japanese tanks and armored vehicles

21) Infantry AFV:

IJA developed a small number of special afv for infantry use. These were mainly used to transport men and supply.


a) Type 98 Armored Transport So-Da:



With the introduction of the Type 97 Tankette Te-Ke a special version for armored ammunition transport was developed. The engine was moved to the right of the driver. The fighting and engine compartments were replaced by an open top cargo bay. It was possible to transport up to 1 t of cargo or 4-6 soldiers. The tank could be loaded and unloaded through a large vertical two hatch door on the rear. A towing bar was mounted for lighter weapons up to the Type 1 47 mm Rapid-fire Gun.

Data:

Vehicles built: unknown
crew: 2 men
capacity: 1 t of cargo or 4 – 6 soldiers
length: 3800 mm
width: 1900 mm
height: 1600 mm
weight: 5000 kg empty
armor strength: 6 – 12 mm
engine: 4-cylinder Diesel
power: 65 hp/2300 rpm
speed: 45 km/h on roads
range: 200 km
armament: None


b) Type 1 Armored Personnel Carrier Ho-Ki:



In the late 1930th the development of full tracked transport vehicles started. After several trials with different suspensions Hino Motors developed a version with a semi-Christie suspension consisting of four large road wheels, a rear driving wheel, a forward idle wheel and two return rollers. Driver and engine were placed in the bow. On the rear a large open top transport compartment for up to 13 men was mounted. Access was possible by a large two door hatch on the rear. There was also a towing bar but with a trailer or gun towed it was a problem to unload the soldiers quick.

The 6 mm armor was vertical with a slightly sloped bow armor. It was possible to mount a standard heavy MG on the driver´s compartment for defense. A 6-cylinder Diesel engine was used. Due to a low priority production did not start before early 1944. Several vehicles were sent to China and the Philippines but most of the limited serial production was issued to the 4rd Tank Division in Japan for homeland defense.

Data:

Vehicles built: at least 200
crew: 2-3 men
capacity: 2 t of cargo or 12 - 13 soldiers
length: 4780 mm
width: 2190 mm
height: 2580 mm
weight: 5500 kg empty
armor strength: 6 mm
engine: 6-cylinder Diesel
power: 134 hp/2000 rpm
speed: 42 km/h on roads
range: 300 km
armament: none, a Type 92 7,7 mm HMG could be mounted


c) Type 1 Armored Personnel Carrier Ho-Ha:



In 1941 IJA ordered Hino Motors to develop a fast half-tracked APC similar to the german SdKfz. 251. It should carry up to 12 soldiers or 2 t of cargo under armor protection against infantry small rounds at a maximum speed of 50km/h. The halftrack design should be taken as it was expected that fully tracked vehicles of that size wouldn´t be able to drive at the necessary speed.

The resulting vehicle had similarities with the SdKfz 251 but was a different design. The front axle wasn´t powered and should only be used to steer on harder ground. The rear suspension consisted of two pairs of large road wheels, a forward driving wheel, a rear idle wheel and a single return roller between the center road wheels. Both sides could be used for steering separately by using the reduction gears or the breaks.

A 6-cylinder Diesel engine was mounted in the bow. A crew compartment for driver and commander was mounted behind the engine. The rear 2/3 of the vehicle were a large storage room. The 6 mm armor was arranged sloped to the front and the sides with the lower bow and side armor negatively and the upper armor positively angled. The rear armor was vertical. A large two-door hatch opening to the sides allowed access to the storage compartment. The whole rear structure was open top but could be covered by a canvas. For close defense three LMG could be mounted on each side behind the crew compartment and on the rear.



Production did not start before 1944 with ca. 300 vehicles built. Most production vehicles were issued to homeland defense units. Only a few were sent to China and the Philippines with fewer reaching their targets due to the large air and sea superiority of the Allies. After the war some of the surviving vehicles were used for civil purposes but most were destroyed.

Vehicles built: ca. 300
crew: 2 -3 men
capacity: 2 t of cargo or 12 - 13 soldiers
length: 6100 mm
width: 2100 mm
height: 2510 mm
weight: 7200 kg empty
armor strength: 6 mm
engine: 6-cylinder Diesel
power: 134 hp/2000 rpm
speed: 51 km/h on roads
range: 300 km
armament: none, three LMG mounts could be mounted behind the crew compartment and the rear


d) Experimental Amphibious Landing Vehicle:



Amphibious wheeled vehicle with a lightly armored fighting compartment developed by Toyota. It was based on the Amphibious Truck Su-Ki. The boat-shaped hull made it possible to use the vehicle even in rougher sea. Details are unknown.

