The Type 1 Ho-Ki Armored Personnel Carrier (APC) was developed by the Imperial Japanese Army between 1941 and 1942, although it saw mass production later on, in 1944. This vehicle was designed by Hino Heavy Industries along with the Type 1 Ho-Ha half-track, with the purpose of modernizing the means of transportation for the Japanese infantry, as well as carrying supplies. Up to that point, the Imperial Japanese forces mostly relied on trucks, horses, and even tanks for this purpose. At the same time, with the introduction of the Type 1 Ho-Ki APC, the Japanese Army would continue to implement a more modern concept of mechanized infantry units among its ground forces. By the start of WW2, this had already been successfully applied by some warring parties, such as Germany, the Soviet Union, and the United States. While these nations mostly fielded armored half-tracks to support their infantry in these roles, the Japanese instead decided to prioritize the development of the Type 1 Ho-Ki, which was a fully tracked transport, thus providing much more effective off-road mobility through rough terrains, such as those encountered in China and, later on, throughout the Pacific Islands after the start of the Pacific War.
Imperial Japan’s Transportation of Troops and Equipment Through Land
Due to a lack of natural resources and a limited industrial base in Japan, a high priority was given to certain areas of the armed forces, such as the surface fleet and the air forces, thus leaving other areas underdeveloped. At the same time, with the increasing rivalry between the Imperial Japanese Navy (IJN) and the Imperial Japanese Army (IJA) during the 1930s, which often involved boycots and even assassination attempts on key figures from either sides, gathering enough budget to cover many of their respective needs was a whole ordeal. As a consequence, one of the areas that was left behind in terms of funding was the development of a more adequate transport vehicle for the IJA, such as an armored tracked vehicle that could effectively be used off-road and on the battlefield.
During this time, in the mid-to-late 1930s, other nations, such as France, Germany, and the United States, were already developing and mass producing armored carriers, such as half-tracks dedicated for troop transport, cargo, and other support roles within their mechanized infantry units. Japan, on the other hand, was still investing almost exclusively in the employment of civilian-based trucks and cavalry horses for its military transportation. Very often, during long marches and when the number of transport trucks available to a regiment was insufficient, both infantry and equipment would simply travel on top of existing tanks whenever it was possible. Throughout the 1930s and early 1940s, this was a trend seen among the Japanese ground forces, which appeared to have no real plans of changing in the near future.
Other than the limited amount of resources previously mentioned, there was also an almost complete lack of interest from many Imperial Army officials in investing the scarce resources they had available into producing an armored tracked transport. In the end, they considered it somewhat unnecessary, despite the possible benefits that it would offer. This was due to the main area of conflict for Japan at the time, the occupation of Manchuria. The occupation began in 1931 and was then followed by the invasion of other Chinese territories after the start of the Second Sino-Japanese War in 1937. All of these had paved roads connecting the main industrialized regions with one another, such as those at Beijing, Shanghai, or Nanjing. This made the use of both quick conventional trucks and even cavalry horses more than adequate for the Japanese forces during the occupation.
The extensive railway system that was built and improved on by the Japanese during their occupation of Manchuria and China more broadly, also significantly eased the transportation of large numbers of infantry, supplies, and vehicles. The maintenance, building, and operation of these railways was normally carried out by the Imperial Japanese Army’s railroad regiments, many of which were formed and dispatched to China with the start of the Second Sino-Japanese War, and were later on sent to South-East Asia as the war expanded.
All these factors mentioned were coupled with the sometimes limited resistance of Chinese defenders which, at the start of the conflict, were mostly underequipped and unprepare, compared to the Japanese forces. This meant that the formation of modernized mechanized infantry regiments that would use suitable armored transports would appear to be at the bottom of the priority list for the Imperial Japanese Army.
Development Leading to the Type 1 Ho-Ki APC
Increasing Tensions with the Soviet Union
During the late 1920s and early 1930s, some European nations were designing a variety of half-tracks to work with their mechanized infantry units. The automobile industry in Japan, however, was much less developed than in some of these Western nations. This resulted in an increase in the production cost of half-tracks at almost the same value of a fully tracked vehicle. For this reason, in 1933, it was decided to focus a small amount of resources into building a fully tracked transport instead, which at the end, would be a lot more suitable than a half-track for off-road use and through rough terrains. Specifically speaking, this decision was made by having in mind the difficult terrains found in the Siberian environment or the Russian Far East, which the Imperial Japanese Army hoped to occupy in case relations with the Soviet Union were to keep on worsening.
