Sunday, September 3, 2017

The Ho-Ri Tank Destroyer

        
        Hello everyone. The last time I posted a write on the Ho-Ri tank was on November 14th, of 2016. Since then my studies on the project have been underway for quite some time. Earlier this year, I obtained documentation files on the tank project from a private collection. In my findings were official schematics and outline drawings of the Ho-Ri tank destroyer, alongside two photographs of the vehicles construction. However I was not given the permission needed to obtain rights to these photographs, I was able to secure property rights to its drawings. Which unfortunately, I do not plan to release publicly for the time being. 

This article will be a brief historical background on the Ho-Ri as of what I have learned since last year. The previous article, no longer being completely up-to-date, will be edited as such and forwarded to this new post - as to clear future confusion. I hope you all enjoy!

- Information on vehicle accurate as of [9/3/2017] -


As the war progressed in the Far East, it became increasingly evident that Japan’s armored warfare doctrine would not suffice against the growing threat from the United States. Prior to America’s declaration of war on Japan, tank doctrine focused solely on the infantry support role during an offensive. Much of the Japanese armor inventory in 1941 was already a decade old. Poorly armed and armored, these Japanese infantry tanks could not counter the M4 Sherman. To remedy this, Japan quickly introduced the Chi-Ha Kai with a 4.7cm anti-tank gun, but it was only a temporary solution.

Japanese crew manual on the M6 Heavy Tank. 
Japanese Intelligence also became aware of the development of the M6 Heavy tank. If such a vehicle was sent to the Pacific, few of the Imperial Japanese Army’s anti-tank guns would have been capable of stopping it at average combat distances. Japan’s military leaders and weapons manufacturers thus realized that they would need more potent tanks with better armor and cannons. After a careful review of German tank doctrine, the Japanese Weapons Administration Headquarters enacted a new tank doctrine in July of 1943.

This new policy focused on the development and deployment of a common medium tank with stronger armament, which would in turn be supported by tank-destroyers with high-caliber weaponry. In furtherance of this policy, both medium and large caliber anti-tank guns were developed for use in new medium tank designs in 1943. Two medium tank designs were selected, the Chi-To and Chi-Ri tanks both adopted their versions of the Type 5 75mm guns.

Development of the Ho-Ri began in late 1943, using the chassis of the Chi-Ri as the base for development. Japan’s 4th Technical Institute of Research understood that the Chi-Ri’s relatively flat front hull plates offered little protection against enemy anti-tank fire. Initial tank designs kept an unchanged hull design, and replacing the turret with a welded casemate. A key focal point in the design of the Ho-Ri was the decision to angle the front armor plate to 70 degrees, drastically increasing the effective armor protection and enabling the vehicle to withstand American 76mm guns.

The concept was presented to the Ministry of War in early 1944 in the form of a wooden mockup. The staff had expressed positive opinions on the vehicle design. Following the presentation, the order to construct a prototype of the Ho-Ri was approved. It took until July for the chassis to be completed. In August, the Ho-Ri prototype had been assembled and put through trials.

National Archive File Ref. C14011075200
The National Institute for Defense Studies
Ministry of Defense, Military Administration
 of Ordnance, 4th Technical Research Institute
 Report Ho-Ri Prototype.

Weighing in at approximately 35 tons, the prototype successfully completed trials with flying colours. The tank had similar armor protection to that of the Chi-Ri, keeping a thickness of 75 millimeters at the front hull plate, with the superstructure at 120 millimeters. The top speed recorded from trials was 40 kph using a Kawasaki Water-Cooled V12 Engine, identical to that of the Chi-Ri medium tank, with a power output of 550 horsepower.

The Ho-Ri prototype mounted an Experimental High Velocity 10.5cm anti-tank gun, which featured a semi-autoloader mechanism to reduce the strain of loading the heavy shells. The gun was designed to counter all fielded armored vehicles the Unites States had in its possession. Japanese Intelligence had been aware of the possible deployment of the M26 Pershing and the M6 Heavy tank in the pacific for the invasion of the mainland. Due to the size of the 10.5cm cannon, natural depression was limited to only a couple degrees. To counter this, there was a top roof hatch that opened by pin to allow full depression of the gun.

The gun was required to effectively penetrate and destroy these tanks at all reasonable combat ranges at most angles. Development of this Experimental 10.5cm anti tank gun was initiated on July 30th, 1943. One member of the development team was a Major of the Army Weapons Administrative Division, and had stated in his records the gun had to achieve a performance figure of 200 millimeters of penetration against RHA at a range of 1,000 meters. With this demand being kept in mind, the first prototype cannon was completed and tested in February of 1944. It lacked sufficient performance, only being able to fire at a muzzle velocity of 916 m/s. It was only capable of penetrating 150 millimeters of armor at the trial range of 1,000 meters. Without a ballistic cap, the performance of its APHE shell at certain angles was drastically poor. The Munitions Council had to alter the design of the experimental gun and work on producing a new one for the Ho-Ri project.

The Ho-Ri tank as drawn by Tomio Hara.



After trials were conducted with the constructed prototype, the Ho-Ri was approved for planned production, and was to be officially adopted into service under the designation Type 5. The Army Weapons Administrative Division listed concerns they had in mind with the prototype to be adjusted with the production of the main series of tank destroyers. Due to rapid development of American anti-tank weaponry, it was ordered to increase the thickness of the Ho-Ri’s armor. However due to the war's end drawing near for Japan, the lack of materials presented an issue for a quantitative supply of Ho-Ri units to be supplied to tank regiments. The choice was then made to limit the number of production models and for them to be kept reserved in vital focal areas of the Japanese mainland. This order was in line with the limited production run of the Chi-To and Chi-Ri tanks.


National Archive File Ref.C13120839500, The National Institute for Defense Studies, Ministry of Defense,
Military Administration of Munitions Mobilization, Production Chart of January to April of 1945.

The thickness of the front hull plate was increased to 120 millimeters for the production model. The sides and angled plating around the vehicle were thickened to a considerable degree as well. This caused the vehicle to have a drastic increase in weight and it would have been underpowered with the old engine. To compensate for the added weight, an Experimental Kawasaki V12 engine with an output of 1,100 horsepower was added. This kept the mobility of the production model Ho-Ri on par with that of the original prototype.

The Experimental 10.5cm anti-tank cannon continued to be developed by the Munitions Council throughout 1944. In December of the same year, the project was once again at a testing phase with a new prototype gun. Performance of this gun reached the required standards - 200 millimeters of penetration at 1,000 meters with a muzzle velocity of 1,005 m/s. The gun was supplied with the Type 2 APHE shell with a ballistic cap to support the trajectory of the shot. It was accepted into service as the Type 5 10.5cm Tank Gun. By the wars end, only a few models of the gun were produced. And a limited supply of tank rounds.


