IJA Armoured Vighting Vehicles

tom · November 28, 2017, 7:05pm

Hi.

As promised I add my Japanese Armoured Fighting Vehicles manual. As the original post seems to be lost I will rebuild it during the next weeks, maybe months. So I have to ask for your patience.

Content::

Introduction
Japanese Designations and a short Dictionary
Armament: Machine Guns
Armament: Guns
Foreign AFV
Early japanese Projects
Armored Cars
Tankettes
Light Tanks
Medium Tanks
Heavy Tanks
Gun Tanks
Gun Carriers
Army Amphibious Tanks
Engineer AFV
Railroad AFV
Remote Operated AFV
Other Special Purpose AFV
Experimental Engineer AFV
Other Experimental AFV
Infantry AFV

I´m quite shure you´ll find a some vehicles unknown to you. I did during the search.

Due to the forum restriction of 10000 characters per post I´ll have to split most of the posts into two or more parts.

Yours

tom!

tom · November 28, 2017, 7:14pm

Hi.

1. Introduction part 1:

The japanese Army (IJA) had a lot of military observers on the European battlefields during WW1 which gathered many informations about modern war material and its use in a battle. This included chemical agents, light machine guns, aircraft, submarines, armored cars, tractors and also tanks. With the upcoming end of the war IJA decided in late 1918 to purchase examples of british and french tanks. As France and Great Britain had built several thousand tanks which weren´t needed any more it was no problem to receive them. A british Mark IV was delivered in late 1918 as technology transfer and propaganda vehicle. In 1919 a few FT 17s and Medium Mark A Whippets were also transferred to Japan. These were used to build up a tank company for test and training purposes at the IJA Infantry School.

During the Siberian Intervention 1918 - 1922 Japan sent several domestically made armored cars to support their troops. During the disarmament operation several white russian Austin armored cars were taken over. These vehicles were more modern and showed their value very soon.

Mark IV unloaded in Japan

In 1921 IJA decided to build up a domestic tank production. After the examinations and tests it became clear that the japanese industry was too weak to support a production at this time. So the tanks were sent on exhibitions throughout Japan to advertise for the necessary expenses in modern technology until 1928. The Kanto earthquake in 1923 delayed several projects. Nevertheless in 1925 the Japanese Army Technical Bureau was sure to be able to develop a domestic tank within 2 years. IJA high command was not convinced but nevertheless technical specifications for a heavy multi-turret tank were given. The design was quite difficult as most details had to be developed from zero. Most surprising the resulting tank, built in 1927, met almost all requirements and showed good characteristics and speed. Only the armor strength was rated too low. So after 1928 the tank was redesigned.

In addition requirements for a fast medium tank were given in 1927. This development was supported by trials to order new tank models for tests. This was quite problematic as most countries had stopped military development after 1918 to recover from the expenses of the war. So the few new designs were all rated top secret making it almost impossible to receive samples. Only rejected designs like the Vickers Medium Mark C were available. These were most useful for the development of the medium tank. Nevertheless there were some design failures making a complete restart in 1928 necessary. The new design used many features from the Vickers Mark C pre-series vehicles including the bow armor. Most important was an accident with the Mark C with the gasoline engine catching fire during an uphill drive. As a result IJA decided to use Diesel engines which used a less valuable fuel and were less vulnerable to fire. The resulting vehicle was fast enough to follow contemporary trucks, well-armed and sufficiently armored. But there were still problems to start a mass production in 1930. Especially the development of a Diesel engine took time and wasn´t finished until 1933. So some 50% of the built vehicles were equipped with gasoline engines.

In addition several foreign tractors and armored vehicles were tested during the 1920th leading to a large mechanisation wave in the early 1930th. This included the development of armored vehicles, special railway vehicles, amphibious AFV, tankettes and special purpose tanks. But due to the restricted available budgets only few projects were finally introduced and built in numbers larger than 10. This problem was solved with the start of the 2nd Sino-Japanese War or “China Incident” as it was called in Japan. Nevertheless tanks and AFV were still rated low priority compared to weapons, trucks, aircraft and ships.

The standard IJA tank tactic was infantry support based on the british and french tactics in WW1. Therefore tanks mainly had to fight field fortifications and bunkers. Enemy tanks should be fought by infantry anti-tank weapons and artillery. So IJA tanks had to be armored against infantry AP ammunition and to be armed with short, larger caliber guns. Speed was not that necessary.

In the mid-1930th IJA introduced a light tank rated as “cavalry tank”. It should be used for fast breakthroughs and had to fight enemy AFV, too. Therefore the tank had to be light. This was reached by using angled armor and finally even reducing armor to a minimum. Armament was a long barreled gun, 37 mm caliber. In 1935 a new medium tank was developed with higher speed and more armor. After this a complete development stop happened as the army high command thought they had all they need and refused any warnings that Japan would be unable to keep pace with the international tank development especially forced by Germany and the Soviet Union. There were several proposals of the Army Technical Bureau but all were rejected. These tanks had modern design features like coaxial MGs, protected suspension, more angled armor, welded armor and a 47 mm gun.

During the 1939 Nomonhan Incident against the Soviet Union a japanese tank regiment participated in the fightings. When they met T-26 and BT-5 tanks they were easily knocked out by the 45 mm long tank guns even on longer ranges. The japanese tanks had to get in closer ranges to penetrate the armor with the short 57 mm tank guns. So they were easy targets. This disaster was deemphasized by IJA High Command by focusing the war reports on the “strength and courage of the fighting forces”. Results were the development of a longer 47 mm tank gun and the necessary turret for the medium tank plus development of a long 57 mm tank and anti-tank gun. Most problematic was the decision to develop a superheavy multi-turret tank with an estimated weight of 120 t. But new, more modern designs were still rejected.

1941 the IJA tank doctrine was finally slowly redeveloped based on the experiences of the german tanks in France and during the early stages of the Operation Barbarossa. This lead to the organization of tank divisions in 1942 and development of tactics different from pure infantry support.
In addition the 1941 US embargo made a war against the allies more likely, if not necessary. First step was to speed up the development of the 47 mm, turret and 57 mm tank guns which only had low priority before. In addition proposals for an uparmored version of the medium tank and a new light tank for the airborne regiments were accepted. In early 1942 the first medium tanks with long barreled 47 mm tank gun were ready for action. They were sent to the Philippines immediately but came too late to participate in the main fightings. Test firings against a US Light M3 showed that the gun easily penetrated even the thickest armor of this tank on 500 m.

Light M3 nach Beschusstests

Part 2 below.

Yours

tom!

tom · November 28, 2017, 7:21pm

Hi.

Introduction part 2

In addition the development of two new tank models able to fight KV-1 tanks were ordered in mid-1942, a medium with the planned 57 mm gun and a heavy with a long 75 mm gun. Before design reached the prototype stage intensive examinations of the contemporary german tanks were started. In early 1943 even the new Tiger and Panther tanks were examined and a sample of each bought. At this time the low stocks of raw materials became problematic and as result all developments were slowed down. Another major drawback was the decision to terminate the development of the long 57 mm tank gun due to a too low firepower.

japanese military personel examining a Tiger tank in Germany

In late 1943 the new tanks were still on the drawing boards. The US Medium M3 and Light M3 and the british Mathilda tanks were superior to anything Japan could field. So the production of the uparmored version of the medium tank was speed up as much as possible. In addition a 75 mm field gun should be converted into a tank gun able to defeat the contemporary enemy tanks as stopgap solution. This made also a new turret necessary which was finished in 1944. During all this time the completely outdated 1935 light tank and 1937 medium tank were still mass produced. All upgraded tanks were held in Japan to counter the expected invasion. In addition most transport routes were under siege by allied submarines and carrier task forces making sea transport very dangerous.

The new medium tank model was not finished before summer 1945 due to problems with the newly developed long 75 mm tank gun based on an aa-gun. The new heavy tank was still in development in August 1945. Both were not serial produced. With them an allied invasion would have been very costly. All developments could be held secret so US intelligence officers were quite surprised after surrender to find such large and quite modern tanks in Japan.

With the development of the long barreled 47 mm gun the tanks lost significant HE-power. So from 1939 on several gun tanks armed with 75 mm, 105 mm and even 150 mm artillery guns were developed and produced. These AFV should be used in special gun tank companies in the tank regiments and used for close support. These vehicles were self-propelled artillery.

The infantry received gun carriers (tanks were only allowed for tank units……) which used long barreled AT-guns. These vehicles were tank hunters.

Type 5 7 cm Gun Carrier Na-To

A lot of special purpose vehicles based on tankette and medium tank chassis were developed and produced, most of them only in smaller numbers. There were a number of special vehicles for railway units, engineers and communication units, also several armored transport vehicles.

IJA tried to develop amphibious tanks during the mid-1930th but only prototypes were produced. Only the japanese navy used amphibious tank and vehicles operational. They also had several IJA tank models and even special close-support tanks for the Special Naval Landing Forces.

Yours

tom!

Rising_Sun · November 29, 2017, 2:37pm

Thanks, tom! for this interesting material.

I wonder whether the IJA gave sufficient consideration to the terrain in which their tanks would be used as part of national military strategy and local tactics, as distinct from just building tank forces based on the use and terrain of other armies?

While terrain in China might have been better suited to tanks, as far as the southward thrust into Malaya, NEI, Burma, Papua New Guinea, Solomon Islands etc was concerned, much of the terrain wasn’t suited to IJA tanks in any seriously useful capacity apart from, occasionally, clearing lightly fortified Allied positions. The terrain certainly didn’t support the sort of tank warfare which occurred in Western and Eastern Europe, whether tank to tank or tank as infantry support in advance.

Apart from the Philippines where IIRC there were about equal numbers of US and IJA tanks, the IJA tanks tended to outnumber the Allied tanks if any Allied tanks were actually present but it wasn’t the relatively few IJA tanks but the superiority of IJA infantry training, battle hardening, tactics, aggression and determination which generally carried the battles in the IJA’s (and IJN land forces in places) favour over Allied forces.

In particular, IJA tanks weren’t suited to or even able to participate in the very effective IJA infantry tactics in close country and jungle of envelopment and infiltration of Allied positions, which were purely infantry operations, and which in Malaya in particular were primarily responsible for Japan’s victory and, separately, Japan’s successful advance in Papua New Guinea in 1942.

Conversely, in close country IJA tanks were largely forced to stay on the roads where they were vulnerable to British Commonwealth artillery, as at Bakri where the Australian anti-tank artillery destroyed most of the advancing IJA tanks. https://www.awm.gov.au/index.php/collection/C31281 Nonetheless, as the IJA had tanks in Malaya and the British Commonwealth didn’t, this gave the IJA a significant advantage.

Separate issue, but the wheel bottom left in the linked picture looks like it has the bearing and stub axle attached (which doesn’t augur well for re-attaching the wheel) and the item to the right rear of the wheel to the right of the gun looks a bit like a gun spade or perhaps the towing attachment, which in the latter case also doesn’t augur well for getting the gun out of there. Anyone know what these parts are and how they worked on reassembling the gun?

Churchill · November 29, 2017, 9:01pm

Nice read Tom!, I look forward to the rest!