Due to the Soviet Union’s expansionist policies and its ideals, which it also wanted to export, many Japanese officials viewed the USSR as a natural enemy for Japan’s overall integrity, and thus believed that an armed conflict between the two was inevitable, or even necessary. Therefore, many of the Imperial Japanese Army’s doctrines and vehicle and weapon designs at the time were made with this possible scenario in mind, which could have easily become a reality after the occupation of Manchuria. For this reason, many Imperial Japanese Army officials designed and actively promoted the Northern Expansion Doctrine, also known as the Northern Strike Force plan. According to this, the Imperial Japanese Army would occupy and secure these Russian Far East territories to acquire their resources and weaken the continuous Soviet expansionism.
In the end, however, this planned scenario did not end up happening, mostly due to the Imperial Japanese Army losing reputation after not achieving a swift victory during the Soviet border clashes of 1939. This, in turn, gave the Imperial Japanese Navy the impetus to go forward with its plan of occupying South-East Asian territories instead, which led to the start of the Pacific War.
Development of the First Japanese APCs
The first prototype of an APC was built in 1933, when the creation of a mechanized infantry unit was being worked on by the Imperial Japanese Army. This was meant as a way of modernizing their troop transportation and being able to provide infantry support more efficiently to the newly produced Type 89 tanks when advancing through rough terrain. This first APC prototype was known as the “TC trial production automatic tracked carrier” and was based on the widely produced Type 92 Heavy Armored Car’s chassis. However, since this design had the engine and radiator at the rear, troops and cargo could only enter through a side door, which proved impractical. This, along with the vehicle’s overall small size, which gave it a reduced cargo compartment, made this first trial APC to be considered inadequate.
In 1934, after the Kwantung Army created the 1st Independent Mixed Brigade, which became Japan’s first mechanized infantry unit, a second APC trial vehicle was developed, called the “TE trial production rail automatic tracked carrier”. This vehicle’s design addressed the main shortcomings of the previous prototype, such as placing the engine at the front-right side of the vehicle and thus allowing for a rear door to be placed on the cargo compartment. The vehicle’s size was also significantly larger in order to increase the transport capacity and the suspension was improved too. However, this APC still used the same engine from the Type 92 Heavy Armored Car, which was underpowered due to the vehicle’s heavier weight.
A year afterwards, in 1935, a third trial APC vehicle was built and was called the “TG trial production automatic personnel carrier”. This vehicle shared many similarities with the previous “TE trial automatic carrier”, such as the size, the engine’s placement at the front-right side next to the driver’s cabin, and its similar suspension system. However, the “TG trial production automatic personnel carrier” had fixed windows around the cargo compartment, with a soft canvas cover on top. Instead of a rear door on the cargo compartment area, this vehicle had a large windowed double door on the side. Therefore, the passenger seats were probably placed at the opposite side and at the rear end. This side door configuration, however, might have made it more awkward to load equipment or supplies into this APC.
There was also another variant of the “TG trial production automatic carrier” built. It was a very similar design, with the only difference being the design of the cargo compartment. The cargo compartment of this other variant was the same design as with the previous “TE trial production carrier”, which had the entrance placed at the back instead of at the side, and had no fixed windows on its sides. However, instead, this vehicle used what seems to be a canvas top that had windows all around on its cargo compartment.
In 1938, the fourth and last trial APC was built. This was the “Trial production 98-type automatic tracked carrier”. This vehicle had many differences compared to the previous two trial APCs. Among the most noticeable were the headlights, which were slightly elevated above the hull, a large single engine grill at the front instead of the two smaller ones, and an improved suspension system. Curiously, however, the sides of the cargo compartment of this APC were made out of wood rather than steel armor, most likely as a way of reducing the production costs for the whole APC project, which had already started several years prior. A few of these Trial production 98-type tracked carriers were built and, despite their unprotected wooden sides on the cargo compartment area, it is believed that these saw limited combat in China alongside the 1st Independent Mixed Brigade in order to test more modern mechanized infantry tactics on the battlefield.
