Japanese Monograph No. 174
OUTLINE OF NAVAL ARMAMENT PREPARATIONS FOR WAR
PART VI
DRAFT
PREPARED BY
MILITARY HISTORY SECTION
HEADQUARTERS, ARMY FORCES FAR EAST
DISTRIBUTED BY
OFFICE OF THE CHIEF OF MILITARY HISTORY
DEPARTMENT OF THE ARMY
HEADQUARTERS
FAR EAST COMMAND
MILITARY HISTORY SECTION, SPECIAL STAFF
JAPANESE RESEARCH DIVISION
Outline of Naval Armament and Preparations for War, Part VI
JAPANESE MONOGRAPH No 174
Through Instructions No. 126 to the Japanese Government, 12 October 1945, subjects Institution for War Records Investigation, steps were initiated to exploit military historical records and official reports of the Japanese War Ministry and Japanese General Staff. Upon dissolution of the War Ministry and the Japanese General Staff, and the transfer of their former functions to the Demobilisation Bureau, research and compilation continued and developed into a series of historical monographs.
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 G3 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.
Under the supervision of the Demobilisation Bureau, the basic material contained in this monograph was compiled and written in Japanese by former officers, on duty in command and staff units within major units during the period of operations. Translation was effected through the facilities of Military Intelligence Service Group, 02, Headquarters, Far East Command.
This Japanese Operational Monograph was rewritten in English by the Japanese Research Division, Military History Section, Headquarters, Army Forces Far East and is based on the translation of the Japanese original Editorial corrections were limited to those necessary for coherence and accuracy.
FOREWORD
This is the last of a series of six monographs in regard to Japan naval armament in preparation for and during the Pacific War.
Additional monographs covering Japan's naval armament plans are.
Mono No |
|
Outline of Naval Armament and Preparations for War, Part I |
145 |
Outline of Naval Armament and Preparations for War, Part II |
149 |
Outline of Naval Armament and Preparations for War, Part III |
160 |
Outline of Naval Armament and Preparations for War, Part IV |
169 |
Outline of Naval Armament and Preparations for War, Part V |
172 |
24 November 1952
TABLE OF CONTENTS
Page |
|
Contraction and Consolidation of Strategic Areas to be Defended at All Costs |
1 |
General Situation |
1 |
Increase in War Production |
2 |
Withdrawals to Shorten the Line of Defense and Concentration of Defensive Power on Inner Lines |
7 |
Preparations Based on Ail-Out Special Attack Tactics |
8 |
Details of Preparations for Special Attack Operations of the Naval Air Forces |
12 |
CHARTS
Chart No 1 |
Increase and Decrease in Bottoms During the Pacific War |
3 |
Chart No 2 |
Status of Aircraft for the "Ketsu-Go" Operation |
12 |
Chart No 3 |
Outline of the Special Attack Production Plan |
16 |
Chart No 4 |
Construction Schedule of Special Planes, 20 June 1945 |
16 |
Chart No 5 |
Actual Results and Estimate of Production of Special Planes, 15 July 1945 |
16 |
Chart No 6 |
Secret Bases |
18 |
Chart No 7 |
Status of Bases for Model 43 Oka |
18 |
Chart No 8 |
Condensed Report of the Results of Tests at Takeyama Base |
21 |
Chart No 9 |
Results of "Ko-Go" Tests at Kure Navy Yard |
21 |
Chart No 10 |
Results of Surface and Underwater Special Attack Weapons Preparation |
22 |
--i--
Page |
||
Chart No 11 |
Table of Organization of Special Attack Squadrons |
22 |
Chart No 12 |
Location of Special Attack Bases, 15 August 1945 |
22 |
APPENDICES
Appendix I |
Major Naval Arms and Weapons Produced from January 1944 to Cessation of Hostilities |
Appendix II |
Agreement between the Army and the Navy Concerning War Preparations for the First Half of Fiscal Year 1945 |
Appendix III |
Naval General Staff Secret Document No 31 |
--ii--
Contraction and Consolidation of Strategic Areas to be Defended at all Costs
General Situation
At the time the War Preparations Plan, Phase Three, was being deliberated, the situation in the Solomons-New Guinea area was rapidly deteriorating. The tremendous amount of equipment able to be produced by the United States as compared with that produced by Japan was having its effect. Taking into consideration her national resources and scientific technical capacity, Japan recognized that it would be impossible to hold her own-on her greatly extended fronts. It was, therefore, decided at a council meeting held in the presence of the Emperor on 30 September 1943, to contract and consolidate the strategic areas at all costs.
The main points decided by the Council, in the presence of the Emperor, were that, by the middle of 1944, strategic preparations would be completed to cope with the Anglo-American offensive; the areas to be held at all costs in the Pacific and Indian Oceans were the Kurile Islands, the Bonin, Mariana and Caroline Islands, western New Guinea, Sunda and Burma, and every effort was to be made to maintain sea communications with these areas.
In accordance with the above, transportation of war supplies to areas outside the areas specified at the conference, which had been conducted up to that time despite heavy losses of warships, transports, aircraft, munitions and men, was to be reduced to a minimum and the main ef-
--1--
fort was to be directed toward the strengthening of defense in the strategic areas to be defended at all costs.
This decision was made too late, however, and even the new line of defense was too extensive for Japan's national resources and military capabilities. The burden of immediate war preparations, therefore, was not eased, and, at the same time, the difficulties in transportation of war supplies mounted daily, caused by the increasing activities of enemy submarines and aircraft. This greatly delayed the bolstering of defenses in the various areas.
Increase in War Production
As stated in Monograph 172, the Navy had embarked upon the Revised Fifth Naval Armament Expansion Program. This called for the nation, as a whole, to muster its entire power in order to attain the production goal set forth by the "Joint Army-Navy Study in regard to the Material Mobilisation Plan for 1943." During the second half of 1943 and the first half of 1944, although production failed to reach the goal set forth in the Revised Fifth Plan, great advances were made, and production reached a peak unprecedented in Japan's history. Had the American invasion of the Marianas, Carolines and Philippines been delayed approximately six months, the implements of war produced by this greatly stepped-up productive effort would have had a marked effect on the war effort.
It is interesting to note that the upward trend in production, which was not affected by the loss of Saipan or Palau, took a sharp downward
--2--
plunge after the line of communications to the Southern Areas was severed following the Battle of Leyte and also after Japan proper was exposed to air raids.
The major arms and weapons required for naval operations which were produced from January 1944 to the end of the war are shown in Appendix I.
Although construction of merchant ships was also greatly accelerated by the drastic measures adopted by the Japanese Navy, ship losses, as a result of enemy action, greatly exceeded the construction tonnage, sharply reducing available merchant ships. This was felt to be one of the main reasons for Japan's defeat in the Pacific War.
Chart 1 shows the increase and decrease in bottoms during the Pacific War.
The intensification of war preparations at the front, which was conducted on the basis of the conference in the Imperial Presence on 30 September, was primarily aimed at training and replenishing the fleet and strengthening defensive power in key areas. However, the fleet training did not progress satisfactorily because the greater part of our air strength had to be diverted to the Solomons and New Guinea areas to fight battles of attrition aimed at slowing the enemy's advance. In early February 1944, the Marshall Islands were occupied by the enemy. This meant that our key areas were directly threatened by the enemy. On 17 February, Truk Island, the anchorage of the main force of our fleet, was subjected to a formidable air raid by an enemy task force. This forced the greater part of our surface units to retreat toward Palau,
--3--
Chart No 1
Increase and Decrease in Bottoms During the Pacific War (Quantities in thousands of gross tons)
Period |
Increase by Construction |
Decrease by Losses |
Decrease |
Total |
Percentage Available |
it the outbreak of the war |
6,384.0 |
100 |
|||
December 1941 |
44.2 |
51.6 |
7.4 |
6,376,6 |
99 |
December 1942 |
661.8 |
1,095.8 |
434.0 |
5,942.6 |
93 |
December 1943 |
1,067.1 |
2,065.7 |
998.6 |
4,944.0 |
77 |
December 1944 |
1,735.1 |
4,115.1 |
2,380.0 |
2,564.0 |
40 |
1945 (up to august) |
465.0 |
1,562.1 |
1,097.1 |
1,466.9 |
23 |
At the end of the war |
1,466.9 |
23 |
Remarks: The above table shows statistics on steel ships of over 100 tons.
--4--
Davao and Lingga areas. Under these circumstances, it was practically impossible to continue fleet training. Moreover, the activities of enemy aircraft and submarines made our sea communications more and more difficult and transportation of personnel, weapons and other supplies to the Fleet were seriously hampered.
The following is an outline of the measures taken for strengthening defenses in the key areas up to the time of the Leyte Operation, including the Battle of Saipan. This covers approximately one year, to the latter part of October 1944.
Air Defense Units: It was decided to activate 103 air defense units and to dispose them at strategic points on the periphery of the key area, and also at such locations inside the area as Formosa, Ryukyu and Bonin Islands. Upon arrival at their destination, such units were to become an organic part of local base forces or guard units.
The original plan called for Type A air defense units, to be equipped with six antiaircraft guns (12.7cm) and two searchlights, and Type B units, to be equipped with 24 25mm machine guns as their basic equipment. The shortage of antiaircraft guns, however, mads activation of Type A units practically impossible. Hence, most of the units that ware sent to the front were Type B and naturally their defensive power was not great. However, losses at sea were only three of the 103 units. Insofar as the number of units was concerned, the scheduled disposition was generally successful. It was also planned to reinforce the front with more antiaircraft guns and mounts as soon as such equipment became avail-
--4--
able. This plan, however, never materialized because of the drastic changes in the war situation.
Construction Units: Arrangements were made to activate 25 construction units and to dispatch them, according to the following schedule, to expedite completion of airfields and the strengthening of the defense setup in the areas concerned:
South Seas Area (Truk, Saipan, Guam and Palau): |
10 construction units |
(Two of these units were later reorganized and diverted to other areas following the sinking of their transports) |
|
Western New Guinea Area: |
4 units |
Ambon, Kai and Aroe Islands: |
5 units |
Philippines: |
3 units |
Andaman Islands: |
3 units |
Each unit was composed of from 700 to 1,000 personnel and was equipped with the necessary construction material, transportation equipment and light weapons. It was no easy matter to send these units forward, not only because of the large amount of transportation required but also because of the debarkation facilities necessary when they arrived at their destination.
As only very few special land combat units (guard units) were activated during this period, it was necessary to station Army troops on even small isolated islands, in accordance with the fundamental concept that the Army would constitute the main force in land combat. At the same time, steps were taken to coordinate the command system of the Army
--5--
and the Navy. Naval units were provided with as many land combat weapons as possible regardless of their assigned areas in order to strengthen the over-all defensive power.
Other major steps taken at this time were: activation and disposition of transport units to increase local transport capacities; strengthening of such organs as the construction and repair departments and air depots to raise construction and repair efficiency in each sector; dispatching of torpedo-adjustment squads as part of the measure to increase the efficiency of supply and maintenance; assignment of tactical guidance squads and technical guidance squads for the improvement of fighting power and techniques; installation of radar equipment at the front, and establishment of personnel recruitment sections in all area fleet headquarters, to which several hundred reserves were assigned.
Despite these efforts, the rapid decline of Japan's national power and industrial potential could not be halted. The main reasons for this were that the implementation of the decisions cams too late; the else of the defensive sphere was too great for Japan's national and war potential; United States forces were driving westward with overwhelming strength through the Mariana and New Guinea areas, making lightening advances, and Japan's surface supply lines were under increasing pressure. This was especially true after the middle of 1943, when communications between the Southern Region and Japan proper were seriously menaced through lack of air supremacy in the Mariana, Caroline and Philippine areas.
--6--
Efforts to strengthen Japan's defensive power merely resulted in a situation where in an effort to defend all points, none were strong. This was attributed to failure to appraise the situation correctly and to adopt a thorough priority system for the areas to be defended.
Withdrawals to Shorten the Line of Defense and Concentration of Defensive Power on Inner Lines
In February 1944, just as several defensive projects, based on the national policy as agreed at the Conference in September 1943, were being put into effect, United States forces, which had already occupied the Marshalls area, launched an all-out air attack against Truk. Next, during the latter part of March and early April, they launched large scale air attacks against the Palau area. Simultaneously, they occupied the northern coast of New Guinea and continued their advance. In the latter part of May they succeeded in seizing Biak Island. Subsequently, on 9 June, they launched operations to occupy Saipan.
The Navy, based on its estimate that the battle for the Marianas would constitute the decisive battle of the war between Japan and the Allies, carried out "A-GO" Operations, throwing almost the entire fleet into the fray. Despite desperate fighting, the battle situation became worse and the Japanese forces retreated after their air and surface forces had sustained critical losses. It was felt that prospects of victory were fast fading with the defeat of the forces in the Marianas area.
The tempo of advance of the United States forces increased steadily. They occupied Tinian Island in July and Peleliu and Morotai Islands by
the middle of September. In October, enemy task forces conducted air
7
raids on Formosa and the Ryukyus. On 20 October, the enemy launched a campaign to occupy the Leyte Gulf area. At this juncture, our fleet, although not fully recovered from the damage sustained in the "A-GO" Operations, and consequently unprepared for a decisive battle, launched a desperate assault upon the enemy with its entire forces. Because of the enemy's air supremacy, however, our fleet was dealt a near fatal blow in this engagement. This resulted in air and sea supremacy, which the Japanese forces had maintained for years in the Far East, being completely yielded to the enemy.
The Japanese Navy, under the circumstances, was confronted with the necessity of drastically shortening its defense lines. It was decided to limit the key area to the area extending from the Kuriles to Formosa, and, at the same time, to establish impregnable defenses on Japanese islands south of the Homeland as well as on Iwo Jima and the Ryukyus. The greatest defensive strength was to be concentrated on Iwo Jima and Okinawa. These emergency changes in policy were carried out within the required time limit because of the proximity of the involved areas to the Homeland, and, at the same time, steady progress was made in the fortification of the inner sectors.
Preparations Based on All-Out Special Attack Tactics The concept of special attack tactics (the tactic of resorting to one-way or suicidal missions for certain destruction of the target) was not entirely new in the history of the Japanese Army and Navy. The Port Arthur blockade in the Russo-Japanese War, the demolition mission of the
--8--
three demolition tube heroes (Nikudan-Sanyushi) in the Chine Incident and the midget submarines employed at Pearl Harbor, all possessed some features of special attack tactics. There are also many instances in the history of Japan in which men voluntarily acted in a manner similar to a special attack mission, but these acts were not specifically ordered by their superiors. The attacks carried out by the Kamikaze Special Attack Unit and the Type A Midget Submarine Unit (Cebu) during the operations in the Philippines area, during and after October 19143, were probably the first attack missions that were planned and ordered by competent commanders. The results achieved by these special attack units were unexpectedly good in comparison to the small force committed. However, it was felt that it was a great tragedy that Japanese field commanders were forced to resort to such tactics because of the rapidly deteriorating situation resulting from the enormous difference in fighting power between the Japanese and Allied forces.
These desperate attack tactics employed by field forces were inevitably reflected in the policies adopted by those concerned with war preparations. Urgent demands for the production of weapons suitable for these special attack tactics originated in the Naval General Staff and immediate response was given to the commands by the Navy Ministry. Inasmuch as the Japanese Navy had been studying weapons for this type of warfare for some time, naval authorities were fairly optimistic regarding the realisation of the project. The greatest difficulty was that the immediate need for such weapons allowed little time for trial manu-
--9--
facture, tests and research.
In October 1943, as a result of negotiations between the Navy Ministry and the Naval General Staff, the following agreement was reached:
The Oka type aircraft (Maru Dai), which had already been tested and approved for special attack purposes, would be used. The Kaiten (commonly known as human torpedoes) and the Shinyo (commonly known as crash boats), in addition to the Type A midget submarine which had already been produced, would be used for surface attacks. Trial manufacture and test runs were made where necessary, and activation of training units was begun.
By adopting latent plans, a variety of new weapons for special attack tactics was produced by the and of 1944. Mass production of such weapons as aircraft known as the "Shusui" and "Kikka", and surface and underwater weapons known as the "Koryu" and "Kairyu" were planned and initiated. In addition, numerous other latent designs were adopted and produced.
In February 1945, the outcome of the Philippines campaign had been decided and, by the end of the same month, the supposedly impregnable fortress of Iwo Jima had been lost after furious fighting. It became increasingly clear that the enemy was about to launch large scale air raids against the Japanese Homeland. Under the circumstances, as were forced to concentrate our war preparations on the production of aircraft and special attack weapons and the completion of defenses for the decisive battle for the Homeland. In view of this situation, the Japanese
--10--
Navy dispersed its production facilities while maintaining a maximum output, strengthened air defenses and, at the same time, initiated all-out war preparations based on special attack tactics.
All war preparations were executed in close cooperation with the Army and each service augmented the deficiencies of the other. This was clearly indicated in the agreement reached between the Army and Navy High Commands on 1 April 1945 (Appendix II).
In accordance with this agreement, on 6 April 1945, the Naval General Staff held a conference with the Navy Ministry in order to decide on the war preparations to be made during the first half of the fiscal year 1945. Details of this conference are given in Naval General Staff Secret Document No 31, 6 April 1945 (Appendix III).