Production of the Type 5 Ho-Ri began in January of 1945. By March, a total of 5 Ho-Ri tanks had been completed; further production of the vehicle was halted by American bombing raids. Japan would not be able to continue production of the vehicles as the Japanese war effort was almost bled dry by this point. The 5 completed Ho-Ri’s were kept with the Chi-Ri and Chi-To tanks at local armories. None of the vehicles were given to standard tank groups. Instead they remained as property under the Munitions Council and supervised by officers of the local battalions.

Lake Hamana in Shizuoka Prefecture. The town has a
reputation for its mysterious sunken tanks deep
in the lakebed.
Some of the built tanks were deployed to Shizuoka Prefecture in August of 1945. The military ordered the sinking of a Chi-To along with two other large vehicles in the lake of Hamana. It is believed that a Ho-Ri tank destroyer was sent with two Chi-To units to the region. The tanks were ordered to be sunken in a deep-water lake in order to prevent the United States military from obtaining them. Two other deployment zones were theorized by post-war Japanese University thesis's; Kanagawa and Osaka Prefectures, where the locations of the Sagami and Osaka arsenals were based. The division of tanks from the Archive mentioned a single Ho-Ri unit with a complement of 2-3 tanks of varying class, Chi-Ri’s or Chi-To’s. The Ho-Ri was to be kept in the rear while the medium tanks were to be placed on the front line to engage enemy armor.

By the end of the war almost all Ho-Ri’s and other end war vehicles were either scrapped, destroyed, or sunk. Leftover prototype and testbed vehicles were captured and brought back to the United States where after being evaluated, quickly scrapped for parts in the years following. As of September 3rd, 2017, there are currently only 2 photographs of the Ho-Ri’s in possession of private collections. Public access to these photographs and other documentation (such as the blueprints and data sheets) are now under review.

- Information on vehicle accurate as of [9/3/2017] -

Friday, June 23, 2017

Through the Gauntlet

It is not often you hear of Japanese war heroes during the War in the Pacific. Due to their reputation, many cases of Japanese bravery went unnoticed as the years went on. Often set aside to instead forget about the tragedies and brutal events that took play throughout the Second World War. However if any account of bravery is to be known, it is the actions of a single tank commander of the Imperial Japanese Army during the Battle for Iwo Jima. A man who took personal responsibility and dared to do the unthinkable to protect his comrades when all had seemed lost. The Battle for Iwo Jima had been one of the most brutal and bloody battles of the war. Japan's last hope of defense against the invading American forces, who needed the island in order for its long range bombers to reach the home island of Japan.




26th Tank Regiment

Takeichi Nishi during the 1932
 Los Angeles Olympic Games.
One of the commanding officers on Iwo Jima was Baron Takeichi Nishi, in charge of the 26th Tank Regiment and its 600 personnel. Takeichi Nishi had been Japan's 1932 Olympic Gold Medalist in equestrian show jumping during events at Los Angeles. and regarded as a celebrity in both Japan and the United States. He had been assigned as the commander of the 26th Tank Regiment in Northern Manchuria for the preparation for a possible Soviet invasion. Nishi and the 26th were stationed in Mudanjiang, which held one of the key logistical railways for supplying the Imperial Japanese Army; should the IJA lose control of the railway, the Soviets would be able to make significant territorial gains. In spite of this risk, the tides of war began to shift; Nishi and the 26th Tank Regiment were eventually ordered to Iwo Jima, to bolster the garrison of Lt. General Kuribayashi on the island fortress. Prior to this deployment, Nishi had been promoted to the rank of Lieutenant Colonel in recognition of the distinguished conduct of the 26th Tank Regiment in Manchuria. Yet this award was effectively hollow; the 26th Tank had no actual combat experience. The same was true of many of the units already on Iwo Jima, which Nishi and his regiment were being sent to reinforce.



Defending Iwo Jima

Preparations for the defense of Iwo-Jima were made under the command of Lieutenant General Tadamichi Kuribayashi,  whose forces were told hold the island at any cost. Kuribayashi had been personally selected by Prime Minister Hideki Tōjō to be the head commander of Iwo Jima due to his reputation as the prior commander of the 2nd Imperial Guards Division. Kuribayashi knew the United States outmatched Japan in all fields; when the defense would begin, there would be no equal ground for engaging the Americans in the field. To counter the Americans, the Japanese defenders would attempt to use attrition to defeat the invasion force. In preparation for the execution of this strategy, the garrisons on Iwo Jima constructed 10 miles of underground tunnels throughout the island. These linked roughly 6000 fighting positions, including pillboxes and caves for gun-emplacements.

An example of a dug-in tank. 
The 26th Tank Regiment only had 23 tanks stationed on the island by the time the American forces arrived. Originally, there were 28 tanks (Mostly Chi-Ha Kais) assigned to the defense of  Iwo Jima, however on July 18th, 1944, a cargo vessel carrying the tanks had been sunk by an American submarine, the USS Cobia. Takeichi Nishi had been forced to wait for a new set of tanks to be supplied to the island. Only 23 units were able to be scrounged up for Nishi and the 26th to use in the defense of Iwo Jima. Among these 23 tanks, there were twelve Type 95 Ha-Go light tanks and eleven Type 97 Chi-Ha tanks. Of the Chi-Ha’s, only 3 were Kai models with the 47mm Anti-Tank gun. Takeichi Nishi decided to use the tanks as pillboxes on the rocky terrain of Iwo Jima. Their weak armour could not match the American M4 Shermans, however they were still a threat to infantry with their guns given appropriate protection by the geography.
The tanks were scattered across the island in various
positions to ambush the American forces as they moved inland.

By the end of 1944, the island’s garrisons reached 12,700 troops of various reserve divisions who mostly had been kept in China during the war, with little experience. 3,000 naval troops were also stationed on the island.  It came as a surprise to Lieutenant General Tadamichi Kuribayashi when the year had ended without any offensives by the Unites States. Japan had expected the island to come under attack sometime during 1944, but nonetheless no such attack happened. It wasn't until the middle of February that the American navy had came with a force of over 110,000 troops to take over the island from the already well-prepared Japanese. The naval bombardments began a few days before the landings were to commence. On the 19th of February, the landing forces stepped foot on the island, and the battle of Iwo Jima had begun.

Tank Trouble

4th tank Battalions combat report.
The American landing forces were met with stiff resistance the moment they came off the beachhead, however it only took 4 days for the American marines to capture Mount Suribachi and establish a major foothold on the island. Dug in within the various underground tunnels, the Japanese kept themselves hidden in order to take advantage of the American marines as they advanced further inland. The Americans had also deployed armoured units in the form of LVT's and M4A2, Shermans to support the advancing marines. However, due to the size and attraction the tanks caused on the island, the marines often pushed without the help of tank support. This led to infighting between company and tank commanders. Instead, most of the tanks moved to the northern airfields without heavily relying on infantry to safeguard the way for mines.