RS*, I presume you’re talking about the Na-To. I don’t know what you mean about the first part with the stub axle, but as for the gun parts, I’m not inclined to believe that the gun was meant to be removed from the vehicle during or after fire. The WarThunder model of the vehicle does not have any provisions for removing the gun from the vehicle, as it is mounted to the chassis directly after the cab with what appears to be a purpose-built mount. While I’m sure they used the best possible sources they could, they may have certain inconsistencies.

Rising_Sun · November 30, 2017, 8:48am

Sorry for any confusion. I was referring to the linked picture of the Australian anti-tank gun n my last post, shown below.

navyson · November 30, 2017, 12:15pm

Thanks for posting!

Churchill · November 30, 2017, 7:01pm

This makes a lot more sense, though I misread the beginning of your last paragraph.

tom · January 2, 2018, 4:12pm

Hi.

The original thread has been recovered by the forum owner. Many thanks.

2. Japanese designations and a short dictionary part 1

The Imperial Japanese Army (IJA) and the Imperial Japanese Navy (IJN) used several designation systems which differed only marginal for land-based weapons (compared to the airforce and naval designation systems). Most designations had the same basic appearance:

Yeartype - sort of equipment - (not always) short designation - (not always) additions

A) Yeartype

The Yeartype consisted mainly of a number indicating the year of introduction or design begin and the syllable “shiki” for “Type” or “Model” (which is still not finally clarified among experts, most tend to “Type”

Until 1940 the year was used in which the weapon system was officially introduced (e.g. Type 95 Light Tank) or finally refused (e.g. Type 95 heavy tank). From 1941 on this system was not longer used that strictly, mainly to hamper enemy intellicgence (e.g. the Type 3 medium tank was introduced in 1944, design was started in 1943)

If there are different weapon systems of the same type introduced in the same year the supplement “model” and a number was added. (e.g Type 94 Model 1 - 4 for four different sized radio sets). Changes in the design of a particular “model” was indicated by the further addition “mark” and number (eg. Type 94 Model 2 Mark 3 bomb fuze).

For the year of introduction two different calendar systems were used:

a) Imperial Calendar:
With this system the additional syllable “nen” = “regency) year” was added between year and “shiki”. The year is given as “Year of regency” of a particular emperor:

Meiji regency: Emperor Mutsuhito (1852 - 1912) , regency 1867 - 1912 (death)
1867 was Year 0 , 1912 was Year 45 of Meiji era. So any weapon introduced in this era received the year- designation Meiji (e. g. the famous Arisaka rifle introduced in 1905 was designated Type Meiji 38 rifle, the 24 cm howitzer introduced in 1912 was designated Type Meiji 45 howitzer…)
Taisho-regency: Emperor Yashihito (1879 - 1927), regency 1912 - 1927 (death)
1912 was Year 0, 1927 was year 15 of Taisho-era. Any weapon introduced in ths era after the death of Mutsuhito received the year-designation Taisho (e. g. the light 37 mm infantry gun introduced in 1923 received the designation Type Taisho 11 infantry gun…)

-Showa-regency: Emperor Hirohito (1901 - 1989), regency 1925 (from 1923 inofficially, from 1925 officially as co-emperor to aid the very ill Emperor Yashihito) - 07.01.1989 (death)
1925 was Year 0, 1989 Year 64 of Showa-era.

To simplify the designation system and to reduce irritations if the Regency addition wasn´t added completely (e. g. if only “juichi nenshiki” = “Type (regency) year 11” is mentioned it could mean a 1923 = Taisho 11 or 1936 = Showa 11 introduced weapon system) IJA and IJN changed from regency year to Jimmu-calendar year in 1928.

But many navy and airforce design orders were designated after the Showa-calendar (e. g. The design of the A6M “Zero” started as “Navy experimental 12-Shi Carrier Fighter” in year 12 of Showa regency = 1937…)

b) Jimmu-Calendar
The Jimmu-Calendar is based on the more or less mythical beginn of the japanese empire. In 660 BC (in 1872 the 11. February was declared as "correct date"a local leader defeated the last larger local enemy and founded the japanese imperial dynasty. He later received the honor name Jimmu. So the standard japanese calender which is still in use began in 660 BC.

From 1928 on IJA and IJN designated their weapon systems using the Jimmu-Calendar-year. 1928 was year 2588. To simplify this system only the last 1 or 2 ciphers were used (2588 = 88, 2604 = 4). For 1940 the possible year designations 0 and 100 were both taken (IJA used 100, IJN 0).

B) sort of equipment

In general the same designations as in western armys were used, translated into japanese language (e. g. light tank, rifle, handgrenade, radio set, gas mask etc.). Sometimes designations were somewhat different but more or less self-explanatory (e. g. “Ju-Sokosha” = “heavily armoured vehicle” for the small Type 92 recon tank used by cavalry units; "recoilless rifle/gun"for rocket-propelled at-weapons and artillery rocket launchers, “kikanho” = “automatic cannon” for light aa-guns)

C) short designation

Several japanese vehicles and some other weapon systems received short designations. Some of these designations were part of a system (e. g. light and medium tanks, gun tanks etc.), others had to do with the intended tasks (e. g. special tractor, gun carrier, armoured vehicle etc.) or were added during development and officially adopted later (e. g. “Ha-Go” or “Ka-Mi”) Some meanings were lost during the years but most are still known. I will cover this topic in a later post here.

Continued in Part 2…

tom · January 2, 2018, 4:35pm

Hi.

2. Japanese designations and a short dictionary part 2

D) additions:

Several pieces of equipment received additions to clear the identity of the piece of equipment. Often used were the following:

KAI
short for “Kaizo”= “modified”
This was added if major modifications were made without changing the complete system (e. g. Type 97 Medium Tank Chi-Ha KAI for the Type 97 armed with the Type 1 47 mm tank gun in a new turret, major upgades on aircraft models etc.)
alphabetic characters
Another system to mark major changes without changing the complete system (similar to the german system, e. g. Panzer III F, G, H etc.). IJA used the first letters of the traditional (chinese) alphabet:
Kou = A
Otsu = B
Hei = C
Tei = D
Bo = E
Ki = F
Kou = G (same pronunciation as Kou(A) but different character)
…
These additions were mainly used for vehicles (e. g. Kou(A) for the gasoline engined version, Otsu for the Diesel engined versions)

-nicknames
Several weapon systems received nicknames officially, mainly aircraft. Other nicknames were adopted officially after beeing used for some time inofficially by the soldiers (e. g. “Reisen” for “Rei Sentoki” = [Type] 0 fighter)

numerations:
several vehicles received numerations meaning “first of this kind of weapon”.The numerations were basically alphabetic or numeric characters followed by “gata” = “of this Kind” or “go” = “Version”(e. g. “Kou(A)-gata” = first of this kind ",here light tank, for the Renault FT-17 tanks, “Otsu-gata” = "second of this kind"for the Renault NC-27 light tanks, “I-go” = “first Version” for the Type 98 mini-engineer vehicle). This was even used as designation of the Army guided air-to ground missile development (I-Go-1)
others:
Sometimes additions were used only inofficially but taken over by allied forces and used in literature as ´official`(e.g. “Shinhoto” = “new turret” as nickname for the modified Type 97 medium tank with the 47 mm gun in a newly designed turret)

E) Special IJA Tank designation systems

a) early years (1925 - 1934)

IJA started domestic tank developments in 1925. At this time tanks were ratet in three categorys:

light: weight up to 10 (metric) t
medium: weight 10,01 t to 20 t
heavy: larger than 20,01 t

Following this system the european tanks purchased until 1930 were rated as follows:

light: Renault FT 17 (13 bought 1919/20), St. Chamond M21 wheelcumtrack (1 bought 1923), Renault NC 27 (10 bought 1927)
medium: Medium Mk A “Whippet” (4 - 6 bought 1919), Vickers Mk C (3 bought 1926)
heavy: Mk IV female (1 bought 1919)

Only the FT 17 and the NC 27 were used operationally. As these were the first light tanks the FT-17 received the designation “Kou(A)-Gata” = “1st (light tank)” and the NC 27 “Otsu-Gata” = “2nd (light tank)”.

The first domestic tank which was finished in 1926 was rated experimental only and so it received the designation “Experimental Tank No. 1”. In 1927 a new design for a light tank was started and received the designation “Experimental Tank No. 2”.

The prototype production domestic tanks received the standard designation consisting of Yeartype and sort of equipment. In addition short designations were added indicating the numer of design:

“Yi-Go” or “I-Go” = “first (domestic tank)” for Type 89 Medium Tank
“Ro-Go” = “second (domestic tank)” for the Type 95 Heavy Tank
“Ha-Go” = “third (domestic tank)” for the Type 95 Light Tank

b) mid-years (1935 - 1941)

In 1935 a new short designation system was introduced. It consisted of a syllable for the size and a numbering syllable for the design number connected by a dash.

Light tanks received the size syllable “Ke” = short for “Kei” = “light”
Medium tanks received the size syllable “Chi” = short for “Chiuu” = “medium”
Heavy tanks should receive the size syllable “Ju” = “heavy” (there was no “heavy” tank adopted in this periode)
Superheavy tanks received the syllable “O”

The nummeric syllable indicated which design of this size the vehicle was. The standart japanese numbering system was used:
Yi or I = first
Ro = second
Ha = third
Ni = fourth
Ho = fifth
He = sixth
To = seventh
Chi = eighth
Ri = ninth
Nu = tenth
Ru = eleventh
…

So “Chi-Ha” means “third medium tank design”, “Ke-Ni” = “fourth light tank design” etc.

It seems that older tank models should not receive this new short designation. “Chi-Ro” = “second medium tank design&”, which is sometimes used for the Type 89 Medium Tank in western literature, does not seem to be used by IJA.

Continued in part 3…

tom · January 2, 2018, 4:52pm

Hi.

2. Japanese designations and a short dictionary part 3

c) late years (1942 - 45)

From 1942 on the mid-years system was enlarged and softened. The weight limit between medium and heavy tanks was discontinued and the syllable “Ju” was dropped. But the heavier tanks were not designated “Medium Tank” but only “Tank” (e. g. Type 5 Tank Chi-Ri). The size syllable “Chi” was still used for counter intelligence purposes.

And some new short designation systems were added:

Close-support tanks (IJA called all AT- and CS-tanks to be used by tank units “hosensha” = “Gun Tanks”) received the purpose syllable “Ho” = “Gun” instead of the size syllable
SPGs (AT- and CS- tanks to be used by infantry units were called “Jisoho”; = “Motorised Gun”) became a short designation consisting of a syllable for the gun caliber followed by the purpose syllable “to” = “(gun) carrier” (e. g. “Na-To” = “7 (cm) (gun) carrier” for the Type 5 tank hunter with it´s modified Type 5 7,5 cm Tank Gun)

F)IJA armored vehicle and gun tractor designations

a) Armoured vehicles

Early armoured cars were named by their builders (e. g. Wolseley armoured car, Chiyoda armoured car, Sumida armoured car etc.). From 1931 on the standard designation system replaced this early system.