Data:

Unknown


Yours

tom!

 

22) Navy Armoured Fighting Vehicles

The Imperial Japanese Navy used AFV since the First Shanghai Incident in 1932. First vehicles were domestic and foreign armoured cars like the Type Crossley Armoured Car or the Osaka Armoured Car. The first tank unit was raised in 1936 as part of the Tokubetsu Rikusentai = Special Naval Landing Forces (japanese Marines). It was equipped with standard Type 89 Medium Tanks. Later navy tank units were based on various pacific islands equipped with Type 95 Light Tanks, Type 97 Medium Tanks and Type 97 Medium Tanks KAI. IJN tanks used an anchor instead of a small yellow star as national emblem. Several units also painted the Rising Sun Flag (the navy war flag) on their tanks. IJA units only used the Hinomaru Flag (the army war flag) on captured tanks to mark them as own vehicles. After 1940 IJN developed several special tank and armoured vehicle types which are covered here.


a) Special Type 2 Motor Launch:



After taking over the results of the army amphibious tank project in 1937 IJN start to think about how to use this kind of vehicles for amphibious operations of their Special Naval Landing Force (SNLF). Several studies were made regarding potential operational use, necessary features and possible tactics. With the decision to start a war in the Pacific in 1940 IJN increased the efforts and in early 1941 the decision was made to develop an amphibious tank. In cooperation with Army Technical Bureau and Mitsubishi such a vehicle should be built based on the Type 95 Light tank. Requirements were among others:
- watertight construction
- fully seaworthy even in heavy weather
- fully welded
- range afloat at least 100 km
- speed afloat 10 km/h
- floating devices removable from inside
- armament consisting of a Type 98 37 mm Tank Gun and two Type 97 7,7 mm Tank MGs
- easy to be build

The first tests with the incomplete prototype started in late 1941 at Lake Hamada, Shizuoka Prefecture. The vehicle was finished until early 1942. It consisted of the tank, two large detachable pontoons, a detachable conning tower and a detachable special air intake extension. All hatches openings and holes were made watertight by rubber seals or bulletproof glass. Crew consisted of driver, bow gunner, commander, gunner, ammunition supplier and mechanic. As IJN was not allowed to operate tanks the vehicle received the designation "Special Motor Launch" instead.

The vehicle was very different from the Type 95 Light Tank. Suspension and power transmission were similar but most parts were newly developed to cope with the larger weight. The rear idle wheel was relocated to the ground to increase ground contact. The springs and bell cranks were all mounted inside the vehicle to protect them from corrosion by sea water.

The armor scheme was completely different. Bow and rear armor were optimised for easy removal of the pontoons. All armor plates were flat and welded together. The lower bow armor consisted of two flat 12 mm armor plates with different negative angles. The upper part covered the tracks. Two clamps were mounted in the upper armor plate to fix the forward pontoon afloat. The upper bow armor was arranged sloped with both sides bent to the rear. A visor port for the driver was mounted on the (in driving direction) right side. In the center a third clamp for fixation of the pontoon was placed. On the left a standard MG mount was riveted to the armor plate. With the MG removed a detachable hemispherical cap covered the MG port watertight. Just before going ashore the cap was dropped off and the MG was mounted.


frontal view

The side armor was arranged vertical. Flotation chambers were placed above the tracks on each side which also gives additional protection by the spaced armor effect. There was no access hatch for driver and bow gunner. On each side a ventilation air intake for the fighting compartment was mounted on the top armor next to the rear part of the turret. Both were covered with a hatch. Above the driver the steering cable for the rudders is starting. Several guide pulleys leads the cable to the rear along the right upper edge of the fighting compartment.

The turret was a modified version of the turret from the Type 98 Light Tank. It was slightly conical with a large hole for optical equipment on each side of the gun mount. A large semicircular hatch on the turret with a two-part lid allowed access. Armament consisted of a Type 98 37 mm Tank Gun and a coaxial Type 97 7,7 mm Tank MG mounted slightly offset to the left. A semicircular handrail was welded on the rear turret to make entering the tank afloat easier. A removable steering mechanism for the propellers and rudders was inside the turret. Afloat the commander steered the tank from there. The gunner left the turret during that phase.