A Taken Out Chi-Ha Kai on Hill 382.
Sherman tank crews were forced to rely on their comrades and fellow tank crew’s for advancing inland. Due to the lack of available engineers on Iwo Jima, the crews had to manually leave their tanks to scout out the rocky terrain to judge how viable crossing would have been. This became apparent to the Japanese 26th Tank Regiment on February 20th, when a marine regiment alongside a tank company assaulted Hill 382 against the Japanese positions supported by tanks of the 26th. The engagement lasted until the 27th when the marines took the hill. Losses on the American side amounted to eight M4A2 Shermans, with another four damaged. The 26th Tank Regiment’s losses are unknown, but all the tanks supporting the defenses of Hill 382 were destroyed. The remaining Japanese tanks and crew retreated further North to Hill 362c. However, while the majority of the 26th retreated, a pocket of tank crewmen decided to stay behind and garrison a cave to ambush the oncoming American forces as they pushed past Hill 382.


On the 28th of February, American marines were unexpectedly attacked by Type 97 Chi-Ha tanks, in a desperate measure to prevent the advance. While surprising the infantry, the tanks were not an issue due to American bazooka’s quickly disabling the attack.


Hill 362c

After the battle of Hill 382, the remains of the 26th Tank Regiment positioned themselves on Hill 362c, one of the last remaining Japanese defenses on Iwo Jima. At this point, there were only 2 tanks left to defend the island. Lieutenant Colonel Takeichi Nishi had been reported as Killed In Action by the time the Japanese had finished gathering on Hill 362c. The American forces had kept the battle on hold temporarily as forces recuperated and were reinforced with supplies and replacements. The 21st Marines and 4th Tank Battalion were ordered to push for a final assault against the Japanese, and take Hill 362c from the defending forces. The United States had successfully captured most of the Island, and only a small pocket of Japanese troops were left. However, the last few Japanese knew that the island mustn't fall at any cost.

The assault on Hill 362c began on March 6th. The 21st Marines scheduled for a naval bombardment on the hill in an attempt to scare the Japanese out of their defenses. The first shells landed at 0845 hours and lasted for quite some time. Once the shelling had ceased, almost abruptly the Japanese began to return fire on American positions. As infantry attacks would not work, the 21st asked for the 4th tank battalion to attempt an assault on the hill. Three M4A2 Shermans were sent across the field to attack the Japanese positions mid-day.


Daring Hero

Photograph of Sec Lt. Otani Michio.
During the defensive, Japanese morale had been shaken despite their self perseverance. The remaining troops did not have the sufficient arms to defend against the oncoming Sherman tanks. However, the 26th Tank Regiment had one remaining Type 97 Chi-Ha Kai on the hill. Its crew being almost entirely killed with the exception of the commander, Second Lieutenant Otani Michio, who had been able to keep the tank covered during the bombardments. Otani Michio had been short on remaining munitions, and the tank being damaged beyond further repair at this point, was left to hold off an American tank column alone.

Otani Michio had the three tanks in his sights as they advanced. His Chi-Ha Kai covered by the terrain, his 47mm anti-tank gun had been able to successfully take out a Sherman within 100 meters of his position. Afterwards, Otani fired his remaining shots at the second Sherman tank, however unable to effectively penetrate and destroy due to the angle of fire the tank was positioned in. The crew had likely bailed due to damage of the repeated hits to the side. It is unknown what happened to his tank, however the gun was no longer useable after firing upon the second Sherman. Shocking his comrades, instead of retreating, Otani instead decided to exit the tank and sprint towards the second Sherman he had fired at. An unprecedented move, Otani managed to get on top of the damaged Sherman.

The damaged Sherman, crewless, gave Otani the opportunity to deal with the remaining M4A2. Otani occupied the gunner position of the second Sherman, and opened fire on the third tank. Due to the blind spots and lack of visibility of the Sherman as reported by the 4th Tank Battalion, Otani managed to make his move without worry of counter fire. Firing the 75mm cannon, he was able to successfully disable the last Sherman. By this point the marines had already gotten to the field and began to engage the Japanese position. Otani managed to exit the sherman, and return to safety as his comrades provided fire support.


Only Known Photograph of the Engagement
with Otani and the Shermans, by American troops.
 His actions gave his fellow troops exceeding morale, and forced the 21st Marines to plan another route of attack. The marines decided to launch a night assault on the Hill, something the Unites States hadn’t done during the Pacific Theatre. On the midnight of March 6th, the 21st’s attack was a success, as most Japanese troops ended up sleeping, unexpecting the American marines to attack under the moon. Once aware of the marines’ actions, the Japanese began engaging the American infantry to desperately protect the Hill. The night assault had been a resounding success, and on the dawn of March 7th, left the already dwindled Japanese even smaller in number. Their morale battered, the tides turned again in the Marines favour.

Aftermath

The Sherman model Otani Captured.
Still residing on Iwo Jima.
It has become a tourist attraction. 
By March 9th, the Unites States’ 21st Marines managed to successfully capture Hill 363c from the Japanese. The American forces during the engagement lost a total of 827 troops. The battle report lists 4 missing in action, likely had being the Sherman crew the Japanese engaged after bailing from their tank whom Otani had damaged. Not long after the battle for Hill 363c, Japan had officially surrendered the Island to the Unites States. Just over 200 Japanese troops had surrendered. Second Lt. Otani Michio had been one of them, and was recognized as a hero by his comrades.

He was regarded as a war hero once he and fellow prisoners returned home when the war had finally ended in September of 1945. Due to his actions not reaching home until the war's end, he was never officially recognized for his feats in battle. The tank he managed to occupy remains on the island today, as a monument for his actions on the 6th of March, 1945.



Hello everyone. Finally I've been able to finish and post this historical article! Hopefully now that this is done, I can also get other projects finished so I can share them here. I'll plan on doing a tank article next to get back in the cycle, and yes... I haven't forgotten the O-I series with Part 3, its coming soon!

Sunday, May 21, 2017

Blog Update [5/21/17]


  Hello everyone. I'm sure its apparent that I haven't been posting many articles so far in these past two months. I'd like to apologize for my extended and unannounced absence. Both on Sensha and on my media outlets. I've been going through a rough couple months with my health taking a turn for the worse. I haven't been feeling that well and it has forced me to spend less time doing my research and connecting with you all here on the web.