The in Europe and USA well known designations “Aikoku” and “Hokoku” for two japanese armoured car models are wrong. The designation comes from the writings on the vehicles. But these particular vehicles were donated by the japanese public organisations “Aikoku” (for IJA) and “Hokoku” (for IJN) which collected money to support the armed forces. The official designations of these vehicles were Sumida Type P Armoured Car (Aikoku) and Typ 93 Armoured Car (Hokoku)

In IJA nomenclature “sensha”= “fighting vehicles” were armoured vehicles used by tank units. Infantry and cavalry units were only allowed to have “Sokosha” = “armoured vehicles” in their arsenals. Therefore the tank short designation system was not used for infantry AFVs. Instead a designation system based on the vehicle´s purpose was developed:

Some examples:

The type 91 armoured railroad car was designated “So-Ki” = short for “Soko Kidosha” = “Armoured Railway (support) car”
The Type 92 light recon tank used by cavalry recon units was designated “Ju Sokosha” = “heavy armoured vehicle”
The Type 94 light AFV was designated “tk” = short for “Tokusyu keninsha” = “special tractor” because he was originally designed as towing vehicle for several trailers
The Type 97 tankette was designated “Te-Ke”. The meaning of this short designation is still discussed in literature but it main interpretation is that it is short for “Tokusyu keninsha - Kei Sokosha&” = “Special tractor - light armoured vehicle”
The engineer tank received the designation “SS” = short for “Soko Sagyosha” = “Armoured Working Vehicle” without a yeartype

b) artillery tractors

Gun tractors (“keninsha”) were designated with their weight and a short designation. The meaning of the short designations is not clear to me.

G) Some japanese vocabulary regarding vehicles:

Sha = vehicle
Sensha = short for sento sha = fighting vehicle or tank
Sokosha = armoured vehcle
Hosensha = gun tank
Jisoho = motorised gun or SPG
Jidosha = motorised vehicle (in general)
Jitensha = bycicle
Sokusha = motorcycle with sidecar
Kijusha = “machine gun vehicle”, motorcycle with machine gun in sidecar
Joyosha = passenger car
shikisha = command car
Jidokasha = truck
Shuri Jidosha = Maintenance vehicle
Rikisakusha = generator vehicle
Keninsha = tractor/prime mover
Kamotsusha = earthmover
Sokikasha = bulldozer
heisha = troop carrier
Jidoteisha = scout car
Sokisha = halftrack vehicle
uchibitei= motor launch, used by IJN for their amphibious tanks (Tokusyu uchibitei = special motor launch)

Yours

tom!

tom · January 3, 2018, 6:38pm

Hi.

3) Armament: Machine Guns

IJA and IJN had several different MGs and machine cannons in their arsenals:

a) french 8 mm Hotchkiss MG

IJA used Hotchkiss-type MGs from 1904 on, rechambered to the domestic 6,5 mm X 50,5 mm Arisaka ammunition. With the Renault FT-17 tanks at least 6 original french 8 mm Hotchkiss MGs were bought in 1919 and several more with the Medium Mk A Whippets. These were standard french army issue Hotchkiss Modellé 1909. The main difference to the infantry version was the use of belted ammunition with 250 shots instead of 24 shot ammo strips.
It´s quite possible that these MGs were replaced by the rechambered japanese version.

Caliber: 8 mm X 50 mm rimmed Type Lebel (6,5 mm X 50,5 mm semi-rimmed Type Arisaka)
Length: 1310 mm
Barrel length: 770 mm
Grooves: 4
Weight: 23,7 kg
Rate of Fire theoretical: 600 shots/min
practical: up to 500 shots/min
Muzzle velocity: 710 m/sec

b) Vickers 7,7 mm MG:

In 1926 IJA bought 3 Vickers Mk C Medium Tanks, armed with these MGs. The water cooling was usefull but made the gun vulnerable to damages inflicted by bullets and splinters. Therefore this MGs were not used by IJA. The tanks were just tested and finally scrapped. IJN used this MG for boarding parties and armament of small ships.

Data:
Caliber: 7,7 X 56 mm rimmed
Length: 1100 mm
Barrel length: 720 mm
Grooves: 4
Weight: 13 kg
Maximum range: 4100 m
Effective range: 800 m
Rate of Fire theoretical: 600 shots/min
practical: 450 shots/min
Muzzle velocity: 740 m/sec

c) Type Taisho 3 6,5 mm MG

This weapon was a modification of the Type Meiji 38 Hotchkiss-type heavy MG made by Army Technical Bureau under command of NAMBU Kijiro from 1914 on. The Hotchkiss ejection mechanism was replaced by the Lewis-type ejection increasing firing speed and reliability. Other changes were done to increase barrel cooling and handling. The result was adopted officially in 1915.

For IJA tank troops the Hotchkiss-type MGs were replaced by this MG in the mid-1920th and all new tanks were armed with it.

Data:
Caliber: 6,5 X 50,5 mm semi-rimmed Type Arisaka
Length: 1204 mm
Barrel length: 742 mm
Grooves: 4
Weight: 27,9 kg
Maximum range: 2000 m
Effective range: 600 m
Rate of Fire theoretical: 600 shots/min
practical: 120 shots/min (continuos fire 480 shots/min)
Muzzle velocity: 740 m/sec

d) Type 91 6,5 mm Tank MG

This MG was a modified version of the Type Taisho 11 6,5 mm lMG used by ground forces. It was air-cooled and hopper-fed with oiled 5-shot-clips. The ammunition was the standard Type Meiji 38 6,5 mm rifle ammunition but with reduced propellant charge. This was necessary to reduce failures due to ripped cartridges inside the chamber. It was introduced in 1931 as the designation indicates.

The forward telescope bracket was attached to the vehicle MG-port. The weapon was then fixed inside a quick-release mount.

In the mid-1930s a removable barrel armour was added to reduce damages by bullets and splinters. A bipod could be attached to use the MG outside the vehicle. If the crew had to bail out without immediate danger e. g. due to internal fire or enemy AT-weapons the MG should be taken with the gunners.

This weapon was used in allmost all IJN and IJA vehicles until it was replaced by its successor in the late 1930th.

Data:
Caliber: 6,5 X 50,5 mm semi-rimmed Type Arisaka
Length: 838 mm
Barrel length: 488 mm
Grooves: 4
Weight: 10,15 kg
Maximum range: 2000 m
Effective range: 600 m
Rate of Fire theoretical: 500 shots/min
practical: 80 - 120 shots/min
Muzzle velocity: 700 m/sec

e) Type 97 7,7 mm Tank MG

Successor of the Type 91 Tank MG. It was based on the czech MG ZB 26/ZB 30s captured in larger numbers during the 1935/1936 northern China operations. This weapons were tested and modified by Nambu Weapons Factory. Main modification was rechambering to the Type 92 MG ammunition developed for the Type 92 7,7 mm Heavy MG (the well known “Woodpecker”). The MG was fed by a box-type 20 shot magazine similar to the ZB-series instead of the 30 shot curved magazine used with the Type 96 6,5 mm lMG, a parallel Nambu development.

This MG was used in allmost all armoured vehicles until 1945 replacing the Type 91 Tank MGs.

Data:
Caliber: 7,7 X 56 mm semi-rimmed
Length: 1180 mm
Barrel length: 712 mm
Grooves: 4
Weight: 11,14 kg
Maximum range: 2000 m
Effective range: 600 m
Rate of Fire theoretical: 500 shots/min
practical: 80 - 120 shots/min
Muzzle velocity: 730 m/sec

g) Type 4 experimental 7,7 mm Machine gun

Late war development of a successor to the type 97 MG. There is not much known on this weapon as most data were destroyed at surrender. It is somewhat similar to the Ho-103 12,7 mm aircraft MG but chambered for the Type 99 7,7 mm round. The gun was belt fed from the left side.

no data found

g) Type 92 13,2 mm Tank Machine Cannon

This MG was an IJA developed from the french Hotchkiss 13,2 mm AA-MG and should not be mixed up with the IJN Type 93 13,2 mm Machine Cannon which was an only slightly modification.

The Type 92 Machine Cannon received a shorter barrel to reduce recoil. A butt stock was added to fire it from the gunner´s shoulder. It fired the Typ 93 Machine Cannon ammunition from a 20 shot clip.

This weapon was used by the Type 92 Heavily armoured vehicle exclusively. It was mounted in a modified standard MG-mount in the oriel in the right. With this mount even aa-fire was possible but to do so the gunner had to lay on the floor looking upwards. This only allowed barrage firing.

no data found

h) Type 96 25 mm Machine Cannon

In 1944 IJN decided to develop a version of this aa-gun for the use in their new development of an amphibious tank model. It was planned to equip the turret with this gun. So several changes were made including a new muzzle brake, a shorter barrel and a smaller recoil mechanism. The gun was never adopted officially as the tank development was ceased in spring 1945.

no data found

Yours

tom!

tom · January 4, 2018, 1:41pm

4. Armament: Tank Guns

IJA and IJN mainly used the same guns. From 1942 on IJN modified few smaller guns from their arsenal to provide more close-support power.

Until 1942 IJA developed tank guns parallel to at-guns and so the tank guns suffered from the strict weight limitations of infantry at-guns. IJA tactics prefered fast strikes using light support weapons. Therefore until 1940 guns for infantry support should not have a weight higher than 500 kgs and should be able to be moved by 2 - 4 men in the field.
To reduce weight the recoil mechanism and the lower lafette of the at-gun had to be as light as possible. Among other problems this lead to a decrease of the maximum possible recoil force. But to reach a better armour penetration the muzzle velocity had to be as high as possible, increasing the recoil force. Therefore a balance between these opposing requirements had to be found. As IJA set the weight top priority the results were almost every time a decrease of the possible penetration power. And for the tank guns the same barrels and breeches had to be used to ensure that both guns could use the same ammuntion.

After the Nomonhan-incident 1939 IJA ordered two new at-/tank guns using the calibers 47 mm and 57 mm. The 47 mm version was introduced in 1941. The 57 mm version was at a dead-end in 1942 as the result was a gun with twice the weight of the 47 mm version but only marginal higher armour penetration. As the engineers saw no chance to improve the gun with the original specifications IJA decided to cease the program. This left the IJA tank forces without a potent gun able to fight the allied medium tanks even at medium ranges from 1943 on. The gap could not be filled until mid-1945.

Part 1: Guns developed until 1940

note:

The data for elevation and traverse are given for the guns in their standard mounts.

a) Puteaux SA18 37 mm tank gun

Standard french 37 mm tank gun of the Renault FT-17 and Renault NC 27 tanks. The gun was originally built as light infantry gun. IJA modified this gun and used it as Type Taisho 11 37 mm Rapid-fire Infantry Gun.

Data:
Caliber: 37 mm
Barrel length: 777 mm
Caliber length: L/21
Traverse:
Elevation: - 20° - + 35°
muzzle velocity: AP 600 m/sec
Rate of fire: 10 shots per minute
penetration: 27 mm on 100 m/90°

b) Hotchkiss QF 6 pdr tank gun:

British tank gun of World War I, still in use with a modified mount in the 1926 Vickers Medium Mk C tanks.