The top armor of the engine compartment was arranged sloped to the rear. The side armor was slightly sloped, too. The side parts next to the engine compartment were arranged sloped with a much lower angle to simplify slipping of the rear pontoon when removing it. The rear armor had a nearly vertical upper part and a negatively angled lower part. Clamps on the armor on the side of the engine compartment and on the upper rear armor fixed the rear pontoon afloat.

The engine was mounted lengthwise in the rear. There was no separating steel plate between fighting compartment and engine making it quite loud inside the tank during movements. Three hatches in the rear top armor allowed access to the rear fighting compartment and the engine. The center hatch was the largest. It had a large air intake covered with a grid. The detachable air intake extension could be mounted on this grid using clamps and hooks. A rubber band on the armor plate made the connection watertight. The mesh-covered muffler was placed on the right side, the tail pipe was raised.

The ammunition supplier and the mechanic had their seats between turret and engine. The ammunition supplier had to help the commander by giving him the ammunition loaded inside the vehicle. He also moved MG ammunition from the transport racks to the bow gunner and gunner. The mechanic had to watch and maintain the complex machinery especially during operations afloat. During operations on land he was not really needed (repairs could be done faster by the maintenance units) and so not inside the tank most of the time.

[
improved forward pontoon

The forward pontoon had a u-shape and was designed streamlined for an excellent driving quality. He had three flotation chambers with a total volume of 6,2 m³. The pontoon could be lifted by a collapsible jib boom (part of the equipment) over three hooks on the upper edge and two short handling rods on the lower part. With the pontoon attached the driver´s visor port was completely covered. A small recess allowed mounting the MG.

The rear pontoon was also u-shaped with the rear edges rounded. It was had three flotation chambers but only with a volume of 2,9 m³. The rudders were mounted under the pontoon on long axles which reached through the whole pontoon to the steering mechanism on top. Six hooks are mounted on the upper edge and two handling rods on the lower part for handling the pontoon with a jib boom.

Afloat the tank was operated from a small detachable conning tower mounted on the turret which could be easily detached. This was necessary as the view from inside the turret was too bad for navigation at sea. The tower was conical with three visor ports next to each other in the forward part and three more mounted in each side and the rear. On top was a small access hatch. On the ocean the commander steered the rudders from inside the tower.

Yours

tom!

 

To prevent spray from the waves to get inside the engine a conical rectangular air intake with a wider cap could be mounted on the engine compartment. This was necessary in bad weather or heavier sea.


rear pontoon

The pontoons, the conning tower and the air intake extension were welded using 3,2 mm thick face-hardened armor plates. It was possible to transport both pontoons with a single Type 94 6X4 Truck. All parts necessary to get the tank ready for operation could be mounted by the crew within 15 minutes with the equipment of the tank.

Afloat two large screws next to the tracks moved the tank. The driving shafts were connected with the engine over a power dispensing devise which separates the two types of propulsion. This device was also responsible for sending power to the bilge pumps. The rudders were mounted on the rear pontoon.

The concept worked very well and so in mid 1942 the decision was made to start a serial production immediately. Official designation was "Special Type 2 Motor Launch". It seems that the popular short designation "Ka-Mi" wasn´t adopted officially but it was used by the units operating the vehicles. 300 vehicles were ordered. The first unit using this tank was formed in late 1942. There are few US reports of early version Type 2 armed with the Type 94 37 mm Tank Gun but there was no japanese source yet.

After the first exercises some changes were demanded by the soldiers. So a radio was added, the antenna base was welded on the rear right of the turret. The forward pontoon was remodeled to improve detaching. Therefore it was cut along the center line making it two-piece. The recess for the bow MG was widened to make the driver´s visor port accessible. The clamp in the upper bow armor was now surplus. A handrail was added to the pontoon. Other changes were made inside the tank to simplify handling. Most important was the installation of an onboard communication system with headphones to compensate the engine noise. The changes were adopted officially in summer 1943.

