Chapter 3: IJA Weapons and Equipment

Back to IJA main page



The story of weapons and equipment procurement of the Imperial Japanese Army in the Second World War is a story reach exceeding capacity. Japan was crippled in the Second World War by the lack of a unified procurement process. The procurement process under which they did operate was hindered by Japans late entry into the industrialization race. Due to Japans late entry she was constantly in a position of trying to play catch up to the more established industrial powers.

Complicating this race to industrialize was Japans lack of vital natural resources in her home islands. In practical terms this meant that before Japan could build the weaponry she craved, she first had to build the factories, educate and train a skilled labor force to operate those factories. Beyond these elemental tasks Japan had to secure and then transport the needed raw materials for the construction of factories and the transportation network as well as the weaponry it self.

Separate from this lack of industrialization a draw materials Japan had two further problems connected to weapons development. The first problem for Japan was the effects of the world wide depression following the American stock market crash of 1929. Furthermore beginning in 1932 Japan had considerable outlays in both cash and materials in order to support her military campaigns in Manchuria (Manchuko) and China. This naturally led to a lack of ready cash for research and development as well as production.

The Development and Production of Armor and Vehicles

Besides the economic and human costs of the Japanese campaigns in China, there was also an experience cost which altered the perceived needs of the Japanese Imperial Army. In the text which follows less emphasis will be given in terms of charts, graphs, or data to actual weapons performance and more focus will be on production numbers and dates. Even a poorly performing weapon is better then no weapon at all. For more detailed information on individual weapons, weights, and capabilities the reader so inclined will have to look elsewhere.

In China the prime areas of operations for Imperial Forces was in the rural and unsettled areas of China. These areas geographically are characterized by their vastness, aridness and lack of roads and infrastructure. This terrain played a crucial role in the development of Japanese weapons systems especially of its armored vehicles. The lack of water lead to the development by the Japanese of the world’s first air cooled diesel engine in 1936. The lack of roads also caused the Japanese to develop armored cars which ran on rail tracks instead of wheels. The demands and limitations of this operational area was coupled by a Japanese belief that their main opponent would be the Soviet Union and that the great battles of the future would be fought in the arid wastes of Soviet Siberia. This factors lead the Japanese to put the bulk of their logistic burden on the horse rather then the truck. This chosen reliance on the horse power focused weapons development along suitable lines. These lines called for the development of light weight and horse portable packages with the traditional maximum limit for horse born bundles being around 200 pounds.

This focus on lighter weight equipment was carried over into armored vehicle design and development because the Japanese soon realized that their vehicles needed to be easily transported on existing transport ships to the mainland and then by rail to the area of operations. Low capacity bridges and roads in China also contributed to design limitations and the Japanese sought to maintain a relatively rapid rate of advance. In effect they tailored their designs to the current theater of operations and threat levels that they were experiencing with out much thought as to developments among possible future enemies. These weight limitations lead to Japanese vehicles tending to be poorly armored and armed when compared to western vehicles of the same period and especially as they encountered western vehicles later in the second world war. Though it must be pointed out that in 1941 when Japan began to actively engager western powers in combat the average armor thickness on her tanks of 25-30 mm was comparable to the allied tanks they were encountering in their initial campaigns of expansion through 1942.

Japanese tank development started in earnest at the close of the First World War when they imported from their British allies several Mk IV tanks in 1918. These few tanks remained in the Japanese inventory as objects to be studied and experimented with until the mid 1920's. In 1925 the Japanese decided to establish their own tank force. Initial plans called for four tank battalions, three light and one heavy. At this time Japan lacked its own tank and was reliant therefore on what they could purchase from abroad. They met obstacles abroad in trying to purchase the most current models of tanks in the desired numbers. As a result they settled on what could be gotten, the French Renault FT-17. Soon the Japanese grew increasingly unhappy with the performance of the FT-17's and in late 1925 they decided that they should design and manufacture their own tanks in accordance with their desired performance abilities.

The first production models came off the lines at 18 tons and this proved to be to heavy. In 1928 the Japanese then produced a lighter tank named the T89 which weighed in at 8 tons. The T89 was initially designed to be a light tank, but later on it was reclassified by the Japanese as a medium tank when production began in earnest in 1931.

In 1933 a new tank design was institutited with the main design requirement being that the tank posses enough speed so as to keep pace with truck borne infantry. The directive indicated that the desired speed was 40km per hour. The first prototype rolled out in 1934. The prototype lingered, falling victim to a rift between the Calvary branch and the infantry branch over the desired levels of armored protection for the new tank. The infantry branch, the single most powerful in the entire military establishment, thought that based on experience that 25mm was adequate for the task. The cavalry branch, who was ultimately responsible for and the end user of the tank, wanted a minimum of 30mm. The net result was that 25mm became the thickness, though the stated reason was to keep unit costs lower. Production finally started in 1937 and the tank was called the T95. It would go on to be come the mainstay of the Imperial Japanese Army in the Second World War.