However, due to underwhelming combat results from the 1st Independent Mixed Brigade during Operation Chahar west of Beijing, the fate of the Brigade was compromised. During the engagement, Lt. General Hideki Tojo, who was in command of the operation, divided his forces, which were commonly known as the Tojo Corps, and used them separately, sending out his tank unit to support the 5th Division that had just arrived from mainland Japan, and then sending his infantry regiment to support the 26th Division. This situation continued, with other units being split throughout the operation and thus forced to attack in smaller numbers, resulting in larger casualties than previously expected.
This lack of coordination and unity between Tojo’s forces, contrary to what had originally been planned, rendered the support role of the 1st Independent Mixed Brigade almost useless during the entire engagement, since it was barely able to have an effective role. That whole situation even sparked a dispute between Hideki Tojo and the Brigade’s commander, Lt. General Koji Sakai, who confronted Tojo and expressed his disagreement about the decisions made during the engagements. However, instead of addressing the shortcomings seen during the operation’s planning and execution, and in how to possibly adapt more modern tactics to improve future performance, the poor results shown in battle by the 1st Independent Mixed Brigade were blamed almost entirely on the Brigade itself and it was therefore disbanded one year later, in 1938. Koji Sakai was transferred to the reserve role and, thus, the first mechanized unit of the Imperial Japanese Army disappeared. This decision to disband the 1st Independent Mixed Brigade immediately halted the years-long development of the tracked carriers, therefore causing the whole APC project to enter into a hiatus.
However, it was not until later on, in late 1939, when Germany’s Blitzkrieg showed everyone the effectiveness of using mechanized infantry units during the invasion of Poland, that the discussion by Japanese officials to start funding the development of a tracked APC again was placed on the table. Meanwhile, the Kwantung Army in Manchuria took the decision to replace its horse cavalry group with a mechanized division equipped with several armored vehicles and trucks by late 1939. One year later, in 1940, the Germans used the same combined arms tactics with success during the invasion of France.
Development and Introduction of the Type 1 Ho-Ki APC
Concerns over a lack of a mechanized force truly started to arise once tensions with the United States and its European allies severely worsened. This caused a chain of sanctions and embargoes to be placed against Japan. They also had to deal with a much better prepared Chinese resistance that was constantly being supplied with Allied weapons. Therefore, as part of a political compromise in response to several criticisms questioning the readiness of the Japanese Army for a war of such large scale, all of the experience gained during the development of the “trial tracked automatic carriers” was used to quickly develop the first prototype of the Ho-Ki APC by the end of 1941. This then led to the official introduction of the Type 1 Ho-Ki APC in 1942, right after the start of the Pacific War.
The prototype of the Ho-Ki APC was built by the end of 1941. It had many features borrowed from the “Trial production 98 type automatic carrier”, such as a similar design at the front, although this was now slightly more angled and the headlights were directly embedded into the hull. The suspension system of the Ho-Ki prototype was also similar to that of the previous trial carrier, although it was slightly improved. Instead of a completely wooden cargo compartment, like the previous trial carrier had, the Ho-Ki APC prototype was entirely made out of armored steel, with both its sides of the cargo compartment area being angled in a diamond shape. These angled sides would have given a better protection for the Ho-Ki’s passengers against small arms fire and artillery shrapnel, similar in this regard to the Type 1 Ho-Ha half-track, which also had similar sloped sides at the cargo area. On the right side of the driver’s cabin, the cargo compartment of the Ho-Ki prototype also had an armored hatch facing forward, through which fire support would have been provided with rifles or a machine gun.
Although the Type 1 Ho-Ki was introduced in 1942, shortly after its prototype development, mass production did not start until years later, in 1944. This was due to the scarce resources which Japan had at its disposal, therefore always having to choose to give priority to other areas of importance throughout the war, such as the Navy and the Air Forces (Imperial Japanese Army Air Force and Imperial Japanese Navy Air Force). However, in 1944, when the defense of the Japanese Home Islands and other key territories seemed imminent, it was decided to start mass producing the Type 1 Ho-Ki APC to try and modernize the ground defenses. Although having even fewer resources than before due to Japan’s increasingly dire war-time situation, the mass-produced Ho-Ki APC would have a few significant design changes when compared to its 1941 prototype.