Data:
Caliber: 57 mm
Barrel length: 2280 mm
Caliber length: 40
Traverse:
Elevation:
muzzle velocity: AP 553 m/sec
Rate of fire:
penetration:

c)modified 37 mm infantry gun “Sogekiho” :

Before the 1931/32 northern China operations the Puteaux SA18 tank guns were replaced by obsolete 37 mm infantry guns designated “Sogekiho” (= “sniper gun”), the predecessor of the Type Taisho 11 37 mm flat-trajectory infantry gun. These guns were developed from french M1916 37 mm trench guns. The guns had to be modified slightly to allow the use in the french gun mounts.

Data:
Caliber: 37 mm
Barrel length: 1036 mm
Caliber length: 28
Traverse : ± 10°
elevation : -21° to +15°
Muzzle Velocity : 530 m/sec
Penetration:

d) Type 90 57 mm Tank Gun:

After the decision was made to develop a domestic tank in 1927 the development of a 57 mm tank gun was started. Main specifications were

caliber 57 mm
maximum ammunition weight 2,5 kg
muzzle velocity 350 m/s
Elevation -8° bis +30°
traverse -10° bis + 10°
barrel weight 90 kg
maximum total weight 180 kg
maximum range 4000 m
able to penetrate 20 mm armour plates on 100 m
operated by one man
simple loading mechanism
easy to handle

So a short 57 mm barrel was placed on a mount similar to the 37 mm Puteaux gun. A vertical sliding wedge breech was attached. A metal buttstock and a deflector plate was attached which allowed the operator to aim the gun safely like a rifle. The gun was fired by a trigger operated with the left hand. The right hand was used to operate the manual turret traverse mechanism and to reload. The empty cartridges were ejected automatically and then fell into a long small bag at the rear of the gun. To minimise the recoil a strong spring inside an oil tank was used to mount the gun.

The gun was introduced officially in 1930 and used in the Type 89 Medium Tanks until it was replaced by the successor

Data:
Caliber: 57 mm
Barrel length: 850 mm
Caliber length: 14,9
Weight: 147 kg
Traverse: -10 ° to + 10 °
Elevation: -15 ° to + 20 °
muzzle velocity: HE 380 m/sec
penetration: 20 mm on 100 m/90°

e)Type 94 37 mm tank gun:

The Type 94 37 mm Tank Gun was developed as main gun for future light tanks parallel to the Type 94 37 mm Rapid-fire Infantry Gun from 1933 on. At this time the Type Taisho 11 Rapid-fire Infantry Gun was outdated regarding armour penetration due to the increase of armour strength of contemporary tanks. Therefore a new gun with longer barrel and higher chamber volume was planned. The resulting increase of weight made a new lafette with wheels necessary. The result was a modern weapon with high mobility. But IJA technicians had large problems developing a better AP grenade. Therefore the gun was not introduced before 1936 when finally a grenade able to penetrate 40 mm @ 300 m/90° became avaliable.

The tank gun suffered from the grenade problems as well but nevertheless early prototypes of the gun were used for the Type 95 Light Tank Ha-Go from the beginning of the prototype production 1934. At this time the gun fired the old grenades of the Type Taisho 11 Infantry gun with a penetration of 30 mm @ 100 m/90°. Later the new AP grenades replaced these.

Inside the tank the gun was operated like the Type 90 57 mm Tank Gun. It was replaced by its successor from 1940 on and then used on army ships and for crew training.

Data:
Caliber: 37 mm
Barrel length: 1358,5 mm
Caliber length: 36,7
Traverse: 20 °
Elevation: -15 °to + 20 °
muzzle velocity: AP 600 m/sec
penetration: finally 40 mm on 300 m/90°

f) Type 94 70 mm Tank Gun:

This gun was specially developed for the Type 95 heavy tank project as the use of a 57 mm tank gun in a heavy tank was a not acceptable waste of ressources for IJA officials. The gun was developed from the low velocity Type 92 70 mm Battalion Gun using the same breech and a slightly longer barrel. Handling followed the same system as with the other contemporary tank guns. The history of this gun ended when IJA decided to cease the heavy tank project in 1935.

Data:
Caliber: 70 mm
Barrel length: 790 mm
Caliber length: 11,3
Traverse: 20 °
Elevation: -15 °to + 20 °
muzzle velocity: HE 220 m/sec
penetration:

g) Type 97 57 mm Tank Gun:

In 1936 the Type 90 57 mm Tank Gun was redesignd to increase the penetration power. Therefore a 200 mm longer barrel was used. In addition the chamber volume was increased. The higher recoil force led to a heavier recoil mechanism. The result was an increase of penetration to 30 mm @ 100 m/90° which was found acceptable even if this would not be enough even against contemporary tanks.

The gun was reliable and accurate making it a good choice against soft targets and field fortifications. From 1937 it replaced the Type 90 57 mm Tank guns of the Type 89 Medium Tanks and it became main armament of the Type 97 Medium Tank Chi-Ha.

Data:
Caliber: 57 mm
Barrel length: 1050 mm
Caliber length: 18,4
Traverse: 20 °
Elevation: -15 °to + 20 °
muzzle velocity: HE 420 m/sec
Penetration: 30 mm on 100 m/90 °

h)Type 98 37 mm Tank Gun:

From 1937 on IJA forces captured several german and russian 3,7 cm Pak Rheinmetall in China. The guns were tested intensively and later introduced as Type 97 (or Type Ra with Ra for Rheinmetall) 37 mm Anti-tank Gun. Additionally the Type 94 37 mm Rapid-fire Infantry Gun was remodelled. Especially the chamber volume was increased which made a heavier recoil mechanism necessary. The resulting gun was found too heavy for an infantry gun and rejected but the parallel designed tank gun was accepted and introduced in 1938. It was planned to replace the Type 94 37 mm Tank Guns with these but the possible production capacities were just able to deliver the necessary guns for the ongoing production of the Type 95 Light Tanks Ha-Go and the Type 97 Tankettes Te-Ke.

Data:
Caliber: 37 mm
Barrel length: 1358,5 mm
Caliber length: 36,7
Traverse: 20 °
Elevation: -15 °to + 20 °
muzzle velocity: AP 700 m/sec

to be continued in part 2…
penetration: 25mm on 500 m/90°

tom · January 4, 2018, 2:11pm

4) Armament: Tank Guns part 2

h) Type 99 75 mm tank gun:

During the innitial stages of the 2nd Sino-Japanese War 1937 fightings in Shanghai showed the need for a close-support tank with a gun larger than the 57 mm gun of the medium tanks. Therefore the concept of special gun tanks was introduced. First project was to equip the newly introduced Chi-Ha with a shot 75 mm gun based on the Type Meiji 41 Mountain Gun. Later the gun breech was changed to the Type 94 75 mm mointain gun breech which was larger for a higher muzzle velocity. The recoil mechanism was placed above the barrel. The result was satisfying but due to low priority only few of this guns were built, exact numbers are unknown (30 of the CS-tanks were finished in 1944).

Data:
Caliber: 75 mm
Barrel length: 1792,5 mm
Caliber length: 23,9
Traverse:
Elevation:
muzzle velocity: 450 km/h
penetration: 40 mm @ 100 m/90° with AP, 100 mm on 100 m with HEAT

i) Type 100 37 mm Tank gun:

With the decision to introduce the Type 98 Light Tank Ke-Ni as airborne tank the decision was made to develop a gun with larger penetration power as it had to face enemy tanks without support of the standard amount of heavy infantry at-guns. Therefore the chamber volume of the Type 98 37 mm Tank Gun was again increased. But the results were not much better with the disadvantage to need another ammunition type. This was found acceptable but only few guns were produced before the successor became avaliable only one year later.

One of the main development design features was the use of a coaxial Type 97 7,7 mm MG.

Data:
Caliber: 37 mm
Barrel length: 1358,5 mm
Caliber length: 36,7
Traverse: 20 °
Elevation: -15 °to + 20 °
muzzle velocity: AP 780 m/sec
Penetration: 27 mm on 500 m/90 °

Part 2: Guns developed after 1940

a) Type 1 37 mm Tank Gun:

This gun was result of a major upgrading program for the Type 94 37 mm Rapid-fire Infantry Gun initiated after the disastrous 1939 Nomonhan-Incident. Basis was the Type 100 tank gun with its enlarged chamber volume. A longer barrel was attached for additional muzzle velocity. This made a heavier recoil mechanism necessary which meant additional weight. This was accepted as the additional power was badly needed.

In 1941 both tank and anti-tank gun were adopted. The tank gun should replace all earlier 37 mm tank guns but this goal could not be reached as the production numbers were not able to deliver the necessary numbers because the production of light tanks was increased at the same time. So the Type 94 37 mm Tank Guns should be replaced primarily with surplus guns which was not done until surrender 1945.

In 1943 the caliber 37 mm was found outdated and the new light tank model should be armed with a short 47 mm tank gun.

Data:
Caliber: 37 mm
Barrel length: 1699 mm
Caliber length: 45,9
Traverse: 20 °
Elevation: -15 °to + 20 °
muzzle velocity: HE 800 m/sec
penetration: 25 mm on 1000 m/90°

b)Type 1 47 mm Tank Gun:

During the 1939 Nomonhan Incident the short 57 mm tank guns and the long 37 mm tank guns were only able to penetrate the soviet T-26, BT 5 and BT 7 tanks on short ranges while the soviet long 45 mm tank guns penetrated the IJA tanks on medium ranges. The result was the destruction of or severe damage on 80 % of the japanese tanks of 3rd and 4th tank regiment within 8 days of combat. So the decision was made to develop a medium AT- and tank gun of 47 mm caliber and a heavy AT- and tank gun of 57 mm caliber. For the 47 mm gun the results of an experimental 47 mm AT-gun developed and tested in 1937 were taken as basis.

The AT-gun was refused several times due to too much weight. In 1941 finally IJA decided to accept a higher weight as the gun was badly needed for the upcomming conflict with the US and its allies. The tank gun was finished in late 1940 but as both guns should use the same ammunition the tank gun could not be introduced until the AT-gun was accepted.

The tank gun made a larger turret necessary as it should be operated by 2 men and as the ammunition was longer. Therefore a new turret with hemispherical front and a box-shaped rear was introduced, too. The new gun was able to penetrate contemporary light and medium tanks on medium ranges. US ordnance tests even showed that this gun was able to penetrate the front armour of an early M4 Sherman on ranges up to 250 yards.

As the 57 mm gun project was cancelled in 1942 the Type 1 47 mm Tank Gun was the standard weapon of the IJA tank forces until surrender. Due to raw material shortages the production numbers of this gun never reached the necessary height even to equip all newly built Type 97 Medium Tanks Chi-Ha with this gun.

Data:
Caliber: 47 mm
Barrel length: 2250 mm
Caliber length: 48
Traverse: 20 °
Elevation: -15 °to + 20 °
muzzle velocity: AP 800 m/sec
Penetration: 60 mm on 100m / 90 °

c) Type 1 75 mm Tank Gun:

With the introduction of the long 47 mm tank gun in 1941 IJA decided to introduce special close-support tanks. The very potent Type 90 75 mm Field Gun was chosen as armament for such a vehicle. Therefore a special tank mount had to be developed. As a tank has less problems to cope with recoil forces the muzzle break was removed.
In 1942 the modifications were finished and the resulting weapon was introduced as Type 1 75 mm tank gun for the use in the Type 1 Gun Tank Ho-Ni I. Less than 100 field guns were modified this way until 1945 due to the low priority of gun tanks and due to the massive need of standard artillery pieces.
The gun was mainly intended for indirect fire but during the Philippine campaign 1944/45 the Ho-Ni I were also used as mobile AT-gun but with limited success as there was no sight for direct fire.