The initial plan from 1925 was to establish tank battalions but the first models which were produced ended up being dispersed to the infantry divisions for use as heavy support platforms. Production of the T89 continued apace and in 1933 the Japanese were able to establish four independent tank regiments. Though called regiments by the Japanese, when compared to western units of the same era they were really just battalions. The establishment of a Japanese tank division would have to wait until 1942. Though established in 1942 the IJA would not operate a mass tank unit of Division size in the field until 1945 and this only in China and Manchuko.

Part of the problem was that Japanese armor production levels remained far below western numbers. Total production in the period from 1931-1940 was around 3,000 total units. From 1941-1945 when Japan was actively engaged in combat with the western powers she managed to produce only 3,500 more units, a portion of which included self propelled artillery pieces and platforms. Their peak year for production of armored vehicles was 1941-1942 when they managed to produce a total of 2,089 (1941=1,024 and 1942=1,065) armored vehicles of all types. This was done with Tank production at priority category A and 12 plants in production for 1941 and 8 plants in production for 1942. In 1943 Tank production was moved to priority category D while higher priority was given to aircraft, naval engines, and prime movers. 1944 production figures reflected this change in priority with production totals of: 294 medium tanks, 48 light tanks, and 385 armored cars. The last year of the war, 1945, under constant allied aerial bombardment and in preparation for a defense of the home islands the Japanese managed to produce: 89 medium tanks, 5 light tanks, and 126 armored cars. At wars end Japan surrendered a total of 1,700 armored vehicles with the vast majority of these being turned over to the Soviets in Manchuko.

Even if the umbers had been sufficient initial uses in combat by the Japanese of armored vehicles was problematic. So problematic that one Japanese commander is reported to have said "that the failure was due to the Japanese soldier’s traditional lack of sympathy with motors." This comment stemmed partly from an institutionalized bias in the Japanese military ethos towards the power of the martial spirit embodied in Japanese thought by the individual soldier and his wielding of the bayonet. Early experience in 1933 also sullied the opinions of decision makers towards armor when all Japanese tanks were put out of commission in the field with the vast majority of them brought low by poor maintenance.

These influences of vast empty terrain, an instinctive bias in favor of infantry, and the Chinese lack of armor and anti-tank weapons further slowed the evolution of Japanese armor.

These evolutionary hindrances showed their power in the evolution of tank weaponry. In terms of main guns the Japanese tanks were equipped initially with short barreled guns better suited to providing infantry support. This changed in the aftermath of the battle of Nomohan (1939). In 1941 Japan introduced a long barreled 47mmm main tank gun which the Japanese had deemed adequate for all likely encounters. The Japanese had tested their new gun on captured US Army M3 Lt tanks. The new gun achieved a 50% successful penetration rate versus the frontal armor of the M3 at 1,000 meters. The defeat at Nomohan also leads to the development of self propelled artillery. Development though was halted in 1943 as priority was given to aircraft production. Self-propelled artillery and tank production both received renewed interest and priority later in the war in response to Japanese encounters with the American M4 Sherman.

Japanese designed tanks did posses some interesting features when compared to western tanks. The first interesting feature was their lack of a coaxial machine gun until the very end of the war in their last designs. Instead of the coaxial machine gun Japanese tanks had a machine gun mounted in a ball mount on the rear of the main gun turret. Additional the main gun of a Japanese tank usually had a degree of free play built into its mounting. This free play allowed for a 10 degree free traverse of the gun in either direction independent of the traverse of the turret.

Allied assessments both during the war and post war of Japanese armor are interesting. They note that Japanese tanks tended to be lightly armored though the quality of the armor plate was consistently good. The extensive use of bolts and rivets to join the armor plates together proved dangerous to the crews. They also noted that the crew entry and exit doors were not conducive to allowing survivors of an initial debilitating hit the chance to exit before they were killed in the vehicle. This was counterbalanced to some degree by adequate amounts, by western standards, of thermal insulation. Japanese crew compartments though were thought to be very cramped and possessing ergonomically poor layouts with little or no thought given to crew comfort or long term functionality. The horsepower, engine and suspension systems were evaluated as more than adequate. Radios were not issued to light tanks and to medium tanks they were issued as one per platoon.