The most noticeable difference of the mass-produced Type 1 Ho-Ki compared to its prototype of 1941 was that the sloped diamond-shape sides were replaced by completely flat sides that had no angling. This was done to simplify production and reduce costs, something that by 1944, Imperial Japan was already doing in many other areas due to its war-torn industry. The armored hatch at the front of the cargo compartment that was seen on the Ho-Ki APC prototype was also removed from the mass-produced vehicle, therefore denying the option of providing fire support through that area. However, this issue was somewhat amended by the machine gun mount that was placed right above the driver’s cabin of the then mass-produced Type 1 Ho-Ki APCs.
Photographs only show the Ho-Ki APCs with the option of having a simple canvas tarpaulin mounted on top of the cargo compartment, rather than the windowed covers that were seen on some of the previous trial tracked carriers.
All of the “trial tracked carriers” had been developed by the Automobile Industry Co., Ltd.. In 1942, it changed its name into Hino Heavy Industries. It then built both the Type 1 Ho-Ki APC and the Type 1 Ho-Ha half-ftrack simultaneously during that year.
Design Layout and Protection of the Type 1 Ho-Ki APC
The Type 1 Ho-Ki APC, as mass-produced in 1944, had completely flat sides almost all around, with the exception of the vehicle’s front, which was slightly angled where the engine compartment and the driver’s cabin were located. One of the most distinctive aspects of this vehicle, just like with the previous trial carriers, was its unusual design at the front, with the driver’s cabin located at the front-left side of the hull and only extending less than halfway across the center.
Meanwhile, on the right side of the driver’s cabin, the engine compartment was found, with a large armored shutter at the front and two smaller ones on the side of the vehicle. The exhaust was also placed at the right side of the engine compartment.
Protection-wise, the Type 1 Ho-Ki APC had 4 mm of armor on its sides, while the front of the vehicle was slightly more protected, with only 6 mm of sloped armor, just enough to stop small arms fire and artillery shrapnel. As for firepower, right on top of the driver’s cabin, there was a machine gun mount for either a 7.7 mm Type 92 heavy machine gun or a 7.7 mm Type 99 light machine gun.
Normally, a Type 92 heavy machine gun squad in the Imperial Japanese Army was composed of 11 members, including 4 ammunition personnels carrying ammunition boxes with 540 rounds each, totaling up to 2,160 rounds per machine gun squad and often even up to 3,450 rounds in total. Therefore, it is likely that a Ho-Ki APC would normally carry more ammunition than that considering the large storage space inside its cargo compartment, and also taking into consideration the need of supplying the infantry it might be transporting. Other than the standard ammunition, the Type 92 heavy machine gun could fire armor-piercing rounds, tracer rounds and incendiary rounds. Once the heavy machine gun was mounted on a vehicle such as the Ho-Ki APC, it only needed at least two personnel to be used effectively.
Cargo Compartment and its Arrangement
Just like the jointly developed Type 1 Ho-Ha half-track, the Type 1 Ho-Ki APC could also transport around 12 to 13 soldiers. Although this vehicle was significantly shorter and slightly lighter than the half-track, it could reportedly carry the same load or even more, between 2 to 3 tonnes of cargo. The Type 1 Ho-Ki was therefore not only useful as a troop transport or for carrying supplies, but it could also be used to tow artillery pieces and other heavy equipment. For this purpose, it had a towing hook at the rear and two smaller towing hooks at the front.
At the front-sides of the cargo compartment, a small door was placed for infantry to access and exit. At the rear, a double door was placed as a larger access and exit to the vehicle, while right under these double doors, a small ramp could also be opened downwards like a flap. This small ramp also had a step so that soldiers could get into the vehicle more easily. Inside the transport compartment, there were six benches, with three on each side to allow for a total of 12 passengers to sit. As another unique feature of the Ho-Ki APC, the floor was made out of separate wooden boards that could be removed to allow for ammunition and supplies to be stored inside.