The Navy Ministry completed all research work and reached full agreement with the War Ministry. Although some slight differences in estimates had to be adjusted, the Navy Ministry mapped out a plan of execution which was generally in line with the Naval General Staff's demand and devoted itself to its enforcement.
In the meantime not only did Iwo Jima fall in late February and the Okinawa Invasion Operation begin in early April, but the Homeland was also subjected to large scale day and night air attacks, which occurred almost continuously after the beginning of March. This resulted in heavy damage to personnel and equipment and gravely threatened communications with China and Korea. As a result, the nation's resources, war potential and productivity began to show a rapid decline.
--11--
Detailed plans were made to ready a total of 5,000 standard aircraft, including those newly built or repaired, to equip most of them with special attack equipment and, at the same time, to accelerate as much as possible mass production of special attack aircraft. As far as standard aircraft was concerned, we fell only slightly short of our goal. However, production of special type aircraft lagged considerably, especially the "Shusui", "Ki 115" and "Kikka" types. Although these latter were begun, they were not completed in time to contribute to the war effort.
The status of aircraft for the "Ketsu-Go" Operation, (Homeland Decisive Battle) as of 15 July 1945, was as shown on Chart 2.
Details of Preparations for Special Attack Operations of the Naval Air Forces
First Phase: Since operations on the Japanese mainland itself were considered inevitable as the next phase of operations at the time of the commencement of the Iwo Jima Operation in February 1945, a plan was formulated on 1 March to reorganize the entire naval air forces, primarily for the purpose of launching special attacks. On the same day, the Naval Combined Air Training Command was reorganized into the Tenth Air Fleet and incorporated into the Combined Fleet. Because of the acute shortage of aircraft, as well as fuel, at that time, priority was given to the training of special attack units and training of flight personnel, in general, had to be temporarily suspended. With preliminary training and preparations for converting training aircraft into special attack planes gener-
--12--
Chart 2
Status of aircraft for the "Ketsu-Go" Operation
No. of Aircraft |
3d Air Fleet |
5th air Fleet |
10th air Fleet |
Total |
||||
Type of Aircraft |
Allot |
Opnl |
Allot |
Opnl |
Allot |
Opnl |
Allot |
Opnl |
"Ko"-type Fighters |
312 |
200 |
242 |
141 |
119 |
75 |
673 |
416 |
"Otsu"-type Fighters (Interceptor) |
137 |
50 |
136 |
55 |
3 |
2 |
276 |
107 |
"Hei"-type Fighters (Night fighter) |
133 |
91 |
28 |
16 |
161 |
107 |
||
Bombers |
88 |
60 |
166 |
111 |
254 |
171 |
||
Carrier-bombers |
157 |
113 |
119 |
99 |
99 |
65 |
375 |
277 |
Carrier-based Attack Planes |
90 |
80 |
52 |
44 |
65 |
24 |
207 |
148 |
Land-based Bombers |
40 |
32 |
49 |
40 |
89 |
72 |
||
Land-based Attack Planes |
25 |
12 |
60 |
48 |
112 |
63 |
197 |
123 |
Land-based Recon Planes |
49 |
31 |
55 |
16 |
104 |
47 |
||
Seaplanes |
152 |
120 |
71 |
69 |
223 |
189 |
||
Intermediate Trainer |
478 |
275 |
1,106 |
978 |
659 |
445 |
2,243 |
1,698 |
"Shiragiku" Utility Trainer |
167 |
131 |
238 |
174 |
19 |
15 |
424 |
320 |
Total |
1,740 |
1,135 |
2,244 |
1,740 |
1,242 |
800 |
5,226 |
3,675 |
Abbreviations: Allot — Allotment Opnl — Operational
ally reaching completion in the middle of May, the 11th Air Flotilla, whose strength was approximately half that of the Tenth Air Fleet, and one-half of the 13th Air Flotilla resumed training.
The bombs to be loaded on the training aircraft which had been converted into special attack planes were as follows:
Type of Aircraft |
Bombs (kg) |
Number |
Type-93 Intermediate Trainer |
250 |
1 |
Type 2 Intermediate Trainer |
250 |
1 |
SHIRAGIKU Utility Trainer |
250 |
2 |
Type-94 Reconnaissance Seaplanes |
250 |
2 |
Type-95 Reconnaissance Seaplane |
250 |
1 |
Type Zero Reconnaissance Seaplane |
250 |
2 |
Type Zero Observation Plane |
250 |
1 |
Type Zero Training Fighter |
250 |
1 |
Type Zero Carrier Fighter |
250 or 500 |
1 1 |
Second Phase: The enemy landed on Okinawa in late March 1945 and as hostile attacks against the Japanese mainland became imminent with the unfavorable conclusion of operations in this area in late June, a speedy completion of preparations for the decisive battle on the mainland became imperative. It was estimated at that time that the enemy invasion of the mainland, anticipated about September at the earliest, would be directed against the southwestern part of Japan proper and that the first wave of the enemy invasion forces would comprise approximately 10 divisions carried by 1,000 transports. It was also estimated that if army and naval
--13--
air forces could succeed in sinking half of the transports within the first ten days of the landing, the enemy's attempt could be smashed. On the basis of the above estimate, the Navy undertook to construct approximately 5,000 standard aircraft by the middle of August.
Furthermore, with a view to compensating for losses and preparing for the second and succeeding assaults of the enemy, the need for special aircraft, taking into consideration such factors as aircraft, fuel and flight personnel, became absolutely imperative. The number of standard aircraft to be built was estimated at 5,000 on the basis of the following figures.
Number of enemy vessels to be sunk: |
500 |
Estimated ratio of hits by suicide planes (based on battle experience gained at Okinawa) |
|
Against the carrier striking forces |
1/9 |
Against troops transports: |
1/6 |
Number of aircraft required against troop transports: |
3,000 |
In addition to the above, taking into consideration the condition of our aircraft at that time, approximately 350 planes were to be assigned to attacks against the carrier striking force and, taking their actual operating capacity and losses prior to the operation into consideration, the number of aircraft required was estimated at 5,000.
In carrying out the decisive battle on the mainland, the naval air forces planned to thwart the maneuverings of the enemy's carrier striking force with one element and attack the troop transport with their main
--14--
Matters to which special attention was given for the maximum utilization of the entire naval air strength, as mentioned above, were as follows: speedy preparation of standard aircraft; speedy preparation of special aircraft; construction and strengthening of air bases, and measures for increasing the efficiency of the special attack planes.
a. Speedy preparation of standard aircraft:
(1) Measures taken to secure aircraft productions The growing intensity of enemy air attacks, as well as the confused state of production and transportation, seriously hampered production of new aircraft. Especially, because of heavy damage to engine plants, production of engines did not keep pace with production of fuselages. Therefore, every effort was made to secure the production of new aircraft by equipping newly-built fuselages with repaired engines.
(2) Acceleration of aircraft repairs: Among the aircraft requiring repairs at that time, the work on approximately 700 planes was expected to be completed by the middle of August. To facilitate maintenance of these aircraft, repair teams, organized by mobilising all technicians of the Air Technician Depot, the Yokosuka Naval Air Group and the research organs of each construction and repair unit, were dispatched to the bases.
(3) Equipping standard aircraft with special attack weapons: All aircraft, except training seaplanes, were equipped with special attack weapons.
--15--
b. Speedy preparations of special aircraft: To supplement the shortage of standard aircraft, construction of special aircraft was required. From the viewpoint of battle preparations, these special attack aircraft, which had originally been designed for special attack purposes, had many advantages compared with the standard aircraft.
Because of the decrease in production and repair capacities due to enemy sir raids and the lack of training for flight personnel, and because of the shortage of aviation fuel, standard aircraft could not meet even half the operations requirements either in quality or quantity. Therefore, special aircraft were required to satisfy the following general conditions: A high ratio of hits (by the adoption of special attack methods): maximum effectiveness: economy of materials; simplicity of operation; simplified training (so that the planes could be operated by young flight personnel); economy of fuel, and high performance.
The plans for the production of special planes and the actual results achieved are shown on Charts 3, 4 and 5.
c. Maintenance and strengthening of air bases: Since the interceptor fighters and the antiaircraft defense capabilities on the ground were inadequate and as aviation fuel was running low, also there was a great strength disparity between friendly and hostile air forces, restrictions on the aggressive use of interceptor fighters were inevitable. Therefore, the adoption of an effective plan for ground defense against heavy air attacks and for the preservation of the necessary air strength until the decisive battle on the Homeland was imperative.
--16--
Chart 3-a
Outline of the Special Attack Production Plan
Kikka |
|||
Objective |
1 |
Acquisition of land attack planes suitable for attacks on enemy ships approaching within a short distance. To be mass production. |
|
Type |
2 |
Turbine-rocket twin-engined monoplane |
|
Principal Measurement (Meters) |
3 |
Smallest possible type. Measurement when wings are folded: Full width: 5.3 Full length: 9.5 Full height: 3.1 |
|
Engines to be Installed |
4 |
Two TR-12 Engines |
|
Crew |
5 |
One |
|
Capacity and Armament |
Maximum Speed (Knots) |
6 |
335 Close to sea level. 365 At an altitude of 6,000 meters |
Range |
7 |
200 miles close to sea level 300 miles at an altitude of 6,000 meters |
|
Climbing Power |
8 |
||
Landing Speed (Knots) |
9 |
80 |
|
Bomb Load (kg) |
10 |
500 |
|
Radio Equipment |
11 |
Model 3, Type-1 Radio-telephone set Receiver only |
|
Air Groups in Charge (Date of Activation) |
12 |
724th Air Group (1 July 1945) |
|
Remarks |
13 |
Undergoing experimental production and tests. About six months behind the scheduled date of completion and still incomplete. |
Chart 3-b
Outline of the Special Attack Production Plan
Oka |
||
Type 11 |
Type 22 |
|
1 |
Acquisition of special attack gliders that may be released from the Type-1 land attack plane |
Acquisition of special attack planes which may be released from "Ginga" and which are capable of .flying by their own power |
2 |
Powder-rocket midwing monoplane |
Rocket-engined midwing monoplane |
3 |
Pull width: 5.6 Pull length: 6.06 Full height: 1.16 |
Full width: 4.12 Full length: 6.88 Full height: 1.15 |
4 |
Three powder rockets |
One Tsu-11 Engine |
5 |
One |
|
6 |
||
7 |
20,000 meters when released at a speed of 250 knots at an altitude of 3,500 meters |
50 miles when released at sea level. 70 miles when released at a speed of 240 knots at an altitude of 4,000 meters |
8 |
||
9 |
||
10 |
1,200 |
600 |
11 |
||
12 |
721st Air Group (1 Oct 1944) |
722d Air Group (15 Feb 1945) |
13 |
Used in the Okinawa operation and proved to have excellent performance |
Experimental production was completed. Although good results were obtained there was no opportunity to use the plane in battle |
Chart 3-c
Outline of the Special Attack Production Plan
Oka |
Shusui |
|
Type 43 |
||
1 |
Acquisition of special attack planes which may be released from the "Renzan" or catapulted from the ground |
Acquisition of rocket-engined interceptor fighters with a great capacity |
2 |
Turbine-rocket midwing monoplane |
Rocket-engined tailless monoplane |
3 |
Full width: 9.0 Full length: 8.16 Full height: 1.15 |
Full width: 9.5 Full length: 5.85 Full height: 2.7 |
4 |
One NE-20 Engine |
One KR-10 Engine |
5 |
One |
|
6 |
10,000 meters |
|
7 |
5.5 minutes after climbing to an altitude of 10,000 m at a maximum speed of 432 knots |
|
8 |
Takes 3.5 minutes to climb to an altitude of 10,000 meters |
|
9 |
||
10 |
800 |
11 30mm machine guns |
11 |
Receiver only |
Receiver only |
12 |
725th Air Group (1 Jul 1945) |
312th Air Group (5 Feb 1945) |
13 |
Now undergoing experimental production and tests. For coastal defense purposes, this type of plane which may be catapulted from the ground, is under production in great numbers. |
Test flights were undertaken twice, but failed owing to defective engines, and the crew perished. Experimental production carried out jointly by the Army and Navy. |
Chart 3-d
Outline of the Special Attack Production Plan
Toka |
KI-115 |
Baika |
|
1 |
"KI-115" plane with "HA-33" engine |
Acquisition of special attack planes in which various types of engines such as the "Kotobuki", "Sakae", "Kinsei" and "Zuisei" nay be installed |
Acquisition of special attack gliders designed to attack small landing craft approaching within a short distance |
2 |
Single-engined low-wing monoplane |
Single-engined low-wing monoplane |
Rocket-engined low-wing monoplane |
3 |
Full width: 6.72 Full length: 8.50 Full height: 3.10 |
||
4 |
One HA-33 Engine |
Rocket engine built fa experimental purposes |
|
5 |
One |
One |
One |
6 |
280 . . . At an altitude of 4,200 m |
250 |
|
7 |
Approximately 600 miles |
150 miles |
|
8 |
|||
9 |
|||
10 |
500 |
500 |
250 |
11 |
Receiver only |
Receiver only |
|
12 |
|||
13 |
Row undergoing experimental production and tests. Converted Army planes |
Now undergoing experimental production and tests. Same type as the Army plane built for experimental purposes. |
War ended while the demand for experimental production was under discussion |
Chart 4
Construction Schedule of Special Planes
(20 June 1945, First Section, General affairs Bureau, Aeronautical Department)
May |
Jun |
Jul |
Aug |
Sept |
Oct |
Nov |
Dec |
|
Oka (Model 22) |
6 |
49 |
30 |
50 |
60 |
60 |
60 |
|
Oka (Model 43) |
2 |
10 |
22 |
38 |
65 |
80 |
||
Kikka (By Aeronautical Department) |
Experimental |
12 |
||||||
Manufacture |
13 |
125 |
||||||
Final |
11 |
|||||||
Kikka (By Naval Technical Department) |
10 |
40 |
||||||
Shusui |
35 |
90 |
145 |
225 |
||||
Ki 115 |
10 |
150 |
320 |
400 |
Chart 5
Actual Results and Estimate of Production of Special Planes
(15 July 1945, Second Section, General Affairs Bureau, Aeronautical Department)
Type |
Name of Manufacturer |
Apr |
May |
Jun |
Jul |
Aug |
Sept |
Shusui |
Mitsubishi Co |
4 |
5 |
14 |
35 |
||
Japan Aircraft Co |
1 |
7 |
22 |
50 |
|||
Fuji Co |
1 |
3 |
|||||
Kikka |
First Depot |
1 |
10 |
30 |
45 |
||
First Air Depot |
(2 Tng) |
5 - (3 Tng) |
|||||
Kyushu Aircraft Co |
5 |
15 |
|||||
Naval Technical Depot |
|||||||
Oka (Model 22) |
First Technical Depot |
||||||
Aichi Co |
5 |
20 |
40 |
||||
Oka (Model A3) |
First Technical Depot |
8 |
12 |
||||
12th Air Depot |
|||||||
Aichi Co |
|||||||
Ki 115 |
Naval Technical Dept |
40 |
|||||
Showa Co |
10 |
Abbreviation: Tng — Training Plane
On the other hand, in order to effect maximum utilization of the counterattacking capabilities of our aircraft within the shortest possible time (in approximately 10 days) against an enemy invasion of the Homeland, training planes of poor maneuverability and special planes had to be assigned in advance to areas near the anticipated invasion point. Since special installations were necessary for these special planes, because of their characteristics, the bases then in use were inadequate. Accordingly, maintenance of the bases was carried out in the following phases.
Strengthening of established bases: To strengthen the 70 established land plane bases and the 24, seaplane bases in the Homeland, construction and maintenance of taxi strips, plane dispersal shelters, covered revetments and tunnels and the speedy establishment of underground as well as dispersed installations for quarters, communications and construction apparatus were undertaken with the time of completion set for the middle of August. The location of the established bases at that time was as follows:
Location |
Land-plane Bases |
Seaplane Bases |
Total |
Hokkaido |
6 |
1 |
7 |
Ou District |
6 |
2 |
8 |
Kanto District |
11 |
4 |
15 |
Chubu District |
9 |
2 |
11 |
Kinki District |
4 |
3 |
7 |
Chugoku District |
3 |
2 |
5 |
--17--
Shikoku District |
2 |
7 |
|
Kyushu District |
19 |
7 |
26 |
Korea |
7 |
1 |
8 |
Total |
70 |
24 |
94 |
Maintenance of secret basest Construction of secret bases (called pasture ground) throughout the country for dispersal and readiness, or for attack bases, of the special attack units, which consisted primarily of training land planes, and maintenance of the western and eastern parts of the mainland by the target dates of 15 August and the end of September respectively, were planned and carried out. In view of the nature of the above bases, attention was paid to camouflage from the time of construction. They were maintained by taking special precautionary measures, such as leaving houses and trees in the secret bases intact until the air units advanced to the bases. The location of the secret bases known as pasture ground was as shown on Chart 6. Chart 7 gives the location of bases prepared for Model 43 Oka special planes in accordance with Yokosuka Naval District Top Secret Order No 496, in May 1945.