Only 184 vehicles were produced by Mitsubishi until surrender due to raw material shortages and a change in IJN strategy. They were issued to independent tank companies of the SNLF. Several units fought against US invasion forces in 1944 and 1945. Most spectacular was the attack of the 101st SNLF which swam from Luzon via Samar to Leyte during the US Invasion in late 1944. Due to the weak gun the success was limited. Nevertheless the US Army and Navy was impressed by the good seaworthiness which was far superiour to any other contemporary amphibious tank in the world. It was even possible to carry the tanks with submarines and launch them shortly below the surface.


rear view

In western literature the first production version is sometimes designated "Type 1 Ka-Mi" or "Type 1 Ka-Sha" which is not correct. There was no change in the official designation.

There are still several Type 2 Ka-Mi rusting on different pacific islands. Only few are on display in museums. A vehicle with both pontoons and the air intake extension can be seen at Kubinka Tank Museum near Moscow.

Data

vehicles built: 184
battle weight: 9,15 (metric) t, 12,5 t with floating equipment
crew: 5-6 men
length: 4800 mm, 7420 mm with pontoons
width: 2800 mm
height: 2300 mm
track width: 305 mm
engine: Mitsubishi A6120VD in-line 6-cylinder air-cooled Diesel engine
power: 115 hp at 1800 rpm
maximum speed: 37 km/h on roads, 9,5 km/h afloat
range: 320 km on roads 140 km afloat
transmisson: 8 forward, 2 reverse
armament: 1 X Type 98 37 mm Tank Gun , 2 X Type 97 7,7 mm Tank MG
Ammunition capacitiy: 132 37 mm grenades, 3900 MG shots

armor strength
turret front
12 mm @ 85 °
sides
12 mm @ 85 °
rear
12 mm @ 85 °
top
6 mm @ 0 °superstructure front
12 mm
sides
6 + 6 mm @ 90 °
rear
12 mm
top
6 mm


Yours

tom!

 

b) Special Type 3 Motor Launch:



After introduction of the Special Type 2 Motor Launch SNLF demanded a similar vehicle with more armor and a 47 mm gun. The development of a successor was started in early 1943. Most data were lost after surrender. So many details are unknown.

Development was done in cooperation with Mitsubishi. To speed up the process many parts of the Type 1 Chi-He were used including the turret, the engine, suspension elements and parts of the transmission and steering. Other elements were modified from the predecessor like the pontoons, steering and propulsion afloat and internal structure. But it was not developed from the Type 1 Chi-He as stated in many sources.

The hull was huge and bulky. Bow, side and rear armor were almost vertical making it easy to penetrate it. Only the upper front and side armor was arranged sloped. There were four access hatches to the flotation chambers in each side armor. Two clamps each in the bow and upper bow armor fixed the frontal pontoon. Driver´s visor port and bow MG were arranged as at the Type 2. The turret was placed in the center line. There were two pairs of ventilation hatches on the sides of the top armor, one between driver and turret and one next to the turret overhang. The cable for operating the rudders started on the right side in front of the turret. Number and location of the access hatches to the fighting and engine compartment are unknown. The air intake extension was mounted at the rear end of the engine compartment. So it can be assumed that the main engine access hatch was there, too. There was an exhaust pipe with muffler and raised tail pipe on each side of the vehicle´s rear top armor. Four clamps on the rear armor fixed the rear pontoon.

The suspension consisted of four pairs of roadwheels. Two pairs each were connected with bell cranks to a large vertical coil spring covered by a semicircular armor plate. The rear idle wheel protruded the vehicle completely. The frontal driving sprocket and four return rollers completed the suspension. All parts were mounted outside the vehicle.

Both pontoons were quite similar to the pontoons of the predecessor but they were larger to cope with the weight. The rear pontoon did not enclose the vehicle rear. It was mounted completely behind the tank. A similar conning tower for the commander´s cupola and a similar air intake extension completed the equipment for seaworthiness.

Only the prototype and 19 pre-series vehicles were built in late 1944. It is unknown if the short designation "Ka-Chi" was adopted officially. The vehicles were only used for exercises. Some internet sources claim that there was a successful test launch from a submerged submarine from a depth of 100 m but I found no more reliable sources yet. There is no known survivor today.

The whole vehicle was far too large for the chosen armament and the armor scheme and strength would have made it an easy to destroy target.