In the end tank production and design suffered from a lack of materials, money, and Japanese satisfaction with their tank performance in the Chinese theater. Tank production took a back seat as Japan choose to put a greater portion of her limited resources into aircraft production. This was done in response to the continual massive bombing by the Allies.

Tank production was not the only significant modern vehicle to have its production severely curtailed as the war progressed. Perhaps of more significance was the saga of Japanese truck production. The peak year for production was 1941. In that peak year they managed to produce a total of 47,901 vehicles for use. By 1943 production had fallen off to a total of 14,000 new vehicles though inventory had been degraded by losses a total of 16,000 which meant that by years end the Japanese had suffered a net loss of 2,000 units. The next year, 1944, was even worse with a total production run of only 11,000 units to replace losses of 20,000 trucks which left Japanese forces with a net loss of 9,000 vehicles. Japan produced four major types of trucks during the war. In general their trucks were not for a lack of adequate power.

Trucks were not the only short coming in Japanese vehicle production. Bulldozers, earth moving equipment, and other engineering type vehicles were seemingly in chronic short supply. An inventory of available bulldozers in the home islands in the spring of 1945 listed a grand total of 37 with which to prepare Japan for the coming Allied invasion.
Small Arms and Artillery
The start of the Second World War found the Imperial Japanese Army in the process of switching small arms calibers from 6.5mm to 7.7mm. The desire for the switch began after the 1905 Russo-Japanese War. The Japanese had been unhappy with the stopping power of the 6.5mm bullets on the larger European physiques. Convinced that the Russians/Soviets would continue to be their major opponent the process was begun to redesign both the weaponry and the production lines to convert the entire establishment to the 7.7mmm caliber.

A major complicating factor in the development of Japanese small arms was that each branch drew up its own requirements for small arms. Beyond branch specific requirements, they each proceeded to develop and contract for manufacture these different weapons. This created competition for and among manufactures for resources and production lines as well as complicating logistics and spare parts in the field. In the text which follows less emphasis will be given in terms of charts, graphs, or data to actual weapons performance and more focus will be on production numbers and dates. Even a poorly performing weapon is better then no weapon at all. For more detailed information on individual weapons, weights, and capabilities the reader so inclined will have to look elsewhere.

The most common hand gun issued among Japanese forces in the Second World War was the 8mm Nambu T94. As the war progressed the manufacturing quality of the T94 degraded to the point where late war models were as dangerous to the shooter as to the intended target of the shooter.

The standard rifle for Haitai was the T38 M1905 6.5mm Arisaka rifle. This rifle was introduced in 1905 and 3,400,000 were ultimately produced. The rifle was issued in three different lengths and was based on the Mauser operating system. The Japanese experience in the 1905 war was confirmed in China. As a result of this experience the Imperial Japanese Army began to issue the T99 rifle in 7.7mm in 1939.

A special sniper version of both rifles was manufactured. It was distinguished by its 4x power of magnification scope. A version with attached flip and down monopod was issued 1942. A simplified version of the T99 was issued beginning in 1943. This version was notable for its poor quality of construction, finish, and materials though it was manufactured in large numbers. There was additionally a specialized parachutist model which disassembled into two sections joined by a threaded coupler. In 1945 the Japanese produced a version of the US M-1 rifle. This rifle was manufactured in 7.7mm caliber and featured a ten round magazine.

Machine Guns:
Moving up the ladder of small arms we come to machine guns. Japanese machine gun development perhaps is the one small arm which showed the greatest amount of diversity. The basis of Japanese machine gun design was the French Hotchkiss models. As in all equipment the Japanese were constantly seeking to lighten the overall weight of their machine guns. All Japanese machine guns which had their roots in a Hotchkiss design suffered from a lack of slow initial extraction which caused excessive stoppages in the feed system. The initial fix for these problems was to provide an oilier for lubricating the bullets. Predictably this lead to dirt attraction in field conditions which in and of itself contributed to stoppages.

Separate from the Imperial Army the Imperial Navy and Naval Air branch opted for a version of the WWI Lewis gun recalibrated for 7.7mm. They also copied the venerable US Browning .50 caliber machine gun. However they manufactured it in a 20mm version. Just as in the Army’s weapons the Navy’s weapons also suffered from manufacturing quality as the war progressed.

Japan initiated a redesign of her small arms inventory beginning in 1925. Machine guns were redesigned to accommodate the caliber change from 6.5mm to 7.7mm and to reduce the weight whenever possible. Machine guns went through two rounds of tinkering. The first round was in 1932 and the second was in 1939 using experience in China as the guide. Japanese Artillery was redesigned in 1925-1926.