In addition, the Osaka Guard District planned to establish six catapults and prepare 25 sheds of Oka bombs in the vicinity of Tanabe.
d. Measures to increase the effectiveness of the special attack planes: Special attack planes were used for the first time in the Philippines in 25 October 1944. They produced not only psychological effects, but also actually inflicted heavy damage on the enemy. This
method of attack was made possible by the imbued patriotism of all com-
--18--
Chart 6-a
Chart Showing Secret Bases (Called Pasture-Ground)
District |
Name |
Runway |
Prefecture, County, Village |
Remarks |
Yokosuka |
Yodanhara |
50 x 1,200; extension made to the east & west |
Miyagi Ken, Kurihara Gun, Fujisato Mura |
Generally completed at the end of August |
Babadaira |
60 x 800; SN |
Fukushima Ken, Adachi Gun, Oyama Mura |
Generally completed |
|
Miyota |
60 x 800 |
Fukushima Ken, Tamura Gun, Moriyama Machi |
Generally completed at the end of July |
|
Asakawa |
70 x 500; EW 30 x 600; SN |
The Suigun Line (Iwagi Asakawa) |
Generally completed |
|
Ebigashima |
60 x 800 |
Ibaragi Ken, Makabe Gun, Omura |
Generally completed at the end of July |
|
Ohatake (Fujisawa) |
60 x 800 |
Ibaragi Ken, Niihari Gun, Fujisawa Mura |
Generally completed |
|
Katsuragi |
60 x 800 |
Ibaragi Ken, Tsukuba Gun, Katsuragi Mura |
Generally completed |
|
Okabe |
60 x 800 |
Ibaragi Ken, Inashiki Gun, Okada Mura |
Generally completed at the end of August |
|
Negata (2d Kisarazu) |
50 x 600 |
Chiba Ken, Kimitsu Gun, Negata Mura |
Generally completed at the end of August. (Hitachi Aircraft Co (Hitachi Sha)) |
|
Oyana (2d Atsugi) |
100 x 1,800 NNW |
Kanagawa Ken, Koza Gun, Ayase |
Same as above |
|
Iwamurada |
50 x 600; NNW |
Nagano Ken, Minami-saku Gun, Iwamurata Machi |
Generally completed at the end of August |
Chart 6-b
Chart Showing Secret Bases (Called Pasture-Ground)
(Cont'd)
District |
Name |
Runway |
Prefecture, County, Village |
Remarks |
Yokosuka |
Yoshioka (2d Oi) |
60 x 900; NNW |
Shizuoka Ken, Oi, Wadaoka Machi |
Generally completed |
Bazu |
50 x 600; extension made |
Aichi Ken, Nukada Gun, Miai Mura (TN Presumably Kawai Mura) |
Generally completed |
|
Iwatsu |
Aichi Ken, Nukada Gun, Iwatsu Mura |
Generally completed at the end of July. (Nakajima Aircraft Co (Nakajima Sha)) |
||
Takanoo (3d Susuka) |
60 x 1,200; NW |
Mie Ken, Kawage Gun, Takano Mura (TN Presumably Takanoo Mura) |
Same as above |
|
Meizuru |
Takegata (TN Presumably Masugata) |
60 x 800 |
Yamagata Ken, Mogami Gun, Yamuki Mura |
Generally completed at the end of July |
Tamanohara (TN Presumably Tamano) |
60 x 800 |
Yamagata Ken, Kita-murayama Gun, Tamanohara Mura (TN Presumably Tamano Mura) |
Same as above |
|
Yonasawa |
60 x 800 |
Yamagata Ken, Nishi-Murayama Gun, Shigematsu Mura (TN Presumably Takamatsu Mura) |
Same as above |
|
Urushiyama |
300 x 1,000; SN |
Yamagata Ken, Higashi-Murayama |
Already established (Hitachi Aircraft Co (Hitachi Sha)) |
Chart 6-c
Chart Showing Secret Bases (Called Pasture-Ground)
(Cont'd)
District |
Hans |
Runway |
Prefecture, County, Village |
Remarks |
Maizuru |
Tazu |
50 x 700; extended to 1,200 |
Ishikawa Ken, Kashima Gun, Soma Mura |
Generally completed at the end of July. (Nakajima Aircraft Co (Nakajima Sha)) |
Atago (Fukui) |
50 x 700; extended to 1,200 |
Fukui Ken, Nibu Gun, Takano Mura (TN Presumably Yoshino Mura) |
Generally completed at the end of July (Aichi Aircraft Co (Aichi Sha)) |
|
Shiga |
60 x 1,000; NNE |
Shiga Ken, Shiga Gun, Shimo-sakamoto Mura |
Same as above |
|
Hikone |
30 x 600 (60 x 1,200) |
Shiga Ken, Inuyama Gun |
30 x 600 . . . completed at the end of July. 60 x 1,200 . . . completed at the end of August. (Mitsubishi Aircraft Co (Mitsubishi Sha)) |
|
Ayabe |
30 x 600; EW |
Kyoto Fu, Ikaruka Gun, Ikuda Mura |
Generally completed |
|
Oshinotsu |
30 x 600 |
Tottori Ken, Seihaku Gun, Oshinotsu Mura |
Same as above |
|
Naoe |
30 x 600; SW |
Shinano Ken, Hinokawa Gun, Naoe Mura |
Same as above |
|
Osaka |
Ichiba (2d Tokushima) |
100 x 1,200; EW |
Tokushima Ken, Awa Gun, Ichiba, Mura |
Generally completed (Kawanishi Aircraft Co (Kawanishi Sha)) |
(2d Yamato) |
Chart 6-d
Chart Showing Secret Bases (Called Pasture-Ground)
(Cont'd)
District |
Name |
Runway |
Prefecture, County, Village |
Remarks |
Kure |
Kuniyasu (Kabe) |
60 x 1,200; KE |
Hiroshima Ken, Takata Gun, Neno Mura |
Generally completed at the end of August |
Shimokawara |
30 x 600; NNE |
Hiroshima Ken, Saeki Gun, Sakagami Mura |
Same as above |
|
Shiroyama (Iwakuni) |
30 x 600; 2 runways, NE |
Yamaguchi Ken, Kuga Gun, Fujisawa Mura (TN Presumably Fujikawa Mura) |
Same as above |
|
Osaba |
30 x 600; NNW |
Yamaguchi Ken, Yoshiki Gun, Osaba Mura |
Same as above |
|
Akago |
30 x 600; NW |
Yamaguchi Ken, Mine Gun, Akago Mura |
Same as above |
|
Tano |
30 x 600; NW |
Shima Ken, Shuso Gun, Tano Mura |
Same as above |
|
Takenoshita |
30 x 600; EW |
Ehime Ken, Onsen Gun, Haishi Mura |
Same as above |
|
Kamimurashima |
30 x 600; EW |
Shima Ken, Kita Gun, Sugeta Mura |
Same as above |
|
Niida (2d Kochi) |
100 x 1,800; EW |
Kochi Ken, Kami Gun, (TN Presumably Takaoka Gun), Niida Mura |
Generally completed at the end of August |
|
Kubokawa (3d Kochi) |
60 x 1,200; SN |
Kochi Ken, Takaoka Gun, Kubokawa Machi |
Same as above |
|
Saikawa |
30 x 600; NE |
Fukuoka Ken, Miyako Gun, Saikawa Mura |
Same as above |
Chart 6-a
Chart Showing Secret Bases (Called Pasture-Ground)
(Cont'd)
District |
Name |
Runway |
Prefecture, County, Village |
Remarks |
Kure |
Nakatsu |
30 x 600; HW |
Oita Ken, Shimoge Gun, Tsurui Mura |
Same as above |
Kusaji |
30 x 600; EW |
Oita Ken, Nishi-Kunisaki Gun, Kusaji Mura |
Same as above |
|
Usuki |
30 x 600; NS |
Oita Ken, Kita-amabe Gun, Usuki Machi |
Same as above |
|
Totsugi |
80 x 1,500; NE |
Oita Ken, Oita Gun, Totsugi Mura |
Same as above |
|
2d Iwakuni |
50 x 520; NS |
Yamaguchi Ken, Kuga Gun, (TN Presumably Kumage Gun), Marifu Mure |
The northern part adjoins the airfield |
|
Sasebo |
Naokata |
30 x 600; NNW |
Fukuoka Kan, Onga Gun, Tonno Mura |
Emergency runway: generally completed on 15 July |
Tatara |
28 x 1,000; NS |
Fukuoka Ken, Chikushi Gun, Kasuga Mura |
Generally completed |
|
Ogi |
30 x 600; ENE |
Saga Ken, Ogi Gun, Ogi Mura |
Same as above |
|
Ainoura |
30 x 600; ESS |
Nagasaki Ken, Kita-matsuura Gun, Ainoura |
(Drill ground of marine corps) |
|
Kawatana |
30 x 600; EW |
Nagasaki Ken, (Higashi)-Sonoki Gun, Kawatana Cho |
Generally completed (Factory site) |
Chart 6-f
Chart Showing Secret Bases (Called Pasture-Ground)
(Cont'd)
District |
Name |
Runway |
Prefecture, Country, Village |
Remarks |
Sasebo |
Shimabara |
30 x 600; NNW |
Nagasaki Ken, (Shimabara Shi), Shimabara |
Generally completed |
Onsen |
30 x 390; ENE |
Nagasaki Ken, Minami-takaki Gun, Obama Machi |
Same as above |
|
Takematau (Shinomura) |
50 x 1,350; NNW |
Nagasaki Ken, Higashi-sonoki Gun, Takamatsu Cho |
50 x 950 Generally completed |
|
Makinohara |
60 x 900; NW |
Kagoshima Ken, Airs Gun, Shikine Mura |
Generally completed |
|
Nagao (Iwakawakaido) |
60 x 1,200; NE |
Kagoshima Ken, Kimotsuki Gun, Kasanohara Mura |
Generally completed |
|
Yokosuka |
Kantatsu |
30x600 |
Ibaragi Ken, Niihari Gun, Ishida Mura |
Already established. Runway of the Tsuchiura Air Group |
Chart 7
Preparation of Bases for Special Planes Bases for Model 43 Oka
(Yokosuka Naval District Top Secret Operational Order No 496, 20 May 1945)
Name of Base |
Catapults |
Completion Date |
Sheds of Oka Bombs |
Completion Date |
Izu Peninsula |
8 |
Middle of August |
5 |
Middle of August |
20 |
Middle of September |
|||
20 |
Middle of October |
|||
Southern Boso Peninsula |
6 |
Middle of August |
Same as above |
Same as above |
Eastern Boso Peninsula |
6 |
Middle of August |
Same as above |
Same as above |
Vicinity of Tsukuba |
6 |
Middle of September |
5 |
Middle of September |
20 |
Middle of October |
|||
20 |
Middle of November |
|||
Miura Peninsula |
3 |
Middle of July |
5 |
Middle of July |
10 |
Middle of November |
|||
Vicinity of Oi |
6 |
Middle of October |
5 |
Middle of September |
20 |
Middle of October |
|||
Vicinity of Toba |
6 |
Middle of October |
Same as above |
Same as above |
bat men from commanders down to crewmen. Therefore, the High Command exerted efforts to produce as highly effective special attack planes as possible. The following are the orders and results concerning experiments and research on special attack planes:
Front Chief, First Bureau, Naval General Staff, Imperial General Headquarters
To: Chief, Navy affairs Bureau, Navy Ministry
Chief, General Affairs Bureau, Navy Aeronautical Department
Chief, General Affairs Bureau, Navy Technical Department
Request Concerning an Increase in the Effectiveness of Special Attack Planes
In view of the great difference in air strength between the enemy and ourselves and the degree of training of Navy airmen, greater importance should be attached to special attack planes. Judging from past combat experiences and statements of prisoners of war, it is impossible to inflict a fatal blow on large enemy vessels, because the equipment and methods used by the present special attack planes are inadequate for complete penetration. Therefore, it is requested that the following matters be immediately studied in order to increase their effectiveness. 1. It is requested that a test be conducted immediately in order to deliver successful bomb hits below the waterline of enemy vessels by special attacks:
20 May 1915
a. Stern attack
--19--
(Even if the bomb does not hit and explode at the ship's bottom, there is a strong probability that it will reduce mobility by hitting the armorless stem near the water line.)
b. Side attack
2. Method of increasing the approach speed of special attack planes: It is requested that the wings of the special attack planes be removed during the dive in order to achieve a sudden increase in speed and to minimize damage by enemy interception and defensive fire. Furthermore, this will increase the effect of the hits by increasing the approach speed. It is requested that this procedure be applied to the Ki-115 and that measures be taken immediately for their mass production.
3. It is requested that tests of V-head bombs be completed immediately and that they be supplied to the operational forces.
4. Testing of explosive charges to increase bursting effect: It is requested that methods of producing a more powerful bursting effect, to be employed by the special attack plane by loading it with liquid oxygen, hydrogen peroxide or yellow phosphorous, be studied and tested.
5. It is suggested as a method of using these new charges as substitutes for bombs, that the obsolete torpedo air chamber (re-
--20--
move rear part, including the torpedo engine room) be used by filling it with hydrogen peroxide, et cetera.
As requested, tests of explosive charges were held at Takeyama and Kure. The results of these tests are shown on Charts 8 and 9.
A request for testing the effectiveness of special attack planes by using a real warship as a target and catapulting special attack planes from catapults was submitted by the Naval General Staff in late May. It was first decided to use two warships, the Ise and the Hyuga. However, in the test, due to various circumstances, the Aso was decided upon.
Except for the Type 0 Fighter, with a 500 kg bomb, and the land bomber (Francis) with two 800 kg bombs, which had actually been used in combat, there were no other planes tested prior to termination of the war. Even the above, two tests were mainly the result of the efforts of the combat forces.
Surface and underwater special attack weapons: The Japanese Navy, which had long been accustomed to building large vessels and big guns, began to concentrate on the construction of small vessels and craft from the time of the Revised Fifth Replenishment Plan. At the same time attention was shifted to mass production of special attack weapons.
Surface and Underwater Special Attack Weapons Preparation Plan
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Total |
|
Submarines (Small) |
2 |
4 |
8 |
13 |
13 |
40 |
|
KORYU (Midget submarine) |
27 |
33 |
50 |
100 |
150 |
180 |
540 |
--21--
Chart 8
Condensed Report of the Results of Tests at Takeyama Base
Date |
Type of Aircraft |
Bombs |
No. of Bombs |
Thickness of Armor Plate |
Angle of Incidence |
Target Angle |
Speed |
Results |
|
1 |
17 Jul |
Type 93 Intermediate Trainer |
250 kg land bombs |
1 |
12 |
30 |
0 |
55 |
Penetration (After action of firing assembly) |
2 |
21 Jul |
Shiragiku Utility Trainer |
250 kg land bombs |
2 |
12 |
30 |
0 |
53 |
Same as above |
3 |
24 Jul |
Type 9 Fighter |
500 kg general purpose bombs |
1 |
12 |
30 |
0 |
55 |
Same as above |
4 |
28 Jul |
Shiragiku Utility Trainer |
250 kg land bombs |
2 |
8 |
60 |
0 |
55 |
Ricochet (After action of firing assembly) |
5 |
3 Aug |
Shiragiku Utility Trainer |
250 kg land bombs |
1 |
8 |
0 |
45 |
55 |
Penetration (After action of firing assembly) |
6 |
15 Aug |
Type 93 Intermediate Trainer |
250 kg land bombs |
1 |
8 |
60 |
0 |
80 |
Same as above |
Chart 9
Results of Ko-Go Tests at Kure Navy Yard
Warship Used |
Type of Bomb Tested |
Installation |
Results |
|
1 |
Aso (Medium-Class Aircraft Carrier) (Not completed, had no flight deck Displacement Tonnage at that time was 10,000 tons) |
Type A Torpedo Warhead (V-Head) |
Angle of incidence, 15 deg on the forelift |
Only small holes were Caused on both side plates; operation of the warship was hardly affected |
2 |
Type 4 Torpedo Warhead (V-Head) |
On the tower whose height is equal to the distance between the shelter deck and the flight deck (in the center of the warship) (Angle of incidence, 45 deg) |
The spaed remained unchanged and navigation was possible in spite of the damage suffered on the shelter deck and the upper deck |
|
3 |
500 kg General Purpose Bomb |
On the armor deck over the fore magazine room (Angle of incidence, 45 deg) |
The armor deck sank and starboard plate was holed 6 m x 12 m Flooding; 2,070 tons |
|
A |
V Bomb (800 kg Oka Model 22) |
On the lower deck near the after lift (Angle of incidence 45 deg) |
Hole 3 m x 7 m was caused on the armor deck. There was no flooding in spite of serious damage |
|
5 |
Sakura Bomb (Army) |
On top of the tower whose height 1a equal to the distance between the shelter deck and the flight deck. (On the aftermost part of the warship) (Angle of incidence 20 deg) |
Hole at the bottom of the warship was 6.9 m x 8 m Flooding, 150 tons |
|
Summary |
||||
1. Effectiveness of the air burst of the Type 4 torpedo head is comparatively small and therefore, its value as a special attack weapon is small. |
||||
2. The V bomb had a greater penetration power than does the general purpose bomb. Therefore, it must be prepared immediately and tested for its effectiveness as compared to the general purpose bomb. |
||||
3. Although the Sakura bomb might inflict comparatively small damage to a ship, it is recognised that the bomb can inflict fatal damage to a war ship, if it hits, for instance, the magazine room. |
||||
4. In general, the penetration bomb can destroy that part of the object in the course of the flame. However, it does hardly any damage to parts not on this course. |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Total |
||
KAIRYU (Midget submarine) |
100 |
95 |
105 |
150 |
150 |
150 |
750 |
|
KAITEN (Human torpedo) |
73 |
83 |
93 |
To be decided later |
249 |
|||
SHINYO (surface craft) |
Model 1 |
300 |
600 |
600 |
600 |
600 |
600 |
3,450 |
Model 5 |
150 |
However, because of various successive bottlenecks in the execution of the plan, only approximately half of the plan was realized. Actual production was as shown on Chart 10.