Crew and Driving Compartment
Right at the front of the somewhat narrow driving compartment was the driver’s seat. Behind it were two more seats for the other crew members of the APC, the vehicle’s commander and the mechanic. In order to give the driver a wide visibility, the cabin had a large hatch facing forward and two other slightly smaller hatches on both sides, with the left one actually being placed on the driver’s side door. Another pair of hatches was also placed on both sides, where the commander and mechanic would sit, with another side door being placed on that area for their use. The driver’s cabin also had a larger hatch on the roof that would open forward, right on top of the commander’s and mechanic’s seat. With a total of six hatches, this gave the crew a wide visibility and, in case of being under enemy fire, only the front hatch had a few narrow grids to give the driver just enough visibility to see forwards. The back of the driver’s cabin was also directly accessible through the cargo compartment, allowing the crew to easily move around the vehicle.
Overall Analysis of the Ho-Ki APC
Compared to some of the fully tracked APC’s commonly fielded by other nations of the time that were in most part based on already existing tanks, such as the Kangaroo or the Churchill APCs, the Type 1 Ho-Ki APC was designed from scratch to be a tracked carrier. With its unique design and configuration, several comparisons have been made with some more modern APC designs seen later on during the Cold War. Among some of the Ho-Ki APC’s noticeable characteristics would be the fact that it was a fully tracked transport rather than the widely used half-track designs seen during WW2. This, along with its overall good performance, its rear layout and spacious cargo compartment with a large double door at the back for easy access, the sloped armored driver’s cabin located at the front left directly connected to the cargo compartment and making room for the engine compartment right next to the driver’s cabin, gave the Ho-Ki APC a more modern appearance when compared to other transport vehicles of the time. Many authors consider it as one of the first modern APCs built.
With a weight of around 6.5 tonnes when fully loaded, the Type 1 Ho-Ki APC performed well, with a maximum speed of 42 km/h on road, while also having a decent mobility off-road and on rough terrains. This was partly thanks to its Type 100 DB52 134 hp@2,000 rpm, 6 cylinder air-cooled diesel engine. Along with its suspension, it allowed the APC to carry up to 3 tonnes of cargo, also making it a suitable towing vehicle for artillery pieces. Its two fuel tanks were located near the engine compartment, a smaller 189 liters and a larger 227 liters respectively, giving the Ho-Ki APC a range of around 300 km.
Regarding the undercarriage, the suspension of the Ho-Ki APC was very similar to that of the previous Trial production 98 type automatic carrier, consisting of 4 separate bogies mounted on bell cranks on each side, with 2 return rollers. The idler wheels were placed at the front of the tracks, while, at the back, the sprocket wheels were driven by the transmission that was also located at the rear. In addition, the gearbox, which had 8 forward and 2 reverse gears, allowed the Ho-Ki APC to have more flexibility with its speed and sustain it easier.
Production and Combat Use
The first prototype of the Ho-Ki APC was built in 1941 and, shortly afterwards, the vehicle was then introduced into service in 1942. At this time, very few Ho-Ki APCs were probably built, with only some slight design changes being made throughout the years until the 1944 mass-produced variant that is more commonly known.
According to some surviving documents, a total of 800 armored transports were built throughout the war, with the largest production batch being made between 1944 and 1945, which consisted of around 500 vehicles built. However, from this total number, it is not specified how many armored transports were built of each type, although fully tracked carriers such as the Type 1 Ho-Ki seemed to have been prefered over the half-track designs, at least assuming from their reportedly wider use throughout the different fronts. It is therefore speculated by some that around 200 fully tracked carriers, including the Ho-Ki APC, were built after 1944.
Once the Type 1 Ho-Ki APC started mass production in 1944, some of these were quickly sent to support the Imperial Japanese Army’s ground forces where they were needed the most. Many of these APCs were shipped over to Manchuria in order to defend the territories occupied by Imperial Japan’s Kwantung Army, while several others were sent over to support Japan’s Expeditionary Army against the Chinese resistance that had been constantly modernized with equipment sent by their US and Soviet allies. With the Kwantung Army’s 3rd Tank Regiment, the Ho-Ki APC could have participated in some of the major engagements that took place in China during the later years of the war, such as in Operation Ichi-Go (April 1944), Operation Shokei (July 1944), or at the Battle of West Henan-North Hubei (March-May 1945).