Japanese artillery was noted for its comparably long range and lightness of the pieces. The greatest deficiency in the Japanese artillery park was in its numbers produced. Need far out paced both initial preconception of use and ability to produce. Once again experience in China proved to be the unhinging factor for the Imperial Army later on when it began to engage western forces. The experience from the defeat at Nomohan was noted and as a stop gap measure the Japanese tried to increase the numbers and tactics of their mortars and mortarmen. The most evident system in this attempt was their development and redesign of the 50mm Mortar (often called a grenade discharger, which were issued three or four to a platoon. They had a range of up to 650m) in the decade between 1929 and 1939.

Total production figures for the artillery establishment of the imperial Japanese Army between 1941 and 1945 was as follows: Mortars of all types, 2,073 tubes were manufactured. Artillery in the calibers between 70mm and 105mm, 6,512 were manufactured. In calibers of 106mm and larger the Japanese produced only 604 tubes. On hand pre-war stocks of artillery were exhausted in 1943.

Production figures for 1943 were as follows:
ADA- 75mm = 1,053, 80mm = 200, 120mm = 21.
Pack Artillery and Field guns - Lt pack artillery = 300, M90 75mm Fld gun = 50 (down from 250 in 1942)
Artillery under 70mm - 2,510
75mm to 105mm - 1,541 (down from 2,130 in 1942)
105mm - 110 (down from 240 in 1942)
106mm and up - 90 pieces total

Production figures for 1944 were as follows:
ADA- 75mm = 500, 80mm = 200, 120mm = 96.
Pack Artillery and Field guns - Lt pack artillery = 120, M90 75mm Fld gun = 0
Artillery under 70mm - 1,280
75mm to 105mm - 0
105mm - 0
106mm and up - 0l

All Japanese weapons suffered in design by western standards. All Japanese weapons were viewed through the prism of the ¼ pound, 15 ½ inch bayonet. Viewing weapons through that prism, a weapon’s effectiveness was judged on its ability to help or allow the infantry soldier to close in with his bayonet and kill the enemy. The Japanese viewed their key weapon with spiritual eyes rather then merely material eyes. By 1941 the Japanese knew that they were comparatively under gunned in weight of shells and numbers but they honestly believed that their spiritual power would equalize out the material deficiency.

Other Equipment:
The material deficiency initially in 1941 on the surface did not perhaps seem as dire as it really was. In 1941 the Imperial Japanese Army field 89 Division sized equivalent units. 51 of these units were actual divisions and the rest comprised 59 independent brigades. For these 89 divisional equivalents the Japanese had on had 103 divisional sets of weapons and equipment. This provided a small reserve to cover losses and expansion on a moderate scale.

The numbers of troops called up and lost fluctuated over the next few years though it tended to rise in the total numbers of men enlisted. In 1943 Japan produced a total of 24 divisional sets of equipment against the loss of 11 divisional sets. In 1944 the situation began to decline as losses occurred at a faster rate then production. In 1944 the Imperial Japanese Army began the year with 123 sets of equipment. They managed to produce 22 new sets but consumed 36 complete sets of divisional equipment. They ended 1944 at a gain in manpower but a loss in the ability to equip and arm that new influx as they showed only 109 sets on inventory.

1945, the final year of the conflict saw no let up in the worsening situation. In August of that year they fielded 171 divisional equivalents but were only able to equip 104 of them. So dramatic was the drop off that in 1945 steel helmets were being issued only to front line troops. Canteens and mess kits were issued on the scale of one for every two soldiers.

In that same month of August, 1945 the Japanese home islands had on hand only a days supply of rifle and machine gun ammunition. Worse yet they listed the rations reserve as 18 days on a meager scale. The initial rice ration in 1941 was 900 grams per day. By 1945 this had been steadily cut to 400 grams per soldier per day.

A key area of deficiency for the IJA was in the area of communications, both wire and wireless. Rather then standardized sets and components between the Army and the Navy the two services competed for the same specialists and developers and proceeded to develop their own types. Typically the radios were of high quality but often to delicate. The shortage of manpower because of the lack of deferments meant that during the war Japan typically could only run one daily shift of production rather then three. Lack of proper materials later in the war meant that filed radios, radars, and telephone wire was manufactured with substandard or secondary metals which degraded performance. Production ability versus production goals in the early war years meant that industry achieved only 50% of the expected number of radios. Often because some of the smaller units were farmed out to local industry the finished products did not always integrate well when put together with products from other factories. Communication problems would continually plague Japanese forces. The stranding of operators and repair technicians on the bypassed islands only magnified the production woes.

Next chapter




Back to the 1JMA homepage

Back to the articles frontpage

Comments, please go the the forum. Direct issues with the article, please .E Mail me