The good news for me is that I'm expecting a new addition to my little family, rather soon. I haven't really mentioned it online, but to those who were curious, yes, I'm going to be having a mini-me running around this year. 😄

Unfortunately, with something this drastic coming into my life, that leaves my frequent trips to and from Japan to do research is limited. To be honest, I do not plan to take another visit for at least another year. I'm suggested not to take flights with a little one due to my health not being as well as it should be. But I am hoping to be able to get back to the work many of you appreciate in the foreseeable future. Not to worry though, I still have many files with me I have yet to dig through. So no short on things to talk about and show you, no doubt!


In regards to new articles, don't worry, they're coming. I'm currently finishing up 3 articles for you guys I really look forward to sharing. One of which has taken me a few months to prepare, as finding all the data on the events has been a lengthy process. But I hope what I've been able to get together will be an satisfying read.



Saturday, April 1, 2017

High-Voltage Dynamo Tank


  Visiting the National Archives as of late has been rather unfruitful. I've found myself finding less data for my current research projects and more on Japan's oddities throughout the war. Last week, I came across a private file in the archive which contained a series of the military's secrets during the period. Secret tank and weapon projects to battle the Allies and support a triumphant victory to end the war. The file was labeled "High Voltage Dynamo Vehicle" Ref. A06033400540.  This had caught my eye, and I spent a day and half analyzing its contents. What I found was fairly odd, and today I wanted to share the Japanese tank project that would have changed the war in the Pacific.

A Young Kesuke Miyagi.
As tensions began to wise globally during the late 30's, Japan knew a new war was closely approaching. Tank development in the nation  had only recently begun, whilst other nations were far ahead in the tank production race. Japan sought other alternatives, ones which relied on science to give Japan their much needed edge. A Japanese science professor and engineer, by the name of Kesuke Miyagi, proposed a solution to Japan's needed problem. Miyagi had studied in the United States during the 20's and 30's as a colleague of Nikola Tesla, the engineer who developed widespread use of electric power. During Miyagi's time in the States, he studied with other scientific minds in developing use of electric energy in the modern world. Miyagi took inspiration off  one of Tesla's designs for an electric ray gun that the Unites States had asked Tesla to construct for the military. It was brought to the Japanese in mid 1937 when Miyagi returned back to Japan to attempt getting his new design for military use to be used within the military.

National Archive File Ref. A06033400540 "High Voltage Dynamo Vehicle".
  
Kesuke Miyagi's design proposal had been accepted in the June of 1938. However it had been delayed soon after due to the Nomonhan Incident with the Soviet union the following year. After Japan's blatant defeat in Manchuria, the high command grew desperate for a weapon to change the tide. The command gave the order to construct the electric repulsion cannon. The cannon was built in prototype form in 1939, and after successful trials entered service under the Military as the Type100.


Prototype Tank

Ka-Ha Prototype during trials. 
 The Japanese high command became fond of the ray gun, and in 1940 ordered for its use in the field. Placed under the 3rd Technical Research group, the Type100 had been decided to be implemented within the chassis of a modified Type97 Chi-Ha tank. To accommodate the need for a specially built electric generator for the gun, the Chi-Ha hull had to have been raised changing the tank's height to 4.12 meters. The generator ran off of diesel, and was able to produce up to 300 million volts, amounting to the common lightning bolt in electric power. No vehicle of the era amounted to the tank's power output, and had been considered a milestone in electrostatic repulsion.

After 6 months the first prototype had been completed. It had been given the name of the Ka-Ha, and was able to complete trials without fail. It was tested against captured Vickers 6-ton tanks captured in Shanghai. The cannon had been capable of tearing apart large holes in the tank’s structures with the electric force. The trial runs showed to Japan the power the tank had been capable with. It was ordered for the tank to be mass produced immediately sent to the field.


Combat Usage

By 1943, four units of the Ka-Ha Voltage tank were manufactured.  Due to the demanding generator needed to power the Type100 electrostatic repulsion cannon, the Japanese lacked the sufficient resourced to produce the Ka-Ha on the projected scale required. This was seen as unacceptable to the high command, who viewed the Ka-Ha as the key to success during the war. To counter this, a series of vehicles were made with lower output generators, from 400-10000 volts that were used in China. They were to fire on telephone lines and disable and kill partisans relaying Japanese positions to the Nationalist Army.

A destroyed Cruiser tank with a ruptured hull
from the blast of the Ka-Ha tank. 
For the 4 units of the Ka-Ha that maintained the original Type100 cannon, they were deployed in Burma regions. Most combat was seen in Burma during the British advances in the South to recapture the occupied territories Japan had taken during the initial stage of the war. Due to the monsoon rains that took place during the campaign, it offered the Japanese a vast superiority of the British when using the Ka-Ha in the field. With the rain amplifying the power of the Type100, whole groups of Cruiser and Matilda tanks were annihilated during their advances. While Britain had been able to ultimately push Japan away from Burma, the losses at the hand of the Ka-Ha reached varying numbers of 10-23 armoured vehicles vehicles.



Wednesday, March 15, 2017

Theorem on Newly Discovered Tanks


   As of late, I have uncovered photos of Japanese tank training in Manchuria sometime in 1937 at a photograph auction. At first I regarded this as just another photographed album of pictures of the inter-war period, but, looking through the album, I came across a photo which deeply intrigued me. Two tanks of unknown design, being tested climbing a rise in the fields outside the Manchurian Tank School. At first glance, I had presumed them to be both Chi-Ha tanks as they fit the typical Japanese medium tank style. Further analysis, however, made me believe that these were not Chi-Ha tanks, rather, two brand new designs of tanks as yet unknown. Consulting with some of my colleagues on this, I have since connected some dots in Japanese tank development history that were previously left unnoticed with the research community. Here today I present my new thesis regarding the steps the Japanese most likely took when producing their tanks.

Two New Medium Tanks I recently discovered through a photograph auction. 


Nomenclature

The Empire of Japan, like other nations, had their own style of classifying things in the military. Japan used the Imperial Calendar when naming weapons and vehicles in the military under the year of enacted service or construction. It emphasized using the last two (or three) digits of the given year as a Type in number form. A common example of this was the Type 95 Ha-Go tank. The Type refers to the fact the given vehicle belonged to the military. The two digit number following the Type meant that the tank was built in 1935 (Imperial Year 2595). This was standard issue for all things in the military, and would follow through to even the current year.