Data

vehicles built: 20
battle weight: 28,25 (metric) t with floating equipment
crew: 5-6 men
length: 10300 mm with pontoons
width: 3000 mm
height: 3820 mm
engine: Mitsubishi Type 100 V-type 12-cylinder air-cooled Diesel engine
power: 240 hp at 2000 rpm
maximum speed: 32 km/h on roads, 10,5 km/h afloat
range: 320 km on roads 140 km afloat
transmisson: 8 forward, 2 reverse
armament: 1 X Type 1 47 mm Tank Gun , 2 X Type 97 7,7 mm Tank MG

Yours

tom!

 

c) Special Type 4 Motor Launch:[/U]



After the Battle of Wake IJN decided to make a larger survey about the causes of the quite large losses. One main cause found was that the landing craft used were open to the top exposing the passengers to enemy small arm fire and especially splinters. In addition the armor was relatively weak making it easy to penetrate the sides and the bow with heavier weapons. This problem became urgent again during the 1942 Solomon Island campaigns. There landing crafts were often attacked by aircraft which shot into the cargo bay from above. As result the decision was made to develop a better protected landing craft for these kind of operations. Requirements were among others:
- easy to unload and load for transport ships
- usable on land and in the water
- closed cargo compartment
- armed with one or two Type 93 13,2 mm Machine Cannons for close defence

In 1943 the US presence was increased especially in the south and central pacific. This lead to increasing losses among transport and supply shippings because of submarines and long-range aircraft. Especially forward garrisons on smaller island were sometimes cut off from supply. So the landing craft should additionally be able to be transported and launched from submarines.

A prototype was finished in late 1943 at Kure Naval Yard. Operational tests were finished in March 1944. Crew consisted of driver, navigator, two gunners and a mechanic. The vehicle had a boat-shaped armored hull with a maximum armor strength of 10 mm. Afloat the landing craft was powered by two propellers in the rear. Rudders were mounted behind them for steering. For movenments on land a track suspension was added. The suspension was similar to the Type 98 Light Tank Ke-Ni. It consisted of four pairs of roadwheels connected with bogies. Each two pairs were connected by bell cranks with large horizontal coil springs. These elements were placed inside the vehicle for protection against corrosion by seawater. A forward driving sprocket, five return rollers and a rear idle wheel completed suspension.

The whole vehicle was covered by an armored deck. Internal chambers on the bow and rear delivered additional buoyancy for stabilty. Crew and engine compartment was in the forward half. A driver and a navigator operated the landing craft from an armored cabin with two visor ports on the bow. The rudders were operated over a cable mechanism similar to the Special Type 2 Motor Launch. During the final approach to the shore the driver could change to a steering position on the deck behind the cabin. There he was protected by armor plates from the front and the sides. The rear was open for a better overview. A visor port was placed in the frontal plate. Type 93 13,2 mm AA-Machine Cannons could be mounted on pivots on each side of the steering position on deck.

The vehicle was powered by the Mitsubishi A 6120 1 in-line 6-cylinder Diesel engine, a modified version of the engine of theType 97 Medium Tank. The air intakes on deck were made water-tight with float valves. A long exhaust pipe lead to the rear mounted muffler with raised tail pipe. A cargo compartment was placed behind the engine compartment. Maximum payload was 4 t or up to 40 men (some of them on deck). It was possible to carry larger loads on deck but vehicles could not be carried. There were three watertight access hatches on the crew compartment and three more on the cargo compartment. Several hooks around the deck allowed easy loading and unloading from ships.

During tests the vehicle was easy to steer but slow. Nevertheless the design was accepted under the designation "Special Type 4 Motor Launch".It is unclear if the short designation "Ka-Tsu" was introduced officially.



In January and February 1944 US forces captured the central pacific atolls of Eniwetok, Kwajalein and Majuro. During the following months US-Navy expanded the already built japanese air and naval bases to a a large forward base for future operations against Truk and the Marianas (Saipan, Tinian, Guam). Japanese submarines and long-range reconnaissance aircraft delivered good reports about these works. So in April 1944 IJN started to plan a massive attack on these bases (Operation Yu-Go). Part of these plans was to launch special attack units using torpedo vehicles from submarines to attack anchorages. For this operation the vehicles should be used. This made several modifications necessary.