The organization and disposition of surface and underwater special attack units for the decisive battle of the Homeland are shown on the following charts:
Chart 11: Table of Organization of Special Attack Squadrons
Chart 12: Chart Showing the Location of Special Attack Bases
Chart 10
Results of Surface and Underwater Special Attack Weapons Preparation
Production |
Total |
Percentage |
||||||||
April |
May |
June |
||||||||
Completed |
Plan |
|||||||||
Completed |
Plan |
Completed |
Plan |
Completed |
Plan |
|||||
Submarines (Small) |
2 |
2 |
2 |
4 |
4 |
6 |
67 |
|||
KORYU (Midget submarine) |
12 |
27 |
12 |
33 |
20 |
50 |
44 |
110 |
40 |
|
KAIRYU (Midget submarine) |
9 |
100 |
42 |
95 |
74 |
105 |
125 |
300 |
42 |
|
KAITEN (Human torpedo) |
66 |
73 |
42 |
83 |
51 |
92 |
159 |
249 |
64 |
|
SHINYO (Suicide surface craft) |
Type 1 |
68 |
300 |
316 |
450 |
284 |
450 |
668 |
1,200 |
56 |
Type 5 |
181 |
150 |
167 |
150 |
111 |
150 |
459 |
450 |
102 |
Chart 11-a
Table of Organisation of Special Attack Squadrons
Force |
Vessels |
Attack Units |
Other Units |
|
Yokosuka Naval District Force |
1st Special Attack Squadron |
Destroyer Sawakase |
Yokosuka Attack Unit |
Yokosuka Naval Defense Corps |
Frigates Amakusa, Shizaka |
11th " " |
|||
Frigate No 37 |
15th " " |
|||
Minesweeper No 27 |
16th " " |
|||
Subchasers Nos 42, 47 & 51 |
18th " " |
|||
Light Minelayer Kamijima |
71st " " |
|||
7th Special Attack Squadron |
Minesweeper No 1 |
12th Attack Unit |
Onagawa Naval Defense Corps |
|
Subchasers Nos 33 ft 48 |
14th " " |
|||
17th " " |
||||
4th Special Attack Squadron |
Submarine Tender Komahashi |
13th Attack Unit |
Ise Naval Defense Corps |
|
Frigates Nos 4, 45 & 50 |
19th " " |
|||
Subchasers Nos 14 & 44 |
||||
Kure Naval District Force |
2d Special Attack Squadron |
Okami Attack Unit |
||
Hikari " " |
||||
Hirao " " |
||||
Kasado " " |
||||
81st " " |
||||
8th Special Attack Squadron |
34th Minesweeper Division |
21st Attack Unit |
Saeki Air Group |
|
23d " " |
Saeki Naval Defense Corps |
|||
24th " " |
||||
Osaka Guard District Force |
6th Special Attack Squadron |
Frigates Nos 30 & 190 Petrol Boat No 104 |
22d Attack Unit |
Kii Naval Defense Corps |
Chart 11-b
Table of Organization of Special Attack Squadrons
(Cont'd)
Force |
Vessels |
Attack Units |
Other Units |
|
Sasebo Naval District Force |
3d Special Attack Squadron |
Kawadana Attack Unit |
||
31st " " |
||||
34th " " |
||||
5th Special Attack Squadron |
Subchaser No 49 |
32d Attack Unit |
||
33d " " |
||||
35th " " |
||||
Maizuru Naval District Force |
Maizuru Attack Unit |
|||
Chinkai Guard District Force |
42d Attack Unit |
|||
Combined Fleet |
10th Special Attack Squadron |
Submarine HA-109 |
101st Attack Unit |
|
Submarine HA-111 |
102d " " |
|||
Oura " " |
||||
Shozushima Attack Unit |
||||
Seventh Fleet |
36th Attack Unit |
Chart 12-a
Location of Special Attack Bases 15 August 1945
Chart 12-b
Location of Special Attack Bases 15 August 1945
(Cont'd)
Chart 12-c
Location of Special Attack Bases 15 August 1945
(Cont'd)
APPENDIX I
Major Naval Arms and Weapons Produced from January 1944 to Cessation of Hostilities
Appended Chart 1-a
Naval Craft Completed After January 1944 (Number and Displacement)
Type of Naval Craft |
Class and Displacement |
1944 |
1945 |
||||||||||||||||||||
First Quarter |
Second Quarter |
Third Quarter |
Fourth Quarter |
First Quarter |
Second Quarter |
Third Quarter |
Incomplete |
||||||||||||||||
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
||||
Aircraft Carrier |
No 110 Class |
62,000 |
1 62,000 |
||||||||||||||||||||
Taiho Class |
30,360 |
1 (TN Number of craft) 30,360 (TN Displacement) |
|||||||||||||||||||||
Unryu Class |
17,500 |
2 35,000 |
1 17,500 |
1 17,500 |
|||||||||||||||||||
Unryu Class |
17,460 |
1 17,460 |
|||||||||||||||||||||
Hiryu Class |
17,260 |
1 17,260 |
|||||||||||||||||||||
Ibuki Class |
12,500 |
1 12,500 |
|||||||||||||||||||||
Monthly total |
1 30,360 |
2 35,000 |
1 17,500 |
1 82,000 |
4 64,720 |
||||||||||||||||||
Quarterly total |
1 30,360 |
2 35,000 |
2 79,500 |
4 64,720 |
|||||||||||||||||||
Cruiser |
Agano Class |
6,500 |
1 6,500 |
||||||||||||||||||||
Quarterly total |
1 6,500 |
||||||||||||||||||||||
Destroyer |
Yugumo Class |
2,040 |
1 2,040 |
1 2,040 |
1 2,040 |
||||||||||||||||||
Akizuki Class |
2,700 |
1 2,700 |
1 2,700 |
2 5,400 |
1 2,700 |
1 2,700 |
|||||||||||||||||
Matsu Class |
1,260 |
1 1,260 |
3 3,780 |
1 1,260 |
3 3,780 |
4 5,040 |
1 1,260 |
3 3,780 |
1 1,260 |
3 3,780 |
1 1,260 |
6 7,560 |
1 1,260 |
3 3,780 |
1 1,260 |
4 5,040 |
|||||||
Monthly total |
1 2,040 |
2 4,740 |
1 1,260 |
2 4,740 |
3 3,780 |
1 1,260 |
3 3,780 |
4 5,040 |
1 1,260 |
3 3,780 |
3 6,660 |
4 6,480 |
1 1,260 |
6 7,560 |
2 3,960 |
3 3,780 |
1 1,260 |
4 5,040 |
|||||
Quarterly total |
3 6,780 |
6 9,780 |
8 10,080 |
7 11,700 |
11 15,300 |
6 9,000 |
4 5,040 |
||||||||||||||||
Submarine |
I-400 Class |
3,430 |
1 3,430 |
1 3,340 |
1 3,430 |
1 3,430 |
|||||||||||||||||
I-351 Class |
2,650 |
1 2,650 |
1 2,650 |
||||||||||||||||||||
I-13 Class |
2,400 |
1 2,400 |
1 2,400 |
1 2,400 |
|||||||||||||||||||
I-1 Class |
2,390 |
1 2,390 |
|||||||||||||||||||||
I-16 Class |
2,180 |
1 2,180 |
1 2,180 |
1 2,180 |
|||||||||||||||||||
I-15 Class |
1,950 |
1 1,950 |
Appended Chart 1-b (Cont'd)
Naval Craft Completed After January 1944 (Number and Displacement)
Type of Naval Craft |
Class and Displacement |
1944 |
1945 |
Incomplete |
|||||||||||||||||||
First Quarter |
Second Quarter_ |
Third Quarter |
Fourth Quarter |
First Quarter |
Second Quarter |
Third Quarter |
|||||||||||||||||
Jan |
Feb |
Mar |
V |
Mar |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
||||
Submarine |
I-52 Class |
2,100 |
1 2,100 |
1 2,100 |
|||||||||||||||||||
I-54 Class |
1,950 |
1 1,950 |
1 1,950 |
1 1,950 |
|||||||||||||||||||
I-361 Class |
1,470 |
2 2,940 |
1 1,470 |
1 1,470 |
4 5,880 |
1 1,470 |
2 2,940 |
||||||||||||||||
I-372 Class |
1,660 |
1 1,660 |
1 1,660 |
1 1,660 |
|||||||||||||||||||
I-201 Class |
1,000 |
2 2,000 |
1 1,000 |
5 5,000 |
|||||||||||||||||||
RO-35 Class |
965 |
2 1,930 |
1 965 |
1 965 |
1 965 |
1 965 |
1 965 |
1 965 |
|||||||||||||||
RO-100 Class |
429 |
2 858 |
|||||||||||||||||||||
HA-101 Class |
370 |
1 370 |
3 1,110 |
3 1,110 |
1 370 |
1 370 |
1 370 |
2 740 |
|||||||||||||||
HA-201 Class |
320 |
2 640 |
2 640 |
1 320 |
5 1,600 |
22 7,040 |
|||||||||||||||||
I-12 Class |
2,200 |
1 2,200 |
|||||||||||||||||||||
Monthly total |
5 4,738 |
3 5,245 |
2 2,915 |
1 2,100 |
4 6,105 |
2 3,420 |
3 4,615 |
4 5,880 |
4 6,565 |
2 2,940 |
3 2,995 |
5 6,940 |
2 6,080 |
5 3,110 |
2 2,770 |
1 1,660 |
3 1,010 |
3 1,040 |
3 4,120 |
5 1,600 |
34 25,310 |
||
Quarterly total |
10 12,898 |
7 11,625 |
11 17,060 |
10 12,875 |
9 11,960 |
7 4,310 |
8 5,720 |
34 25,310 |
|||||||||||||||
Minelayer |
Minomo Class |
3,000 |
1 3,000 |
||||||||||||||||||||
Quarterly total |
1 3,000 |
||||||||||||||||||||||
Frigate |
Etorofu Class |
870 |
1 870 |
||||||||||||||||||||
Mikura Class |
940 |
1 940 |
2 1,880 |
1 940 |
2 1,880 |
2 1,880 |
2 1,880 |
1 940 |
1 940 |
3 2,820 |
5 4,700 |
3 2,820 |
3 2,820 |
4 3,760 |
4 3,760 |
1 940 |
4 3,760 |
||||||
No 1 Class |
750 |
2 1,500 |
4 3,000 |
4 3,000 |
4 3,000 |
3 2,250 |
4 3,000 |
5 3,750 |
5 3,750 |
5 3,750 |
2 1,500 |
3 2,250 |
2 1,500 |
3 2,250 |
4 3,000 |
1 750 |
2 1,500 |
4 3,000 |
|||||
No 2 Class |
740 |
3 2,220 |
9 6,660 |
1 740 |
2 1,480 |
2 1,480 |
5 3,700 |
5 3,700 |
6 4,440 |
4 2,960 |
7 5,180 |
3 2,220 |
5 3,700 |
6 4,440 |
2 1,480 |
2 1,480 |
1 740 |
5 3,700 |
|||||
Monthly total |
1 940 |
8 6,470 |
13 9,660 |
6 4,680 |
4 3,360 |
4 3,360 |
6 4,480 |
9 6,890 |
10 7,640 |
14 11,010 |
9 6,710 |
17 13,630 |
8 6,540 |
11 8,770 |
12 9,700 |
9 7,490 |
4 3,000 |
1 750 |
5 3,920 |
1 |
13 10,460 |
||
Quarterly total |
22 17,070 |
14 11,400 |
25 19,410 |
40 31,350 |
31 25,010 |
14 11,240 |
6 4,660 |
13 10,460 |
|||||||||||||||
Naval Transport |
No 1 Class (TN APDI) |
1,500 |
1 1,500 |
3 4,500 |
3 4,500 |
3 4,500 |
3 4,500 |
3 4,500 |
2 3,000 |
1 1,500 |
1 1,500 |
1 1,500 |
1 1,500 |
||||||||||
No 101 Class (TN LSMI) |
890 |
2 1,780 |
4 3,560 |
2 1,780 |
3 2,670 |
4 3,560 |
4 3,560 |
3 2,670 |
12 10,680 |
5 4,450 |
3 2,670 |
1 890 |
3 2,670 |
1 890 |
1 890 |
1 890 |
4 3,560 |
Appended Chart 1-b (Cont'd)
Naval Craft Completed After January 1944 (Number and Displacement)
Type of Naval Craft |
Class and Displacement
|
1944 |
1945 |
Incomplete |
|||||||||||||||||||
First Quarter |
Second Quarter |
Third Quarter |
Fourth Quarter |
First Quarter |
Second Quarter |
Third Quarter |
|||||||||||||||||
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
||||
Naval Transport |
Monthly total |
2 1,780 |
5 5,060 |
2 1,780 |
3 2,670 |
7 8,060 |
4 3,560 |
6 7,170 |
15 15,180 |
5 4,450 |
6 7,170 |
4 5,390 |
3 2,670 |
2 3,000 |
1 890 |
2 2,390 |
1 1,500 |
2 2,390 |
5 5,060 |
||||
Quarterly total |
7 6,840 |
12 12,510 |
25 25,910 |
15 17,010 |
6 6,560 |
3 3,890 |
2 2,390 |
5 5,060 |
|||||||||||||||
Minesweeper |
No 19 Class |
630 |
1 630 |
2 1,260 |
1 630 |
1 630 |
|||||||||||||||||
Quarterly total |
1 630 |
3 1,890 |
1 630 |
||||||||||||||||||||
Subchaser |
No 13 Class |
440 |
2 880 |
3 1,320 |
1 440 |
1 440 |
1 440 |
1 440 |
|||||||||||||||
Quarterly total |
5 2,200 |
2 880 |
1 440 |
1 440 |
|||||||||||||||||||
Light Minelayer |
Ajiro Class |
720 |
1 720 |
||||||||||||||||||||
Kamishima Class |
766 |
1 766 |
1 766 |
||||||||||||||||||||
Monthly total |
1 720 |
1 766 |
1 766 |
||||||||||||||||||||
Quarterly total |
1 720 |
1 766 |
1 766 |
||||||||||||||||||||
Special Duty Ship |
Hario Class (AO) |
18,500 |
1 18,500 |
||||||||||||||||||||
Ohama Class (target ship) |
2,670 |
1 2,670 |
1 2,670 |
||||||||||||||||||||
Monthly total |
1 18,500 |
1 2,670 |
1 2,670 |
||||||||||||||||||||
Quarterly total |
1 18,500 |
1 2,670 |
1 2,670 |
||||||||||||||||||||
Auxiliary Patrol Vessel |
No 1 Class |
238 |
2 476 |
4 952 |
2 476 |
6 1,428 |
4 952 |
5 1,190 |
4 952 |
26 6,188 |
|||||||||||||
Quarterly total |
6 1,428 |
12 2,855 |
9 2,142 |
26 6,188 |
|||||||||||||||||||
Auxiliary Subchaser |
No 1 Class |
130 |
4 520 |
8 1,040 |
9 1,170 |
6 780 |
9 1,170 |
10 1,300 |
13 1,690 |
12 1,560 |
10 1,300 |
11 1,430 |
14 1,820 |
910 |
5 650 |
||||||||
Quarterly total |
21 2,730 |
25 3,250 |
32 4,160 |
||||||||||||||||||||
Monthly total |
12 7,078 |
23 17,205 |
35 55,225 |
16 10,600 |
25 19,745 |
28 20,990 |
30 17,795 |
36 60,280 |
43 35,725 |
35 39,030 |
37 90,975 |
37 52,030 |
23 25,090 |
21 16,616 |
25 21,872 |
16 15,976 |
17 10,718 |
9 4,602 |
16 12,386 |
11 6,292 |
88 120,214 |
||
Quarterly total |
70 79,508 |
69 51,335 |
109 113,800 |
109 182,035 |
69 63,578 |
42 31,296 |
27 18,678 |
88 120,214 |
Remarks: The naval craft listed as incomplete refer to those not yet completed at the end of war and also those whose construction was suspended during the war.
Appended Chart 2
Transports and Freighters Completed After January 1944
Year |
Month |
Quarter |
Freighter |
Tanker |
Others |
Monthly total |
Quarterly total |
|||||
No |
Tonnage |
No |
Tonnage |
No |
Tonnage |
No |
Tonnage |
No |
Tonnage |
|||
1944 |
Jan |
First Quarter |
28 |
56,520 |
11 |
36,470 |
3 |
15,250 |
42 |
108,240 |
203 |
514,840 |
Feb |
45 |
89,100 |
13 |
38,370 |
58 |
127,470 |
||||||
Mar |
72 |
183,430 |
27 |
89,570 |
4 |
6,130 |
103 |
279,130 |
||||
Apr |
Second Quarter |
34 |
72,590 |
8 |
6,960 |
42 |
79,550 |
161 |
370,610 |
|||
May |
40 |
82,180 |
19 |
61,110 |
3 |
2,000 |
62 |
145,290 |
||||
Jun |
40 |
97,650 |
17 |
48,120 |
57 |
145,770 |
||||||
Jul |
Third Quarter |
33 |
50,620 |
17 |
55,270 |
3 |
2,000 |
53 |
107,890 |
180 |
398,470 |
|
Aug |
33 |
38,820 |
24 |
71,890 |
57 |
110,710 |
||||||
Sep |
40 |
52,050 |
29 |
127,320 |
1 |
500 |
70 |
179,870 |
||||
Oct |
Fourth Quarter |
40 |
48,830 |
23 |
97,200 |
1 |
500 |
64 |
146,530 |
189 |
418,990 |
|
Nov |
40 |
59,720 |
24 |
77,480 |
1 |
900 |
65 |
138,100 |
||||
Dee |
41 |
76,810 |
18 |
57,050 |
1 |
500 |
60 |
134,360 |
||||
1945 |
Jan |
First Quarter |
31 |
63,170 |
16 |
51,000 |
3 |
10,500 |
50 |
124,670 |
130 |
386,320 |
Feb |
36 |
101,930 |
12 |
50,920 |
48 |
152,850 |
||||||
Mar |
27 |
85,080 |
3 |
13,720 |
2 |
10,000 |
32 |
108,800 |
||||
Apr |
Second Quarter |
12 |
23,180 |
1 |
500 |
13 |
23,680 |
41 |
128,550 |
|||
May |
19 |
63,470 |
1 |
500 |
20 |
63,970 |
||||||
Jun |
8 |
40,900 |
8 |
40,900 |
||||||||
Jul |
Third Quarter |
11 |
36,580 |
11 |
36,580 |
18 |
56,401 |
|||||
Aug |
7 |
19,821 |
7 |
19,821 |
Appended Chart 3-a
Aircraft Produced January 1944 - August 1945
Month Year |
1944 |
||||||||||
Item |
Type of Aircraft |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
|
Standard Planes |
Carrier-borne fighters |
1 |
363 |
269 |
362 |
339 |
327 |
300 |
278 |
367 |
224 |
994 |
966 |
889 |
|||||||||
Interceptors |
2 |
35 |
67 |
75 |
117 |
58 |
116 |
127 |
117 |
125 |
|
177 |
291 |
369 |
|||||||||
Night fighters |
3 |
25 |
18 |
18 |
35 |
40 |
40 |
27 |
35 |
40 |
|
61 |
115 |
102 |
|||||||||
Carrier-borne bombers |
4 |
140 |
H7 |
141 |
125 |
133 |
118 |
107 |
106 |
122 |
|
428 |
376 |
335 |
|||||||||
Carrier-borne attack bombers |
5 |
30 |
25 |
39 |
36 |
36 |
57 |
79 |
85 |
76 |
|
94 |
129 |
240 |
|||||||||
Land-based reconnaissance planes |
6 |
1 |
2 |
6 |
6 |
0 |
1 |
4 |
8 |
19 |
|
9 |
7 |
31 |
|||||||||
Land-based bombers |
7 |
11 |
20 |
35 |
46 |
46 |
51 |
47 |
48 |
69 |
|
66 |
143 |
164 |
|||||||||
Land-based attack bombers |
8 |
53 |
46 |
50 |
73 |
70 |
79 |
89 |
85 |
91 |
|
H9 |
222 |
265 |
|||||||||
Patrol planes |
9 |
1 |
1 |
2 |
1 |
2 |
3 |
3 |
3 |
3 |
|
4 |
6 |
9 |
|||||||||
Land-based transport planes |
10 |
8 |
14 |
15 |
3 |
3 |
17 |
H |
16 |
19 |
|
37 |
23 |
49 |
|||||||||
Seaplane fighters |
11 |
9 |
10 |
10 |
0 |
0 |
0 |
0 |
0 |
0 |
|
29 |
0 |
0 |
|||||||||
Reconnaissance seaplanes |
12 |
51 |
49 |
51 |
53 |
53 |
62 |
52 |
59 |
40 |
|
151 |
168 |
151 |
Appended Chart 3-b
Aircraft Produced January 1944 - August 1945
(Cont'd)
1944 |
1945 |
Japanese Designation of Aircraft (Factory) |
||||||||||
Oct |
Nov |
Dec |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
||
1 |
339 |
360 |
268 |
251 |
167 |
247 |
267 |
285 |
208 |
153 |
101 |
Type-0 fighter (Nakajima and Mitsubishi) |
967 |
665 |
760 |
254 |
|||||||||
2 |
129 |
121 |
95 |
89 |
97 |
140 |
128 |
101 |
56 |
44 |
8 |
Shiden (Kawanishi and Showa). Raiden (Mitsubishi) |
345 |
326 |
285 |
52 |
|||||||||
3 |
23 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
Gekko (Nakajima) |
23 |
0 |
0 |
0 |
|||||||||
4 |
116 |
133 |
150 |
115 |
98 |
101 |
96 |
46 |
67 |
33 |
4 |
Suisei (Aichi and 11th Naval Air Depot) Type-99 (Aichi and Showa) |
399 |
314 |
209 |
37 |
|||||||||
5 |
96 |
87 |
60 |
75 |
83 |
94 |
65 |
12 |
42 |
13 |
1 |
Tenzan (Nakajima). Ryusei (Aichi and 21st Naval Air Depot) |
243 |
252 |
119 |
14 |
|||||||||
6 |
25 |
26 |
25 |
30 |
38 |
64 |
60 |
58 |
47 |
35 |
4 |
Saiun (Nakajima) |
76 |
132 |
165 |
39 |
|||||||||
7 |
75 |
88 |
84 |
90 |
52 |
52 |
63 |
64 |
53 |
40 |
20 |
Ginga (Nakajima and Kawanishi) |
247 |
194 |
180 |
60 |
|||||||||
8 |
109 |
108 |
60 |
55 |
60 |
50 |
65 |
31 |
25 |
1 |
0 |
Type-1 (Mitsubishi) |
277 |
165 |
121 |
1 |
|||||||||
9 |
8 |
11 |
14 |
16 |
11 |
13 |
13 |
15 |
12 |
12 |
6 |
Tokai (Kyushu) |
33 |
40 |
40 |
18 |
|||||||||
10 |
20 |
16 |
17 |
19 |
9 |
21 |
15 |
14 |
3 |
7 |
1 |
Type-0 (Showa) |
53 |
49 |
32 |
8 |
|||||||||
11 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
Kyofu (Kawanishi) |
0 |
0 |
0 |
0 |
|||||||||
12 |
61 |
70 |
73 |
49 |
47 |
32 |
22 |
16 |
11 |
4 |
4 |
Type-0 (Kyushu) Zuiun (Nippon Hikoki and Aichi) |
204 |
128 |
49 |
8 |
Appended Chart 3-c
Aircraft Produced January 1944 - August 1945
(Cont'd)
Item |
Year Month |
1944 |
|||||||||
Type of Aircraft |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
||
Standard Planes |
Observation planes |
1 |
50 |
40 |
35 |
30 |
35 |
30 |
15 |
6 |
0 |
125 |
95 |
21 |
|||||||||
Seaplane bombers |
2 |
0 |
1 |
0 |
0 |
0 |
2 |
1 |
1 |
1 |
|
1 |
2 |
3 |
|||||||||
Flying boats |
3 |
9 |
9 |
10 |
9 |
8 |
8 |
5 |
3 |
3 |
|
28 |
25 |
11 |
|||||||||
Total of combat aircrafts |
4 |
786 |
718 |
849 |
873 |
811 |
884 |
848 |
939 |
852 |
|
2,353 |
2,568 |
2,639 |
|||||||||
Trainer |
5 |
212 |
223 |
281 |
297 |
281 |
278 |
262 |
212 |
147 |
|
716 |
856 |
621 |
|||||||||
Total |
6 |
998 |
941 |
1,130 |
1,170 |
1,092 |
1,152 |
1,110 |
1,151 |
999 |
|
3,069 |
3,424 |
3,260 |
|||||||||
Special-Type Planes |
Oka, Model 11 |
7 |
10 |
||||||||
10 |
|||||||||||
Oka, Model 22 |
8 |
||||||||||
Shusui |
9 |
||||||||||
Kikka |
10 |
||||||||||
Total |
11 |
10 |
|||||||||
10 |
|||||||||||
Grand Total |
12 |
998 |
941 |
1,130 |
1,170 |
1,092 |
1,162 |
1,110 |
1,151 |
1,009 |
|
3,069 |
3,424 |
3,270 |
Appended Chart 3-d
Aircraft Produced January 1944 - August 1945 (Cont'd)
1945 |
Japanese Designation of aircraft (Factory) |
|||||||||||
Oct |
Nov |
Dec |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
||
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
Type-0 (21st Naval Air depot) |
0 |
0 |
0 |
0 |
|||||||||
2 |
2 |
1 |
1 |
1 |
2 |
2 |
2 |
4 |
2 |
3 |
0 |
Seiran (Aichi) |
4 |
5 |
8 |
3 |
|||||||||
3 |
3 |
4 |
6 |
4 |
2 |
2 |
3 |
0 |
0 |
0 |
0 |
Type-2, Soku (Kawanishi) |
13 |
8 |
3 |
0 |
|||||||||
4 |
1,006 |
1,025 |
853 |
794 |
666 |
818 |
799 |
646 |
526 |
345 |
149 |
|
2,884 |
2,278 |
1,971 |
494 |
|||||||||
5 |
153 |
123 |
132 |
157 |
154 |
158 |
86 |
89 |
72 |
63 |
68 |
Type-0 training (Hitachi) Shiragiku (Kyushu) Type-93 intermediate trainer (Fuki and Nippon Hikoki) |
408 |
469 |
247 |
131 |
|||||||||
6 |
1,159 |
1,148 |
985 |
951 |
820 |
976 |
885 |
735 |
598 |
408 |
217 |
|
3,292 |
2,747 |
2,218 |
625 |
|||||||||
7 |
50 |
95 |
93 |
160 |
197 |
150 |
(1st Air Technical Depot) |
|||||
238 |
507 |
|||||||||||
8 |
50 |
(1st Air Technical Depot) |
||||||||||
50 |
||||||||||||
9 |
1 |
4 |
(Mitsubishi and Nippon Hikoki) |
|||||||||
1 |
4 |
|||||||||||
10 |
1 |
(Nakajima) |
||||||||||
0 |
1 |
|||||||||||
11 |
50 |
95 |
93 |
160 |
197 |
151 |
51 |
4 |
||||
238 |
508 |
51 |
4 |
|||||||||
12 |
1,209 |
1,243 |
1,078 |
1,111 |
1,017 |
1,127 |
885 |
735 |
649 |
412 |
217 |
|
3,530 |
3,255 |
2,269 |
629 |
Appended Chart 4A-a
Guns and Ammunition Produced January 1944 - August 1945
Weapons and Ammunition |
Type of Guns |
Caliber |
1944 |
|||
First Quarter |
||||||
Jan |
Feb |
Mar |
||||
Guns |
Flat |
220mm |
1 |
3 |
2 |
1 |
6 |
||||||
140mm |
1 |
1 |
1 |
|||
2 |
3 |
|||||
127mm |
6 |
6 |
6 |
|||
3 |
18 |
|||||
200mm short barrel and 120mm |
33 |
51 |
46 |
|||
4 |
130 |
|||||
Miscellaneous |
5 |
2 |
3 |
2 |
||
7 |
||||||
Total |
6 |
45 |
63 |
56 |
||
164 |
||||||
Dual purpose guns |
127mm |
7 |
30 |
30 |
30 |
|
90 |
||||||
120mm |
8 |
62 |
81 |
95 |
||
238 |
||||||
100mm |
9 |
8 |
12 |
2 |
||
22 |
||||||
80mm |
10 |
8 |
2 |
8 |
||
18 |
||||||
Total |
11 |
108 |
125 |
135 |
||
Total |
12 |
153 |
188 |
191 |
||
532 |
||||||
Automatic cannon and Machine gun |
Machine guns |
30mm |
13 |
15 |
5 |
|
25 |
Appended Chart 4A-b
Guns and Ammunition Produced January 1944 - August 1945
(Cont'd)
1944 |
|||||||||
Second Quarter |
Third |
Quarter |
Fourth Quarter |
||||||
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
1 |
2 |
1 |
2 |
1 |
2 |
1 |
1 |
1 |
1 |
5 |
4 |
3 |
|||||||
2 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
3 |
3 |
3 |
|||||||
3 |
1 |
1 |
0 |
0 |
1 |
0 |
0 |
1 |
0 |
2 |
1 |
1 |
|||||||
4 |
50 |
50 |
60 |
60 |
60 |
60 |
50 |
40 |
30 |
150 |
180 |
120 |
|||||||
5 |
3 |
3 |
3 |
3 |
3 |
3 |
3 |
3 |
3 |
9 |
|||||||||
6 |
56 |
56 |
65 |
67 |
65 |
55 |
46 |
35 |
|
169 |
197 |
136 |
|||||||
7 |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
20 |
90 |
90 |
80 |
|||||||
8 |
100 |
120 |
150 |
140 |
180 |
200 |
200 |
180 |
130 |
370 |
520 |
510 |
|||||||
9 |
4 |
4 |
4 |
4 |
4 |
3 |
4 |
4 |
4 |
12 |
11 |
12 |
|||||||
10 |
5 |
6 |
5 |
5 |
5 |
5 |
5 |
5 |
5 |
16 |
15 |
15 |
|||||||
11 |
139 |
160 |
189 |
179 |
219 |
238 |
239 |
219 |
159 |
488 |
636 |
617 |
|||||||
12 |
196 |
216 |
245 |
244 |
286 |
303 |
294 |
265 |
194 |
657 |
833 |
753 |
|||||||
13 |
15 |
20 |
0 |
10 |
15 |
20 |
0 |
25 |
15 |
35 |
45 |
40 |
Appended Chart 4A-c
Guns and Ammunition Produced January 1944 - August 1945
(Cont'd)
1945 |
||||||||
First Quarter |
Second Quarter |
Third Quarter |
||||||
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
|
1 |
1 |
1 |
1 |
0 |
0 |
0 |
0 |
0 |
3 |
0 |
0 |
||||||
2 |
1 |
1 |
1 |
0 |
0 |
0 |
0 |
0 |
3 |
0 |
c |
||||||
3 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
c |
||||||
4 |
30 |
30 |
20 |
20 |
10 |
5 |
5 |
0 |
80 |
35 |
5 |
||||||
5 |
3 |
3 |
3 |
1 |
1 |
1 |
0 |
0 |
9 |
3 |
0 |
||||||
6 |
35 |
36 |
25 |
21 |
11 |
6 |
5 |
0 |
96 |
38 |
5 |
||||||
7 |
15 |
15 |
10 |
10 |
15 |
10 |
10 |
5 |
40 |
35 |
15 |
||||||
8 |
110 |
100 |
90 |
80 |
60 |
40 |
5 |
0 |
300 |
180 |
5 |
||||||
9 |
4 |
1 |
0 |
4 |
3 |
2 |
1 |
0 |
5 |
9 |
1 |
||||||
10 |
5 |
5 |
5 |
4 |
3 |
2 |
1 |
0 |
15 |
9 |
1 |
||||||
11 |
134 |
121 |
105 |
98 |
81 |
54 |
17 |
5 |
360 |
233 |
22 |
||||||
0 12 |
169 |
157 |
130 |
119 |
92 |
60 |
22 |
5 |
456 |
271 |
27 |
||||||
13 |
70 |
110 |
350 |
500 |
350 |
460 |
500 |
140 |
530 |
1,310 |
640 |
Appended Chart 4A-d
Guns and Ammunition Produced January 1944 - August 1945
(Cont'd)
Weapons and Ammunition |
Type of Guns |
Caliber |
1944 |
|||
First Quarter |
||||||
Jan |
Feb |
Mar |
||||
Automatic cannon and machine guns |
Machine guns |
25mm |
1 |
800 |
1,000 |
1,000 |
2,800 |
||||||
20mm |
2 |
770 |
1,195 |
1,710 |
||
3,675 |
||||||
13mm |
3 |
600 |
740 |
780 |
||
2,120 |
||||||
7.9mm and 7.7mm |
4 |
1,475 |
1,710 |
1,825 |
||
5,010 |
||||||
Total |
5 |
3,660 |
4,650 |
5,320 |
||
13,630 |
||||||
Ammunitions |
For flat guns |
20mm and above |
6 |
1,000 |
1,000 |
1,000 |
3,000 |
||||||
155mm and below |
7 |
21,000 |
20,000 |
20,000 |
||
61,000 |
||||||
Total |
8 |
22,000 |
21,000 |
21,000 |
||
64,000 |
||||||
For dual purpose gun |
9 |
30,000 |
30,000 |
30,000 |
||
90,000 |
||||||
Total for flat and dual purpose guns |
10 |
52,000 |
51,000 |
51,000 |
||
154,000 |
||||||
For automatic cannon and machine gun (thousand of rounds) |
11 |
10,860 |
12,008 |
15,395 |
||
38,263 |
Appended Chart 4A-e
Guns and Ammunition Produced January - August 1945
(Cont'd)
1944 |
|||||||||
Second Quarter |
Third Quarter |
Fourth Quarter |
|||||||
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
1 |
1,500 |
1,700 |
1,700 |
2,000 |
2,000 |
2,000 |
2,200 |
2,200 |
2,000 |
4,900 |
6,000 |
6,200 |
|||||||
2 |
1,240 |
1,520 |
2,340 |
2,340 |
3,375 |
3,080 |
3,660 |
3,830 |
3,490 |
5,100 |
8,795 |
10,980 |
|||||||
3 |
900 |
1,000 |
1,150 |
1,080 |
1,300 |
1,320 |
1,455 |
1,605 |
1,590 |
3,050 |
3,700 |
4,650 |
|||||||
4 |
1,430 |
1,545 |
1,550 |
1,685 |
1,265 |
1,210 |
1,500 |
1,195 |
1,030 |
4,525 |
4,160 |
3,725 |
|||||||
5 |
5,085 |
5,785 |
6,740 |
7,115 |
7,955 |
7,630 |
8,815 |
8,655 |
8,125 |
17,610 |
22,700 |
25,595 |
|||||||
6 |
1,000 |
1,200 |
800 |
500 |
500 |
500 |
500 |
0 |
0 |
3,000 |
1,500 |
500 |
|||||||
7 |
15,000 |
10,000 |
10,000 |
5,000 |
5,000 |
5,000 |
3,000 |
2,000 |
0 |
35,000 |
15,000 |
5,000 |
|||||||
8 |
16,000 |
11,200 |
10,000 |
5,500 |
5,500 |
5,500 |
3,500 |
2,000 |
0 |
38,000 |
16,500 |
5,500 |
|||||||
9 |
30,000 |
40,000 |
40,000 |
40,000 |
40,000 |
50,000 |
50,000 |
60,000 |
60,000 |
110,000 |
130,000 |
170,00 |
|||||||
10 |
45,000 |
51,200 |
50,800 |
45,500 |
45,500 |
55,500 |
53,500 |
62,000 |
60,000 |
148,000 |
146,500 |
175,500 |
|||||||
11 |
13,543 |
13,390 |
12,306 |
12,728 |
12,210 |
11,193 |
11,391 |
11,466 |
10,419 |
39,239 |
36,131 |
33,276 |
Appended Chart 4A-f
Guns and Ammunition Produced January 1944 - August 1945
(Cont'd)
1945 |
||||||||
First |
Quarter |
Second Quarter |
Third Quarter |
|||||
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
|
1 |
1,800 |
1,600 |
500 |
800 |
800 |
500 |
400 |
100 |
3,900 |
2,100 |
500 |
||||||
2 |
3,195 |
1,695 |
1,855 |
1,405 |
1,435 |
1,625 |
785 |
400 |
6,745 |
4,465 |
1,185 |
||||||
3 |
1,755 |
2,040 |
1,905 |
1,685 |
1,545 |
1,330 |
1,205 |
375 |
5,700 |
4,560 |
1,580 |
||||||
4 |
1,140 |
805 |
1,245 |
1,010 |
1,110 |
785 |
740 |
310 |
3,190 |
2,905 |
1,050 |
||||||
5 |
7,960 |
6,250 |
5,855 |
5,400 |
5,240 |
4,700 |
3,630 |
1,325 |
20,065 |
15,340 |
4,955 |
||||||
6 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
||||||
7 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
||||||
6 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
||||||
9 |
40,000 |
35,000 |
10,000 |
30,000 |
20,000 |
20,000 |
10,000 |
5,000 |
85,000 |
70,000 |
15,000 |
||||||
10 |
40,000 |
35,000 |
10,000 |
30,000 |
20,000 |
20,000 |
10,000 |
5,000 |
85,000 |
70,000 |
15,000 |
||||||
11 |
10,068 |
10,114 |
11,441 |
11,240 |
11,087 |
8,013 |
5,738 |
3,446 |
31,623 |
30,340 |
9,184 |
Remarks:
The guns listed here are those produced for naval craft, aircraft and naval land bases and do not include guns for land mobile combat use. However, the automatic cannon and machine guns and the ammunition to include those for land mobile combat use.