Type 95 Heavy "Ro-Go".
Prior to the Battle of Shanghai in 1937, the Japanese used a specialized system for labeling tanks. Instead of using a class system to label tanks under specific weight groups like Light, Medium, Heavy, etc, they merely used the order in which they were built. The first Japanese tank built in significant numbers had been the Type 89 I-Go, produced in 1929. It had been the Japanese tank that began mass production for the military, and was named accordingly. I-Go is translated to First Domestic Tank in the Japanese Army. “I” representing First, and “Go” for Domestic [vehicle]. This had been applied to produced tanks until 1937. Three known tanks used this system;

I-Go: First Domestic Tank
Ro-Go: Second Domestic Tank
Ha-Go: Third Domestic Tank

The Ro-Go is commonly known as the Type 95 Heavy Tank. Until 2015, the heavy tank was simply referred to as a heavy tank due to no found naming term applied to it. However discoveries with the O-I documentation release confirmed the tank was given the name Ro-Go, as it was the second tank in Japan produced in numbers outside one or two. It was never labeled as a heavy tank in name, only in its description. Hence the common theory arose that the tank was only referred to as the Type 95 Heavy, instead of the proper name Ro-Go. Other tanks such as the Type 94 Te Ke were not included in this nomenclature due to being a tankette, classified as an armoured car. Hence only three tanks were given naming.

Starting in 1937, the Japanese enacted this new nomenclature starting with the Chi-Ha tank, with the new system being  called the Iroha Naming Convention. Replacing the previous system where tanks were named in their domestic order, they were instead classed under their weight and the number in which they followed through in order. The Chi-Ha, for instance, is translated as “Third Medium” in the army. Other tank classes were given their own names in Kanji and the respective numbers:

Weight Terms:
Chi-Ni Medium Tank. 

Ke: Light
Chi: Medium
Ho: Gun Tank
Ju: Heavy
O: Super Heavy
Shi: Car

Numbering:
1: I
2: Ro
Chi-Ha Medium Tank.
3: Ha
4: Ni
5: Ho
6: He
7: To
8: Chi
9: Ri
10: Nu
11: Ru
12: O


Popular Examples of the Iroha system:

Ke-Ni: Fourth Light
Chi-Nu: Tenth Medium
O-I: First Super Heavy
Chi-Ri: Ninth Medium


Holes in History

The glaring issue with this system was that the Chi-Ha had been labeled the Third Medium tank, despite there being no First and Second Medium tank (I and Ro). Many historians came to the commonly agreed upon conclusion that since the system was only applied to tanks produced from 1937 onwards, the vehicles prior to this were not given the integrated naming change. Japan had produced two medium tanks with the old classification system, the Experimental I tank, which was classed as a medium-like tank, and the Type 89 I-Go. With no knowledge of any other tanks, it was believed the Japanese considered these two tanks the predecessors of the Chi-Ha, and falsely labeled the Experimental I and I-Go tanks as the “Chi-I” and “Chi-Ro” tanks respectively.

Of course, there were problems in this common interpretation that were left unanswered. The Type 98 Ke-Ni, dubbed the Fourth Light Tank, was the first Japanese light tank design  with the new Iroha classing nomenclature. The Ha-Go, which was referred to as the Third Domestic light tank in Japan, had too been incorrectly placed before the Ke-Ni in the Iroha naming system. This left a gap in light tank development that had simply been left unfilled. The lack of documented records with early Japanese tank history had given many historians decades later the trouble of securing a firm timeline of tank development and naming.

Tank "A".
As I mentioned earlier, two new tanks were found that did not match known tanks of the Japanese military. The fact that these two tanks existed in 1937, and had not been commonly known to the world only connects the hiccups in the applied Iroha system. These two tanks, which I for now I will refer to as Tank “A” and Tank “B”, logically fill the spots for the First and Second Medium tank naming that was incorrectly put with the Experimental and I-Go. During the mid ‘30s, Japan began developing a medium tank to became the new battle tank to support the infantry in the field. A series of prototypes were proposed take the spot. The two most known were the Chi-Ha and Chi-Ni tanks. While the Chi-Ha took the role, the Chi-Ni was labeled as the Fourth Medium tank as it was built after the Chi-Ha. However if these two tanks are in fact mediums that were also considered for the role, it is safe
to presume them to be the first series of tanks to compete for
 the role as Japan’s new battle tank.

Tank "B". 
One of my work colleagues, by the name of David Lister (Listy), had two years ago, uncovered more tanks that were produced in Japan during the interbellum period. Hidden within the British archives were a series of heavy and light tanks that according to documents of multiple nations (such as Britain, Japan, Sweden, Australia, America, and Russia) were produced in small numbers and serviced throughout the Chinese mainland and Pacific islands. With these tanks are three light tanks, all supposedly built. If the two tanks I uncovered are truly the Chi-I and Chi-Ro, this even further supports the theory as the three light tanks fit perfectly into the Iroha system where the Ke-Ni is the Fourth Light, with no known predecessor to fit the first three spots as circumstantial evidence supporting my theory.

In this new proposed theory, every spot in the Iroha classing system falls into their proper order up until the 1944-1945 gap where many tanks were scrapped and remain unknown.

Chi-I:  (Medium First) Tank “A”
Chi-Ro:  ( Medium Second) Tank “B” 
Chi-Ha: ( Medium Third) Type 97 Chi-Ha
Chi-Ni: (Medium Fourth): Type 97 Chi-Ni
Chi-Ho: (Medium Fifth) Type 98 Chi-Ho
Chi-He: (Medium Sixth): Type 1 Chi-He
Chi-To: (Medium Seventh): Type 4 Chi-To
Chi-Ri: (Medium Ninth): Type 5 Chi-Ri
Chi-Nu: (Medium Tenth): Type 3 Chi-Nu

Ke-I: (Light First) Unreleased Tank*
Ke-Ro: (Light Second) Unreleased Tank*
Ke-Ha: (Light Third) Unreleased Tank*
Ke-Ni:  (Light Fourth) Type 98 Ke-Ni
Ke-Ho: (Light Fith)  Type 5 Ke-Ho
Ke-He: (Light Sixth) Currently Unknown
Ke-To: (Light Seventh) Type 2 Ke-To
Ke-Ri: (Light Ninth) Type 3 Ke-Ri
Ke-Nu: (Light Tenth) Type 4 Ke-Nu

Ju-I: (Heavy First) Type 96 Heavy*
Ju-Ro: (Heavy Second) Type 97 Heavy*
Ju-Ha: (Heavy Third) Mitsu-104*
Ju-Ni:  (Heavy Fourth) Ishi-108*

* = Tanks currently not publicly available. Kept private with David Lister and I until his book, which was recently contracted, is published.


Sunday, March 5, 2017

O-I Size Comparisons

While I finish up the next history article for you guys, Here is something interesting for those curious about the O-I superheavy tank. I've put together a few diagrams comparing the size of the O-I with popular tanks of other nations many are familiar with.

Built in 1943, the O-I tank was one of the largest armoured vehicles produced, dwarfing even the notorious Tiger tank serviced in Germany during the Second World War. The tank had a height of 3.63 meters, a length of 10.12 meters, and a width of 4.84 meters. The dimensions of the vehicle closely matched those of the Panzer VIII Maus. These proportions were massive and required the equally large amount of crew to operate it. The crew consisted of 11 manned positions. These were; 1 Driver, 1 Co Driver, 3 Main turret gunners, 1 Commander, 2 secondary turret operators, 1 rear turret operator, 1 Radio signaler, and 1 Engineer to maintain the tank. It maintains one of the highest crew count for any produced tank.




O-I with the Tiger I tank (Front View)


O-I, Maus, T-95 (Front View)



O-I, Maus, T-95 (Side View)



O-I and Type95 Ro-Go heavy (Side View)


Context

If someone came to you and asked the question; "what comes to mind when you hear the term super-heavy tank?", the average answer would be the notorious Maus or E-100 respectively. Big clunking tanks with large slabs of thick steel and armed with monstrous cannons. The idea of this class of vehicle had lingered on since the First World War, often relegated to the domain of prototypes and experimental designs. It would not be until the inter-war period that the concept captured designers' imaginations and drawing-boards as the 'next big thing' to turn the tide in the wars to come. Japan was no exception; in the dawn of the 40's, this super heavy tank would be known to the public as the O-I.

History: http://sensha-manual.blogspot.com/2016/10/too-big-to-stop-too-heavy-to-start_16.html


The O-I was conceived out of the necessity to produce a mobile bunker to contest the Soviet Union in the then-expected Second Russo-Japanese conflict. The flaw with the routine bunker or pillbox is that you cannot maneuver and relocate them with the frontline constantly being pushed. Japan would need a sustainable fortress that could push with the infantry and advance further into the USSR without the need to construct more immobile bunkers with resources already scarce.

Characteristics: http://sensha-manual.blogspot.com/2016/10/between-bolt-and-hard-place.html


Thursday, February 16, 2017

Development of the Modern SPAAG


  As the Korean War began and tensions escalated in Asia, the United States began to supply the Japanese in the event that they would need military aid or a form of protection against the rise of the communist states in the region. The United States had already began developing their own new and improved combat vehicles for similar purposes. Because of this, they were left a large surplus of outdated military vehicles and no where to use them effectively. Hence, many were later donated to the Japanese for them to use in training new troops. The Japanese Self Defense Force was created in 1954, allowing the Japanese to have their own defensive military to protect the home island when needed. During this period, the United States had officially decommissioned the M19 Gun Motor Carriage SPAA vehicle from service. These were anti air tanks based off the M24 Chaffee chassis, and mounted twin 40mm Bofors multipurpose guns. A few of them were supplied alongside the M42 Duster.



These lend lease tanks were short lived, however. During their initial time spent in the SDF, they were used as trainers for anti air tactics and methods of engagement. Even for the Japanese Self Defense Force, the short ranged 40mm Bofors guns were inadequate and couldn't meet the requirements needed to successfully engage and destroy modern aircraft of the era. These concerns were voiced to the United States over the years ,however the US simply ignored these requests as well as Japanese requests for modern armor. Faced with the refusal of the US to supply more modern vehicles, the Japanese decided to initiate their own SPAAG program during the late 60's.

The First Prototypes
In the late 1960s the the Technical Research Department came together to conceptualize a new SPAA-like vehicle to meet the needs of the military. Their logical conclusion was to use the chassis of the Type 61 main battle tank as the starting point. While the tank was a failure to the military, the use of its chassis  for an anti aircraft tank could have given it a new lease on life; Japan had already started working on a new main battle tank project to replace it, and the choice seemed to be the best use of resources at the time.

M51 at Chiba, Japan. I have yet to receive visual details
from the SDF on the prototype vehicle. I am currently
awaiting access to the details. 
The research staff concluded instead of designing its own anti aircraft gun, it would also rely on the technology the United States left behind with the lending program. The gun they had in mind was the M51 Skysweeper, a 75mm anti aircraft system and one of the first to utilize an automated targeting system with an auxiliary predictor and gun laying radar stations in one platform. The gun relied on an autoloading mechanism with two 5 shell belts. The gun had proved to be very useful during its time, albeit fairly outdated during the 70's. Nonetheless, it was selected to be used as the candidate armament.


The first prototype was completed  in 1972, and was put through various trials. Ultimately, it was rejected by the Self Defense Force for its turret being "excessive" and unreliable. Due to this unwanted outcome, the project for a new SPAAG was canceled. No attempt  to find a suitable replacement would be attempted for six years. In 1978 the decision was made to again attempt to base a new SPAAG off the Type 61 main battle tank chassis. The Japanese Self Defense Force worked out a cooperation agreement with Oerlikon Contraves, a renowned anti aircraft gun manufacturer of the era. Oerlikon provided Japan with a design proposal for a set of 35mm autocannons on a rotatable turret design which would house a search and track radar.

The second prototype of the SPAA project. Mounting the new twin 35mm autocannon system into the Type61 chassis. It was labeled the AWX. 

Various tests were carried out using the completed prototype vehicle. It had became clear that the combined weight of the turret, radar, and computer systems was too heavy to allow the vehicle to maintain the desired level of mobility. The prototype was canceled. Instead, the hull of the newer Type74 main battle tank would be used as the chassis for the new SPAAG. The original Type 61 prototype would eventually be converted to a bridge-laying vehicle in the 80s.


The Guntank

Development and trial production of a self-propelled rapid-firing aircraft gun vehicle based off of the Type 74 MBT would begin in 1982; one set of two prototype hulls was ordered in that year. A third hull was procured in1983. The first prototype was completed at the end of 1983, and technical tests were conducted from 1984 to 1985. A practical test by the Ground Self Defense Force was carried out in 1986, and it was formulated as '87 self-propelled gun' on August 21, 1987.



National Defense Agency File H 4001B 1 &2
To save weight and avoid the flaws of the original Type 61 derivative, the turret of the Type 87 was made with a lighter composite. The replacement was the AMS 4050A Specialized aluminum alloy. A complex alloy of bulletproof materials that offered decent protection for its weight. It could not defend against dedicated anti-tank weapons, however.

The turret of Type 87 was developed by Japan Steel Works, with the radar and fire-control systems housed in a boxy structure which gives the turret a distinctive shape similar to that of the German Gepard.  The similarly is furthered by the fact that both tanks have their 35mm autocannons on the right and left sides of the turret. The variety of ammunition used for the 35mm autocannons is extensive. HEI (535g) is used for targeting general aircraft. The guns also use SAPHEI (380g) for ground targets, and APDS for armoured targets. The APDS rounds have a penetration capability of 40mm RHA at 1000 meters (at 60 degrees slope) distance with a muzzle initial velocity of 1,385 m / sec.

The 35mm's drastic gun elevation can be seen
here during this SDF exercise. 
The gun barrel is an air-cooled type, and six grooves are engraved on the outer circumference to increase the surface area and enhance the cooling efficiency. The rate of fire of 35 mm high fire aircraft gun KDA equipped on the Type87 is around 1,100 shots per minute with the gun elevation angle of  -5 to +85 degrees. The turret can rotate a full 360 degrees with no impediments. The turret and cannons are by default operated electronically, however they can also be operated manually if the need arises. The gun's elevation speed is 760 mils / second, and the turret's traverse speed is 1,000 mils / second. The turret is also equipped with two sets of smoke launchers to offer a base of protection if under threat of engagement from the ground and air, similar to the Gepard.



The detection range of the Type 87's laser detector was 360 degrees in a horizontal direction and -22.5 degrees to +90 degrees vertically. The Mitsubishi Electric Corporation was in charge of development of the tank's systems. The detection radar antenna was located to the rear of the turret, posted as a long protruding object, boasting a detection range of 20 kilometers.  The search radar antenna can continuously turn 360 degrees, and the turning speed of the antenna is 30 rpm. The dish type equipped on the top of the turret in front of the search radar antenna is a tracking radar antenna and the tracking range is said to be 20 km. The tracking radar antenna can continuously turn 360 degrees, and the range of elevation is -80 to +1, 500 mils. The turning speed of the antenna is 1,600 mils per second, and the elevation speed is 890 mils per second.

During the late 80s, Japan began to test the protection capability of composite armour. The new STC project was at the forefront of development. The Type74 had been tested with examples of composite, as was the Type87. The prototype adjusted to this by adding two spaced armour pads while the chassis remained produced in steel. The front hull was only protected by a thin 33mm RHA plate.

National Defense Agency
File H4002C 1
Although the chassis of the Type87 is a welded structure of rolled homogeneous steel based on the Type74 battle tank, the shape and composition  have been changed drastically to the point where only a few similarities remain between the two vehicles. The front plate has since adopted a method of composite armour inside the front hull of the vehicle, instead of the externally placed pockets on the prototype. The front hull remained 33mm thick, whilst behind the plate a formulation of internal fins adjustably angled, made up of mostly NERA (Non-Explosive Reactive Armour). The method used is similar to American and German designs,  which used this method of protection on the sides of their tanks, effectively defeating light guns and autocannons of the 30-50mm range.  For the Type87 this method proved adequate for its anti aircraft role.

There was a downside, however. The complexity of the armour and the technology of its turret raised the price of the vehicle to over 1.4 billion yen per unit. Due to this steep price, the SDF was forced to only produce 1-2 units a year. The series production ran until 2002, where by this time a total of 52 units were manufactured and in service. The tank remains in SDF operation to this day. Because of this, many specifications and details are considered classified. This leaves much to be questioned in terms of the secrets under the armour.

The Type87 retained the excellent mobility of the modified Type74 chassis. The tank was equipped with a Mitsubishi Heavy Industries built Type 5 10ZF22WT two-stroke 10 cylinder air-cooled turbocharged diesel engine. It was capable of forward speeds of 53 km/h with an output of 720hp at 2200 rpms. Since the suspension of the Type87 was directly copied from the Type74, the vehicle could control the hydro pneumatic movement of the chassis in the forward, backward, side to side, and up and down motions to varying degrees. While tactically useful for the type74, the Type87's suspension had acted more for novelty than anything else.



The auxiliary power unit for the tank is located to the tank's right frontal side. This station provides electrical power for the tank's fire control computer, search and tracking radar, and turret drive generator. The APU is powered by a four stroke diesel engine with 29 liters of displacement and 75hp with a 2850rpm output. It is visible through the heat exhaust panels.



I know this is a long post, but I wanted to write a brief rundown of Japanese anti aircraft tanks after the world war. It's a very complex history and I wanted to summarize it for you readers in the best fashion possible. The SDF has been kind enough to share such snipbits, and today I used information from two files belonging to the National Defense Agency. The first being H 4001B 1 &2, and second  H4002C 1.

Monday, February 13, 2017

The Tigers of Corregidor


One of the longest standing myths regarding Japanese tanks was the infamous "Tiger of Corregidor ". How come a lone Type 97 Chi-Ha was able to defeat nearly 40 American M3 Stuarts and allow the Japanese victory over the island of Corregidor? Today I want to end such myths as I go over the historical events of the engagement that led to the American's surrender of the Philippines.

Fall of Luzon 

   As the war in the Pacific took a turn for the worst, with the United States declaring war on the Empire of Japan on the 8th of December 1941, the Japanese high command realized they would need to act in haste after their unexpected attack on Pearl Harbour. During the month prior, the Japanese high command had created the Southern Expeditionary Force, so as to engage in the territorial capturing of various islands of Southeast Asia. Their first target was the Philippines under the protection of the United States. The final plan of engagement had been adopted in mid-November. On the same day as the declaration of war, the Japanese 14th Army, under the command of Lieutenant General Masaharu Homma, had embarked from Taiwan and landed on Batan Island. On the 10th of December, the 14th successfully occupied the Port of Aparri on Luzon and began advancing further south. The 16th Division landed on southern Luzon to force the capitulation American General Wainwright's defense forces with the aid of the 14th from the north.

 Lt. Morin's Captured M3 Stuart on Luzon. 
General Wainwright had received information that the Japanese 4th Tank Regiment, commanded by Lieut. Colonel Kumagaya, was approaching his lines of defense. The General ordered Captain Hanes of the 192nd Tank Battalion to engage the mechanized forces of the Japanese in the town of Damortis. However, Hanes’ M3 Start's force was nearly out of fuel at the time. Because of this, he ordered lieutenant Ben Morin to command a platoon of 5 Stuart tanks to engage the Japanese assault. On December 22nd, the 192nd and the 4th met in combat, however the Japanese were expecting the lieutenant's force and staged an ambush for the oncoming platoon. Once the 192nd had sight on the Japanese Type 95 Ha-Go’s, Morin's Stuart immediately broke formation to meet the tanks head on but was crippled with a hit to the engine, setting the tank on fire. The remaining four Stuarts were taken by surprise and damaged severely, but managed to escape the battle. Ben Morin and his crew were able to survive, however they were captured as prisoners of war by the 4th Tank Regiment. As a result, the M3 Stuart belonging to Morin was captured and repaired to be serviced by the 4th, later to be commanded by the 7th Tank Regiment.


As the American forces retreated further into Bataan’s interior they were able to receive effective air cover, preventing the Japanese advances through the Subic bay area. This allowed General Wainwright to secure a foothold in the region while the Japanese spent the 1st through the 14th of January formulating a new battle-plan. The fighting resumed on January 23rd, and lasted just two weeks before Lieutenant General Masaharu Homma withheld further attacks due to casualties on the 8th of February. Once reorganized fully, the Japanese 14th Army during March began pushing once more against the American and 57th and 45th Infantry, coupled with the Philippine 31st Division along the Alangan River. The Allied forces could not sustain engagements with the Japanese, and were forced to surrender deeper to Corregidor Island.