The exhaust pipes and the steering mechanism for the rudders were relocated below the deck. On each side a mount for a modified Type 91 Model 3 450 mm aircraft torpedo was welded on the deck above the fighting compartment (Many western sources claim that the torpedoes were Type 93 610 mm Long Lance but almost all japanese sources say Tpe 91 Model 3). A simple aiming device was mounted in the driver´s cabin. Special hooks to carry the vehicle with submarines were also added. To mount the torpedoes the machine cannons had to be removed. During the first trials the crew had problems to keep the vehicle watertight submerged. The air intakes finally had to be sealed with special coverages to prevent the engines from flooding but it took some 20 minutes to remove them and to make the vehicles ready to start. During this time the submarine had to stay at the surface. A submerged start as planned was not possible. Nevertheless IJN decided to introduce the vehicle with these changes. Production numbers are unknown but at least 50 vehicles were built.

Operation Yu-Go was cancelled in mid 1944 due to the fast US advance to the Marianas. The operating soldiers disliked the slow speed afloat but they had to use the vehicles because there was nothing similar avaliable. Crew training continued and until late 1944 800 soldiers were trained on these vehicles. In late 1944 operations against US ships at Luzon were planned but cancelled after a tanker destined for fuel supply was sunk during a convoy mission.

Some sources claim that the unit was used in 1945 to resupply cut-off pacific island garrisons. The plans for homeland defence included suicide torpedo attacks of the Special Type 4 Motor Launches on the invasion fleets.


2 vehicles equipped with torpedoes carried by the B2-class submarine I-41

Most vehicles were scrapped postwar but at least one is on display at WWII and Korea LVT Museum, Camp Del Mar, Marine Corps Base Camp Pendleton, California, USA

Data

vehicles built: 50 or more
battle weight: 16 (metric) t
crew: 5 men
maximum armor: 10 mm
length: 11000 mm with pontoons
width: 3300 mm
height: 2250 mm to deck, 4050 mm maximum
engine: Mitsubishi A 6120 1 in-line 6-cylinder air-cooled Diesel engine
power: 120 hp at 2000 rpm
maximum speed: 20 km/h on roads, 8 km/h afloat
range: 300 km afloat
armament: 2 X Type 93 13,2 mm Machine Cannon or 2 X Type 91 Model 3 450 mm Torpedo


d) Special Type 5 Motor Launch:

no picture, sorry



There are only few informations about this vehicle avaliable. It is even not sure that the prototype was finished before surrender.

Upon the avaliable drawings (which differ largely in details) it can be assumed that the tank was a try to remodel the Special Type 4 Motor Launch to make it less vulnerable against enemy fire. Size and shape are similar, most known data also fit for both vehicles. The most significant changes are a far better bullet deflecting armor scheme, a change in armament and different pontoons.

The upper bow armor was now sloped with a lower angle. The lower part was still negatively sloped but with a shallower angle. The superstructure armor wasn´t changed on front and sides. The rear armor was now similar to the Special Type 2 Motor Launch.

The Type 1 47 mm Tank Gun was now mounted on the position of the bow MG. The MG was replaced to the right between gun and driver´s visor port. In the turret a modified Type 96 25 mm Machine Cannon replaced the gun.

The frontal pontoon was now flatter to allow using the bow armament during landing. The rear pontoon was shorter and had the shape of the rear pontoon of the Special Type 2 Motor Launch


Scale model, details are surely different to the historical Vehicle

Due to an error in the book "Tanks of the World 1915-1945" from Peter Chamberlain and Chris Ellis many internet sources show a picture of the Special Type 2 Motor Launch without floating equipment as a picture of this tank. This is definitely wrong. There is no known picture of the Special Type 5 Motor Launch.

Data

vehicles built: 1
battle weight: 29,1 (metric) t
crew: 5-7 men
maximum armour: 50 mm
length: 10800 mm with pontoons
width: 3000 mm
height: 3380 mm
engine: Mitsubishi Type 100 V-type 12-cylinder air-cooled Diesel engine
power: 240 hp at 2000 rpm
armament: 1 X Type 1 47 mm Tank Gun, 1 X Type 96 25 mm Machine Cannon, 2 X Type 97 7,7 mm Tank MG


Yours

tom!

 

e) Short Barrel 120mm Gun Tank:



In late 1944 the SNLF demanded a gun tank similar to the IJA Type 2 Gun Tank Ho-I but with a larger gun for close support. So the decision was made to upgun the Type 97 Medium Tank KAI with the short 12 cm gun developed in 1942/43 for close defence of transport ships.

