy submarines they knew about our departure from TAWITAWI on the thirteenth and our departure from GUIMARAS on the fifteenth, and it would not have been difficult for them to assume what our intentions were. Therefore, judging from the strategic speed employed by the Americans formerly, they probably know that our task force is going to attack in the vicinity of the Archipelago between the eighteenth and the nineteenth.)
(b) From looking at the distribution of enemy forces up to the fifteenth we see that most of the task force striking power has been distributed along the Archipelago. However, one force is always maintained in the rear for purposes of supply or as a reserve force. In attacking and occupying an Archipelago it is necessary to maintain re-enforcements. So it is thought that the distribution of the enemy is in general as follows:
i. In the vicinity of the Archipelago: At the most they will probably distribute their forces so as to be centered around two-thirds, or ten, of their aircraft carriers.
Moreover, judging from the present conditions of the invasion battle, the distance traveled west by them will not be great but it is presumed to be, at the most, 300 nautical miles.
ii. They will probably station between one-third and one-half of their forces to the west of the Archipelago, and the remainder will aid in the land fighting and act as reserve strength.
iii. From the present battle conditions there is very little possibility that they will remove all of their forces away from the invasion battle line and deploy them temporarily to the east of the Archipelago.
iv. It is very improbable that they intend to send part of their task force far to the west to make a flank attack on our advancing task force, or to makes surprise attack, because they would be entering an area within the limits patrolled by our land-based aircraft.
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v. Our air bases extend far to the southwest part of the Archipelago; however, since we are weak in the north, the enemy will probably attack the southern islands and try to cut aircraft and other supply lines while, at the same time, they will employ one element of the task force to attack in the north.
vi. It is very possible that the enemy will employ a great number of escort carriers in the vicinity of the Archipelago to reinforce the battle on land.
b. Things which should be considered in the tactical directions of task forces.
(1) From the standpoint of the maneuverability of a task force and, especially from the standpoint of fuel supplies, great delays in time schedules are not to be permitted.
(2) It is necessary to choose a time when the distribution of those of our fighting power which can participate in a decisive battle in the battle area has the most potentialities and, especially, when our land-based air power has great potentialities. This necessitates a consideration of present fighting strength and of the capacity of reinforcements.
(3) The strength of endurance of the forces defending the MARIANA Archipelago:
From the above considerations, we see that it is not possible to delay the engagement of our task force in a decisive battle beyond the nineteenth, we must, rather, consider how we can hasten the engagement.
c. Decision.
Tactical policies which should be adopted by the tank force: As previously planned, the main, tactical objective will be to shell the enemy task force in the vicinity of the Mariana Archipelago on the nineteenth and, thereafter, to carry out Operation "A", launch into a battle of pursuit and completely annihilate the enemy.
(1) We must be on guard against any surprise movements of the enemy after the sixteenth and must maintain the required observation of the enemy. In the south, the scouting of the enemy will be
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left to our land-based air power. Their main objective shall be to watch for a northerly frontal attack.
Especially, when one considers how the enemy is deployed, it is quite possible that the eighteenth shall be the day of the decisive battle. Therefore, we must sufficiently patrol and search out the enemy.
(2) At dawn on the nineteenth we shall arrive at a point three hundred miles west of the Archipelago and, while taking in aircraft we shall make tactical moves, so that we shall be able to attack the enemy task force power (regular aircraft carriers) in the vicinity to the east of the Archipelago.
(3) Our attack will consist of battle plan one, which depends on a long, longitudinal array of forces, and battle plan two, for daylight aerial warfare. We shall reserve the 2 Air Flotilla as reinforcements against surprise attacks of the enemy and it shall carry out strict patrols in the north.
(4) We shall strengthen the reconnaissance of the enemy by our land-based aircraft, both the day before and the day of the battle, and we shall strengthen our defensive contacts with the enemy. We shall distinguish between regular aircraft carriers and escort carriers, and we shall demand that each unit concerned put forth its utmost strength in the decisive battle.
(5) The disposal of aircraft in accordance with the results of the battle: Based, in general, on the plan for directing combined fleet tactics.
(a) When we have obtained very good results, the entire force shall pursue and annihilate the enemy.
(b) If results are not good, we shall retreat temporarily, reorganize our forces, and resume the attack.
Through the communication from the Central Pacific Area Fleet on 16 June, the general conditions of the enemy task force were made known to us.
In addition to the above, the enemy has been continuing the attack, begun yesterday, on IWO JIMA. Therefore, it has been decided
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that there will be no aircraft carrier groups raiding from the west, so we shall stop the scheduled reconnaissance of the enemy in the east. We endeavored to search out the enemy west Of PALAU by intercepting their wireless messages, however, we were not able to obtain any information about the enemy.
Today, at 1530 hours, we joined forces with the First Supply Unit and the Operations KON Unit (1 Squadron (excluding the NAGATO); the 5 Squadron; the 2 Destroyer Squadron (NOSHIRO, SHIMAKAZE, and OKINAMI); the 10 Destroyer Division and the 4 Destroyer Division (excluding the MICHISHIO).) After we had joined forces, all ships of the main unit and of the vanguard which were smaller than cruisers took on supplies at sea.
On 17 June we continued this supplying operation. On this day we dispatched an operational plane to PALAU so that telegraphic communications could be relayed to the combined fleet and to other places.
The gist of top secret Message No 170845 from the 1 Task Force was as follows:
"From: Chief of Staff of the 1 Task Force
To: Headquarters of the Combined Fleet, the 5 Land-based Air Unit, and the Central Pacific Fleet.
Text: The 1 Task Force, being at location "E" on the evening of the seventeenth and having finished supplying operations, will advance to a general location west of SAIPAN by dawn of the nineteenth, going via point "O" (TN May be point "C") at 15.0 degrees north latitude and 136.0 degrees east longitude. In the meantime, this fleet shall guard against westerly advances of the enemy and their movements from the north. The objective is first to shell regular aircraft carrier groups and then, by employing all fighting power, to annihilate the enemy task force and their invading forces."
The following are the requests made of land-based air units:
(1) It is requested that, from the evening preceding the decisive battle, you shall maintain a constant reconnaissance of the regular aircraft carriers of the enemy in the vicinity of the MARIANA
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Islands. If this is impossible, notify us immediately of the condition and deployment of regular aircraft carriers as of noon.
(2) We request intensified patrolling of the area west of the MARIANAS by each base on the day previous to the decisive battle. Special attention shall be paid to carry on reconnaissance in the sector from 160 degrees to 210 degrees from IWO JIMA.
(3) If the forces of the YAWATA Unit are not deployed on time, it is believed that we shall be forced to delay the decisive battle by one day. Please notify us of such a probability.
Since we had completed supplying operations at 1530 hours, the first disposition of forces was ordered, and we prepared ourselves for battle.
4. The battle on 18 June
a. Discovery of enemy planes:
We began reconnaissance of the enemy at 0500 hours, in accordance with Strategy Two and Three (concentrated air attacks on aircraft carriers.) for daylight air warfare. The course of advance was 60 degrees at a speed of 20 knots.
The above mentioned reconnaissance revealed one enemy plana at 73 degrees and 410 nautical miles moving east, and three planes of unknown nationality at 60 degrees and 425 nautical miles.
b. Discovery of the enemy fleet.
At 1100 hours the second group of reconnaissance planes were dispatched at 14 degrees 40 minutes north latitude and 135 degrees 40 minutes east longitude. (Scope of reconnaissance, 100 to 340 degrees). One plane of the above group discovered the following three enemy aircraft carrier groups between 1425 hours and 1540 hours.
First Group
Location: u, 1, 2, chi
Two regular aircraft carriers
10 to 15 destroyers
Second Group
Location: u, ra, 4, e
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Two ships, presumably regular aircraft carriers
Tea and some odd other vessels
Third Group
Location: u, ra, 1, a
Two ships, presumably aircraft carriers
Ten and some odd other vessels.
All were heading west and were 380 nautical miles from their main unit.
Attack planes of the 3 Air Flotilla were sent out to attack the above objectives with intentions of landing on GUAM. However, due to the cancelling of the alert for the attack by the commander of the task force, the attack was discontinued.
The decisions regarding the disposition of pertinent matters, as of the afternoon of the 18th, are as follows:
(1) Decision concerning enemy conditions: The three enemy aircraft carrier groups are advancing forward, west of the MARIANA Islands. There are no indications of the feared flank attack by enemy units from the north. (It was discovered that the reports of the morning reconnaissance, to the effect that enemy fighter planes were in the direction of 0 degrees, were false). It is decided that the range of the enemy reconnaissance and attack planes is approximately 300 nautical miles. Also, in regard to the battle conditions in the Saipan area, it is improbable that most of the enemy task force will advance to an extreme eastern position. However, it is necessary to consider that the enemy will advance approximately 300 nautical miles east of the archipelago.
(2) Disposal: As the attack on the eighteenth is impossible without the transferring of airplane units to land bases, the attack was discontinued and we firmly resolved to use our utmost strength on the nineteenth, the day of the decisive battle. The plan is to annihilate the enemy's regular aircraft carrier groups advancing on the western side of the archipelago in the coming air battle of the nineteenth.
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In order to do this the plans are that the attack will commence from a southern direction. The distance between our fleet and the enemy aircraft carrier groups and the distance from the archipelago will be 300 and approximately 580 nautical miles, respectively. Plans have been made to attack the enemy ships in the vicinity of the archipelago in case there are no enemy aircraft carrier groups. It has also been planned that in case it is possible for our reconnaissance plans to keep in constant contact with the enemy task fores on the night of the eighteenth, reconnaissance and attacks shall be carried out simultaneously.