Appended Chart 4B
Land Mobile Combat Weapons Produced January - 1944 - August 1945
Year |
1944 |
1945 |
||||
Month, Quarter |
Jan to Dec |
Jan to Mar |
Second Quarter |
Jul to Aug |
||
Gun and Ammunition |
Apr |
May |
Jun |
|||
120mm gun, short barrel, for land mobile combat |
Unknown |
Unknown |
5 |
29 |
0 |
Unknown |
34 |
||||||
Ammunition for 120mm short barrel, for land mobile combat |
" |
" |
5,800 |
4,700 |
3,000 |
" |
13,500 |
||||||
80mm mortar |
" |
" |
393 |
345 |
200 |
" |
938 |
||||||
Ammunition for 80mm mortar |
" |
" |
37,000 |
37,000 |
70,000 |
" |
144,000 |
||||||
200mm rocket gun |
" |
" |
50 |
10 |
190 |
" |
250 |
||||||
100mm antitank gun (rocket type) |
" |
" |
0 |
5 |
50 |
" |
55 |
||||||
80mm antitank gun (rocket type) |
" |
" |
210 |
60 |
345 |
" |
615 |
||||||
Ordinary rocket shell |
" |
" |
2,500 |
3,400 |
5,500 |
" |
11,400 |
||||||
Antitank rocket shell |
" |
" |
1,000 |
500 |
500 |
" |
2,000 |
||||||
Hand grenade |
" |
" |
15,000 |
85,000 |
300,000 |
" |
400,000 |
Remarks:
1. The weapons listed here are these for land mobile combat.
2. Since records for months other than April, May and June of 1945 are not available, nothing definite is known.
3. Land mobile combat weapons, other than those listed here, are chiefly rifles and pistols transferred from the Army, but their number is unknown because of a lack of records.
4. Re vehicular weapons, tanks were chiefly transferred from the Army and the rest were appropriated by the Munitions Ministry. Their number also is unknown.
Appended Chart 5
Gunpowder Produced After January 1944 (Quantity in Kilograms)
Year and Month |
Quarter |
Powder for Guns |
Powder for Machine Guns |
Propellants |
Explosives |
Total |
||||||
1944 |
Jan |
First Quarter |
464 |
1,351 |
233 |
746 |
8 |
25 |
1,937 |
6,187 |
2,642 |
8,309 |
Feb |
474 |
233 |
7 |
2,061 |
2,775 |
|||||||
Mar |
413 |
280 |
10 |
2,189 |
2,892 |
|||||||
Apr |
Second Quarter |
452 |
1,426 |
347 |
1,002 |
59 |
194 |
2,156 |
6,803 |
3,014 |
9,425 |
|
May |
487 |
335 |
65 |
2,297 |
3,184 |
|||||||
Jun |
487 |
320 |
70 |
2,350 |
3,227 |
|||||||
Jul |
Third Quarter |
487 |
1,423 |
319 |
1,000 |
70 |
249 |
2,451 |
7,512 |
3,327 |
10,184 |
|
Aug |
466 |
330 |
89 |
2,412 |
3,297 |
|||||||
Sep |
470 |
351 |
90 |
2,649 |
3,560 |
|||||||
Oct |
Fourth Quarter |
444 |
1,318 |
355 |
1,079 |
116 |
336 |
2,632 |
7,902 |
3,5,47 |
10,635 |
|
Nov |
452 |
354 |
110 |
2,697 |
3,613 |
|||||||
Dec |
422 |
370 |
110 |
2,573 |
3,475 |
|||||||
1945 |
Jan |
First Quarter |
422 |
1,286 |
420 |
1,220 |
145 |
508 |
2,489 |
7,789 |
3,476 |
10,803 |
Feb |
422 |
420 |
164 |
2,520 |
3,526 |
|||||||
Mar |
442 |
380 |
199 |
2,780 |
3,801 |
|||||||
Apr |
Second Quarter |
317 |
930 |
155 |
688 |
262 |
818 |
1,907 |
6,220 |
2,641 |
8,656 |
|
May |
319 |
236 |
279 |
2,538 |
3,372 |
|||||||
Jun |
294 |
297 |
277 |
1,775 |
2,643 |
|||||||
Jul |
Third Quarter |
229 |
343 |
142 |
193 |
170 |
237 |
1,281 |
1,927 |
1,822 |
2,700 |
|
Aug |
114 |
51 |
67 |
646 |
878 |
Appended Chart 6
Fuel Produced After January 1944
Year and Month |
Item |
Aviation Gasoline |
Heavy Oil |
||
Unit |
(Kilograms) |
(Tons) |
|||
Quarter |
|||||
1944 Jan |
First Quarter |
18,000 |
56,000 |
29,000 |
83,000 |
Feb |
21,000 |
29,000 |
|||
Mar |
17,000 |
25,000 |
|||
Apr |
Second Quarter |
20,000 |
60,000 |
25,000 |
80,000 |
May |
20,000 |
27,000 |
|||
Jun |
20,000 |
28,000 |
|||
Jul |
Third Quarter |
19,000 |
49,000 |
28,000 |
75,000 |
Aug |
15,000 |
25,000 |
|||
Sep |
15,000 |
22,000 |
|||
Oct |
Fourth Quarter |
15,000 |
49,000 |
22,000 |
71,000 |
Nov |
19,000 |
29,000 |
|||
Dee |
15,000 |
20,000 |
|||
1945 Jan |
First Quarter |
14,000 |
34,000 |
18,000 |
58,000 |
Feb |
13,000 |
19,000 |
|||
Mar |
7,000 |
21,000 |
|||
Apr |
Second Quarter |
8,000 |
17,000 |
20,000 |
59,000 |
May |
3,000 |
19,000 |
|||
Jun |
6,000 |
20,000 |
|||
Jul |
Third Quarter |
7,000 |
10,000 |
11,000 |
15,000 |
Aug |
3,000 |
4,000 |
Appendix II
Agreement Between the Army and the Navy Concerning War Preparations for the First Half of Fiscal Year 1945
Army General Staff
Navy General Staff
1 April 1945
Deputy Chief, Army General Staff
Vice-Chief, Navy General Staff
I, General Principles
The war preparations of the Army and the Navy for the first half of the fiscal year 1945 will be accomplished in accordance with the following principles:
1. Priority will be given to the equipment of the Air Forces and the Special Attack Forces. Of the Army land forces (operational forces, including the 40 newly-organized divisions) and the Navy forces (excluding Air Force and Special Attack Forces), those which can be relied upon to display fighting power to repel the enemy during the decisive battle for the Homeland will be provided promptly with sufficient equipment. War preparations for the defense of surface communications routes will be restricted to a minimum, while other preparations will be executed in consonance with national power and within a limit which will not affect major war preparations.
2. Efforts will be made by both the army and the Navy to cooperate in their war preparations. In exchanging assistance, the Array will facilitate the Navy's procurement of aircraft and special underwater attack
weapons for attacking enemy task forces. The Navy will assist the Army in its procurement of aircraft and ground weapons to be used in the local air defense of the Homeland.
3. The Supreme Command will maintain close contact with the Government and extend all-out support and cooperation to the latter in concentrating the resources of the entire nation for war purposes, as well as in building up such war preparations.
U. The planning of Array and Navy war preparations, (items, quantities, priority, et cetera) will be based on the principles enumerated herein and implementation of such plans will be carried out with a view to adequate realization of such plans.
II. Essentials of the Goal for Army and Navy War Preparations
1. The order of priority in war preparations by the Army and Navy will be as follows:
a. Aircraft and special attack weapons
(1) Aircraft and special air attack weapons. The position on the priority list to be determined separately.
(2) Underwater and special surface attack craft.
(a) Koryu midget submarines and small submarines.
(b) Kairyu midget submarines.
(c) Kaiten human torpedoes.
(d) Shin-yo crash boats.
(3) A minimum number of simple base installations required for operating the above.
--ii--
b. Ground weapons.
(1) Antitank weapons.
(2) Weapons for use against heavy weapons, landing craft and large caliber machine guns.
(3) Close-range automatic weapons and anti-aircraft guns.
(4) A minimum number of simple ground combat fortifications
required for operating the above.
c. Naval craft and weapons for severing the enemy's rear lines and for protecting friendly surface communications lines.
(1) Submarines.
(2) Light minelayers and mines.
(3) Coastal defense craft and depth charges. (4) Frigates.
d. Transports
(1) Navy transports.
(2) Large landing barges.
e. Fortifications and installations
(1) Base for general aircraft and special attack aircraft.
(2) General preparations for land combat.
f. Other items (clothing, materiel, medical and veterinary
supplies)
Minimum requirements proportionate to Army and Navy strength estimated for September 1945.
To secure the necessary provisions, every possible measure
--iii--
will be taken with the nation's food supply taken into consideration. The Army and Navy will collaborate in providing various types of fuel and ammunition in the maximum quantity and in such proportion as to meet the requirements of the different weapons. Maximum efforts will be made in making preparations for chemical warfare. The essentials of this measure will be prescribed in a separate agreement.
2. Essentials concerning procurement and distribution of the principal weapons to the Army and the Navy for the first half of fiscal year 1945 will be determined in accordance with Charts 1 through 7.
--iv--
Chart 1-a
The Number of Aircraft to be Made Available During the First Half of Fiscal Year 1945
Outline of Plan
1. In procuring aircraft, the Army will give top priority to those planes which can be used for attacking enemy vessels, especially transports, and for defending strategic points of the Homeland; the Navy will place too greatest emphasis upon the procurement of those planes which can be used against hostile carrier task forces for the retention of air and sea superiority.
2. Both the Army and the Nary will convert all their planes into special attack planes, procure high priority aircraft and make every effort to ready the various types of aircraft by the middle of the current fiscal year.
3. To meet the minimum operational requirements, the any and the Navy will each procure more than 1,200 front-line planes a month. They will cooperate with each other to facilitate dispersion and transfer underground production facilities.
Classification |
Type of aircraft |
Minimum Requirements |
Production Goal |
|
Army Aircraft |
Fighter |
Type I fighter |
1,390 |
1,600 |
Type IV fighter |
2,500 |
3,000 |
||
KI-100 fighter |
1,200 |
1,500 |
||
KI-102 fighter** |
300 |
500 |
||
Type III fighter |
300 |
|||
Total |
5,390 |
6,900 |
||
Bomber |
Type IV bomber |
700 |
1,200 |
|
KI-74 bomber |
50 |
150 |
||
Total |
750 |
1,350 |
||
Hq Recon Plane |
Type 100 Hq racon plane |
500 |
800 |
|
Transport Plane |
KI-54 (or KI-110) transport plane |
100 |
150 |
Chart 1-b
The Number of Aircraft to be Made Available Daring the First Half of Fiscal Year
(Cont'd)
Classification |
Type of Aircraft |
Minimum Requirement |
Production Goal |
|
Army Aircraft |
Transport Plane |
Type 100 transport plane |
100 |
|
KI-105 transport plane |
50 |
|||
Total |
100 |
150 |
||
Trainer |
KI-54 (or KI-110) trainer |
100 |
||
Type II advanced trainer |
300 |
|||
Type IV trainer |
250 |
|||
Total |
650 |
|||
Grand Total |
6,740 |
10,000 |
||
Navy Aircraft) |
Fighter |
Shiden-Kai |
2,400 |
2,400 |
Zero fighter |
1,800 |
2,700 |
||
Kaiden-Kai |
600 |
|||
Saiun |
300 |
300 |
||
Ginga |
100 |
100 |
||
Total |
4,600 |
6,100 |
||
Reconnaissance Plane Saiun |
850 |
850 |
||
Attack Plane |
Ginga |
700 |
700 |
|
Ryusei |
300 |
300 |
||
Renzan |
50 |
100 |
||
Total |
1,050 |
1,100 |
||
Patrol Plane |
Type I land-based attack plane*** |
240 |
250 |
|
Tokai |
250 |
|||
Total |
500 |
Chart 1-c
The Number of aircraft to be Made Available During the First Half of Fiscal Year 1945
(Cont'd)
Classification |
Type of Aircraft |
Minimum Requirements |
Production Goal |
|
Navy Aircraft |
Sea Reconnaissance Plane "Seiran" |
80 |
||
Type I Transport Plane |
320 |
|||
Type Zero Transport Plane |
||||
Trainer |
Land-based medium trainer |
200 |
||
Utility trainer |
200 |
|||
Zero training fighter |
350 |
|||
Type 99 training bomber |
100 |
|||
Tokai trainer |
200 |
|||
Total |
1,050 |
|||
Grand Total |
6,740 |
10,000 |
Notes: * Number of planes to be procured by all means. Most of the planes to be produced at dispersed, underground facilities.
** Types of KI - 202 fighters that must be acquired by any means are the Type A and C.
*** Type I land-based attack planes will also be used as torpedo bombers.
Chart 2-a
List of Special Attack Weapons to be Produced Daring the First Half of 1945 Fiscal Year
Weapons |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Total |
Responsibility for Procurement (The one marked "*" will be mainly responsible) |
Remarks |
"KI" 115 Special Attack Plane |
50 |
150 |
300 |
400 |
500 |
600 |
2,000 |
Army |
|
Special Type Plane |
2,000 |
Navy |
|||||||
Oka |
300 |
300 |
300 |
300 |
300 |
300 |
1,800 |
Navy |
|
Koryu Midget Submarine |
35 |
35 |
50 |
100 |
150 |
180 |
540 |
Navy |
|
Kairyu Midget Submarine |
100 |
120 |
130 |
150 |
200 |
200 |
900 |
Navy |
Maximum efforts will be made to increase production |
Kaiten Human Torpedo |
100 |
100 |
100 |
110 |
120 |
120 |
650 |
Navy |
|
Small Submarine |
1 |
5 |
8 |
13 |
13 |
40 |
Navy |
||
Shusui |
100 |
150 |
200 |
200 |
250 |
300 |
1,200 |
*Army Navy |
To be allocated equally to the Army and the Navy |
Chart 2-b
Weapons |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Total |
Responsibility for Procurement (The one marked "*" will be mainly responsible) |
Remarks |
Shinyo Navy Crash Boat |
600 |
600 |
600 |
600 |
600 |
600 |
3,600 |
Army *Navy |
|
Maruhachi Army Crash Boat |
500 |
500 |
1,000 |
1,000 |
3,000 |
Army |
|||
Fu Go Bomb carrying Balloon |
1,000 |
1,000 |
1,000 |
3,000 |
Army |
Notes
1. In addition to the weapons mentioned in this table, 10,000 "Ke" rocket bombs, 1,000 "I Go" bombs and 300 "Kikka" suicide attack planes are scheduled to be procured during the first half of the current fiscal year. But the decision relative to their procurement will depend upon the results of research and examination.
2. Procurement of other weapons now under consideration will be determined and added to this table after the research results are made available.
Chart 3-a
Quantity of Land Combat Weapons to be Produced During the First Half of Fiscal Year 1945
Part 1. Firearms and Guns
Classification of Weapons |
Quantity to be Procured |
Distribution |
Responsibility for Procurement (The one marked "*" will be mainly responsible) |
||
Model 99 Rifle |
540,000 |
Army |
440,000 |
* Army |
|
Navy |
100,000 |
Navy |
|||
Sub-machine Gun |
6,200 |
Army |
Amy |
||
Pistol |
26,000 |
Army |
19,000 |
Army |
24,000 |
Navy |
7,000 |
Navy |
2,000 |
||
Heavy Grenade Discharger |
20,900 |
Army |
18,000 |
Amy |
18,000 |
Navy |
2,500 |
Navy |
2,500 |
||
Light Machine Gun |
10,300 |
Army |
Amy |
||
Heavy Machine Gun |
4,200 |
Army |
3,500 |
Amy |
3,000 |
Navy |
700 |
Navy |
1,200 |
||
Battalion Gun |
1,050 |
Army |
Army |
||
"Rota" Rocket Launcher |
23,500 |
Army |
13,500 |
Army |
6,000 (70 mm) |
Navy |
10,000 |
Navy |
17,500 (100mm, 80mm) |
||
47mm antitank Gun |
325 |
Amy |
Army |
||
105mm Recoilless Gun |
120 |
Amy |
Army |
||
Type 41 Mountain Gun |
230 |
Amy |
Army |
||
Type 94 Mountain Gun |
130 |
Amy |
Army |
||
Field Gun (Models 90 & 95) |
38 |
Amy |
Army |
||
150mm Cannon, 150mm Howitzer |
27 |
Army |
Army |
Chart 3-b
Quantity of Land Combat Weapons to be Produced During the First Half of Fiscal Year 1945
(Cont'd)
Classification of Weapons |
Quantity to be Procured |
Distribution |
Responsibility of Procurement (The one marked "*" will be mainly responsible) |
||
100mm Howitzer, 100mm Cannon |
54 |
Army |
Army |
||
120mm Mortar |
720 |
Army |
Army |
||
120mm Short Flat-trajectory Gun |
800 |
Army |
400 |
Navy |
|
Navy |
400 |
||||
80mm Mortar |
10,000 |
Army |
5,000 |
Navy |
|
Navy |
5,000 |
||||
Rocket Gun |
4,300 |
Any |
2,300 |
Army |
(120 200mm guns and 180 400mm guns) |
Navy |
2,000 |
Navy |
(4,000 200mm or 120 mm guns) |
||
Rocket Bomb Launcher |
10,000 |
Army |
1,000 |
Navy |
Production goal will be set at 200,000 |
Navy |
9,000 |
Army |
|||
Model 98 Grenade Discharger |
3,000 |
Army |
Army |
||
Tanks |
300 |
Army |
Army |
||
Self -mobile powered Gun |
310 |
Army |
270 |
Army |
270 |
Navy |
40 |
Navy |
40 |
Part 2. Close-Quarter Combat Weapons
Classification |
Quantity |
Distribution |
Responsibility for Procurement |
||
Flame Thrower |
2,400 |
Army |
2,100 |
Army |
2,100 |
Navy |
300 |
Navy |
300 |
Chart 3-c
Quantity of Land Combat Weapons to be Produced During the First Half of Fiscal Year 1945 (Cont'd)
Classification |
Quantity |
Distribution |
Responsibility for Procurement |
||
Antitank Mine |
40,000 |
||||
(5-kg hemispherical) |
Army |
Army |
|||
(2-kg conical) |
|||||
(type 3 hand mine) |
|||||
Yardstick Mine |
200,000 |
Army |
100,000 |
Amy |
90,000 |
Navy |
100,000 |
Navy |
110,000 |
||
Small-type Mine (Assault) |
150,000 |
Navy |
150,000 |
Navy |
|
Conical Hand Mine |
100,000 |
Army |
50,000 |
Navy |
|
Navy |
50,000 |
||||
Hand Grenade |
500,000 |
Amy |
250,000 |
Amy |
125,000 |
Navy |
250,000 |
Navy |
375,000 |
||
Molotov Cocktail Incendiary (Smoke) Grenade |
300,000 |
Army |
180,000 |
Amy |
180,000 |
Navy |
120,000 |
Navy |
120,000 |
||
Part 3. Land Transport Weapons
Classification |
Quantity |
Distribution |
Responsibility for Procurement |
|
Tractor |
210 |
Amy |
Amy |
|
Armored Troop Carrier |
350 |
Amy |
Amy |
|
Track |
6,100 |
Army and Navy To be fixed according to the else of the ground force |
Army |
5.100 |
Navy ■avy |
1,000 |
Chart 3-d
Quantity of Land Combat Weapons to be Produced During the First Half of Fiscal Year 1945 (Cont'd)
Classification of Weapons |
Quantity to be Procured |
Distribution |
Responsibility for Procurement |
|
Amphibious Motor Transport |
270 |
Army |
Army |
|
Small-type Track |
1,100 |
Army and Navy To be fixed according to the size of the ground force |
Army |
100 |
Navy |
1,000 |
|||
Trailer |
620 |
Army |
Army |
|
Army Transport Car |
To be determined separately |
Army and Navy To be fixed according to the size of the ground force |
Army |
3,000 |
Navy |
To be determined separately |
|||
Carts |
To be determined separately |
Same as above |
Army |
3,600 |
Navy |
To be determined separately |
Part 4. Simple Weapons
To be fixed separately.
Remark: Distribution of ground weapons to the Army and the Navy will be made through a separate channel in order to best meet the war situation and will be based on practical consideration of the ground warfare of the Army and the Navy.
Chart 4-a
Production of Vessels During the First Half of Fiscal Year 1945 (For Escort, Transportation and Traffic Interruption Warfare)
Classification |
Completion Expected During the First Half |
Maintenance and Distribution |
|
Destroyers |
Tei |
10 |
Navy |
Submarines |
Ko |
2 |
|
Tei |
1 |
||
Special |
2 |
||
Supply |
1 |
||
High speed |
4 |
||
Coast Defense Ship's |
Ko |
20 |
|
Hei |
|||
Tei |
|||
Navy Transports |
1st class |
4 |
Navy and Army |
2d class SB Type Landing craft |
9 |
||
Bombardment Target Ship |
1 |
Navy |
|
Minelayer and Concurrently Target Ships |
2 |
Navy |
Chart 4-b
Production of Vessels During the First Half of Fiscal Year 1945 (For Escort, Transportation and Traffic Interruption Warfare)
Cont'd
Classification |
Completion Expected During the First Half |
Maintenance and Distribution |
|
Minelayers |
6 |
Including 4 converted merchant vessels |
|
Coast Defense Boats |
Ko |
6 |
Navy |
Otsu |
18 |
||
Special Patrol Boats |
40 |
||
Large Landing Barges |
Special |
30 |
Army |
Steel |
1,350 |
Army 900, Navy 450 |
|
Wood |
1,850 |
Army 900, Navy 900 |
|
Amphibious |
30 |
Navy |
|
Engined Barges |
360 |
Army |
|
Small Transport Barges |
400 |
||
Folding Boats |
600 |
||
Type 1 Submersible Transport Craft |
30 |
||
Remarks: Naval transports, submersible transports and barges shall be employed jointly by the Army and the Navy. |
Chart 5-a
Antiaircraft Equipment to be Produced in the First Half of 1945 Fiscal Year
Classification |
Quantity (Ammunition) |
|||
Antiaircraft Gun |
For Army Land Defense |
Mode1-88, 70 mm antiaircraft gun (Includes those for mounting on airplanes. |
1160 (210,000 rounds) |
|
Model-4, 70mm antiaircraft gun |
200 (190,000 rounds) |
|||
80mm antiaircraft gun |
240 (360,000 rounds) |
|||
120mm antiaircraft gun |
95 (50,000 rounds) |
|||
150mm antiaircraft gun |
5 (3,000 rounds) |
|||
For Nary Land Defense and for Vessels |
Mode1-1, 127mm antiaircraft gun |
30 |
500 rounds per gun |
|
127mm antiaircraft gun |
100 |
500 rounds per gun |
||
120mm antiaircraft gun |
410 |
400 rounds per gun |
||
Mode1-98, 100mm antiaircraft gun |
50 |
500 rounds per gun |
||
Total |
1,350 |
Chart 5-b
Antiaircraft Equipment to be Produced in the First Half of 1945 Fiscal Year
(Cont'd)
Classification |
Quantity ([Estimated]) |
|||
Antiaircraft Machine Gun |
25mm antiaircraft machine gun |
7,200 |
3,500 rounds per gun |
|
20mm antiaircraft machine gun |
(Type-4 twin mount) |
900 (30,000,000) |
||
13am antiaircraft machine gun |
1,00 |
4,000 rounds per gun |
||
40mm antiaircraft machine gun |
560 |
4,000 rounds per gun |
||
Searchlight |
1.5 m reflector |
230 |
||
2 m reflector |
106 |
|||
Antiaircraft Balloon |
Type 1 |
10 |
||
Type 2 |
175 |
|||
Small Sound Locator |
110 |
|||
80mm Barrage Mortar Shell |
(300,000 rounds) |
|||
Antiaircraft Kits |
1,600 |
Notes:
Employment of antiaircraft firearms for land defense shall be coordinated between the Army and the Navy.
Chart 6
Antisubmarine Weapons to be Constructed in the First Half of Fiscal Year 1945
Classification |
Quantity |
Distribution |
Responsibility for Procurement |
|||
Sonar Equipment |
2,000 |
Navy |
4 |
Navy |
||
Antisubmarine Radar |
1,200 |
Army |
200 |
|||
Navy |
1,000 |
|||||
Magnetic Radar for Aircraft |
1,500 |
Army |
300 |
|||
Navy |
1,200 |
|||||
Mine |
Ordinary |
30,000 |
Navy |
|||
For Beaches |
20,000 |
Navy |
||||
Depth Charge |
50,000 |
Army |
10,000 |
Army |
10,000 |
|
Navy |
40,000 |
Nary |
40,000 |
Chart 7
Fuel and Powder to be Produced in Japan, Manchuria and China
Classification |
Quantity |
Remarks |
|||
For Fiscal Year 1945 |
For the First Half of Fiscal Year 1945 |
||||
Liquid Fuel |
Aviation gasoline |
60,000 kl |
26,000 kl |
||
Ordinary gasoline |
50,000 kl |
23,000 kl |
|||
Alcohol |
400,000 kl |
120,000 kl |
|||
Methanol |
50,000 kl |
20,000 kl |
|||
Heavy oil |
Heavy oil for Navy use |
250,000 kl |
120,000 kl |
||
Heavy oil for civilian use |
160,000 kl |
60,000 kl |
|||
Kerosene |
130,000 kl |
50,000 kl |
|||
"RO" - Go Fuel |
40,000 tons |
10,000 tons |
|||
Powder (Explosive) |
Powder |
70,000 tons |
Army 10,000 ton Navy 25,000 ton |
Details of the allotment of powder and explosive to be used in the first half of fiscal year 1945 shall depend upon the distribution of weapons. |
|
Explosive charges |
80,000 tons |
Army 20,000 tons Navy 20,000 tons |
|||
Notes: 1. The distribution is determined separately. 2. Measures shall be jointly taken by the Army and the Navy to drastically increase the production of turpentine extracted from pine roots and other oils which are not mentioned in this table. |
Appendix III
Naval General Staff Secret Document No 31
Data: 6 April 1945
Subject: Conference on War Preparations in the First Half of Fiscal Year 1945
From: Vice Chief of the Naval General Staff
To: Vice Minister of the Navy
In order to cope with the recent critical situation, it is requested, that arrangements be made to carry out immediately and resolutely the plans appended hereto concerning this subject matter. Relative to the conference, it is requested that the details be worked out by competent persons.
An agreement on the war preparations to be made during the first half of fiscal year 1945 was made between the Naval General Staff and Army General Staff Headquarters, as described in the annex.
Distribution:
Chief of Naval Aeronautical Department.
Chief Of Naval Technical Department.
Chief of Naval Civil Engineering Department.
Annex
I. Plan for War Preparations
A. In the first half-year period, efforts will be made to build
defense positions around Japan from which the advancing enemy can be destroyed, thus ensuring ultimate victory. The latter half of the year will be devoted to strengthening these fortifications in order that the offensive can be resumed at the earliest possible opportunity. These war preparations will be carried out as follows:
1. All war preparations will be carried out in the spirit of suicide attacks, and the total national power will be united into a fighting force that can furnish the necessary manpower for the coordinated war plans of the Army and Navy.
2. The main combat strength will be composed of air forces (including air special attack forces) and underwater and surface special attack forces. The greatest emphasis will be placed on the maximum development of their combat capabilities.
Relative to war preparations, other than those mentioned above, if they will not obstruct the build-up of the air forces and the special underwater and surface attack forces, priority will be given to important land defense forces, submarine forces, surface escort forces and supply forces in that order so that these forces, combined with the main forces, may meet the operational demands. In order to increase the air forces and the special underwater and surface attack forces to the size urgently required for these operations, it is expected that all other war preparations scheduled for completion prior to September will be postponed and those scheduled for completion after October will be temporarily suspended. Preparations for chemical warfare for both offen-
--ii--
sive and defensive operations will be effected promptly.
3. Relative to war preparations for intercepting the enemy at the center of our fortified region, all human and material strength will be mobilized so that they can be immediately and most effectively employed in action at the right moment. All possible steps will be taken to enable important combat forces to continue fighting with tenacity.
4. War preparations for the counteroffensive will be drawn up in a separate document.
B. Division of War Preparations
1. The first quarter of 1945 (from the beginning of April to the end of June):
a. The greatest emphasis will be placed on gaining control of the air and sea covering the area in which decisive action is being contemplated and especially on the destruction of enemy carrier task and occupation forces.
For this purpose emergency measures will be taken for the rapid build-up and employment of land-based air forces and special attack forces.
Preparations for offensive and defensive operations in the Homeland will be effected according to and in parallel with the foregoing program.
Specially designated surface forces will be ready by the end of June to conduct raiding operations on the sea near the Homeland. Steps will be taken to intensify the defense of industrial centers and commu-
--iii--
nications facilities against air attacks. Preparations for land combat on the Homeland will be carried out to the extent required by the war situation, provided that they do not obstruct other important war preparations of the Navy itself.
b. The protection to be given to surface traffic between Japan and Manchuria and China will be governed by the war preparations mentioned in the foregoing paragraph. Communications with the southern areas will be especially arranged so that they will be maintained even under the most serious combat situation. Sea transportation along the coasts of the Homeland will be so planned that it will be protected by land bases along the coast.
The surface-protecting forces will, for the time being, protect surface traffic between Japan and Manchuria and North China. Merchant vessels will be equipped with weapons which are adequate for antiaircraft and antisubmarine defense.
c. Most of the war materiel will be transported on suitable merchant vessels and the amount of supply will be kept to the minimum.
d. Preparations to frustrate the enemy's attempts to sever our short distance supply lines will be strengthened.
2. War preparations in the second quarter (from the beginning of July to the end of September):
a. An invincible structure will be established.
b. A portion of the preparations for counteroffensives will be carried out.
--iv--
c. Other war preparations will be the same as those prescribed for the first quarter.
d. Whether efforts are to be directed at preparations for war in the Homeland or at preparations for counteroffensives and sustained warfare will be decided according to the war situation in May.
3. War preparations in the third quarter (from the beginning of October to the end of December) and the fourth quarter (from the beginning of January to the end of March 1946):
War preparations prescribed for the second quarter will be continued and other programs for this period will be mapped out separately.
C. Urgent measures will be taken to procure important materials, especially for fuel and powder, so that a sufficient quantity can be rapidly supplied in Japan, Manchuria and China. The greatest emphasis will be placed on the securing of aircraft gasoline.
D. The Homeland will be organized so that production, training and war preparations can be carried out with the least possible amount of difficulty; the Homeland will be organized immediately into the front line with each area establishing a self-sustaining and self-defensive structure.
E. The overseas key areas will strive to establish self-sustaining and self-defensive structures.
II. Outline for the Execution of War Preparations
A. Aircraft with its Equipment and Facilities
--v--
efforts will be made to elevate the actual working efficiency of factory workers and to secure and expand aircraft production, while taking every possible measure to minimize damage from air raids. At the same time, the combat strength required as the main force of the Navy will be built up according to the following plant
a. Maximum emphasis in air preparations will be directed toward annihilation of enemy carrier task forces. A capable force will be maintained and strengthened as quickly as possible during the first quarter of preparations and thereafter the strength necessary for destroying other enemy objectives will be reorganized. For this purpose, importance will be attached to the preparation of fighter, reconnaissance and attack planes. In order to increase the effectiveness of the attack planes, principal emphasis will be placed on the over-all conversion of attack planes into special attack planes, the combined use of special attack planes and special type planes with acceleration of the production of large, extremely powerful aircraft.
b. Relative to aircraft for antiaircraft defense, fighting power will be increased by improving the performance of the aircraft now in use, by converting them into special attack planes and by accelerating production of special type planes. Relative to aircraft to be employed in attacking enemy invasion forces, plans will be drawn up to convert most of the aircraft used in training and those presently in storage into Special attack planes by late April. At the same time, efforts will be made to accelerate production of small special attack
--vi--
planes and conversion of other aircraft into small, special attack planes as soon as possible. With reference to escort aircraft for sea communications, these will be replenished with second-line planes, in addition to the planes being used exclusively for this purpose. Relative to aircraft for attacking enemy air bases, they will be maintained and strengthened as long as such aircraft are available.
2. The number of aircraft to be produced: Standard aircraft will be maintained and strengthened according te Chart 1. Special planes will be maintained and strengthened in accordance with the following section on Special Attack Planes.
3. Equipment and facilities relative to aircraft:
a. Antiaircraft defense measures for aircraft production facilities (including important related production facilities) will be completed quickly and thereafter intensified. Underground aircraft production facilities, capable of producing 1,200 frontline planes monthly (including special planes), will be completed during the first quarter of preparations.
b. Air bases will be prepared and strengthened in the following general order: Kyushu Area bases to be used for the coming decisive battle, Kanto Area bases for launching attacks on enemy carrier task forces, bases for use by special attack planes of the training air group and rear echelon bases in the Sanin, Korea and Hokkaido areas.
c. In addition to strengthening the radar network for air operations (including air defense), and the air defense for communica-
--vii--
Chart 1-a
Production of Aircraft for the First Half of Fiscal Year 1945
Naval Aircraft |
Type of Aircraft |
Minimum Requirement (The majority will be produced at dispersed underground factories The minimum requirements must be met at all costs) |
Ultimate Goal |
Remarks |
|
Fighters |
Shiden, Improved Model |
2,400 |
2,400 |
||
Zero Fighter |
1,800 |
2,700 |
To be converted into Shiden, Improved Model, as soon as possible |
||
Raiden, Improved Model |
600 |
||||
Saiun |
300 |
300 |
|||
Ginga |
100 |
100 |
|||
Total |
4,600 |
6,100 |
|||
Recon Plane |
Saiun |
850 |
850 |
||
Bomber and Attack Planes |
Ginga |
700 |
700 |
||
Ryusei |
300 |
300 |
|||
Renzan |
56 |
100 |
|||
Total |
1,050 |
1,100 |
Chart 1-b
Production of aircraft for the First Half of Fiscal Year 1945
(Cont'd)
Naval aircraft |
Type of Aircraft |
Minimum Requirement (The majority will be produced at dispersed underground factories. The minimum requirements must be met at all costs) |
Ultimate Goal |
Remarks |
|
Patrol Planes |
Type 1 Land Attack Planes |
240 |
250 |
Scheduled to be employed as attack planes |
|
Tokai |
250 |
||||
Total |
240 |
500 |
|||
Recon Seaplanes |
Seiran |
80 |
|||
Transport Planes |
Type Zero and Type I Transport Planes |
320 |
|||
Training Planes |
Medium Land-based Training Planes |
200 |
|||
Utility Trainer |
200 |
||||
Type Zero Training Fighters |
350 |
||||
Type 99 Training Bombers |
100 |
||||
Training Planes Tokai |
200 |
||||
Total |
1,050 |
||||
Grand Total |
6,740 |
10,000 |
ions, supply and repair facilities, everything will be done to improve these defense facilities in order to minimize damage from air attacks and maintain secrecy of preparations.
d. Weapons for air operations will be readied in sufficient quantity to maintain the air potential.
e. Additional details will be discussed in other sections, 4. Readying a carrier-based air force: Some of the already completed aircraft carriers are slated to be manned by special attack forces in the middle of 1945 and details will be discussed elsewhere.
B. Special Attack Craft and Related Facilities
1. Special attack craft will be readied in accordance with Chart 2. Special emphasis will be placed on the special underwater attack force, which will be the main strength in the annihilation of the enemy's invasion force and in the interception of his short-range supply lines. Also it will be the training force to be used against the enemy carrier task force. If necessary, details for preparations will be discussed elsewhere.
2. Related Facilities.
a. Production facilities will be dispersed and moved underground as promptly as possible and production will be greatly increased.
b. Various base facilities will be completed within the first quarter and strengthened thereafter. Additional details will be discussed separately.
C. Ships
--viii--
Chart 2-a
Special Attack Craft
Period |
First Quarter From April to June 1945 |
Second Quarter From July to September 1945 |
Third Quarter From Oct 1945 to End of Mar 1946 |
Remarks |
Classification |
||||
Special-type Aircraft |
2,000 |
To be determined by a later conference |
To be replenished with Suisei, Tenzan, Ki-115 and others. The details will be determined by a special conference. |
|
Oka Plane |
900 |
900 |
" |
A special conference will be held to discuss improvement of performance |
Kikka Plane |
300 |
" |
||
Shusui Plane |
450 |
750 |
" |
To be constructed through cooperation between the Army and Navy. Approximately one-third of this number will be constructed by the Navy. |
Karyu Plane |
5 |
" |
||
Kaiten Human Torpedo |
300 |
360 |
300 |
Chart 2-b
Special Attack Craft
(Cont'd)
Period |
First Quarter From April to June 1945 |
Second Quarter From July to September 1945 |
Third Quarter From Oct 1945 to end of March 1946 |
Remarks |
|
Classification |
|||||
Kairyu Midget Submarines |
350 |
550 |
1,000 |
To be constructed by advancing the deadline as much as possible. Improvement in the performance of the Kairyu will be considered in the last half of the fiscal year |
|
Koryu Midget Submarines |
110 |
430 |
1,000 |
||
Small Submarines |
40 |
120 |
Of the submarines scheduled for the first half, 40 will be readied by August. They will be equipped to recharge while cruising underwater as soon as possible |
||
Shinyou |
No. of Vessels |
1,680 |
1,800 |
1,200 |
|
Engines |
2,250 |
2,250 |
1,300 |
||
Notes |
The number scheduled for the Third Quarter and thereafter is an approximate figure. The details shall be determined by a later conference. |
1. Ships will be readied in accordance with Chart 3. All ships will be made as compact as possible and whenever possible small ships will be used.
2. Armament
a. Armament will be conducted strictly in accordance with the priority system. At the same time, ships capable of carrying special attack planes will, if possible, be fitted for this purpose.
b. Every effort will be made to simplify the fitting out of vessels. At the same time, coast defense ships, starting with those to be newly constructed, will be equipped, if at all possible, with a mixed firing boiler in order to shorten the construction time. Above all, the construction period for antisubmarine craft and submarines will be drastically reduced and the submarines will be fitted so that they may recharge their batteries while cruising underwater.
c. Details will be discussed elsewhere.
3. Air defense measures will be taken to protect the construction of ships as well as ships already constructed.
D. Weapons (Excluding weapons employed in aerial combat). Weapons will be readied in accordance with Chart 4.
E. Surface Defense
Defense of communications between Japan, Manchuria and China
and, especially, defense of the seas adjacent to the Homeland, the Tsushima Straits, the Japan Sea and North China, will be stressed. Harbor and bay facilities, air bases, communications facilities, defense
--ix--
Chart 3-a
Ship Construction
Priority |
Type of Ships |
Requirement |
Notes |
|
4 |
Aircraft Carriers |
2 |
Work will be suspended temporarily after the launching. Their use will be determined separately. Work on the "Ibuki" and "Kasagi" sill be suspended temporarily. |
|
4 |
Otsu |
1 |
Work will be suspended temporarily. |
|
2 |
Destroyers |
Tei |
20 |
Six will be completely equipped in the first quarter of the fiscal year. Construction of the others will be started according to the situation. Loading of Kaiten will be made possible. |
3 |
Submarines |
Tei |
2 |
|
Tei 2 (Bo) |
5 |
In unavoidable cases torpedo-tubes will be equipped later. |
||
2 |
High speed |
16 |
||
2 |
Special type |
2 |
Construction of ship No 5236 will be abandoned. |
|
2 |
Supply |
1 |
||
1 |
Escort-ships |
Ko |
30 |
Twenty will be completely equipped in the first half of the fiscal year. Construction of the others will be started according to the situation. |
Hei |
||||
Tei |
Chart 3-b
Ship Construction
(Cont'd)
Priority |
Type of Ships |
Requirement |
Motes |
||
3 |
Transports |
First-class |
5 |
||
Second-class |
10 |
||||
Small Patrol Boats |
40 |
To be completed by July. |
|||
1 |
Ko |
40 |
|||
Auxiliary Escorts |
Otsu |
80 |
|||
2 |
Light Minelayers |
2 |
|||
2 |
Converted Minelayers |
6 |
To be completed by the end of June. (Four of them will be reconverted merchant ships.) |
||
5 |
Special Landing Barges |
460 |
200 will be made of iron and 200 of wood. 30 will be for amphibious purposes. |
Remarks: If obstacles arise in the construction and equipping of the special attack craft, the date of completion for those expected to be completed by September will be extended, while those expected to be finished after September will be temporarily suspended.
Chart 4-a
Weapons
1. Antiaircraft Weapons
Classification of Weapons |
Quantity |
No. of Shells per gun or Projector |
Remarks |
||
AA Gun |
Type-1 127mm gun |
30 |
500 |
Armour piercing shells will be about 10% of land based AA Guns' shell. |
|
127mm gun |
100 |
500 |
|||
120mm gun |
470 |
400 |
|||
Type 98 100 mm gun |
50 |
500 |
|||
Total |
650 |
||||
Large Calibre Machine Gun |
40mm machine gun |
500 |
4,000 |
1. Land based machine guns will be of vehicle types. 2. Armour piercing shells will be about 20% of all machine gun shells. |
|
25mm machine gun |
10,000 |
3,500 |
Including 2880 guns scheduled for delivery to the Army |
||
13mm machine gun |
1,200 |
4,000 |
|||
Balloon, Kite |
AA balloon |
150 |
|||
AA kite |
1,600 |
||||
Searchlight |
150 |
Chart 4-b
Weapons
2. Land Combat Weapons
Classification of Weapons |
Quantity |
No. of Shells Per Gun or Projector |
Remarks |
|
Rocket Gun |
200mm rocket gun |
1,200 |
50 |
|
120mm rocket gun |
4,000 |
50 |
||
ROTA gun |
17,500 |
4 |
||
Bomb Launcher |
For 250 kilo bomb |
10,000 |
||
For 60 kilo bomb |
20,000 |
|||
Quick Firing Gun |
Medium and Small calibre gun |
200 |
300 |
Guns will be converted from shipboard guns |
Large calibre gun |
12 |
300 |
||
200mm short barrel gun |
50 |
60 |
||
120mm short barrel gun |
850 |
400 |
||
80mm gun |
50 |
400 |
||
Others |
80mm mortar |
10,000 |
300 |
|
7.7mm machine gun |
2,000 |
4,000 |
• |
|
Rifle |
100,000 |
300 |
||
Pistol |
12,000 |
60 |
||
Grenade thrower |
2,500 |
100 |
||
Small mine |
150,000 |
Chart 4-c
Weapons
Classification of Weapons |
Quantity |
No. of Shells Per Gun or Projector |
Remarks |
||
Others |
Attack mine |
100,000 |
|||
Stick mine i |
150,000 |
||||
Hand grenade (corn-shape) |
100,000 |
||||
Hand grenade |
5,000,000 |
||||
Molotov cocktail bomb |
150,000 |
||||
Incendiary grenade |
60,000 |
||||
Dynamite |
100,000 |
||||
Smoke bomb |
60,000 |
||||
Small smoke bomb |
150,000 |
||||
Steel helmet |
1,000,000 |
||||
Sword |
300,000 |
||||
Others |
Secondary small arms necessary for the above mentioned weapons will be prepared. Simple hand weapons will be decided later |
||||
Chemical Weapons |
Gas mask |
1,000,000 |
|||
Light anti-gas suit |
300,000 |
||||
Anti gas cover |
300,000 |
||||
Neutralizer |
Powder No 3 |
600 tons |
|||
Powder No 4 |
2,500 sets |
||||
Powder No 5 |
2,500 sets |
||||
Others |
Secondary small arms necessary for the above mentioned weapons will be prepared. Preparation for positive chemical warfare will be decided separately |
Chart 4-d
Weapons
Classification of Weapons |
Quantity |
No. of Shells Per Gun or Projector |
Remarks |
|
Smoke Screen Weapons |
Smoke powder |
3,000 tons |
||
40 kilogram smoke screen apparatus |
3,000 sets |
|||
Gunpowder |
25,000 tons |
|||
Explosive |
20,000 tons |
|||
Vehicles |
Amphibious tank |
70 |
||
Tractor |
70 |
|||
Other vehicles |
To be decided later |
|||
3. Anti-submarine Apparatus [Split table here.] |
||||
Classification |
Quantity |
Remark |
||
Depth Charge |
40,000 |
|||
Mine |
30,000 |
|||
Hydrophone, Magnetic Detection Apparatus |
Necessary amount for the anti-submarine vessels and airplanes |
4. Other Weapons
Necessary amount for vessels, planes and other strength will be prepared.
facilities, patrol facilities and repair facilities, which are necessary for antisubmarine and antiaircraft defense, will be readied and strengthened.
As for the defense of the Southern Area communications routes, every effort will be made to preserve and strengthen the coastal shipping lanes along the continent.
F. Defense of the Areas.
1. The defense priority for the various areas will be as follows:
a. Homeland, Ryukyu Islands, Bonin Islands and South Korea.
b. Central and North China, and North Korea.
c. Other areas.
2. Outline of Defense:
a. The Homeland, South Korea Area, Ryukyu and Bonin Islands sector:
(1) Defense of the Homeland area will be carried out under the plan that the Kanto, Kyushu, South Korean and Hokkaido areas will be major fortresses linked with each other by intermediate fortifications and that control will be maintained over the Tsushima, Tsugaru, and Soya Straits and the southwestern channels of the Homeland. As for defense of the Ryukyu and Bonin Islands, the existing program will be strengthened in order to covert them into truly impregnable strongholds.
Above all, special efforts will be directed toward completion of the facilities necessary for displaying the combat effi-
--x--
ciency of the air forces and the special attack forces, which are to be used in the decisive battle, and toward perfection of communications facilities of every kind.
These defenses will be completed generally by the end of the first quarter and quickly strengthened during and after the second quarter.
(2) More thorough measures will be taken to strengthen antiaircraft defenses. These measures, which have already been discussed will be speedily completed so that the vital sources of the nation's fighting power, as well as vital supply stockpiles, may be developed to the maximum and so that various production capacities may be maintained at peak level on a long range basis.
(3) A strong and effective supply line, combining sea, land, and air routes, will be established.
b. Central China, North China, and Korea: Relative to defenses in Central China, North China and Korea, emphasis will be placed on disruption of enemy operations aimed at cutting off our Homeland from the continent. This operation generally will be conducted in accordance with the foregoing paragraph.
c. Other areas: Local defense facilities will be used and every effort will be made to strengthen these defenses.
G. Fuel and Powder "RO"
1. Fuel: The production goal for the principal fuels shall be as shown in the following table:
--xi--
First Quarter |
Second Quarter |
|||||
Homeland |
Southern Area |
Total |
Homeland |
Southern Area |
Total |
|
Aviation Fuel (kiloliters) |
130,000 |
60,000 |
190,000 |
140,000 |
70,000 |
210,000 |
Heavy Oil (tons) |
120,000 |
160,000 |
280,000 |
130,000 |
150,000 |
280,000 |
Ordinary Gasoline (kiloliters) |
9,000 |
10,000 |
27,000 |
9,000 |
10,000 |
46,000 |
Light Oil (kiloliters) |
8,000 |
27,000 |
2. Powder "RO" Ten thousand tons. This amount represents the total Army and Navy requirements.
--xii--