Several other Type 1 Ho-Ki APCs were sent over to the Philippines to support the Imperial Japanese Army in some of the major engagements that were to take place as the Japanese defenders attempted to prevent the American forces from retaking the territory. This was crucial for Imperial Japan since, by keeping control of the Philippines, it allowed them to continue receiving a certain amount of resources despite the tight sea blockades that were being carried out by the US forces and its allies.
Although it is not known how many Ho-Ki APCs were sent to the Philippines, only a limited number made it to land, since some of the transport ships carrying these APCs, together with the Type 1 Ho-Ha half-track among other vehicles and supplies, were sunk on their way there by a US submarine. Some of the Ho-Ki APCs that were sent to the Philippines also belonged to the 2nd Tank Division that was stationed in Manchuria. This Division was transferred over to Luzon in different stages in July 1944, shortly after having received the Ho-Ki APCs. While being transferred on transport ships, the 2nd Tank Division also suffered losses from the US submarine attacks.
While several Ho-Ki APCs were sent abroad to support the Imperial Japanese Army in different engagements that were taking place, it is believed that most of them were kept with the 1st Armored Regiment over at the Home Islands to aid the Japanese defenders against the upcoming Allied invasion. This invasion, also known as the Mainland Decisive Battle by the Japanese, was believed to occur somewhere between late 1945 and early 1946. However, Japan surrendered before such a scenario took place.
After the war, most of the Ho-Ki APCs, along with the majority of Japan’s military equipment, were scrapped. However, according to some sources, a few Ho-Ki APCs kept being used during the post-war by the then newly formed Japanese Self-Defense Forces until the 1950s or early 1960s.
The Type 1 Ho-Ki APC was introduced in 1942, after many years of development starting in the early 1930s, with different trial APCs being built. However, due to limited resources invested into the APC project, with top priorities being placed on other matters, such as the air forces and the surface fleet, mass production of the Ho-Ki APC did not start until 1944. Although too late, this was when the Japanese command started to focus on better equipping the ground forces of the Imperial Japanese Army for the major defensive battles that were expected to come. During these, the Japanese would try to hold on key territories, such as Manchuria, the Philippines, and to defend the Home Islands.
Had the Ho-Ki APC been delivered in larger numbers and earlier, it would have certainly given the Japanese infantry a much needed support as well as overall improving the logistics of the Japanese forces by carrying supplies and towing heavy equipment, such as artillery pieces through rough terrain. Throughout the war, conventional cargo trucks were often forced through rough terrains where they were unsuited for travel. Whenever no alternative was available, tow animals such as donkeys or horses would also be used for this same purpose and very often, even Japanese infantry would also have no choice but to carry supplies and equipment on their own backs.
Therefore, with an earlier mass-production and deployment of the Type 1 Ho-Ki APC, alongside the Type 1 Ho-Ha half-track that was developed at the same time, many of these logistical shortcomings which the Imperial Japanese Army had to deal with would have certainly been addressed. Not only that, but they would also have been able to modernize their mechanized infantry units and try out newer combat tactics, something which many Japanese officers had planned on doing since the early 1930s. They never had the chance of putting this into practice, not even with the limited number of armored transports that were mass-produced by the end of the war.
The Type 1 Ho-Ki APC, with its good performance due to its power to weight ratio and being fully tracked, along with its unique design characteristics, would have been more than suitable to take part in any of these intended support roles, whether it is for carrying supplies and towing artillery pieces over to the battlefield, or to be part of the planned mechanized infantry doctrines that were drafted. With all of this put into consideration, many authors and sources have referred to the Type 1 Ho-Ki APC as one of the first modern APCs built.
Type 1 Ho-Ki APC Specs Table
|Dimensions (L-W-H)||4.78 x 2.19 x 2.58 m|
|Total weight||6.5 tonnes|
|Crew||3 (driver, commander, mechanic) + 12 to 13 passengers|
|Propulsion||Type 100 DB52 air-cooled 6 cylinder diesel engine, 134 hp@2,000 rpm|
|Top speed||42 km/h|
|Armor||4 mm to 6 mm|
|Armament||7.7mm Type 92 heavy machine gun or Type 99 light machine gun|
|Range (maximum at cruise speed)||300 km (200 miles)|
|Total production||around 200 built|