The hull of the tank was not changed. The gun mount was replaced by a massive mount with a large recoil mechanism. There were several recoil cylinders mounted around the barrel and covered with a round armour for protection. This recoil mechanism was still not able to cope with the recoil forces and so a flat muzzle break had to be added, too.

The gun was developed as high-angle multi purpose gun. It should provide close-range fire against aircraft , submarines and small attack boats. Due to the short barrel it was almost impossible to hit moving targets so only barrage fire was made. Data for the gun are:

- caliber: 120 mm
- gun length: 1510 mm
- bore length: 1440 mm (L/12)
- rifling length: 1127 mm
- grooves: 24 (1.0 mm x 11.78 mm)
- lands: 3,93 mm
- twist: Increasing RH 1 in 30 to 1 in 13
- weight: 2950 kg with mount
- chamber volume: 3 dm³
- muzzle velocity: 290 m/sec
- rate of fire: up to 15, 10 for continuous fire
- ammunition: HE, Incendary, Chemical, Anti-submarine
- grenade weight: HE 11,8 kg with a warhead of 2,5 kg and a propellant charge of 0,49 kg
- fuzes: time, impact, anti-submarine (time and/or preasure)
- maximum range: 5300 m
- maximum ceiling: 3100 m

Maximum range was reduced due to the limited elevation of the gun mount. Due to the screw-type breech of the new gun the already low space inside the turret was reduced. In addition the ammunition was heavy.

Further details are unknown.

An unknown number of Chi- HA KAI were modified this way in 1945. After surrender US units found at least 4 vehicles at Sasebo SNLF base and 10 more at Yokosuka SNLF base. All were scraped postwar.

Data

as Type 97 Medium Tank Chi-Ha KAI except:
vehicles built: at least 14
armament: 1 X Navy Short 12 cm Gun , 1 X Type 97 7,7 mm Tank MG


f) Long Barrel 120 mm Gun Tank:


only known picture

Informations on this vehicle are rare. After surrender US forces found at least one vehicle at Yokosuka Naval Yard. It is unknown if it was a local conversion or an official development.

A Type Taisho 10 120 mm gun was mounted on the hull of a Type 97 Medium Tank. The turret was removed and the hole closed by steel plates. Additional steel plates were welded on each side of the fighting compartment to create a platform for the gun crew.

Data of the gun are:

- caliber: 120 mm
- gun length: 5600 mm mm
- bore length: 5400 mm (L/45)
- rifling length: 4649 mm
- grooves: 34 (1.45mm x 6.688 mm)
- lands: 4,4 mm
- twist: uniform RH 1 in 28
- weight: 218 kg without Pivot
- chamber volume: 10,774 dm³
- muzzle velocity: HE 830 m/sec Illuminating 700 m/sec, anti-submarine 250 m/sec
- rate of fire: up to 11 per minute, 7 for continuous fire
- ammunition: HE, AP , Incendary Shrapnel (AA), Illuminating, Anti-submarine
- grenade weight: HE 34 kg with a warhead of 1,9 kg and a propellant charge of 5,5 kg
- fuzes: time, impact, anti-submarine (time and/or preasure)
- maximum range: 16000 m
- maximum ceiling: 10000 m

There are no further infos. Due to the gun weight and dimensions it can be assumed that the vehicle was top-heavy making it a quite unstable firing platform.

Data:

unknown



Yours


tom!

 

Hi.

That´s it, I´m done.

Discussions, corrections and additional infos are very welcome.

Yours

tom!

 

Very impressive! I had no idea they had so many AFVs or projects.

Sorry for "interrupting" with my #7; I posted just as you were getting started.

 

Hi.

Thx. Took me 15 years of Hobby research to get that far but I think it was worth the time.

Most do not know much about the japanese armor developments and there are still many rumors and personal opinions around but only few facts and even less details.

Yours

tom!

 

Sorry for the bump, but are you able to provide a source for the type 95's face harden armour?

 

Hi.

I haven´t forgotten your question but I was busy with RL a long time now. There was a japanese website mentioning this but I can´t find it any more.

But in general in the early 1930s IJA built prototype tanks with only one vehicle completely done including armor plates and the other pre-series vehicls with mild steel plates for field tests etc. In 1929 the Type 89 prototype was even finished with steel plates being removed from a Vickers Mk C IJA bought and imported in 1927. This was because of the lack of raw materials and available steel manufacturers capacities. After 1935 there was enough hardened steel capacities around to built all prototypes with a complete set of armour plates.