Following the above plane, at 2000 hours the vanguard left the carriers and deployed for our battle.
5. The battle on 19 June
The task force took the position about 100 nautical miles distant from the vanguard main unit. The 2 Air Flotilla took a position 15 kilometers north of the 1 Air Flotilla. The air battle began with our planes flying in a column formation. Our course was 50 degrees and the relative bearing of the enemy was 50 degrees. The position of the main force was 12 degrees 20 minutes north latitude and 136 degrees 25 minutes east longitude on 0430 hours. Sunrise on the nineteenth was at 0522 hours.
0330 hours: Departure of the forward first wave of reconnaissance planes (16 reconnaissance seaplanes from the Second Fleet).
0415 hours: Departure of the forward second wave (13 carrier-borne attack planes from the 3 Carrier Division, and one reconnaissance seaplane from the CHIKUMA) and forward third wave (11 SUISEI's (TN Dive Bombers) from the 1 Carrier Division and two carrier-borne reconnaissance seaplanes from the MOGAMI.)
0634 hours: Number 7 of the forward first wave reconnaissance planes reported that it had discovered, at 264 degrees and 160 nautical miles off SAIPAN (location: na, so, 4 te) two large aircraft carriers, four battleships and ten and some odd other vessels (objective name 7 i) heading west. Afterward, a report
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came in that there were four additional large aircraft carriers.
0820 hours: A reconnaissance plans of the 8 Carrier Division reported that a large unit, including battleships, was spotted at point re, i 3 tsu this time. (This report was made after the plane had returned to its carrier.) At 1245 hours two carrier-borne attack planes made a report to the effect that they had not sighted anything in their search, which covered a radius of 75 nautical miles around their base of departure.
0845 hours: Plane 15 of the forward third wave of reconnaissance planes reported the discovery of three large enemy aircraft carriers, five enemy battleships and ten and some odd other enemy craft, approximately 70 nautical miles southwest of GUAM (Location: Ko, Ki, 3 u ). (Objective Name: 15 ri) Their courses was 240 degrees.
0900 hours: Plane three of the forward third wave of reconnaissance planes discovered one large aircraft carrier, one converted aircraft carrier, one battleship and five destroyers (objective name: 3 ri) 50 nautical miles north of point 7 i.
We considered that with the use of the abovementioned three waves of reconnaissance planes, we were able to ascertain in general the overall condition of the enemy task forces operating in the vicinity.
The distances from our vanguard and main unit to the enemy, were approximately 300 and 380 nautical miles, respectively.
a. General outline of measures taken by the commander of our task force.
(1) After the discovery of objective 7 i, the A unit put about temporarily to maintain a distance of approximately 400 nautical miles from the enemy. However, following the departure of the attack force, it again changed its course by 120 degrees.
(2) At 0730 hours, upon receiving notice that the first wave of reconnaissance planes, after reconnoitering to their maximum range, had not spotted other aircraft carriers, the 1 Carrier Division of the first attacking force was sent out.
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Strength: 48 land based attack planes, 54 bombers, 27 attack planes.
Object of Attack: 7 i
Attack Course: 64 degrees
Maximum Advancing Distance: Approximately 380 nautical miles.
0730 hours: Departure of the 3 Carrier Division of the first attacking force - 14 fighters, eight attack planes, 46 land based attack planes.
Object of attack: 7 i
(3) 0900 hours: With the discovery of objective 3 ri, the 2 Carrier Division of the first attacking force (26 land-based fighters, 16 fighters and seven attack planes), which was heading for objective 7 i, was order, at 0930 hours, to change its course.
(4) At 1000 hours, planes for keeping in contact with objective 15 ri were dispatched. The order was given for the 1 and 2 Carrier Divisions of the second attacking force to head towards this objective.
(5) Attacks.
0945 hours: The 2 Carrier Division of the first attacking force attacks objective 7 i.
1045 hours: The Carrier Divisions of the first attacking force attacked objective 7 i.
However, there are indications that part of the above units attacked objective 3 ri.
Moreover, our 1 Carrier Division of the first attacking unit, while flying towards its objective, flew over our vanguard, which opened fire. There were several casualties. A thorough search by the 2 Carrier Division of the first attacking force for objective 3 ri ended in failure. Objective 15 ri was also search for in vain by both the 1 Carrier Division of the second attacking force (10 land-based fighter planes, four carrier attack planes, four carrier bombers - time of departure 1230 hours) and the 2 Carrier Division of the second attacking force (26 fighter planes, 36 carrier bombers, two carrier bombers, time of departure: 1000 hours).
All three divisions abandoned attempts to continue the search. The 2 Carrier Division of the first attacking force and the 1 Carrier Division of the second attacking force returned to their respective
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carriers. The 2 Carrier Division of the second attacking force headed for GUAM. this division, (approximately 50 planes) at 1511 hours, met and fought with a large number of enemy fighter planes above the first airfield on GUAM and consequently received considerable damage. The number of planes landing at the second airfield on GUAM were nine fighter-planes, seven carrier bombers and one carrier bomber, all of which were damaged beyond repair. The reports going to the headquarters of the task force, notifying them of this loss, were delayed considerably. Also the fact that the 2 Carrier Division of the first attacking force was unable to attack its objective was known to the Commander of the task force only after he had transferred to the HAGURO. Moreover, the 3 Carrier Division of the second attacking force lost its opportunity and cancelled its departure because of the arrival and accommodation of planes from other carriers.
(6) If the 1 Carrier Division of the first attacking force is to be used for an attack again, we must anticipate a landing at night, as the landing and accomodations for the above planes returning from the second attack should commence at approximately 1500 hours. Therefore, preparations were made for the attacking of objective 15 ri by part of the second attacking force. However, because of the sinking of the TAIHO as the result of an explosion, this was not carried out. Despite this, most of the planes of the second attacking force on the TAIHO were transferred to the ZUIKAKU before the former sank.
b. The decision of the task force commander after the attack by the first attacking force.
In the event that the enemy losses are heavy, we shall advance to the area around the archipelago on the following day, the dawn of the 20th, and resume the air battle, and while destroying the enemy aircraft carrier groups, dispatch diversion attack forces and annihilate the enemy.
In the event that the losses inflicted by the first attacking wave on the enemy are not great, the task force will temporarily retreat to the west and attempt a decisive battle again, after reorganizing our forces and taking on additional supplies.
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c. The sinking of the TAIHO.
At 0810 hours on the 19th, the TAIHO, immediately after dispatching the first attacking force, was attacked by enemy submarines. (It was one direct torpedo hit.) (Location: 12 degrees 24 minutes north latitude and 137 degrees 20 minutes east longitude). A terrific explosion occurred within the ship at 1432 hours and at 1628 hours it sank (location: 12 degrees five minutes north latitude and 138 degrees 12 minutes east longitude).
d. Sinking of the SHOKAKU.
The SHOKAKU was also attacked by enemy submarines at 1120 hours on the same day (four direct torpedo hits). As a result, fire broke out and at 1401 hours it also sank. (Location: 12.0 degrees north latitude and 137 degrees 46 minutes east longitude).
e. The strategy after the flagship had been changed.
When the TAIHO exploded at 1432 hours, we were in the midst of a raging air battle. As a result, it was decided that the flagship should be a vessel capable of communication and that the transferring should be done immediately. Utilizing the WAKATSUKI, which was in the field of vision, the commander transferred to the HAGURO at 1606 hours. After the arrangement of necessary emergency matters, he continued directing operations. At 1200 hours on the next day the ZUIKAKU became the flagship.
.After the commander of the task force had boarded the HAGURO, he received notice of the battle results despite the fact that the communications system of the above ship was incapable of completely handling the directing of air battle strategy. As the results of the air attacks were insufficient, it was decided that we should carry out another attack on the enemy task force. However, as there were only 100 planes capable of combat (the number of planes accommodated in aircraft carriers only), the necessity for reorganising the forces was recognised.
Thus, it was decided that we should attack the enemy only after reorganising our forces and obtaining the support of our land-based air strength. Consequently, the following orders concerning
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the assembling of our forces were issued:
1800 hours:
From: Commander of the Task Force
To: Task Force
"Take a position at 0700 hours tomorrow, the 20th, as indicated in Battle Order No 8. location of Unit "A": he, chi, chi, 00 (TN 14400) course: 90 degrees. Speed: 16 knots."
2000 hours:
From: Commander of the Task Force
To: 1 and 2 Supply Units.
"The First and Second Supply Units will proceed to point he, chi, chi 00."
2245 hours:
From: Commander of the Task Force
"The task force shall immediately proceed in a north-westerly direction and maneuver in such a way as to be able to receive supplies on the 21st."
Due to the above conditions, the relieving telegram was received from the Headquarters of the Combined Fleet.
(1) "It has been planned to direct a running battle after reorganizing our forces and in accordance with the battle conditions."
(a) "On the twenty-first, the task force shall reorganize its strength and take on supplies. Disabled vessels shall proceed to the homeland. Also, part of the aircraft carriers shall proceed to the training base (LINGA)."
(b) On the twenty-second, according to the situation, you shall advance and direct your attacks against the enemy task force, co-operating with the land-based air units. After this has been done, you shall dispatch your air units to land bases. Thereafter, operations shall be carried on under the commander of
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the 5 Air Unit. The aircraft carriers shall proceed to their training base.
(c) After the twenty-second, according to the conditions, you shall engage, most of your craft in mopping up operations around SAIPAN.
6. The battle on 20 June
At 0400 hours, units were sent out to reconnoiter the area east of the point where we were to take on supplies, as designated by the commander of the diversion attack force.
0700 hours: Upon combing the 1 and 2 Supply Units, we started taking on supplies.
In the morning, we received no reports as to the enemy conditions. At 1130 hours, a patrol plane from PALAU reported seeing a task force 20 degrees and 540 nautical miles off PELELIU. This report had already been decided to be a mistake - the task force was Japanese. This was confirmed later when it revised its course by 5 degrees.
1200 hours: We dispatched one group (three carrier attack planes of the 3 Carrier Division) of reconnaissance planes and three more reconnaissance planes from the 1 Carrier Division to reconnoiter the enemy. discovered by the patrol plane near PELELIU.
In the afternoon, we received one notice after another from the first wave of reconnaissance planes of the diversion attack force that they had discovered airplanes of unknown origin, approximately 240 nautical miles east of the point where the supplies were being taken on. Also, at 1515 hours, the ATAGO reported that it had picked up enemy radio signals and thus it became clear that enemy seaplanes had discovered us. So, disregarding the taking on of supplies, we decided on an immediate retreat in the direction of 320 degrees.
At 1505 hours, we intercepted an enemy wire. Judging from the wire, it seemed that enemy planes had given their main unit a complete description of our task force.
Because of the above circumstances, at 1520 hours we ordered the 1 and 2 Supply Units to retreat immediately towards the west. At 1610
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hours, a group of what seemed to be enemy carrier-borne planes were discovered flying west, approximately 200 nautical miles east of the flagship of our task fores. At 1615 hours, our reconnaissance planes discovered an enemy unit, including aircraft carriers, (Centered around two aircraft carriers and two battleships) heading west. (Position: 14 degrees 20 minutes north latitude and 138 degrees 30 minutes east longitude).
We decided to attack this enemy unit with aerial torpedoes at dusk (with the intention of having the planes return to a land base). 1655 hours: We ordered the vanguard to keep in constant contact with this enemy.
1700 hours: Commenced the fourth disposition of forces and ordered practically all our vessels to enter the night battle as diversion attack forces.
1707 hours: The MOGAMI was included in the vanguard.
1720 hours: The torpedo bomber plane unit (three planes for keeping in contact with enemy and seven torpedo bomber planes) set out. The attacking of the enemy at night by the diversion attack forces was decided upon by considering the following points: first, the results of the torpedo unit and the possibility of air support the following morning; second, the reconnaissance of enemy units by land based aircraft; third, the fact that no enemy units existed in the vicinity other than the ones discovered. However, due to the fact that our torpedo bomber units could not locate the enemy and also because of the air-raid on our task force and supply units at about 1530 hours, which resulted in the loss of most of our carrier-borne air force and thus obliterated any hopes for air support, the following order was issued to the diversion attack unit at 2100 hours:
"In the event that there is little opportunity for a battle at night, immediately retreat to the northwest."
On the twentieth, the 1 Carrier Division, the 2 Carrier Division and the diversion attack force were subjected to an air attack, starting at 1730 hours and lasting approximately one hour. The results were as follows:
a. Number of attacking planes: approximately 130 to 150 planes.
The following approximate number of planes attacked the 1 Carrier Division, the 2 Carrier Division the diversion attack force and the Supply Unit respectively: 50 planes, 40 planes, 20 planes and 35 planes.
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b. Planes shot down:
More than 40 planes were shot down as a result of the air battle (results obtained by those of our planes which have not returned here not been recorded).
Approximately 70 planes were shot down as a result of antiaircraft fire.
c. Damage (Refer to appended section):
1945 hours: Because of the prevailing circumstances, the task force was ordered by the commander of the combined fleet to break away free the enemy at opportune moments and act as directed by the commander.
1950 hours: Received a wire from the chief of staff of the combined fleet, stating that it was their intention to temporarily postpone pursuit action and, upon taking into consideration the prevailing circumstances, attempt a renewed attack.
2015 hours: We ordered the 1 and 2 Supply Units to immediately retreat towards the west and then head for NAKAGUSUKU harbor.
7. Actions after 21 June
21 June: The 3 Carrier Division was ordered to reconnoiter in the direction of 90 to 180 degrees from the fleet, within a radius of 350 nautical miles. However, the enemy was not sighted.
0715 hours: The "A" and "B" units were ordered to proceed to NAKAGUSUKU Bay and the diversion forces were ordered to GUIMARAS.
0818 hours: In the event that we discovered the enemy task force on this day, we were to commence the final attack using the entire strength of our air flotillas. Therefore, we gave orders to anticipate and make preparations for such.
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Explosions (destroyed by fire) |
Not Returned |
Crash Landed (Hit by enemy fire) |
Died in Battle |
Whereabouts unknown |
Wounded | |
1 Air Flotilla |
29 |
122 |
12 |
8 |
215 |
1 |
2 Air Flotilla |
6 |
47 |
(15) |
14 |
65 |
6 |
3 Air Flotilla |
65 |
(1) |
93 |
|||
TOTAL |
100 |
169 |
12 (16) |
115 |
280 |
7 |
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In the afternoon, we dispatched all the carrier attack planes of the 3 Carrier Division as the rear second wave of reconnaissance planes in search of the enemy but in vain.
On or about 1030 hours, it was decided that we had drawn away far enough from the enemy tank force which was pursuing us.
1030 hours: Due to fuel conditions, the ASAGIRI was ordered to proceed to NAKAGUSUKU harbor alone, at a speed of 16 knots.
1545 hours: We ordered all units of the main force to enter NAKAGUSUKU harbor the next morning and the diversion attack force to cruise about the central and southern part of the PHILIPPINE Islands and wait in readiness. Also, the FUSO and the 1 and 2 Supply Unite were transferred and included in the diversion attack force.
Later it was decided that, because of the enemy and the difficulties of refueling at sea, the diversion attack force would temporarily drop anchor at NAKAGUSUKU harbor, refuel, and than set out for GUIMARAS.
22 June: The diversion attack force and the main unit arrived at and entered NAKAGUSUKU harbor at 1300 and 1500 hours, respectively. Then the transferring of personnel was put into effect for the following vessels: TAIHO (ZUIKAKU), SHOKAKU (MAYA), HITAKA (HAYATAKA), Aircraft Carrier Number 601 (ZUIKAKU). 2303 hours: The Task Force was ordered by the commander of the combined fleet to proceed to and cruise in the vicinity of the western part of inner sea (Excluding the FUSO and the NATORI).
23 June
0330 hours: All supply units were ordered to cruise in the vicinity of the eastern part of the inner sea.
0525 hours: The disposition at forces was changed as follows
Main Unit - Third Fleet
Diversion attack force - Second Fleet
1100 hours: Departure of task force from NAKAGUSUKU harbor
24 June:
1800 hours: Arrival of task force at the eastern part of the inner sea
The operational outline of the 1 Task Fores from 23 June to 24 is as follows:
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8 Results
a. Battle results.
(1) The results of the first attack force were not definite and could not be verified, due to the great number of our planes which did not return and also due to our inability to view the damages inflicted because of enemy fighter plane interference. However, estimated damages inflicted on the enemy are as follow:
(a) The attack planes of the 3 Carrier Division made direct hits on one battleship (TN Abbreviated letters not clear) and one light cruiser.
(b) After the planes of the 1 Carrier Division had attacked, they saw smoke rising from four aircraft carriers.
(c) The condition of the enemy just prior to the attack by the 1 Carrier Division
One aircraft carrier burning.
One battleship emitting white smoke.
(2) Decision
(a) The attack of the 3 Carrier Division had caused fires aboard one aircraft carrier and one battleship or cruiser.
(b) The attack of the 1 Carrier Division caused fires aboard three or four aircraft carriers. (Delete one in the event that one carrier was the vessel set afire by the 3 Carrier Division). The final results are that four or five aircraft carriers and one battleship or heavy cruiser were sunk or damaged.
(3) Number of enemy planes shot down
(a) Although the results were not clear on account of our numerous casualties, we had shot down at least 50 enemy planes on the nineteenth, judging from the statements of the pilots who returned (they had shot down 14 planes with nine of their own) and from the number of planes involved in the battle.
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(b) We had shot down at least 40 planes in air battle on the twentieth.
The number of enemy planes shot down by our anti-aircraft fire was approximately 70.
In the final results, at least 160 of the enemy aircraft haw been definitely shot down.
(Note) According to the battle reports of the American side:
There was some damage inflicted to their aircraft carriers by near misses.
The number of planes lost was nine.
Moreover, it seems that our airplane units were attacked by enemy fighters while in cruising formation, and practically all our planes were attacked and shot down before our fighter planes could protect them.
b. Damage.
(1) Damaged Surface Craft:
Battle of 19 June. TAIHO, SHOKAKU sunk.
Battle of 20 June.
(a) ZUIKAKU-One direct hit to the rear of the bridge and six near misses; no trouble while cruising under combat conditions.
(b) HITAKA—Subjected to joint attack by torpedoes and aircraft: steering impossible due to one direct aerial torpedo hit; suffered submarine attack while drifting and one hit caused a large fire aboard ship; finally sank at 1932 hours.
(c) HAYATAKA—Two direct hits near the smoke stack and total of six near misses: take-off and landing of aircraft difficult; no trouble in cruising.
(d) RYUHO-Small damage due to near miss: no trouble in cruising
or participating in combat.
(a) CHIYODA—One direct hit aft the flight deck; small damage;
no difficulty In cruising or participating in combat.
