During the 1930s the Japanese considered mechanization. Studies focused on armored cars at first, but with the terrain in Asia, it was decided to go with tracked vehicles. Ishikawaijma designed the Type 92 'combat car'.
During the 1930s the Japanese Army and Navy decided that only aircraft and engines designed and built by Japanese companies would be considered for purchase.
The Imperial Japanese Army ordered ten French Renault NC 1 tanks because of the delays in production of the Type 89.
By 1932, Mitsubishi Heavy Industries was producing an air-cooled diesel engine that was suitable for tanks. This was placed experimentally into a Type 89. This later became known as the Type 89-B.
The first of the Dokuritsu Sensha Chutai (independent tank companies) that was created when companies were detached from tank regiments was created in China and sent to Shanghai. Saipan and the Philippines received 12 Dokuritsu Sensha Chutai during World War II. Most of these were set up in static defensive positions.
The 1st Special Tank Company was sent to Manchuria with Renault FT and NC tanks after the Manchurian Incident in January 1932. Near Harbin the company saw action.
The 1st and 4th Cavalry Brigades were sent to Manchuria. When their armored cars were replaced by Type 95 light tanks in 1937 they became the Kihei Ryodan Senshatai (tank units). In 1942 these units were then converted into reconnaissance units and were placed into the 3rd and 1st tank divisions.
During the Shanghai Incident in February 1932 five Type 89 and ten Renault NC tanks were used. In action the NC's suspension proved to be inadequate and was retired.
The Imperial Japanese Navy started the 7-Shi production program that wanted carrier and seaplanes. Most were failed designs except for the Kawanishi E7K1 seaplane.
During the Shanghai Incident, Vickers Crossley armored cars were sent to the Special Naval Landing Force (SNLF). The Shanghai SNLF were equipped with 6 – 8 Type 89 medium tanks and some armored cars to form a tank company. These vehicles had the Imperial Japanese Naval anchor symbol placed on them and painted olive drab. When the Sino-Japanese war started the tank company was disbanded and its vehicles were distributed to the SNLF infantry.
The SNLF tank school was located at the Tateyame IJN Ordnance School that was across from Tokyo on the Boso Peninsula.
In 1933 Major Tomio Hara designed the basis of many of the suspensions of future Japanese tanks, the bellcrank scissors which had paired bogie wheels connected by a coil spring.
The first three tank regiments were formed:
- 1st Regiment at Kurume
- 2nd Regiment at Chiba Tank School
- 3rd Regiment at Kurume
Four tank regiments were formed during 1933-34 in Japan and Manchuria. Three of the regiments had 2 companies of 10 Type 89s each. The 4th had 3 Type 89 companies and was known as the Independent Mixed Brigade which included:
- motorized infantry
- artillery regiment
- engineer company
In 1933 the Independent Mixed Brigade was formed in China of mainly Type 95 and Type 89 tanks. It was a combination of 3 Type 89 companies, infantry regiment, artillery regiment, and engineer company, all of which were motorized. The Mixed Brigade was used to spearhead attacks in 1937 but the lack of Chinese opposition prevented the leadership to see it's potential and was disbanded.
In the Jehol Province the 1st Special Tank Company saw action with only Type 89 tanks.
During the war in China the Japanese used the tanks as mobile pillboxes as the Chinese didn't have quantities of antitank weapons. Also air-cooled diesel engines were preferred as water was scarce in Mongolia, Manchuria, and North China.
In 1934 the Type 89B was fielded.
In 1934 the Imperial Japanese Army (IJA) formed the 1 st Independent Mixed Brigade.
The Imperial Japanese Navy instituted its 9-Shi construction program which resulted in the successful production of the Kawanishi H6K, Mitsubishi A5M, Mitsubishi G3M, and Yokosuka B4Y.
Eleven infantry divisions had tankette training centers established.
In 1935 the Type 94 tankette, with a gasoline engine, was fielded.
By 1937 Japan had approximately 1,060 tanks and 8 tank regiments.
In 1937 the 1st Independent Mixed Brigade was deployed to China. Due to the terrain many of these tanks broke down. During operations in Quhar the brigade’s tanks were dispersed to support the infantry directly.
In July 1937 thirteen tankette companies were created and sent to China. The companies had four platoons each with four tankettes. There was one tankette in the company HQ.
The Army reorganized their air units into more flexible unit structures. The basic unit was the Sentai (group) commanded by a Lieut-Colonel or Major. The Sentai was usually made up of three Chutais (squadrons) of nine to twelve aircraft and a Sentai Hombu (HQ section). A Major-General or Colonel commanded a Hikodans (wing). Two to three Hikodans made up a Hikoshidan (air division) and two to three Hikoshidans made up a Kokugun (air army).
From 1938 to 1940 two (1st and 3rd) Senshadan (tank groups) were formed in Manchuria to control armored regiments. The group’s job was to provide administrative and logistical support and not tactical control. By 1942 these groups were found not able to do the job and were merged into the tank divisions created in 1942.
From July to September 1939, in border clashes with the Soviets, the Japanese army was defeated by infantry supported by tank units. Still many IJA generals wouldn’t admit to the superiority of tanks. However, Germans successes in Poland and France finally convinced most of them.
Khalkin Gol / Nomonhan Incident
Starting in May 1939 several border classes near the village of Nomonhan, in Manchuria, steadily escalated until the 23rd Infantry Division attacked the Soviet Army near the Khalka River. There were two tank regiments in support. The Soviets put General Georgi Zhukov into command and he was successful in defending off the Japanese attacks that clearly defeated the Japanese forces.
On August 20, 1939, the Soviet forces sent three rifle divisions, two motorized infantry divisions, two armored divisions, two armored brigades, and two Mongolian cavalry divisions into the attack and surrounded the 23rd Infantry Division. The Japanese forces suffered 40,000 casualties with the 23rd Infantry Division losing 73% to casualties.
After the battle of Khalkin Gol in 1939 against the Soviet Union and the successes in Europe by the Germans, two armored divisions were formed in 1940 in Manchukuo.
The 3rd and 4th Tank Regiments were equipped with 26 Type 89B Otsus, eight Type 89A Yi-Gos, four Type 97 Chi-Has, 35 Type 95 Ha-Gos, ten Type 94 tankettes, and four Type 97 tankettes.
The Soviets fielded five Mechanized Brigades with 550 tanks and 450 armored cars.
Initially the Japanese forces were able to penetrate the Soviet defenses but within days the Japanese were decimated. 42 out of the 73 tanks were destroyed or damaged.
The Soviets lost 32 BT tanks and 35 armored cars.
Due to their failure the Japanese tanks were recalled on July 9, 1939.
The defeat also prompted the Imperial Japanese Army to rethink tactics and formations of armored units.
Armored production was to be ramped up from 500 tanks per year to 1,200.
The Japanese decided they needed a better antitank gun and developed the 47 mm in response to the Soviet 45 mm guns encountered in combat in 1939. This was placed into the Type 97 and designated the Type 97-Kai Shinhoto Chi-Ha. Production started in 1942. Around 300 of the Type 97s were upgraded.