Data:
Caliber: 75 mm
Barrel length: 2883 mm
Caliber length: 38,4
Traverse:
Elevation:
muzzle velocity: HE 680 m/sec
Penetration: 80 mm on 100 m/90 °

d) Type 3 75 mm Tank Gun:

In 1942 new tank designs was started which should receive new heavy tank guns. As these projects were assumed to be done not before 1945 and as a better tank gun was badly needed the desision was made to develop a stopgap solution from the Type 90 75 mm Field Gun. For the use inside a tank turret the recoil length had to be limited. Therefore the muzzlebreak was still used. In addition a pair of coil springs was attached below the breech inside the tank to support the original recoil system. Several minor changes were done until mid-1943. The result was a quite good gun with acceptable power.

Due to a higher priority in comparison to the earlier tank guns Osaka Army Arsenal was able to produce around 200 guns from mid-1944 (production start of Ho-Ni III) until surrender which were used in the Type 3 Medium Tanks and the Type 3 Gun Tanks Ho-Ni III.

Data:
Caliber: 75 mm
Barrel length: 2883 mm
Caliber length: 38,4
Traverse:
Elevation:
muzzle velocity: HE 680 m/sec
Penetration: 80 mm on 100 m/90 °

e) Type 5 75 mm Tank Gun:

With the decision to develop a new 25 t tank in 1943 the order was given to develop a high power 75 mm tank gun for this vehicle. As in other countries an AA-gun was chosen as basis, here the new Type 4 75 mm AA-Gun (a modified copy of the swedish Bofors M29 75 mm AA-Gun). The development of the tank gun started in early 1944 after the basic design for the turret was done. It was planned to put an aa-gun barrel in a modified gun mount of the Type 3 75 mm Tank Gun. The result was not satisfying as the recoil mechanism was overburdoned. Several modifications were made until fall 1944 but with only small success.

So the decision was made to restart the development. Now the barrel and the recoil mechanism of the aa-gun were taken. The turret design made it necessary to place the recoil cylinders above the barrel. Trials started on March 9th 1945 and after only few modifications the gun was introduced at the end of May. Until surrender preparations were made for a serial production which should start in September 1945. Just 2 pre-series guns were built in June on for prototype tests of the Type 4 Tank Chi-To. Improved ammunition was about to be produced, too

Postwar US ordnance tests showed that this gun was able to penetrate most allied medium tanks of 1945 on longer ranges even with the grenades used with the Type 3 75 mm Tank Gun. The penetration table below shows the results.

Data:
Caliber: 75 mm
Barrel length: 4230 mm
Caliber length: 56,4
Traverse:
Elevation: -6,5° - 20°
muzzle velocity: HE 852 m/sec
Penetration: 90 mm on 100 m/90 °

to be contionued in part 3…

tom · January 4, 2018, 2:13pm

4) Armament :Tank Guns Part 3

f)Type 5 88 mm Tank Gun:

no Picture, sorry

After inspecting the german Tiger I IJA bought in summer 1943 the idea was Born to equip the new 45 t tank ordered in 1943 with a domestic 88 mm tank gun. The designers choose the Type 99 88 mm AA-Gun (a modified version of a german naval aa-gun captured in China) as basis. Development started in 1944. But the design of the 88 mm gun was slowed down because the 75 mm gun had top priority binding most of the avaliable ressources. In addition the development of the Type 5 Tank Chi-Ri suffered from massive raw material shortages. So the development of the gun was not finished until summer 1945. It is most likely that the design was cancelled but no official papers survived the war.

Data:
Caliber: 88 mm
Barrel length:
Caliber length:
Traverse:
Elevation:
muzzle velocity:
Penetration:

g) Type 5 105 mm Tank Gun:

This gun was originally intended as main armament for the super-heavy multi-turret tank project started in 1939. Originally the Type 92 105 mm Cannon should be taken as basis. But due to the very low priority of the project only few design studies were done until 1942. Then the development benefited much from the cancelling of the development of a successor for the Type 92 Cannon. The prototype gun was then used to develop the 105 mm tank gun which was done in summer 1944. After a short trial series in fall 1944 the gun was combat-ready in late 1944. At this time no vehicle was able to carry this gun as the tank project was delayed due to massive raw material shortages and suspension problems. New projects for this gun were not started before spring 1945 and none reached the prototype stage until surrender.

Data:
Caliber: 105 mm
Barrel length: 4720 mm
Caliber length: 44,9
Traverse:
Elevation:
muzzle velocity: HE 900 m/sec
penetration: 150 mm @ 100 m/90 °

h) Experimental Short 47 mm Tank Gun:

For smaller turrets e.g. of light tanks a special version of the Type 1 47 mm Tank Gun was developed from 1943. Main focus was reducing the necessary space to operate the gun. Therefore the barrel was shortened by 590 mm reducing the recoil length to 200 mm. In addition the recoil mechanism was replaced to the sides of the barrel for a lower necessary turret height. There was no traverse mechanism used to simplify production.

Ammunition was the same as for the Type 1 gun. Prototype tests started in summer 1945 but were not finished until surrender.

Data:
Caliber: 47 mm
Barrel length: 1658 mm
Caliber length: L/35
Traverse: 0 °
Elevation: -15 ° to +20 °
muzzle velocity: 740 m/sec
penetration:

Yours

tom!

tom · January 5, 2018, 5:51pm

Hi.

5) Foreign Armour part 1:

In World War 1 IJA participated in several campaigns against german colonies and settlements in China and in the Pacific. In addition many IJA observers were attached to french and british troops in France. So Japan was aware of the possibilities of early armour. So in 1918 and 1919 IJA bought few british and french tanks. They were delivered to Japan until late 1920. During the following years these vehicles were tested intensively at infantry and cavalry school. With these tests IJA developed specifications for future tank designs.

From 1925 on IJA began to form tank units. Besides the old Renault FT17 tanks some Renault NC 27 tanks were issued to these unit and tested during operations in Manchuria 1931 and during the 1932 Shanghai Incident. In addition some new tank designs were bought from the mid-1920th to 1930 to get samples of contemporary state-of-the-art technologies.

During the battles of 1937 - 1942 IJA and IJN captured many chinese and allied tanks and armoured vehicles. Most of these were used by the unit which captured it until they broke down or until fuel or ammunition ran out. Only the US Light M3s captured in the Philippines and in Burma were taken over officially and supplied from captured stocks and local productions.

a) British Mk IV Tank:

In mid-1918 IJA bought a Mk IV female Tank and transported it to Japan with a british crew and some military advisors. This was done to show the japanese people and industry the european superiority regarding military technology and to get the necessary political support to start a massive military modernisation campaign. After arrival IJA presented it to the people on the 1918 Tokyo Tank Week.

The vehicle made several shows and test trials in 1919. After finishing the tests it used as exhibit for a travelling exibition through Japan and Manchuria. Later it was displayed at the Yasukuni Shrine in Tokyo until it was scrapped between 1940 and 1944.

Data
vehicles bought: 1
battle weight: 27 (metric) t
crew: 8 men
armor strength: 6 - 12 mm
length: 8060 mm
width: 3200 mm
height: 2460 mm
engine: Daimler, 6-cylinder in-line
power: 105 HP at 1000 rpm
maximum speed: 6 km/h /3,7 mph
range: 56 km
fuel capacity: 318 l
transmission primary: 2 Forward, 1 Reverse
Power/weight ratio: 3,88 HP/t
armament: originally 6 X 7,7 mm Vickers MG, no armament installed in Japan

b) British Medium Mark A Whippet:

In mid-1919 IJA bought 6 british Medium Mk A tanks. After arrival these tanks were tested intensively by IJA infantry and cavalry school.

The cavalry disliked the tanks as they were found too clumsy and too heavy. But the infantry officers were very impressed by this tank as it was quite fast for a vehicle with a weight of 14 t and it could turn on the spot. Several basic tank tactics were tested,too, and the decision was made to develop or buy a number of tanks within 10 years. This was the beginning of the IJA tank doctrine to use tanks as infantry support which was not dropped before 1942. And it was also the birth of the IJA tank force as part of the infantry.

After the trials the tanks were used to establish a tank school from 1920 on. The Whippets were replaced by Renault FT 17 tanks after 1922 and scrapped.

vehicles bought: 6
battle weight: 14 (metric) t
crew: 3 men
armor strength: up to 14 mm
length: 6100 mm
width: 2620 mm
height: 2740 mm
engine: 2 × Tylor Twin 4 cylinder side-valve JB4 petrol engine
power: 2 X 45 HP
maximum speed: 13 km/h
range: 129 km
transmission: 4 Forward, 1 Reverse
Power/weight ratio: 6,4 HP/t
armament: 4 X 8 mm Hotchkiss MG

c) French Renault FT17:

In late 1919 IJA bought 13 MG or gun (exact number of each version is unknown) eqipped Renault FT 17 tanks from the french army as cavalry tanks. They received the designation “Renault Kou(A) Gata Sensha” = “First Tank (Model)”. IJA cavalry school was very impressed by these tanks due to the thick armourand good mobility even in rough terrain. Only the low maximum speed was critisised. Until 1922 several tests and exercises were done leading to the decision to equip at least cavalry recon units with armoured vehicles within 10 years.
In 1922 IJA decided to refuse this demand and also that only infantry units should be allowed to have tanks, mainly because they realised that the japanese industry would not be able to built the necessary numbers of tanks within 10 - 15 years. Therefore the Kou Gata were removed from cavalry school and handed over to infantry school where they were issued to the small tank school unit.

Around 1925 the Renault tanks were rearmed with Type Taisho 3 MGs or “Sogekiho” 37 mm infantry guns but the gun made problems as the turret was too small to operate it properly. Until 1929 all tanks were rearmed with the MG. During the 1929 Mukden Incident a small tank unit (around 10 FT-17 and NC1/NC27 tanks) were sent to Manchuria. While the NC1/NC27 tanks had massive suspension problems the FT 17 operated with good success. In 1931 a provisional tank unit was formed which used FT 17 tanks, NC1/NC 27 tanks with modified suspension and the first domestic Type 89 Medium Tanks. During several incidents in northern China and Manchuria and during the 1932 Shanghai Incident the Kou Gatas again showed their value but it became also clear that they were outdated. So they were withdrawn from active service in late 1932 and issued to the enstrengthened IJA tank school where they were used for drivers training until they were worn out. Until 1937 all FT17 had been scrapped.

Data
vehicles bought: 13
battle weight: 6,8 (metric) t
crew: 2 men
armor strength: up to 22 mm
length: 4880 mm
width: 1740 mm
height: 2140 mm
engine: Renault 4-cyl petrol engine
power: 39 HP
maximum speed: 8 km/h
range: 65 km
Power/weight ratio: 5,7 HP/t
armament: 1 X 8 mm Hotchkiss MG, later 1 X Type Taisho 3 6,5 mm MG or
1 X 37 mm Puteaux SA18 Tank Gun, later 1 X Sogekiho 37 mm low-trajectory Infantry Gun, later 1 X Type Taisho 3 6,5 mm MG

d) French St Chamond M21 Wheelcumtrack:

In 1923 IJA lent the prototype of the St Chamond Modellé 1921 Wheelcumtrack Tank from France to test the new wheelcumtrack technology. The results wer not satisfying. The change from wheels to tracks was quite simple and could be done within 10 minutes by raising the wheels. But he change from tracks to wheels was complicated. As the wheel suspension was not able to raise the tanks during lowering the tank had to move on a ramp first. Then the wheels were lowered in traveling position without ground contact. Now the tanks drove back until the wheels touched ground. As the ramp had to be as small as the track gauge it took a lot of time to built a suitabel ramp with the necessary enstrengthened side walls. In addition the raised wheels limited the drivers view to the sides. So the design idea was rated poorly conceived and the vehicle returned to France.

Data
vehicles bought: 1
battle weight: 3,5 (metric) t
crew: 2 men
armor strength: up to 6 mm
length: 3610 mm on wheels
width: 2080 mm
height: 1930 mm
engine: 6-cyl petrol engine
power: 15 HP
maximum speed: 28 km/h on wheels, 6 km/h on tracks
armament: 1 X 8 mm Hotchkiss MG

e) Italian Fiat 3000 Model 1921:

In the mid-1920th IJA bought one Fiat 3000 tank for test purposes. The tank was an improved version of the Renault FT 17 tank with a stronger engine and a larger turret. The test results are unknown. But at the same time IJA was cooperating directly with Renault which designed a new suspension and so the italian model seemed to be rated outdated.

Several Fiat 3000 were taken over from the armed forces of the local warlord Chang Tso-lin, ruler of the northeast regions of China. He was killed by a terrorist bomb attack on his train (most likely done by the japanese military intelligence). The vehicles were used by the japanese Kwantung Army to built up a temporary Armoured Car Company during the Mukden Incident 1929. After the birth of Manchukuo 1931 the tanks were handed over to the manchurian army.

Data
vehicles bought: 1
battle weight: 5,5 (metric) t
crew: 2 men
armor strength: 6 - 16 mm
length: 4330 mm with ditching tail
width: 1660 mm
height: 2200 mm
engine: Fiat 4-cylinder gasoline engine
power: 50 hp
maximum speed: 21 km/h
Power/weight ratio: 9,1 HP/t
armament: originally 2 X 8 mm Breda MG, armament was not installed in Japan; 2 X 7,7 mm Lewis MG on the captured tanks

to be continued in part 2…

tom · January 5, 2018, 5:53pm

Hi.

5)Foreign Armour part 2:

f) British Vickers Medium Mark C:

In 1926 IJA bought 3 Vickers Medium Mk. C tanks as samples of contemporary modern armour technology to gather design ideas for their domestic development program. The tanks arrived in March 1927 together with engineers and crews from Vickers. During the tests in one vehicle gasoline vapours infiltrated the fighting compartment and exploded when the tank climbs up a hill, wounding two Vickers engineers. This incident led to the decision to develop Diesel engines for domestic tanks to minimise the risk of such explosions.

IJA wanted to develop a domestic tank and Vickers didn´t want to built up a production line for spare parts for only 3 vehicles So the tanks became exibits after finishing the tests and were finally scrapped. Several details of the Mk. C were taken over for the Experimental Tank No. 2 which was introduced in 1929 as Type 89 Medium Tank.

Data
vehicles bought: 3
battle weight: 12 (metric) t
crew: 6 men
armor strength: up to 6,5 mm
length: 5330 mm
width: 2540 mm
height: 2400 mm
engine: Vickers gasoline engine
power: 110 hp
maximum speed: 30 km/h
fuel capacity: 320 l
range: 220 km
transmisson: 4 forward, 1 reverse
Power/weight ratio: 9,2 HP/t
armament: 1 X 6 pdr QF gun, 4 X 7,7 mm Vickers MG

h) Renault NC1/NC27:

[

During the mid-1920th Renault tested several new types of suspensions for the FT17/18 tank. IJA was very interested in these developoments and even supported Renault by buying 10 vehicles (5 armed with MG, 5 armed with a gun) tanks from the pre-series production of the NC1 Modellé 1927 and allowing Renault engineers to lead the trials at Kurume in late 1929/early 1930. The results were rather unsatisfying as the suspension made several problems during duration tests.

Nevertheless IJA used a provisional tank unit during the early 1932 Manchurian Incident when chinese warlord troops entered the japanese controlled area around Harbin/Manchuria from northern China but retreated after recognising the tanks. During these operations several NC1 tanks, which were now armed with “Sogekiho” 37 mm infantry guns, broke down due to suspension failures. Renault immediately modified several suspension parts after tests with this new configuration in France 1931 were successful. In Europe these vehicles are known as “Renault NC1Modellé 1931” or “NC31”. IJA designated both versions “Renault Otsu Gata” = “second (tank) model”. During the 1932 Shanghai Incident IJA used some of the modified vehicles. But the suspension still had many problems reducing the operational time. So IJA finally decided to retire the NC1 tanks in late 1932.

Data
vehicles bought: 10
battle weight: 8,5 (metric) t
crew: 2 men
armor strength: 18 - 34 mm
length: 4410mm
width: 1710 mm
height: 2140 mm
engine: watercooled Renault 4 cylinder gasoline
power: 60 hp
maximum speed: 35 km/h
fuel capacity: 240 l
range: 120 km
transmisson: 6 forward, 1 reverse
Power/weight ratio: 7,6 HP/t
armament: 1 X Sogekiho 37 mm Gun or 1 X Type Taisho 3 6,5 mm MG

h) Carden-Loyd Tankette

In mid 1930 IJA bought 2 britsh Carden-Loyd Tankettes Mk VI to test them as support vehicles for cavalry units. The vehicle was found generaly useful but the cross-country abilities of the suspension were found too weak, a revolving turret was found necessary and the open fighting compartment with armoured caps for driver and gunner was found inacceptable. So the decision was made to develop a domestic lightly armoured, tracked vehicle with a turret as armoured support vehicle.

In 1931 the two tankettes were tested at IJA infantry school. There the vehicle concept was found useful for armoured transport, especially due to the tracked trailer with its loading capacity of 400 kg. This allowed protected transport of men, mail, supply and ammuniton. The vehicles themselfs were rated underpowered, weakly armoured and with low self defence capacities due to the missing turret. So the decision was made to develop a similar vehicle with a larger transport compartment, a turret and a 0,75 t trailer.

The two Carden-Loyd tankettes were handed over to IJN in late 1931. At this time the tensions in China raised and the decision was made to sent armoured vehicles to Shanghai to support the naval troops stationed in the japanese settlement. Therefore four more Carden Loyd tankettes were bought in late 1931/early 1932. These vehicles were modified by replacing the small straight armour plates on the sides by higher trapeziod armour plates which were arranged sloped. In addition the two armoured caps were replaced by a single cap which closed the fighting compartment completely. During the 1932 Shanghai incidents the vehicles were used during the fightings as transport vehicles and for infantry support designated “Type Ka (for Carden-Loyd) MG vehicle” .The further fate of these vehicles is unknown.

Sometimes these tankettes are also designated “Type 88 Tankette” in literature but this is not correct.

Data
vehicles bought: 2 + 4
battle weight: 1,5 (metric) t
crew: 2 men
armor strength: 6 - 9 mm
length: 2460 mm
width: 1700 mm
height: 1220 mm without armored caps
engine: Ford Model T 4-cylinder gasoline
power: 22,5 hp
maximum speed: 45 km/h
fuel capacity: 38 l
range: 140 km
transmisson: Ford planetary transmission
Power/weight ratio: 15 HP/t
armament: 1 X 7,7 mm Vickers MG

i) Vickers Mark E 6-ton Tank:

In 1930 IJA also bought two Vickers Mark E Version A tanks and tested them. During competitive tests with the new Type 89 Medium Tank the british susupension was rated slightly superiour and the stronger engine made the british tank more agile. On the other hand the use of two MG-turrets with traverse angles of only 265 ° was found a waste of ressources on such a heavy vehicle. So IJA refused to introduce this tanks.

From 1937 on IJA was able to capture several Vickers Mark E Versions B and F Tanks tanks with its single turrets armed with a 47 mm gun in China. Competitive tests with the Type 95 Light Tank Ha-Go showed a superiority of the japanese model regarding suspension and engine but also a slight inferiourity regarding armament.

Data (Version A)
vehicles bought: 2
battle weight: 7 (metric) t
crew: 3 men
armor strength: up to 13 mm
length: 4880 mm
width: 2410 mm
height: 2080 mm
engine: Armstrong-Siddeley 4-cylinder gasoline
power: 80 hp
maximum speed: 35 km/h
fuel capacity: 182 l
range: 160 km
transmisson: 4 X forward, 1 X reverse
Power/weight ratio: 12 HP/t
armament: 2 X 7,7 mm Vickers MG

j) US Light M3:

During the 1941/42 Philippines campaign IJA first met the US Light M3 tanks of the US-Army 192nd and 194th Tank Battlions. The M5 37 mm Tank Gun was able to defeat any japanese tank even on long ranges while the japanese Type 95 Light Tanks could only penetrate the frontal armour of the M3 on short ranges, the Type 89 and 97 Medium tanks even had to attack from the sides on very short ranges. Due to the IJA infantry tactics and the terrain plus a bad tactical use the M3s were not the threat they could be during this campaign. As result IJA speeded up the production of the Type 97 Medium Tank KAI and the training of crews for this tanks in January 1942. But before the first tank company equipped with this tanks reached Luzon the fightings were over. Only corregidor remained as US strongpoint. IJA tankers took over several operational Light M3 tanks after surrender of the US tank battalions. During the amphibious attack of Corregidor in May 1942 a Type 97 Medium Tank KAI and two US Light M3 landed on the island. Shortly after that the US defenders surrendered.
The captured Light M3 were taken over officially by IJA as medium tanks due to their weight of 12,7 t. All tanks and all captured stocks of supply for these vehicles were handed over to IJA 7th Tank Regiment which formed at least one tank company with these vehicles. One platoon from this unit was shipped to Java to support the attack on the vital cities of this island.

During the 1942/43 Burma campaigns IJA captured some british Light M3 Stuart tanks and formed at least one company for the 14th Tank Regiment. These tanks fought quite hard during the 1944 Imphal campaign where a Light M3 became the first japanese tank who destroyed a Medium M3 Grant. The 14th tank regiment was almost annihilated during this campaign and only few Light M3s remained operational. Due to the low stocks of replacement parts the remaining tanks were finally used as pillboxes during the 1945 retreats.

The 7th Tank Regiments Light M3s fought hard during the 1944/45 Phillipines campaign but were finally destroyed due to the massive superiority of the attacking US troops.

Data
vehicles captured: between 50 and 80
battle weight: 12,7 (metric) t
crew: 4 men
armor strength: up to 44 mm
length: 4531 mm
width: 2240 mm
height: 2500 mm
engine: Continental W-670-9A 7-cylinder radial gasoline
power: 262 hp
maximum speed: 58 km/h
fuel capacity: 204 l
range: 110 km
transmisson: 5 X forward, 1 X reverse
Power/weight ratio: 21 HP/t
armament: 1 X 37 mm M5 Tank Gun, 2 - 4 X .30 cal Browning M1919A4 MG

Yours

tom!

tom · January 6, 2018, 11:20am

Hi.

6) Early japanese Projects part 1:

After World War I IJA was quite impressed by the new tank technolgy. But the low speed and the short duration of these vehicles were also seen. So IJA decided only to buy several contemporary tank models for basic tactics development and to get modern technology samples.

With the Vickers Mark I light tank and Mark I medium tank developed from 1922 on the first tanks with quite high speed (more than 20 km/h) and a good duration became avaliable. IJA sent several observers to watch test trials at Vickers. After the reports were evaluated in 1923 IJA decided to equip their forces with such modern vehicles. At this time the japanese heavy industry wasn´t able to develop or to produce such tanks within the next years. So several military missions were sent to USA, Great Britain and France to negotiate about buying tanks. Great Britain refused to give the necessary permmissions as their own troops were not fully equipped with the planned vehicles. The armies of France and USA hadn´t ordered new tank models and so IJA talked directly with Christie and Renault but both developers did only have few designs of new tanks without plans to built prototypes.

So IJA had to realise that a quick success was impossible. So in early 1925 the decision was made to delay the purchase for several years as they saw no chance for the japanese industry to develop a domestic tank within 5 to 10 years. At this point the Army Technical Headquaters contradicted and offered to develop a domestic tank in cooperation with the industry within 2 years. IJA headquaters was sceptic but decided to give it a try.

a) Experimental Tank No. 1:

In early 1925 IJA decided to give design orders for a lightweight tank for tank school training (similar to the Renault FT 17) and for a medium tank with a weight of not more than 20 (metric) t (similar to the Medium Mark A Whippet) with a tinme frame of 2 years. At best the whole project should boost the dometic heavy industry to a level that it could be able to develop own tanks within 5 years. Army Technical Bureau was not satisfied with these limitations but they took the chance. The official orders were used as cover to design a full-scale battle tank able to compete with european tanks. The Operational Chief of Staff knew this but he gave the engineers a carte blanche to do as they wanted.

Until mid 1925 the Army Technical Bureau developed the specifications for a 15 t tank:

weight around 15 t
suited for attacking heavy field fortifications while having good road mobility
maximum concentration of firepower around the tank to enhance independent combat capabilities within enemy field fortifications
therefore a 57 mm main gun in a central rotating turret
and two separate MG turrets with one mounted in the front and one in the rear behind the engine as armament
armour strength to defeat contemporary 37 mm at-guns even on short ranges
road speed of 25 km/h
suspension for maximum off-road capabilities with an easy and precise one-man steering
trench crossing capability 2,5 m, maximum climbing gradient 43°
crew of 5 men
width and height fitted for railway transport even on the mountain railroads
operational time at least 10 h

IJA expected that the development and testing of the multiple components would have been done separately before fitting to the prototype. This would have led to a massive time delay and so the developers decided to test the components on the prototype. Several components were designed and built from the domestic industries, especially Mitsubishi and Kawasaki, and delivered to Osaka Army Arsenal where the prototype was built in secrecy. A parallelogram-type suspension with 8 pairs of roadwheels on the ground and three single roadwheels (two at the front and one on the rear) for additional climbing capabilities was chosen which delivered the necessary stability. In addition five return rollers with the first raised, a forward idle wheel and a rear driving sprocket were used. This gave the tracks a distinctive buckling after roughly 1/4 of the return travel. A 6 mm armour plate protected the central suspension components.
A new 8 cylinder gasoline engine was placed behind the main turret. The engine compartment could be reached through an access hatch from the main fighting compartment. The necessary gasoline and oil tanks were placed in separate compartments on the left and right of the main fighting compartment which made them quite vulnerable for enemy fire. The exhaust gases were discharged by an exhaust pipe on the right and lead to a muffler on the rear of the vehicle.

The MG-turrets were built cylindrical with sloped upper side parts. A Type Tasho 3 6,5 mm MG was mounted in each turret. In and around the turrets ammunition boxes for a total of 500 10-shot ammuniton frames were placed. Both turrets were placed offset to the left (in driving direction) of the central axis. The driver sat in the right front next to the bow gunner.

The main turret was conical with a high rotating cylindrical comanders cupola on the rear right. A 57 mm tank gun of unknown origin was mounted in the 2-men turret. The commander was also used as loader. The gun shield was placed inside the turret which lead to a small hole in the armour below the gun at high elevation. The ammunition stowages inside and around the turret allowed a maximum load of 110 grenades.

The armour plates should be riveted on a massive frame. Due to the lack of experience several components had to be modified several times and the production of the face-hardened armour plates was problematic as the japanese industry had only experience in making thicker plates for the naval projects. The prototype was finished in February 1927 but it only had mild steel plates. Fortunately the initial trials showed only limited problems which were quickly solved.

In June 1927 the Army Technical Bureau presented the vehicle designated "Experimental Tank No. 1& officially to IJA High command during several field trials at Mount Fuji Training Ground. The army officialy were very impressed by the vehicle which was able to drive with high speed even through rough terrain. All specifications were at least met with one exception: the weight. The resulting vehicle had a battle weight of 20 t which was found too high for most railroad and road bridges. Nevertheless the results exceeded the expectations of IJA High Command by far and so in fall 1927 the decision was made to allow the development of a 10 t light tank. This was the birth of the domesic japanese tanks.

Data
vehicles built: 1
battle weight: around 18 (metric) t empty, 20 t fully loaded
crew: 5 men
armou strength: up to 17 mm
length: 6030 mm
width: 2400 mm
height: 2430 mm without commanders cupola, 2780 mm with cupola
ground clearance: 400 mm
track width: 350 mm
trench crossing capability: 2500 mm
climbing capability: 43°
maximum vertical obstacle: 1000 mm
engine: 8-cylinder V-type gasoline
power: 140 hp
maximum speed: 20 km/h on roads
fuel capacity: for an operational time of 10 h cross-country
range: n. a.
transmisson: 6 forward, 1 reverse
Power/weight ratio: 7,78 HP/t
armament: 1 X 57 mm tank gun, 2 X Type Taisho 3 6,5 mm MG

b)Experimental Tank No. 2:

no pic, sorry

In mid 1927 IJA developed specifications for the 10 t tank:

maximum speed 25 km/h (which was the maximum speed of the contemporary trucks used by mechanised infantry units)
trench crossing capability 2000 mm
maximum gradient: 43°
maximum length 4300 mm
width and height fitted for railway transport even on the mountain railroads
main armament one 37 mm tank gun
one or two MGs
armor strength to defeat contemporary 37 mm at-guns on medium ranges
steering components similar to the Experimental Tanks No. 1

Design started in fall 1927 based on the Experimental Tank No. 1. Several design features of the Vickers Mark C tank were also copied and/or modified. But in early 1928 it became obvious that the design would result in a weight higher than 12 t. In addition the french 37 mm tank gun and the japanese “Sogekiho” 37 mm Gun were rated unsatisfying regarding HE-power. Therefore the development was stoped to modify the design.

to be continued in part 2…

tom · January 6, 2018, 11:24am

6) Early japanese Projects part 2:

c) Type 89 Medium Tank:

Type 89 Medium Tank prototype during early trials

In mid 1928 the design of the Experimental tank No. 2 continued. Now more design features of the Vickers Mark C were used to reduce further weight and the development of a domestic 57 mm tank gun based on the Vickers 6cwt tank gun was started.

Especially the suspension was remodelled and simplified. It now consisted of four pairs of slightly larger road wheels connected by bogies and semi-elliptical springs and a ninth road wheel mounted vertically in front of the forward horizontal road wheel for better climbing and trench crossing. Five return rollers, a forward idle wheel and a rear driving sprocket completed the suspension. Bogies and springs were protected by a 6 mm armour plate.

In the bow a driver sat in the left (in driving direction) behind a simple hinged visor port. A MG gunner/technician sat in the right operating a Type Taisho 3 6,5 mm MG mounted in a fork behind an elevateable and traversable armour shield. Several ammunition boxes were placed on the right of the bow gunner.

The frontal armour was split with the upper 1/4 mounted vertical and the lower 3/4 sloped. In the lower part a large access door was implemented on the right. Due to problems producing the necessary armour plates the first prototype was built with parts of the frontal armour disassembled from one of the Vickers Mark C´s.

The main turret was slightly conical wit an extension for the main gun. A MG-port was placed in the turret rear at 180° to the gun. A small hatch for the commander was placed in the rear right of the turret. The main gun was operated by a gunner and the commander as loader, the MG by the gunner. Several grenades could be stored left and right of the gun upright with the fuse facing down. MG ammunition was also stored next to the turret MG. Additional diagonal stowages were placed on the left and right of the turret in the hull. Several further stowages were placed below the floor plates left and right of the central shaft for the steering and clutch cables allowing a total payload of 110 57 mm grenades and 2745 MG shots.

A licence-built 6 cylinder Daimler gasoline aircraft engine limited to 100 hp was placed offset to the right in the rear. A small hatch allowed limited access to the engine from the fighting compartment. Large access cover plates in the upper rear armour easily allowed the exchange of the engine. A 180 Ah battery placed in the rear of the engine delivered the necessary electrical power to start the tank. Gasoline tanks were mounted in the sides of the tank above the tracks. The upper side armour over the gasoline tanks was mounted sloped. An oil tank was placed on the left of the engine. For ventilation most of the necessary combustion air was sucked off the fighting compartment.

All armor plates were face-hardened and riveted to a frame. Besides the 17 mm frontal bow armour all other armour plates were available in early 1929 and so the prototype was finished in April 1929 at Osaka Army Arsenal armed with a Vickers 6cwt tank gun. Mechanical and performance tests were finished fast and almost all specifications were met but the weight limit could only be reached without ammunition and sparse fuel in the tanks (empty weight 9,8 metric t). The battle weight was 11,5 t. At this time IJA badly needed a successor for the outdated Ko Gata tanks, especially as the Otsu Gata tanks were disappointing. And so the vehicle was officially adopted as “Type 89 Medium Tank” in late 1929. Nevertheless several modifications were demanded:

use of a Diesel engine as gasoline engines were rated dangerous after an accident during the tests with the Vickers Mark C tanks
use of a domestic tank gun
a commanders cupola should be added

Mitsubishi Heavy Industries (which was largely involved in the development of the tank) was ordered to built up a production line within one year and they built a complete new tank factory until late 1930. And they also started the development of a light, compact Diesel engine.

The tank gun was finished at Osaka Army Arsenal in late 1930 and implemented in the tank with only few necessary changes, but the production was delayed. So some of the first tanks were equipped with 37 mm “Sogekiho” infantry guns. A small, high cupola with horizontal slits was added on the hatch on the turret roof. Serial production could start in mid 1931 but only 10 vehicles were delivered in that year due to much handwork. The vehicles were issued to IJA Tank School where the crews were trained. In spring 1932 the 2nd Independent Tank Company was formed and equipped with 5 Type 89 Medium and 10 modified Otsu Gata (Renault NC27 modified) Tanks. During the 1932 Shanghai Incident the vehicles were used under naval command during the street fightings with different success. While the Otsu Gata often broke down with suspension failures the Type 89 Medium Tanks were very successful.

]
A Type 89 in Shanghai 1932 with 37 mm “Sogekiho” gun

After the end of the fightings the crews were interviewed. The general performance was found good but they also demanded several changes. Main problem was the internal gun shield which opened a gap in the armour at high elevation. So the shape of the frontal turret armour was changed to close this gap. Another problem was the vertical upper bow armour which was often hit by bullets bouncing off the sloped lower bow armour. So a new fully sloped bow armour was developed which made an extension for the drivers visor port and a different shape of the MG mount necessary. A ditching tail was also added. The changes were implemented in the ongoing production leading to several intermediate versions but also slowing down the production. Until 1933 the 2nd Independent Tank Company was completely equipped with this tank and another company, the 1st Special Tank Company changed from Kou Gata to Type 89 Tanks which were rearmed to Type 90 57 mm guns. This unit participated in the early 1933 Jehol operation in northern China where it was able to move 320 km in just three days against enemy opposition. This was remarkable at this time especially as they suffered no losses by mechanical failures.

The crews participating in this operation demanded further changes. This includes modification of the suspension to increase self-cleaning from mud, a change of the rear turret MG position and a lager commanders cupola. The necessary changes were made until 1934. The upper part of the suspension was remodelled by removing one return roller to increase the space between the remaining rollers where the mud could fell off. The suspension armour plates received a sloped upper part to let the mud slide off easier. The turret was remodelled, too. A large cylindrical commanders cupola was installed and the turret MG was moved from 180° position to 210°position in an armour extension. Several minor changes were also done.

The changes were also implemented in the serial production leading to more intermediate versions. In late 1933 Mitsubishi was able to finish the development of a 120 hp 6 cylinder Diesel engine. This engine was implemented in the Type 89 Medium Tank until 1934 which made several changes regarding cooling air intakes and transmission necessary. In addition IJA decided to standardise the crew positions in their tanks. So the drivers and bow gunners position in the Type 89 Tanks had to be exchanged which was also done in 1934.

With the beginning of the production of the Diesel-equipped tanks the gasoline version received the additional designation “Kou(A)”, the Diesel-engined “Otsu” But the Diesel engine production never reached the same numbers as the tank production, gasoline engines still had to be used until the end of the production in 1936. A total of 278 Type 89 Medium Tanks Kou and 126 Type 89 Medium Tanks Otsu were built.

Type 89 Medium Tanks were involved in almost all IJA and IJN tank unit operations until 1940. They did a good job in their intended task, infantry support. From 1939 on they were replaced by the successor, the Type 97 Medium Tank Chi-Ha. The Nomonhan Incident in 1939 showed that the Type 89 Medium Tanks were outdated regarding armour and armament but they were used until 1945, finally as mobile pillboxes in the Philippines and Burma.

to be continued in part 3…

tom · January 6, 2018, 11:27am

6) Early japanese Projects part 3:

Type 89 Medium Tank part 2:

After the war the Type 89 Tanks were still used by local chinese forces, the indonesian liberation forces and french forces in Indochina.

french Type 89 Medium Tank in Indochina

Data (version Ko / version Otsu)
vehicles built: 278 / 126
battle weight: 12 (metric) t early version, 14 (metric) t late version
crew: 4 men
length: 4300mm, 5750 mm with ditching tail
width: 2180 mm
height: 2560 mm
ground clearance: 480 mm
track width: 305 mm
trench crossing capability: 2000 mm, 2500 mm with ditching tail
climbing capability: 34°
maximum vertical obstacle: 840 mm
engine: 6-cylinder Daimler gasoline / 6-cylinder Mitsubishi Diesel
power: 118 hp at 1400 rpm / 120 hp at 1800 rpm
maximum speed: 25 km/h on roads
fuel capacity: for an operational time of 10 h cross-country
range: n. a.
transmisson: 6 forward, 1 reverse
Power/weight ratio: 10 HP/t / 8,57 hp/t
armament: 1 X Type 90 57 mm Tank Gun , 2 X Type Taisho 3 6,5 mm MG, later Type 91 6,5 mm Tank MG

armor	strength
turret front	15 mm @ 80 °
sides	15 mm @ 80 °
rear	15 mm @ 90 °
roof	10 mm @ 0 °
superstructure front	17 mm @ 75 °
sides	11 mm @ 90 °, upper part @ 35 °
rear	8 mm @50 °
roof	6 mm @15 °

The only remaining operational Type 89 Medium Tank Otsu at JSDF Tank School Tsuchiura, Japan

d) Experimental Amphibious Halftrack AMP:

Prototype during trials

In 1929 IJA decided to develop a fast amphibious armoured car similar to the french AMC Citroën-Kégresse P 16 for cavalry reconnaissance units. The halfrack system was chosen as it has a better cross-coutry ability than wheels.The Sumida factory of Ishikawajima Automotive Works (later became Isuzu Motors) was ordered to develop such a vehicle. The company was chosen as they also had experiences in shipbuilding. The specifications were:

amphibious, able to cross rivers with medium current
maximum weight 2,5 t
maximum armour able to defeat contemporary infantry rifle AP ammunition
2 men crew
length 4000 mm, width 1600 mm, height 1900 mm
armament one MG in a revolving turret
maximum speed 45 km/h, 9 km/h swimming

The design was done quickly using a boat-shaped hull and a french Kégresse suspension. The prototype was finished in summer 1930. It had two drivers positions, one on the track side for driving on land and one on the wheel side for driving in the water. A 40 hp Ford gasoline engine was used. The turret was conical with an extension for the MG. During trials the hull showed very good swimming abilities allowing the projected speed of 9 km/h. The road speed also reached the 45 km/h but the cross country abilities were rated disappointing. In addition the armament of a Type Taisho 3 6,5 mm MG was found too weak. So in late 1930 the decision was made to drop the design in favor of a full-tracked vehicle. The fate of the prototype is unknown but there are photos of the vehicle used without the turret during a 1934 test of an amphibious tank prototype.

Data
vehicles built: 1
battle weight: 2,5 t
crew: 2 men
armor strength: up to 5 mm
length: 4000 mm
width: 1600 mm
height: 1900 mm
ground clearance: 400 mm
engine: 4-cylinder Ford Type A gasoline
power: 40 hp
maximum speed: 45 km/h on roads, 9 km/h on water
Power/weight ratio: 16 HP/t
armament: 1 X Type Taisho 3 6,5 mm MG

e) Type 92 Heavy Armoured Vehicle:

early prototype with a Type 92 13,2 mm MG in the bow

After ending the trials of the Carden Loyd Tankettes and the AMP prototype IJA ordered the development of an armoured reconnaissance vehicle for cavalry units. The specifications were developed until early 1932:

fully tracked
maximum possible speed
maximum possible mobility
all-welded armour, able to defeat infantry ball ammunition
3 men crew
2 MGs or one MG, one Machine Cannon
bow weapon with maximum possible elevation and traverse for indirect and even aa-fire
a tow-bar in the rear for trailers up to 750 kg

Ishikawajima Automotive Works received the development order in March 1932 as they had experiences in welding thin steel plates for non-warship hulls. The hull was completely electrically welded, only the frames of the access hatches on the bow and on the engine compartment were riveted on the 6 mm thick face-hardened armour. Both rolled and casted steel was used. In the bow the driver sat on the left (in driving direction) , the gunner in the quadrangular armour extension in the right. The bow armament should consist of a Vickers 12,7 mm MG or a Type 92 13,2 mm MG but a Type 91 6,5 mm Tank MG could also be mounted. An enlarged standard MG mount was used for a maximun elevation of around 45° and a traverse of ± 60 °. A special optics allowed firing at high angles while sitting. A revolving conical turret with an MG-port for a Type 91 6,5 mm Tank MG in an extension was placed in the center of the fighting compartment.

The side armour was vertical with sloped upper parts. A 6-cylinder gasoline engine for 40 km/h was placed in the centerline in the rear. It was covered by sloped armour plates. For the suspension two pairs of road wheels were spring-mounted by leaf springs and a forward driving sprocket, a rear idle wheel and three return rollers were used.

Prototype tests of the 3,2 t heavy vehicle started in late 1932 and lead to several changes. The large space between the road wheels led to problems with shed tracks in rough terrain. So a third pair of road wheels was added on each side. The close defence was rated problematic due to blind spots on the forward left and right. So hatches were added in the forward right and left hull armor. The vertical armour of the bow armament extension was identified as a shot trap and so the upper part was arranged sloped. The changes were implemented fast and so the vehicle could be introduced in early 1933. It was designated “Heavy Armoured Vehicle” as IJA had decided that only infantry units should receive “tanks” but it was in fact a light tank.

early production vehicle

Serial production started immediately. First operational use was in March 1933 when 2 pre-series vehicles were used during the Operation Jehol in northern China. During the following years several cavalry reconnaissance units in China were equipped with the Type 92 Heavy Armoured Vehicle. Especially the high speed and good mobility even in rough terrain were badly needed. One of the few things which were criticised were the poor weld seams on some vehicles which lead to cracks between casted and rolled armour parts. This could not be solved until production end.

In 1934/35 after introducing the new standard suspension on the Type 94 Special Tractor IJA ordered to change the suspension to standardise the parts. Therefore two pairs of larger road wheels were attached and a larger return roller in the middle and a smaller directly behind the driving sprocket replaced the old rollers. The changes were taken over into production in 1935.

late production vehicle

In 1937 several vehicles were rebuilt as communication tanks with a Type 94 wireless set replacing the bow armament and a rod antenna in the rear of the fighting compartment. To increase the at-abilities trials were made to install a modified Type 98 AA Machine Cannon and even a Type 94 37 mm Tank Gun in the bow but the available space was not enough at least for the tank gun. The vehicle was replaced in the cavalry units by the Type 95 Light Tank Ha-Go but continued its service in the reconnaissance units of the IJA tank regiments from 1937 on. After introduction of the Type 97 Tankette Te-Ke as successor the production of the Type 92 Heavy Armoured Vehicle was stopped in 1939 after delivering 167 of these vehicles.

There was also a trial prototype of an amphibious version without bow armament.

Data
vehicles built: 167
battle weight: 3,5 (metric) t early version, 14 (metric) t late version
crew: 3 men
armor: up to 6 mm
length: 3940 mm,
width: 1620 mm
height: 1830 mm
ground clearance: 280 mm
track width: 210 mm
trench crossing capability: 1600 mm
climbing capability: 30°
engine: 6-cylinder Mitsubishi gasoline
power: 45 hp at 1600 rpm
maximum speed: 40 km/h on roads
range: 100 km
Power/weight ratio: 12,8 hp/t
armament: 1 X Type 91 6,5 mm, later 1 X Type 97 7,7 mm Tank MG in the turret, 1 x Type 91 6,5 mm, later 1 X Type 97 7,7 mm Tank MG or 1 X Type 92 13,2 mm MG in the bow

Yours

tom!