(f) HARUNA—One direct hit on the after deck and near misses; seepage into powder magazine; in need of repair at dry docks; for the time being, no trouble in cruising or participating in combat.
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(g) MAYA.—Fire in left torpedo chamber caused by near miss.
In need of repair at drydocks. For the time being, no difficulty in cruising or participating in combat.
(h) GENYO MARU-Great damage to machinery by three near misses; navigation impossible because of heavy leakage; abandoned ship (ship disposed of by gunfire free UZUKI).
(i) SEIYO MARU-Large fire due to enemy bombing; abandoned ship (ship disposed of by torpedoes from YUKIKAZE.).
(j) HAYANAMI—One direct hit, two near misses; small damage; no difficulty in cruising or participating in combat.
(2) Damage to Flying Units: (TN See chart on following page)
Chapter III. Base Air Units
The commander of the 5 Base Air Force (Commander-in-Chief of the 1 Air Fleet), Vice-Adm SUMIDA, Kakuji took direct command of the 61 Air Flotilla with headquarters located on TINIAN Island. The Commander of the 21 Air Flotilla and the commander of the 26 Air Flotilla, their headquarters respectively located at TRUK and PALAU, conducted operations in the CAROLINE and MARIANA Areas, while the Commander of the 23 Air Flotilla, his headquarters located at KENDARI*, conducted operations in the Area north of AUSTRALIA.
Furtherance, as of 15 June, the main force of the YOKOSUKA Navy Air Unit had seen placed under the command of the Commander-in-Chief of the Combined Fleet by a navy directive of Imperial General Headquarters; the YAWATA Unit was organized with this unit and ordered to proceed to IWO JIMA, where it was placed under the command of the commander of the 5 Base Air Force.
As a result of the foregoing, practically all of the decisive strength of our naval land-based air units at that time were to have participated in Operation A under the command of the commander of the 5 Base Air Unit.
However, prior to the beginning of the decisive battle, approximately one half the strength of the 5 Base Air Force (The 2 and 3 Attack Groups) was ordered to transfer operations to the area north of AUSTRALIA in order to participate in the operations there, particularly in the BIAK Operation. The major part of the strength ordered to participate in these operations was lost while being transferred, and in frequent small-scale attacks.
The reasons for this were, basically, the incompleteness of base facilities, the personnel's being unaccustomed to the newer planes (land-bombers, SUISEI, etc.) and the poor health of the crewmen (Malaria and other illnesses). Aside from these, it was difficult to expect a decisive strength in view of the operational waste.
The remaining strength in the other Marianas Areas was largely exhausted by attacks of the enemy task force after 11 June. Until the beginning of the decisive battle, around 18 June, it was difficult to even organise a systematic attack force and, in the end, only the 2 Air Attack Force and the YAWATA Unit of the IWO Area remained. At the time the decisive battle started, the nucleus of the 2 Air Attack Force was to be dispatched to the GUAM Area to participate
--52--
in the decisive battle. However, air battles were fought with enemy fighter craft in the skies over GUAM, whereby many enemy planes were shot down but we also suffered considerable damage. Later, with a small force, all they did was to carry out attacks on enemy vessels in the SAIPAN vicinity.
The YAWATA Unit again engaged the enemy task force in battle, but their potential as a decisive force was lost before they were able to strike the death blow.
Thus, even the 5 Base Air Force, which was organized out of practically the entire strength of our base air units, was disbanded because, from the very beginning, it could not make an effective assault in the decisive battle of Operation A or even provide suitable reconnaissance in obtaining enemy information for our task force.
The reason for the failure and near self-destruction of the 5 Base Air Force was the tactical shortcomings of the command, the inadequate training of crew members and the lack of base facilities in the Mariana and Caroline Areas (either in time or materiel).
Chapter IV. Submarine Force
The commander of the Advanced Forces (Commander-in-Chief of the 6 Fleet) Vice-Adm TAKAKI, Takeo, with headquarters on SAIPAN, directed the entire operation.
The total number of submarines used in this operation was 20, which was practically all that our navy could use in the decisive battle at that time.
As reconnaissance of enemy basse in this operation was principally conducted by aircraft, and as the submarines were mainly concentrated and used in the neighboring waters of the MARIANA Islands, no submarine warfare which had any direct influence on Operation A was conducted. Furthermore, this subject is fully explained in the history of submarine warfare.
--63--
The "A-GO" Operations Log.
Supplement May - June 1944
Through Instruction No. 126 to Japanese Government, 12 Oct 45, entitled "Institution for War Records Investigation", steps were initiated to exploit military historical records and official reports of the Japanese War Ministry and the Japanese General staff.* Upon the dissolution of the Mar Ministry and the General staff, and the transfer of their former functions to the Demobilization Bureau, the general research job continued and resulted in the development of a series of historical monographs. Detailed instructions covering the preparation of these monographs were included in Memoranda 15 December 1945 and 21 November 1946, subject "Japanese Operational Histories.",
The basic material contained in this operational record was developed by former officers, on duty in command and staff units within major units during the period of operations. It should be noted at once, that the enormous destruction by aerial bombardment and fire has practically wiped out the Tokyo records; much of this material was reconstructed from memory.
The paucity of original orders, plans and unit journals, which are normally essential in the preparation of this type of record, most of which were lost or destroyed during field operations or bombing raids rendered the task of compilation most difficult; particularly distressing has been the complete lack of official strength reports, normal in AG or G-3 records, however, while many of the important orders, plans and estimates have been reconstructed from memory and therefore are not textually identical with the originals, they are believed to be generally accurate and reliable. Further data as a result of continuing research and the occasional recovery of hitherto unavailable original documents will be covered in the subsequent publication of "supplements" by the demobilization bureau.
* The action under this memorandum and incidental detailed instructions, which followed, were initiated by the Assistant Chief of Staff, G-2, GHQ, charges with responsibility for execution of the program under G.O. No. 9, SCAP, 2 October 1945.
In order to protect the interest of the United states, in the exploitation of Japanese Military Information, sub-paragraph 4 of G.O. No. 9 further provided for the screening of enemy documents and established inventories in Japanese Governmental archives. Careful examination of the first records submitted by the Japanese Government in the summer of 1946 detected a misconception on the part of the Japanese as to what should be included in comparative histories; in a memorandum issued by Assistant Chief of Staff, G-2, on 21 November 1946, the Imperial Japanese Government was directed to record the operations of the Japanese forces more extensively. The G-2 Section thereafter assumed coordination of the entire program, including the establishment of a small historical research section within the ATIS (Allied Translator and Interpreter Section.)
Daily- Record of Operations "A".
Date: 3 May 42.
Principal dispatches, etc:
Order No 373 by the Imperial Headquarters, Naval Section. Present Operational policy to which the combined fleet must conform.
Date: 4 May.
(TN No entry).
Date: 5-6-7-8 May.
Notes: Communications in the Marshall area is active.
Dispatches from the Hawaii Area Command are numerous.
Strict air security is being maintained over the Midway area, and there is possibility of an attack by a strong force.
Date: 9 May.
(TN No entry).
Date: 10 May.
(TN No entry).
Date: 11 May.
Notes: The Diversion Attack Force (Submarine No 4, Submarine No 1, Submarine No 3, Submarine No 1, and the 2 Destroyer Squadron) left the Linga anchorage (south of SINGAPORE) at 0300 hours.
Date: 12 May.
Notes: The 1 Carrier Division, Submarine No 5, and Submarine No 10 departed from Linga anchorage.
Date: 13 May.
(TN No entry).
Date: 14 May.
Notes: The Diversion Attack Force reached TAWI-TAWI at 1650 hoars. The INAZUMA was sunk by mines at 0400 hours outside Tawi-Tawi Harbor.
Date: 15 May.
Notes: The 1 Carrier Division, Submarine No 5, and Submarine No 10 reached TAWI-TAWI at 1100 scare.
Date: 16 May.
--1--
Notes: The 2 Carrier Division, 3 Carrier Division, and the MUSASHI reached TAWI-TAWI at 1915 hours.
Date: 17 May.
Notes: A powerful enemy force landed at WAKDE and SARMI. The air strength in the area north of AUSTRALIA is 12 fighters and six land-based attack planes.
Principal dispatches, etc: A portion of the enemy's task force attacked various points in JAVA.
Date: 18 May.
Notes: Cruising maneuvers wore held by Carrier Divisions 1 and 2 of 1 Task Fleet.
The 1 Air Fleet started deployment which will be completed by the 26th.
Date: 19 May.
Notes: The Commander of 1 Task Fleet (Commander of Task Force) Issued instructions to all men.
Summary of instructions:
1. Disregard damages.
2. Portion of the unit will be sacrificed when deemed necessary for overall success.
3. If communications should become unsatisfactory, the commanders of each unit will be expected to use his own discretion.
Date: 20 May.
Notes: Operation "A" begun. The 1 Task Fleet completed mobilisation at TAWI-TAWI. Stand-by tine is to be six hours later this day.
The Base Fleet will start deployment on the 23rd and deployment will be completed on the 26th. Supplementary supplies from JAPAN have been delayed due to weather and other conditions. Two hundred and seventy eight aircraft must be transported by air by the end of the month.
The total of 94 carrier planes attacked MARCUS Island in five waves.
A reconnaissance plane, based on TINIAN, sighted an enemy task force consisting of two aircraft carriers, four battleships, and eight
--2--
other ships in the area 150 sea miles southwest of MARCUS Island.
Date: 21 May.
Notes: Twenty enemy carrier-based aircraft attacked MARCUS Island at dawn. Orders issued to the Central Pacific Area fleet to strengthen security, especially in the BONIN Islands, East Carolines, and the Marianas area. Air reconnaissance was reinforced from IWO JIMA and TINIAN.
The 1 Task Fleet reviewed operational procedures (on flagship TAIHO).
Date: 22 May.
Notes: Flagship OYODO of the Combined Fleet left Tokyo Bay at 1300 hours and headed towards the Katsurajima Anchorage.
Enemy submarines are active in the vicinity of TAWI-TAWI.
Flagship CHITOSE of 3 Carrier Division was torpedoed during maneuvers, no damage.
Date: 24 May.
Notes: A total of 185 enemy carrier-based airplanes attacked WAKE Island in seven waves.
Date: 25 May.
Notes: Tanker, TATEKAWA Maru (vanguard tanker of the task force) was torpedoed and sunk by an enemy submarine in Davao Bay.
Date: 26 May.
(TN No entry)
Date: 27 May.
Notes: Enemy attack unit started landing on BIAK Island.
Twenty-one land-based attack planes of 23 Carrier Division are to leave for SORONG via Davao and WASHIN.
A reconnaissance plane from the 1 Air Fleet reconnoitered the Tulagi area from TRUK to Buin Airfield.
Aircraft carriers (Saratoga class) - one.
Converted carriers - two.
Battleships - four.
Cruisers - five.
Destroyers - three.
--3--
Unknown - one.
Small ships - 50.
Large transports - seven
Medium transports - 16.
Small transports - 23.
Sea trucks - 40.
These ships ware anchored at various ports in the FLORIDA Islands and off LINGA.
A review of operational procedures was held by the task force for Operation "A*" (on TAIHO).
Principal dispatches, etc:
Orders of the Combined Fleet: A part of the forces disposed in the Mariana and Caroline areas and the air force in the homeland scheduled to be assigned to the same area will be diverted to the western New Guinea area.
Remarks: Approximate strength of force to be diverted:
Fighter aircraft - about 70 (of these, 50 are in JAPAN).
Observation aircraft - about four.
Bomber aircraft - about 16.
Date: 29 May.
Notes: The enemy carried out full-scale reconnaissance and attack on strategy points in the Central Pacific Area.
The attack of one enemy land-based attack plane and four fighter aircraft on BIAK was repulsed.
Army photographic reconnaissance shows four cruisers, two submarines, eight destroyers, nine medium transports, 10 small transports anchored in Humboldt Bay and five destroyers and nine transports cruising outside the bay.
Date: 30 May.
Around 1000 hours, communications with reconnaissance planes was broken in the vicinity at 200° and 450 sea miles from TRUK, and another in the vicinity at 135° and 500 sea miles from PALAU.
--4--
Raiding air reconnaissance was carried out against MAJURO Island and the vicinity of Port FINSCH. (TN Presumably FINSHAFEN.) (Air unit 121 and 151 of 22 Carrier Division:
A. Port MAJURO.
Regular aircraft carriers - five.
Converted carriers - two.
Battleships - three.
Cruisers - three.
Destroyers - 10.
Transports - two.
Tankers - six.
A total of 31 at anchor.
Regular aircraft carriers - two.
Battle cruisers - three.
Destroyers - eight.
A total of 13 departing from the port.
Remarks:
Two regular aircraft carriers are of the Essex class.
One regular aircraft carrier of the Enterprise class.
Two carriers are of the Casablanca class.
One battleship is of the Iowa class.
It is not known whether two of the aircraft carriers are regular or converted carriers.
B. Port FINSCHAFEN.
Large transports - five.
Medium transports - six.
Small transports - five.
Destroyers - three.
Total - nineteen.
Date: 31 May.
Operation KON.
Operation KON designates the escort operations and transporting of the 2 Amphibious Brigade which is to reinforce BIAK Island. The
--5--
participating forces are now making preparations in DAVAO. Invasion of the island is planned for approximately 3 June.
The 16 Squadron with the AOBA, KINU, URANAMI, and SHIKINAMI.
The 5 Squadron with the MYOKO, HAGURO, FUSO, and ITSUKU-SHIMA.
Destroyer Group 10.
" " 27.
Air strength capable of participating in Operation KON:
SORONG:
Fighter aircraft - two.
Land-based attack planes - four.
BABO:
Fighter aircraft - 10.
KAU:
Fighter aircraft -six.
WASHIN:
Land-based attack planes - eight or more.
Fighter aircraft - 18.
Land-based attack planes - 12.
Furthermore, there are 48 fighter aircraft, eight reconnaissance planes, and two bombers, totaling 76 planes, that are being diverted from YAP to WASHIN via DAVAO. Expected date of arrival is 1 or 2 June.
The 5 Squadron and the FUSO arrived at DAVAO.
Principal dispatches, etc:
Order of the Combined Fleet.
Date of Biak Invasion changed to 4 June.
Date: 31 May.
Notes: Raiding air reconnaissance against KWAJALEIN. (Results of photographic readings.)
Kwajalein Anchorage:
Destroyers - eight.
Small ships - nine.
Small ship tenders - one.
--6--
Transports - 18.
Tankers - one.
Other. - 20.
Kwajalein airfield:
B-24's - one.
Medium land-based attack planes - seven.
Small aircraft - three.
Transport aircraft - one.
Ruot Anchorage:
Destroyers - two.
Transports - two.
Ruot Airfield:
Medium aircraft - five.
Small aircraft - 84.
Raiding air reconnaissance against the ADMIRALTY Islands.
In the anchorage:
Aircraft carriers, Saratoga-class - one.
Battleships - one.
Cruisers - one.
Small-type ships - 40.
Transports - one.
There were approximately 150 large and small aircraft on the airfield.
Principal dispatches, etc:
Orders of the Combined Fleet, 2219.
Orders issued to 1 Air Fleet to assume formation for Operation "A" to give decisive battle in the seas near PALAU.
Remarks: Judging from the results of the raiding air reconnaissance in the Marshall, Solomon, and Admiralty Areas and from radio reports, there are signs of enemy ships becoming active in ESPIRITU SANTO. North-west of NEW GUINEA, there is a possibility of enemy action in connection with Operation KON.
--7--
Date: 1 June.
(TN No entry).
Date: 2 June.
Notes: Fighter aircraft, attack aircraft, and Navy "SUI" dive bomber unit (TN Presumably "SUISEI", dive bombers) of 1 Air Fleet participated in the attack on the Biak Island area.
Reconnaissance against BROWN Island (seaplane unit 151):
Eniwetok area:
Cruisers - two.
Destroyer - one.
Transports - 17.
Tanker - one.
Small aircraft - 10.
Medium aircraft - 10.
Large aircraft - 30.
ENCHABI* area:
Large transports - three.
Small aircraft - 10.
Medium aircraft - 10.
The Kon unit cruised out from DAVAO.
Principal dispatches, etc:
Orders of 1 Air fleet.
Brief of the second raiding air reconnaissance:
Air Unit 121: MAJURO, BROWN.
Air Unit 151: ADMIRALTY, South Sea Area, Tulagi region.
The raid reconnaissance is scheduled to take place as soon as possible, after the 3rd.
Date: 3 June.
Notes: The Kon Unit was approached by two B-24's, 330 sea miles southeast of DAVAO. According to another report, there is a great possibility of the movement of strong enemy force into the same region.
Supply Unit No 2 of the Task force, consisting of the GENYO Maru, AZUSA Maru, and two destroyers cruised out from TAWI-TAWI. Destination
--8--
Point I (approximately 130 sea miles east of the northern part of MINDANAO).
Principal dispatches, etc:
DENREISAKU 11* (TN Operational Wire Order) of the Combined Fleet (communication number 031420): Attack group No 2 of the Base Force will concentrate and form in the Halmahera area. Advance bases are to be at SORONG and BABO. Rear bases are to be at WASHIN and KAU.
Wire Order of the Combined Fleet (2200): Operation KON temporarily suspended. FUSO of 5 squadron is to return to original unit.
Date: 4 June.
Note: The 1 Air fleet (fighter aircraft -22; bomber aircraft -nine) attacked enemy ships at BIAK in conjunction with army aircraft. Aside from the above-mentioned ships, Army reconnaissance aircraft sighted two aircraft carriers (later found to be an error) and 10 to 20 other ships in the vicinity of BIAK Island. The attack was carried out by 17 fighters, six bombers, and 17 army aircraft.
Date: 5 June.
Notes: A raiding reconnaissance was made on MAJURO at 1050 hours.
Regular aircraft carriers - six (all of either the Essex or Enterprise class). Half of then had 60 small fighters on the flight deck.
Converted carriers - eight (among them, two of the Independence class).
Battleships - six.
Cruisers - eight or more.
Destroyers - 16 or more.
Tankers - 10.
There were many other ships.
Reconnaissance against the ADMIRALTY: Due to clouds, the reports are doubtful. However, there were one aircraft carrier, two battleships or cruisers, and three destroyers anchored on the southern side of Port ADOLA*.
--9--
TAKASAKI and ASHIZURI were sunk by mines in the SULU Sea (6° 33 minutes north, 120° 13 minutes).
Principal dispatches, etc:
Orders by the Task Force: Supply Unit No 2 will stand by at point J (anchorage in Surigao Strait).
Date: 6 June.
Notes: Reconnaissance planes from MEREYON* Base sighted a force organized around one carrier and four landing crafts at 145° and 470
sea miles from the same island.
Destroyer MINATSUKI was sunk in an encounter with an enemy submarine in the vicinity of TAWI-TAWI while escorting OKIGAWA Maru. (There were 45 survivors).
Date: 7 June.
Notes: HAYANAMI was torpedoed and sunk at 1242 hours by an enemy submarine south of TAWI-TAWI while sub-chasing.
The 5 Squadron and Destroyer Group 10, which were transferred to the Kon Unit, cruised out from DAVAO, KAZAKUMO of Destroyer Group 10 was sunk by a mine at the mouth of Port DAVAO at 0330 hours.
Principal dispatched, etc:
Orders of the Combined fleet: Squadron 5 and Destroyer Group 10 (KAZAKUMO, ASAGUMO) will be transferred to the Kon Unit.
Date: 8 June.
Notes: Destroyer Group 19 (SHIKINAMI, URANAMI) and Destroyer Group 17 (SHIRATSUYU, SHIGURE, SAMIDARE, HARUSAME) under the command of Squadron Command 16 of the Kon Operational Unit, encountered enemy aircraft, one battleship, four cruisers, and eight destroyers.
HARUSAME - sunk.
SHIRATSUYU - slightly damaged and flooded.
SHIKINAMI and SAMIDARE - slightly damaged.
Four land-based attack planes of 1 Air fleet attacked WAKDE and six bombers of the same fleet attacked BIAK.
Date: 9 June.
Notes: Raiding reconnaissance carried out against MAJURO at 0930 hours. The enemy ships which were anchored during the previous reconnaissance had departed, and 10 transports and two destroyers remained within the reef.
--10--
Reconnaissance against the ADMIRALTY at 0900 hours:
A. Anchorage:
Battleship - one.
Cruisers - three.
Transports - 20.
Destroyers - 20 or less.
1. Airfield:
Largs fighters - 55.
Small fighters - 80.
Total - 135.
C. Seas east of the ADMIRALTYS:
Two large transports and three destroyers navigating Co 150° (TN Presumably course).
Destroyer TANIKAZE torpedoed and sunk outside Port TAWI-TAWI while sub-chasing (126 survivors).
Principal dispatches, etc:
Order of the Combined Fleet: Reconnoiter BROWN and KWAJALEIN; strengthen patrols in all areas.
Date: 10 June.
Squadron 1, consisting of the YAMATO, MUSASHI, Destroyer Squadron 2, NOSHIRO, and two destroyers were transferred into the Kon Operational Unit under the command of 1 Squadron. The said unit departed from TAWI-TAWI at 1600 hours.
Reconnaissance against HOLLANDIA (Army aircraft):
Cruisers - three.
Destroyers - three.
Large transports - 19.
Medium transports - 25.
Two of the observation planes which left SAIPAN in the morning has not returned. (Reconnaissance patrol strengthened.)
Formation of sub-chaser unit; commander is commander of 3 Destroyer Squadron.
--11--
Strength:
Destroyers - two.
Minesweeper - one.
Sub-chasers - three.
Aircraft - some.
Purpose: Attack enemy submarines in the Southern Philippine area.
Principal dispatches, etc:
Order of the Combined Fleet: Attack Groups 1 and 2 of the Base Force will prepare for decisive battle.
Remarks: Attack Group No 2, which was scheduled to be dispatched to the Halmahera area, returned to the Tinian area.
Date: 11 June.
Notes: Enemy task force attacked the MARIANAS at 0720 hours. Our patrol planes sighted enemy carrier planes approximately 300 sea miles east of GUAM.
At 1150 hours, our patrol planes sighted a large enemy unit including aircraft carriers 170 sea miles east of GUAM. At 1300 to 1500 hours, enemy aerial attack was carried out against SAIPAN, TINIAN, ROTA, and GUAM, simultaneously. They then temporarily retreated to the east.
1. A second ware totaling approximately 190 airplanes attacked SAIPAN.
Shot down - 40 (ground fire).
Damage - slight.
2. First ware attacking TINIAN totaled approximately 140 airplanes.
Second wave: No battle results; no damage.
3. A total of approximately 139 airplanes attacked GUAM. They were intercepted by eight fighters.
Shot down - seven.
Damaged and unaccounted for - four fighter aircraft.
This evening, an attack was carried out against the enemy task force with a portion of the forces in the MARIANAS.
--12--
Principal dispatches, etc:
Orders of the Combined Fleet: YAMAGUMO and NOWAKI will be assigned to the Kon Unit.
Remarks: YAMAGUMO and NOWAKI (Submarine 10) are escorting 1 Squadron.
Date: 12 June.
Notes: Enemy tank force attacked the Mariana Base again at approximately 0230 hours.
1. At 0420 to 0930 hours, a total of approximately 480 aircraft attacked SAIPAN in four waves.
Shot down - 25.
Airfield damaged beyond use.
2. At 0240 to 1713 hours, a total of approximately 700 aircraft attacked GUAM in nine waves.
Shot down - 32.
Airfield damaged beyond use.
3. 0730 to 1500 hours, a total of 175 aircraft attacked TINIAN in four waves.
Shot down - six.
Airfield could not be used until evening.
4. At 1000 hours, six aircraft attacked ROTA and several attacked PAGAN.
Attacks to be made against the enemy task force will be governed by the policies in Operation "A" and efforts will be made to determine enemy conditions. No definite attacks will be made against the enemy task force other than surprise attacks until the enemy's plan is definitely known.
At approximately 0300 hours, our contact planes confirmed the sinking of an enemy ship. (At the same time, our land-based attack planes reported completion of torpedo attacks.)
The convoy (escorting ships - seven; ships - 13), which departed from SAIPAN for YOKOHAMA, previous to the aerial attacks of the enemy task force, engaged in battle with enemy carrier aircraft for
--13--
approximately eight hours from 0930 hours in the vicinity 200 sea miles northwest of SAIPAN. Torpedo-boat OTORI and three ships were sunk. Several other ships are also feared to have been sunk.
BOKUYO Maru (B2726 tons) (TN "B" normally represents battleships, but these ships are listed as transports) was sunk while under repair at Port SAIPAN. KEIYO Maru (B6441 tons) was damaged and beached.
The 2 Destroyer Squadron of 1 Division reached BACHAN* at 0800 hours. The Kon Unit (Organised around 1 Division, consisted of two battleships, five cruisers, eight destroyers, and approximately other ships) is anchored and making preparations at BACHAN*.
The Enemy Situation on 12 June:
A. From reconnaissance on the morning of the 12th and from documents taken from enemy air crews shot down over SAIPAN, enemy strength is estimated as follows:
Group 1: Organised around two large aircraft carriers, one small aircraft carrier, and one battleship.
Location: Ninety sea miles east of SAIPAN at 0550 hours.
Group 2: Organised around two aircraft carriers. Location: Ninety sea miles northeast of SAIPAN at 0500 hours.
Group 3: Organised around five aircraft carriers. Location: Unknown at 0640 hours.
Group 4: Organised around two large aircraft carriers, two small aircraft carriers, and three battleships. Location: Ninety sea miles southeast of SAIPAN at 1230 hours.
Reconnaissance is continuing to ascertain the presence of an invasion unit. A supply force appears to be on the move east of SAIPAN.
B. Appearance of enemy submarines in conjunction with the movement of their task force has decreased somewhat, but it appears that they are concentrating in the MARIANAS, CAROLINES, and the South Philippine Island area for concentrated attack upon our shipping. Date: 13 June.
--14--
One hundred to 200 carrier-borne aircraft attacked SAIPAN, TINIAN, and GUAM in waves between 0430 and 0500 hours, followed by strafing attacks by several aircraft throughout the day.
The enemy bombarded TINIAN and GUAM and moderately throughout the day with three aircraft carriers, eight battleships, two cruisers, and 22 destroyers. Targets of the shelling were the coastal positions gun emplacements, roads, and jetties. We are on the lookout for enemy landings.
The main force of our Task force left Tawi-Tawi anchorage. Two fighter planes left RABAUL to reconnoiter the ADMIRALTY Islands, but were forced to return by bad weather.
Combined fleet Order:
A. Prepare for Operation "A*".
B. Temporarily suspend Operation KON.
C. Transfer 1 and 5 Squadrons, 2 Destroyer Squadron, 10 and 4 Destroyer Divisions back to the Task Force.
Combined Fleet Order:
A. Task Force 2 and 3 and other units of the Base Force, which were deployed as reinforcements in the HALMAHERA area, were dispatched to the West Caroline area.
B. The remaining forces of the 23 Carrier Division will be transferred to the Southwest Area force and the Southwest Area force will continue operations in the New Guinea area.
Enemy Situation on 13 June.
A. A reconnaissance plane, which reconnoitered the area north of TRUK, spotted four units in which two to three aircraft carriers were included, 400 sea miles north of TRUK between 0630 and 0930 hours.
B. A reconnaissance plane, which reconnoitered the Mariana area from IWO JIMA, spotted a unit, in which two aircraft carriers and two battleships were included, moving north at a point 170 sea miles north of GUAM at 1530 hours.
C. Our patrol plane spotted a unit comprised of one aircraft carrier and 10 other vessels at a point 70 sea miles east of GUAM.
--15--
Date: 14 June.
The enemy fleet continues to operate near the MARIANA Islands.
A. The following naval craft cruised in the area designated at about 0500 hours, and bombarded SAIPAN and TINIAN, respectively:
Three battleships and 18 destroyers in the Saipan area.
Two aircraft carriers, three battleships, and five destroyers in the area east of TINIAN.
Two battleships and five destroyers in the area vest of TINIAN.
Later, eight or nine battleships, five or six cruisers, and a considerable number of destroyers cruised near SAIPAN and bombarded the east, west, and south coast of SAIPAN, as well as taking soundings and minesweeping vest of SAIPAN. TINIAN was later bombarded by two cruisers and two destroyers.
B. Attack by enemy carrier-borne aircraft: fifty attacked TINIAN; 180 in 16 waves (throughout the day) attacked GUAM; and a few attacked ROTA.
C. About 0900 hours, eight battleships, eight aircraft carriers, 14 cruisers, and a considerable number of other craft operated within sight of ROTA.
The patrol plane, which left TRUK, spotted a unit moving west at 352° and 350 sea miles from TRUK. It was composed of six aircraft carriers (of which two had islands), five battleships and cruisers, four destroyers, three tankers, and three transports (believed to be a supply convoy).
Reconnaissance of ADMIRALTY Islands: Two fighters dispatched from RABAUL spotted two cruisers and two destroyers leaving the harbor, and four large and four medium aircraft carriers, 10 battleships, and 80 transports at anchor. The main force of our Task Force arrived at GIMARASU* Anchorage.
Date: 15 June.
Formation for decisive battle by all units of Operation "A*" can be completed by the 19th at the latest.
The enemy has started landing at SAIPAN.
--16--
TINIAN is bombarded occasionally by surface craft at night.
The enemy carried out sorties with 80 airplanes in 15 waves (0515 -1645 hours).
About 80 enemy carrier-borne aircraft raided CHICHI SHIMA. (Lasted an hour, starting from 1410 hours.)
About 60 enemy carrier-borne aircraft raided IWO JIMA in two waves. Interception was made with 37 fighters. Considerable damage was inflicted on the enemy, but 28 of our aircraft did not return.
Combined Fleet Order: Move out for Operation "A".
Combined fleet Order of the Day: The destiny of our Empire lies in the outcome of this battle. Each member will fight to the end. Imperial Headquarters Naval Section Directive No ______: Move out for Operation "A".
A patrol plane from TRUK spotted a unit composed of three aircraft carriers and several other vessels at 335° and 4000 sea miles from TRUK at 0720 hours.
Towards evening, 11 fighters from TRUK attacked enemy surface waits east of SAIPAN. Direct hits were made with torpedoes on one battleship and one cruiser. Direct hits were made with torpedoes on two transports.
Main force of our Task force mowed out of GIMARASU*.
SHIRATSUYU, which was guarding the 1 Supply Unit of the Task Force, rammed the tanker SEIYO MARU and sank.
Plans of the Combined Fleet:
Using for the most part bases at IWO JIMA, MARCUS Island, TRUK, MEREYON*, TAP, and PAPUA and bases at MARIANA when the situation permits, the land-based air force will attack the enemy and await the arrival of the Task Force. At the opportune moment, 7 Air Attack Force, less forces dispersed in HOKKAIDO and the KURILE Islands, and the Yokosuka Air Expeditionary force will throw their fall strength with the task force and the land-based air force against the invading enemy task force. The 18th is the tentative date set for the decisive battle.
--17--
Enemy Situation Near SAIPAN on 15 June.
a. Between 0430 and 0500 hours, 28 large and 40 special transports plus a battleship and 50-60 other surface craft approached the west coast of SAIPAN. At 0520 hours, about 70 large and 100 small landing craft were lowered. About 0650 hours, the landing craft divided into two groups and made an attempt to land on the west coast of SAIPAN and TINIAN. Intense shelling by our coastal guns forced them to withdraw temporarily.
B. At 0900 hours, the enemy made another attempt to land at Saipan Harbor. Part of the unit landed, but the greater part kept circling offshore. After heated engagements along the shore following the initial landings, the enemy landed at Point SUSUBE*. About 1200 hours, the enemy succeeded in capturing positions north and east of OREAI* Airfield and established positions with tanks. Army units and the Yokosuka 1 Suicide Unit counterattacked without success.
C. A complete picture of the enemy task force (those which were detected): About two groups are in the Saipan area, one group in the Bonin area, one or two groups 450 sea miles north of TRUK, and two other groups, consisting of troopship convoys and converted aircraft carriers are in the same area. One troopship convoy is near SAIPAN under strong surface craft protection.
Date: 16 June.
The enemy tank force continues to attack various points in the MARIANAS.
A. After 0500 hours, about 200 carrier-borne aircraft attacked GUAM. Starting at 0715 hears, GUAM was bombarded for two hours by three aircraft carriers, three battleships, 12 cruisers, and 12 destroyers. At 1100 hours, one Iowa Class battleship was sunk 25 (TN Presumably sea miles) from GUAM. (Believed due to our submarine action).
B. About 50 enemy (TN presumably aircraft) raided TINIAN, and the airfield was put out of action until 1800 hours.
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c. About 100 enemy aircraft raided IWO JIMA and 11 enemy aircraft were shot down. Our casualty consisted of 11 dead.
D. Several large enemy aircraft raided YAP.
Reconnaissance of ADMIRALTY Island: Enemy task force and others which were seen on the 14th could not as spotted. Seven ships, probably battleships, eight large transports or cruisers, and five destroyers were seen.
At 0200 hours, twenty-odd B-29's raided northern KYUSHU from CHINA.
Enemy Situation near SAIPAN on 16 June.
A. Twenty enemy aircraft flew over SAIPAN and carried out continuous bombing and strafing. About 200 landing craft are situated west of Saipan Harbor. Ships were coming and going continually.
B. Enemy naval craft and troopship convoy as seen from TINIAN: Three battleships, five cruisers, twenty-odd destroyers, and 14 transports were seen, and most of them were located west of SAIPAN. A task force built around two aircraft carriers and 10 transports was spotted east of TINIAN.
c. A patrol plane from TRUK spotted two task forces organized around two aircraft carriers about 330 sea miles north of TRUK between 0600 and 0830 hours, and another group consisting of two aircraft carriers, two battleships or cruisers, and 12 destroyers heading southeast at 200° and 350 sea miles from TRUK at 0538 hours. (Leaving an oil trail for 80 sea miles.)
Reply to the Emperor from the Commander of the Combined Fleet: "Your humble subject is filled with awe upon receiving word from Your Majesty through Your Majesty's Chief of Staff. All members of the Fleet and Army Units under my command, in obedience to Your Majesty's Command, will fight and achieve victory by the Grace of God. Our garrison in the Saipan area intends to annihilate the enemy, and the task forces intend to annihilate the enemy task force at an opportune time when the enemy is occupied with the landings of SAIPAN. Thus,
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the wishes of Your Imperial Majesty shall be fulfilled." (16 June 44.)
Date: 17 June.
Our striking force replenished supplies and departed to arrive vest of SAIPAN at dawn of the 19th. There are many enemy submarines transmitting messages in the area of the task force which arrived in the mornings. Therefore, care must be exercised against enemy flying boats.
Our submarine waits are slowly concentrating in the Mariana area. It is possible that about 20 submarines will be assembled by the 20th.
Attack on enemy task force: One night fighter and five attack planes, which left TRUK at 1650 hours, attacked a convoy which included 20 transports at 330° and 400 sea miles from TRUK and sank 13 transports and left one destroyer listing heavily. Thirty-one fighters, 17 bombers, and two land bombers, which left the Yap area, attacked an enemy task force 30 sea miles east of TINIAN and destroyed two or three aircraft carriers and left a destroyer or a transport burning (1930 hours).
Intelligence on enemy task forces:
A. Saipan and Tinian Area:
Four or five converted aircraft carriers.
Four or five battleships.
Four to six cruisers.
About 30 destroyers.
About 60 transports.
B. Area north of ROTA:
Six aircraft carriers.
Eight battleships.
Eighteen cruisers or destroyers.
Saipan airfield No 1 fell into enemy hands and four or five enemy flying boats landed at SAIPAN about 1400 hours. (Attack by part of the bombers which leaded at GUAM is expected.)
The enemy raided GUAM with hundred-odd airplanes throughout
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the day, and the airfield it temporarily out of commission.
About 38 (TN Presumably aircraft) raided 20 BANKA* on ROTA. Damages were slight.
There is no change in the situation at TINIAN, and a battle is raging at SAIPAN.
Date: 18 June.
Attack by land-based air attack unit: A total of 57 aircraft (49 fighters, six land reconnaissance, one reconnaissance, and one bomber), which were concentrating in the Palau and Yap areas, took off to attack a enemy task force southeast of SAIPAN at 1230 hours.
Enemy Occupation force was sighted and attacked at 1500 and 40 sea miles from SAIPAN at 1545 hours.
Damage caused by fighters and bombers which returned to GUAM before 1800 hours were:
One transport suffered direct bomb hit and was listing.
Two transports were hit and white smoke was billowing.
Four enemy fighters and one bomber were shot down.
Reconnaissance of ADMIRALTY by one fighter at 0500 hours:
Four aircraft carriers (size unknown), six henry cruisers, one battleship, 10 destroyers, and about 30 transports were spotted at anchor, and two destroyers were seen entering the harbor.
Reconnaissance of NEW GUINEA and Humboldt Bay:
Nine cruisers or destroyers, 69 large and medium transports, and four small transports were seen at anchor.
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Usable Airfields in Mariana Area on 18 June.
Location |
Airfield |
Types of Aircraft to be Accommodated |
TINIAN |
No 2 Airfield |
Bombers, observation pianos, reconnaissance planes, land reconnaissance planes. |
No 3 Airfield |
Fighters, night fighters. | |
GUAM |
No 1 Airfield |
Fighters, observation planes, night fighters. |
No 2 Airfield |
Observation planes, fighters, reconnaissance planes, land reconnaissance planes. | |
ROTA |
ROTA Airfield |
Fighters. |
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Enemy Situation in the Central Pacific Area on 18 June.
A. Saipan, Tinian, and Guam Areas:
Seven battleships.
Four to six converted aircraft carriers.
Five cruisers.
Twenty-odd destroyers.
Eleven transports.
B. Area southeast of SAIPAN: A unit organised around four aircraft carriers at 110° and 110 sea miles from SAIPAN (numerous converted aircraft carriers) was sighted. A unit organized around four transports was sighted at 155° and 40 sea miles from SAIPAN.
C. Area west of SAIPAN: A unit organized around six aircraft carriers (two regular aircraft carriers, two escort aircraft carriers (TN AE) (size unknown), and two aircraft carriers (size unknown)) was sighted at 256° and 240 sea miles from SAIPAN. The possibility of C being the main force of the enemy task force is great, and security has been strengthened.
Date: 19 June.
Our task force attacked the enemy task force.
Three fighters from GUAM attacked two converted aircraft carriers east of SAIPAN scoring direct hits on each of the carriers. RO 115 (TN submarine) attacked a Wasp-type aircraft carrier northwest of ROTA. The results are unknown.
Aside from those engaged in battle with our task force, there are 11 or 12 converted aircraft carriers, 11 battleships or cruisers, and numerous other vessels in the Mariana area which are divided into three or four groups. They are giving direct support to landings at SAIPAN and guarding and neutralising our airfields on TINIAN, ROTA, and GUAM Islands.
Combined Fleet Order: All land-based air waits will concentrate as many aircraft as possible on GUAM on the 20th and support our task force in their attack on enemy task force.
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Report On Our Task Force's Attack on Enemy Task Force on 19 June.
A. The enemy task force, with which contact was lost at 0630 hours on the night of the 18th, was discovered at 260°, 150' from SAIPAN. The distance between our force and their force was 280 to 360 sea miles.
B. At approximately 0800 hours, the attacking units were dispatched for the initial attack.
Targets:
First group: force organized around four or five large aircraft carriers and four battleships at 280°, about 100 sea miles from GUAM.
Second group: Force organized around three large aircraft carriers, two seaplane tenders, and one battleship at 316°, about 160 sea miles from GUAM.
Third group: Force organized around three large aircraft carriers, six battleships, and nine cruisers at 230°, about 80 sea miles from GUAM.
The 3 Carrier Division attacked the first group, scoring bomb hits on one large battleship and one cruiser.
The 1 Attack Unit, 1 Carrier Division, attacked the first group with unknown results.
The 2 Attack Unit, 2 Carrier Division took off to attack the third group, but failed to sight the enemy. However, as they were about to land on GUAM, they encountered and engaged approximately 190 enemy airplanes, of which they shot down 31. More than half of our planes were lost. Seven Type-99 carrier bombers (dive bombers) and one Sui carrier bomber landed on GUAM. One dive bomber was unfit for further action. The 2 Attack Unit, 1 Carrier Division, also went out to attack the third group, but the enemy were not sighted.
C. During the above battle, after the 1 Attack Unit had taken off, the flagship of the task force, (TAIHO), was attacked with torpedoes from an enemy submarine at 0813 hours and sank at 1432 hours,
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about 230 sea miles to the north. The task force commander hoisted the flag on the HAGURO. The SHOKAKU also received a torpedo attack at 1430 hours and sank.
D. Due to these circumstances, it was planned to disengage ourselves temporarily from the enemy in the North during the evening and to continue the operations after evaluating the battle results and our remaining air power.
Date: 20 June.
A. Our task force is engaged with the enemy task force.
B. Enemy airplanes landed on SAIPAN and ASRIT. Desperate ground fighting is proceeding on SAIPAN.
C. Approximately 760 enemy airplanes came to raid SAIPAN and TINIAN.
D. Approximately 43 planes raided GUAM. We engaged them in fierce fighting with 20 carrier fighters. No damages were incurred.
Report on Battle Situation Between Our Task force and Enemy Task Force.
A. The enemy strength sighted on the morning of the 20th in the Mariana area was:
1. About 140 sea miles southeast of GUAM:
First group: One aircraft carrier, two battleships, and several cruisers.
2. About 130 sea miles east of SAIPAN:
Second group: five battleships, 10-15 carriers, four battleships, and a force whose main body consisted of 15 cruisers (type of cruisers vague).
3. Surrounding SAIPAN and TINIAN: five battleships, two cruisers, 32 destroyers, and 31 transports.
B. Our task force temporarily withdrew from battle to replenish supplies and to reorganize. They intended to resume attack on the Mariana area on the 22nd in coordination with base forces assembling in that area. At 1025 hours, our patrol plane discovered an enemy task force consisting of one aircraft carrier, two battleships, and several other ships, at 3° and 280 sea miles from YAP. Our patrol plane withdrew to the northwest.
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C. Our task force was attacked by enemy carrier-borne aircraft, resulting in the rapid sinking of the HITAKA and GENYO Maru and light damage to the HARUNA, MAYA, etc.
D. At 1735 hours, seven carrier attack planes and two carrier bombers were sent out with the intention of attacking the enemy task force, but they could not be found.
E. Since our task force had lost practically all of the carrier planes and since night fighting was impossible due to our inability to contact the enemy, we had to give up the attack on the enemy on the following day and night.
Comprehensive Situation Report of the Engagement Between Task Forces (By the task force commanders).
18th: Enemy task force sighted west of a chain of islands in the afternoon.
19th: Early in the morning, we commenced our attack, using our full strength against the enemy task force which consisted of three groups (10 aircraft carriers). In carrying out the attack, we did not pursue the enemy. Since the various units were scattered, it was planned to continue the attack on the 22nd, after first consolidating and replenishing the force.
20th: We formed in the vicinity of 15°00' N, 133°00' E. That evening, about 300 sea miles to the east, a group (two aircraft carriers, two battleships, and other ships) of the enemy task force was sighted. The task force, which became engaged in air combat, continued the dusk attack and dispatched an attack force. However, the torpedo-bomber unit failed to contact the enemy, and the various units withdrew to the northwest.
Comprehensive battle results:
1. Success: Over four aircraft carriers damaged or sunk. Over 100 aircraft shot down.
2. Losses:
The TAIHO and the SHOKAKU, on the 19th, and the HITAKA,
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on the 20th, were burned and sunk by one or two torpedoes from enemy submarines during air engagements. On the 20th, the HARUNA and the MAYA received slight damage.
3. Surviving carrier air power: 25 airplanes.
Date: 21 June.
A. Our task force is en route to Chujo Bay.
B. Patrol planes failed to sight the enemy task force today. Three of the patrol planes which went northeast from PALAU failed to return. At 1800 hours, a radio wave similar to the one used by the enemy task force was intercepted about 400 sea miles north of YAP.
C. Four carriers, four battleships, eight cruisers, 10 destroyers, and several transports were sighted near SAIPAN.
D. Sixty airplanes raided GUAM and 28 airplanes raided ROTA.
E. Our air fleet, on route to IWO JIMA, attacked enemy positions on SAIPAN with 12 long-range bombers.
Date: 22 June.
A. Enemy strength sighted today consisted of:
1. Task force organised around two aircraft carriers and one battleship at 30° and 540 sea miles from PALAU.
2. Ten battleships, 10 cruisers, 40 destroyers, 19, large transports, and 20 small transports around SAIPAN.
3. A large force including two aircraft carriers, about 250 sea miles west of SAIPAN.
B. It was planned to attack the enemy task force sighted at 30° and 340 sea miles from PALAU with seven long-range bombers (full strength) at PALAU. Most of them returned due to bad weather. A few attacked with uncertain results.
C. One carrier bomber (SUI), one carrier attack plane, and two long-range bombers from TRUK attacked an enemy convoy near SAIPAN with no effect. The carrier bomber and attack plane failed to return.
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One long-range bomber was heavily damaged, one moderately damaged.
Date: 23 June.
A. Our task force is anchored in Chujo Bay.
b. Strength of the enemy task force in the Mariana area:
1. Within a 50 sea mile radius of SAIPAN: Over four aircraft carriers, three battleships, 10 cruisers, 10-15 destroyers, and 30 transports.
2. At 0920 hours, at 70° and 60 sea miles from SAIPAN: A force, composed of four aircraft carriers, four destroyers, and seven transports, was seen; however, it is considered the same force as the above.
3. At 1055 hours, at 265° and 100 sea miles from SAIPAN: A force, composed of two battleships and one cruiser, was seen.
C. Ten carrier fighters from GUAM were used to attack four aircraft carriers, 50 sea miles east of SAIPAN. No hits were obtained, and two failed to return due to damage.
D. Approximately 90 airplanes, which came to raid GUAM, were engaged in fierce combat by 22 of our carrier fighters, fifteen were shot down (four of which are uncertain); five of our airplanes failed to return due to explosions. (TN Presumably in suicide attacks.)
B. There also were air raids on ROTA, PAGAN and SAIPAN.
Date: 24 June.
A. There were air raids on GUAM, ROTA, and SAIPAN.
B. Two long-range bombers from PALAU attacked the convoy west of SAIPAN at 2030 hours with unknown results.
C. Enemy task force came to attack IWO JIMA at 0710 hours.
1. The task force was discovered before the attack. The Yawata force (long-range bombers - 21, carrier fighters - 59, carrier attack planes - 27, carrier bombers - 9, shipborne reconnaissance plane - 4, total - 122) threw its fighters into fierce combat and routed the enemy airplanes. The carrier fighters intercepted 50 to 60 aircraft and shot down over 37. Twenty-four of our carrier
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