Landing on Corregidor 

To Japan, the island of Corregidor was of the utmost importance to the war effort; its position ultimately decided who owned Manila Bay, a strategic location in south-east of the Pacific. Beginning in early February, Japanese airstrikes targeted the island in an effort to cripple American fortifications there. While major damage was inflicted on Corregidor, the morale of the US soldiers remained high. Unlike the Japanese,however, the Americans were not used to combat and were unable to accurately hit Japanese targets in the air and ground with their coastal artillery. Because of this, Major General Kureo Taniguchi decided to strike with a landing force immediately in first week of May. Using a force comprised of 790 infantrymen and supporting armor, the Japanese attacked at midnight on the island fortress. However because of Taniguchi's lack of planning, the first landing force met stiff resistance as they were blown off course by strong winds, and struggled to get a foothold on the beach. With this temporary setback, American troops were able to inflict heavy casualties on the Japanese until they were able to reorganize. The landing succeeded largely due to the overwhelming Japanese advantage in numbers, but would come at high cost; the second landing force was almost entirely destroyed when strong winds carried it into range of US machine-guns.

Tanks on Corregidor
Tsuchida's Chi-Ha Kai on Corregidor.
Since the 4th Tank Regiment was kept on Luzon and Manila, the 7th Tank Regiment had been ordered to remain on hold at Limay in Bataan. The 7th were tasked to support the Japanese strike on Corregidor island alongside General Kureo Taniguchi. The 7th Tank Regiment was originally under the command of Colonel Sonada, an officer who took part with the Tank Research Committee and Ministry of the Army. He sought to utilize Japan's newest weapon, the Chi-Ha Kai, a new tank produced by the Japanese to better engage in tank combat against the Americans. The 7th regiment was equipped with two such vehicles during the invasion, the first such deployment prior to the vehicle’s official acceptance into IJA service. The deployment of these vehicles was relatively inauspicious, however; Colonel Sonada was killed in battle during the capture of Bataan in April, so the regiment fell under new command of Major Matsuoka, who promptly fell ill with dengue fever.This left the 7th Tank Regiment without a commander. Temporary command of the regiment was given to an officer by the name of Masuda while Major Matsuoka recovered. However, shortly after the battle Major Matsuoka passed away due to the severity of the fever.

When the landings took place at 11:00 PM on a stretch of land between Cavalry and North points, the 7th sent a platoon comprised of the two Chi-Ha Kai tanks and the captured M3 Stuart with the first landing force. Commanders Tsuchida, Takahisa, and Ho were assigned to the three tanks. Ho was commanding the Stuart, while Tsuchida and Takahisa led the Chi-Ha Kai tanks. The presence of Japanese tanks proved effective in boosting the morale of the assaulting infantry they accompanied, and led them to continue assaulting the beaches of Corregidor. Japanese tanks could not account for the weather, however; the 7th’s second tank platoon, which was landing with the second wave of infantry, were blown off course by a storm. Caught in American spotlights, they were destroyed when their transports were sunk by US and Filipino 37mm guns. The crews of the vehicles survived, however, and swam to shore with the rest of the landing troops until they were sent back to Bataan the following day. The remaining forces cleared the beach of American troops by 2:30 AM.

Earning the Title
    In spite of the landing’s overall success, the three remaining tanks met with significant challenge. The exit from the landing beach was blocked by a large 50 meter hill near Denver Battery, with many large rocks and rough terrain discouraging easy passage. The Chi-ha Kais commanded by Tsuchida and Takahisa attempted to climb the hill, but met with little success thanks to teething problems and a lack of engine power. Eventually, the M3 Stuart under Commander Ho towed the two Chi-ha Kais up the hill. It was not until 8:30 in the morning that the tanks were able to completely climb the hill. Later that day, the Japanese advance was halted by American infantry counter-attacking from Denver Point on the island's plateau. Caught by surprise, the Japanese took many infantry casualties, and were pinned down by a pillbox to the right of the main axis of Japanese advance. The troops informed Commander Tsuchida of the pillbox to their right, and the Chi-Ha Kai was able to destroy it after a successful first shot, allowing the advance to continue. Commander Ho took his Stuart to move up to the right of the advance to support the infantry.

Tsuchida's Chi-Ha Kai on Corregidor engaging American Positions.


The second leg of the Japanese advance, towards American positions on Malinta Hill, was spearheaded by tank commander Tsuchida and his Chi-Ha Kai. As the tanks drew near to the American defensive lines there, they encountered and destroyed prepared positions containing anti tank guns and the few Stuart tanks that had survived the battles on Luzon. This second engagement took place at Water-Tower Hill. The Japanese took no casualties during this engagement since Tsuchida's Kai destroyed or forced the surrender of all resistance met en-route to the American facilities.


 Having defeated all American resistance at Water-Tower Hill, the Japanese force took position some distance away from Malinta Hill and dug in awaiting further orders. Intimidated by the presence of the new Japanese medium tanks, on which the US forces on Corregidor had no information, one staff officer of the United States approached Tsuchida's tank with a white flag, asking for a compromise. Tsuchida ordered one of the infantrymen to direct the officer to the Japanese regimental HQ, where after half an hour talks ceased without a viable compromise. The HQ thus ordered for the advance on Malinta Hill to continue. Japanese forces began to open fire as the tanks continued down the road towards Mantila Hill. As they advanced,the Chi-Ha Kai tanks began targeting American pockets of troops scattered around the island's tunnels, with the fiercest fighting taking place near San Joseph tunnel.


Japanese forces move into the American HQ in the afternoon of May 6th.
Takahisa's Chi-Ha Kai can be seen at the rear.

 Eventually the tanks reached Corregidor's highest point, Malinta Hill. Once stationed there, the two tanks had a commanding view of the remaining American facilities and barracks. To their surprise, a white flag was raised upon their arrival at 2:00 PM, officially surrendering to the Japanese forces on Corregidor. On May 7, General Wainwright officially surrendered to the Japanese landing force, and relayed orders to remaining American forces on Corregidor to lay down their arms. It was at this point that the two Kai tanks under command of Tsuchida and Takahisa were brought to the attention of the Japanese public, and labeled as the "Tigers of Corregidor" in the papers. The American intelligence committee also referred to the new and mysterious medium tank as the “Tiger of Corregidor” until it was to later be known as the Improved Chi-Ha medium tank. While commanders Tsuchida and Takahisa were received as heroes back home, they never single handedly faced endless numbers of American tanks as the myth tends to claim. However, they did force the Americans to surrender the island, a task of equal merit. Their actions were documented in Japanese and American news reports, and the exaggerations therein became the basis for the myth.