Type 89 prototype with Vickers Mk C lower bow armor plate


And for your info:
I´m moving my website to another server at the moment. I hope the actual security issues on some websites with my pics will be history after that. But due to the change it´s possible that my website will be unavaillable for some days. Just be patient I will be back......

Yours

tom!

 

Hi.

One addition to chapter 19:

d) Experimental Minesweeper Tank GS:

I was able to find a picture of this vehicle.



Yours

tom!

 

Hi Tom!

Am I looking at a Type 87 medium tank variant with rocket launchers fitted to its rear. Do we know much about how this was meant to work, were there a number of rockets to be fired?

 

Hi.

This was an 8-barrel (2 rows of 4) exploding rope launcher similar to the modern days systems (MCLC). The barrels are quite simple mesh constructions. The tank drove towards the expected or located mine field and fired one of the small unguided rockets. The attached rope was transported in the box below the respective launcher barrel and was laid over the open field by the rocket. Then it was detonated from inside the tank hopefully clearing a path through the mines.

It looks like most data regarding the rockets and the rope did not survive the war (I´m still looking for additional infos).

The main "gun" fired an over 2 m long obstacle clearing bangalore torpedo using a propellant charge and a sabot. It was a similar system as used by the Type 98 50 mm Grenade Discharger developed especially for demolition teams of engineer troops.


muzzle of the bangalore launcher and details of the tip of the torpedo

Yours

tom!

 

Thank you tom!, most informative. I wonder if this machine was studied by the Americans after Japan's surrender?

 

Hi.

I doubt that the US intelligence was able to locate such vehicles among the large amount of captured tanks. And I don´t think IJA officials were of much help after surrender....

Most captured tanks were sunk in deep rivers and lakes around the scrapyards in Japan. And there is the story of US transport officers being unable to differ between the Type 4 and Type 5 Tank prototypes even with transport orders on their sides only sending the Type 5 to Aberdeen Proving Ground/Maryland. There was much confusion after the war....

Yours

tom!

 

Sounds like a similar(ish) principle to the Conger and Snake conversions of the Universal Carrier

 

Hi.

I have to correct myself regarding one entry at the Armoured Cars chapter:

"f) Osaka Armored Car:



This vehicle was seen during the 1932 Shanghai Incident operated by naval troops. But it was designed by Osaka Army Arsenal from a domestic 2,5 t truck chassis. The armor sheme was similar to the Wolseley Armoured Car but built with thicker armour plates. The turret was slightly larger. Armament consisted of one Type Taisho 3 6,5 mm MG in the bow and a second in the turret.

It seems that only one prototype was built as technology test vehicle. The official designation is not known but european sources from 1935 used "Osaka Armoured Car" which would fit to the earlier designation system. Today the vehicle is mostly designated "Hokoku-Go Armoured Car" but this is a misinterpretation of the writings on the vehicle during the 1932 Shanghai Incident. "Hokoku-Go" or "Hokoku" was a donation organisation which supported IJN with money and military goods. So it seems that the vehicle was bought by Hokoku after the test trials were finished by IJA and then donated to IJN.

Data:

vehicles built: 1
battle weight: 5,85 t
crew: 4 - 5 men
armor 8 - 11 mm
length: 5000 mm
width: 1850 mm
height: 2650 mm
ground clearance: 280mm
engine: 4 cylinder gasoline
power: 35 hp
maximum speed: 60 km/h forward, 7 km/h reverse
Power/weight ratio: 6 hp/t
armament: 2 X Type Taisho 3 6,5 mm MG"


This vehicle is in fact a captured chinese armoured car and so has to be moved to the Foreign Armor chapter. And ignore my false description. It is based on Franz Heigl´s "Taschenbuch der Tanks" from 1936 which was most likely basis for all other false descriptions I also used for my entry.

It was built in 1929 at the chinese Nationalist Army Shanghai Army Arsenal. and first used by nationalist army forces in the Shanghai area. For further infos see the following chinese website:

船坚炮利︱从荣耀到末路：上海兵工厂自制装甲汽车的曲折命运_搜狐汽车_搜狐网 (sohu.com)

(machine translation works nicely).

And the armament was 2 X Vickers 7,7 mm MG, not Type Taisho 3 HMGs .

Yours

tom!

 

Interseting article. I am much taken with the mystery Chinese tank: