| Type 89 I-Go (Chi-Ro) | |
|---|---|
 A restored Type 89 I-Go at Tsuchiura JGSDF Base open day | |
| Type | Medium tank |
| Place of origin | Empire of Japan |
| Production history | |
| Designed | 1928 |
| Unit cost | ModelOtsu: 97,000yen ($26,064 USD) in August 1939, excluding armaments[1][2] |
| No. built | 404[3] |
| Specifications | |
| Mass | 12.79metric tons (14.10short tons) |
| Length | 5.73 m (18 ft 10 in) |
| Width | 2.15 m (7 ft 1 in) |
| Height | 2.56 m (8 ft 5 in) |
| Crew | 4 |
| Armor | 6 to 17 mm (0.24–0.67 in) |
Main armament | 57 mm Type 90 gun 100 rounds[4] |
Secondary armament | 2 x 6.5 mmType 91 machine gun (hull, turret rear) 2,745 rounds[4] |
| Engine | Mitsubishi A6120VDair-cooled inline 6-cylinderdiesel 120 hp (90 kW)/ 1800 rpm 14,300cc |
| Suspension | leaf spring |
Operational range | 170 km (110 mi) |
| Maximum speed | 26 km/h (16 mph) |
TheType 89 medium tankI-Go (八九式中戦車 イ号,Hachikyū-shiki chū-sensha I-gō) is amedium tank used by theImperial Japanese Army from 1932 to 1942 in combat operations of theSecond Sino-Japanese War, atKhalkhin Gol against theSoviet Union, and in theSecond World War. The Type 89B model was the world's first mass-produceddiesel engine tank.[5] The tank was armed with a short-barrel 57 mm cannon for knocking outpillboxes and masonry fortifications, and proved effective in campaigns inManchuria and China, as the ChineseNational Revolutionary Army had only three tank battalions to oppose them, which consisted primarily ofVickers export models, GermanPanzer Is, and ItalianCV33tankettes.[6] The Type 89 was a 1920s design medium tank, built to support the infantry, and thus lacked the armor or armament of 1940s generation Allied armor; it was regarded as obsolete by the time of the 1939 battles of Khalkhin Gol, against the Soviet Union.[7] The code designation "I-Go" comes from thekatakana letter [イ] for "first" and thekanji [号] for "number". The designation is also transliteratedChi-Ro and sometimes "Yi-Go".[8][9]
The Type 89 evolved from Japan's first domestic tank project initiated by theImperial Japanese Army’sOsaka Technical Arsenal in 1925. The original plan was for two types of tanks to be created: a 10-ton light tank based on the FrenchRenault FT tank, and a 20-ton design modeled after theVickers medium tank.[10] "Experimental tank No.1" a/k/aType 87 Chi-I was completed by February 1927 and ready for field trials.[11][12][13] However, it was 20-ton and under-powered.[11] The weight of the initial prototype and its low speed did not impress theImperial Japanese Army General Staff Office, and a new requirement was issued for a lighter tank, with a nominal 10-ton weight. The new design was modeled after the Vickers Medium C which had been bought by the Japanese Army in March 1927.[14]
By April 1928, the new "light tank" design was finished. "Experimental tank No.2" was completed in 1929 and designated as the Type 89.[9][12] Later, the Type 89 was re-classified as a "medium tank" because the weight increased to over 10 tons due to improvements.[9] As the army's Sagami Arsenal lacked the capacity for mass production, a contract was awarded toMitsubishi Heavy Industries, which built a new tank factory to specifically produce this model. Production of the Type 89 began in 1931 and it soon became the main battle tank of the Japanese Army.[15]
Although the Type 89 was well regarded by the army, there were several small problems to be rectified, notably a gap under the mantlet on early models that allowed rifle fire to enter the turret. Work continued on improving the Type 89 after the production started, and as a result variants were developed.[7]
The Type 89 required a crew of four (commander/gunner, loader, driver and hull gunner).
The design of the Type 89 was relatively conventional with a forward-mounted gun turret carrying the main armament, a Type 90 57 mm gun that was complemented by twoType 91 6.5 mm machine guns.[4] One was located in the front hull and the other placed in a turret ball mount pointed towards the rear, a practice followed with most Japanese tanks.[16] The Type 90 57 mm tank gun had a barrel length of 0.85 metres (33 in) (L14.9), an angle of fire of −15 to +20 degrees in elevation and 20 degrees in azimuth, and amuzzle velocity of 380 m/s (1,200 ft/s), and could penetrate of 20 mm of armor at 500 m (0.8 in/550 yd). During the later stages of World War II, HEAT shells were developed to provide greater penetration of enemy armor.[17]
Rather than using softiron armor, as on the earlier Chi-I, the designers chose to use steel plate armor developed by the Nihon Seikosho Company (JSW). The type of armor was referred to as 'Niseko steel', an abbreviation of "Nihonseikosho".[18]
The Type 89 was driven through the rear drive sprocket and featured ninebogies, mounted in pairs on each side, with the forward bogie on an independent suspension. Five smaller return wheels were mounted along a steel girder.[19] The Type A could only communicate with signal flags.[19] Some vehicles were provided with two searchlights for night operations. Later the Type 94 Mk 4 Hei (1934 model) radio communication device with range of 0.97 kilometres (0.6 mi) and weight of 90 kilograms (198 lb), linked with a radio antenna of 8.99 m (29 ft 6 in) in a reverse L shape was installed.
The Type 89 served with Japanese infantry divisions and first saw combat use during theFirst Battle of Shanghai in 1932.[22] The short-barreled 57 mm gun was effective at destroying machine gun nests and its 15 mm (0.59 in) armor, although thin, was enough to stop small arms fire. The relatively low speed of 25 km/h (16 mph) was not an issue in these types of operations.[18]
The following year, the Japanese Army formed its first independent armor force by creating three regiments armed with the Type 89,[5] each consisting of two companies with ten tanks each. Three more regiments were formed in 1934. It was deployed forinfantry support operations in theSecond Sino-Japanese War and in various campaigns throughout China after 1937. After the out-break of war with China, the peacetime budgetary limitations were removed and the more capable and expensiveMitsubishiChi-Ha model was accepted as the newType 97 medium tank by the army to replace the Type 89. Type 89s were the main medium tank of the Japanese military through 1937.[23][24]
On the evening of 2 July 1939, during theBattles of Khalkhin Gol, the Japanese Army's 1st Tank Corps, commanded byLt. GeneralYasuoka Masaomi, launched an offensive against theSoviet Union's 11th Tank and 7th Armored brigades.[25] The 1st Tank Corps consisted of the3rd Tank Regiment and4th Tank Regiment; of which the 3rd regiment consisted of 26 Type 89s, fourType 97 medium tanks, sevenType 94 tankettes, and fourType 97 tankettes, and the 4th regiment contained 35Type 95s, eight Type 89s, and three Type 94 tankettes respectively.[26] In this battle, the Type 97 medium tank was a newly fielded machine, and was primarily reserved for home units, as well as transitioning into Japanese Army forces stationed in China (Manchuria).[27]
The 3rd Tank Regiment had, after charging through Soviet artillery barrages, successfully overrun the Soviet motorized infantry and taken the high ground, which had been quickly abandoned by the Soviets. However, by 2100 hours, Soviet counter battery fire had begun pounding the newly taken position, and the 3rd Tank re-positioned themselves behind the objective.[28]
The 4th Tank Regiment, which had become separated from the 3rd Tank Regiment, advanced upon an objective under the cover of a thunderstorm that masked their movements but exposed the Soviet positions.[29] The 4th Tank Regiment continued to advance, when suddenly a shift in the lightning flashes illuminated the advancing Japanese tanks, whereupon the Soviets immediately opened fire withanti-tank guns, heavy machine guns, and artillery.[29] However, the range was so close that the Soviet artillery could not depress their guns far enough, and the 4th Tank Regiment was ordered to charge at about 0020 hours (12:20 am). Soviet shells passed wildly over the charging tanks as they penetrated over a thousand yards into the Soviet lines.[30] Now isolated, and deep within the Soviet lines, the 4th Tank Regiment moved several thousands yards[31] where they met up with Japanese infantry.
The 4th Tank Regiment had expended 1,100 37 mm and 129 57 mm tank shells during the fight, as well as about 16,000 machine gun rounds. Of the approximate 73 light and medium Japanese tanks from both regiments committed to the offensive, 13 were damaged beyond repair by Soviet gunfire, about 14 others were repaired after major overhauls, and 17 tanks were repaired in the field.[32]
Soviet forces concluded that the 1st Tank Corps had penetrated the defenses of their 9th Armored Brigade and 149th Infantry Regiment and had reached Sovietartillery positions.[33]
By 1942 the Type 89 was gradually being withdrawn from front-line combat service, but many units saw action in theBattle of the Philippines,Battle of Malaya, andBurma campaign, and continued to be used in China. They were also often used in static defense positions in the Japanese-occupied islands of theNetherlands East Indies and in theSouth Seas Mandate, but with their weak armor and low muzzle velocity main gun they were a poor match for the AmericanM4 Sherman.[7]
Some Type 89 tanks were used by elements ofRoyal Netherlands East Indies Army, such as the 1eBataljon, 3eRegiment Infanterie (1-3 RI "De Watermannen") which used the tanks as tractors and the 1eBataljon, 9eRegiment Infanterie (1-9 RI "Friesland") during the early period of theIndonesian National Revolution.[34][35]
During the early stages of theFirst Indochina War, France set up an ad hoc unit of French and Japanese armour called theCommando Blindé du Cambodge from tanks left over from theJapanese invasion of French Indochina. This unit included one Type 89B tank.[36]
 Japanese armored fighting vehicles of World War II | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tankettes | |||||||||||||||
| Light tanks | |||||||||||||||
| Medium tanks | |||||||||||||||
| Amphibious tanks and vehicles | |||||||||||||||
| Self-propelled artillery (includingtank destroyers) | |||||||||||||||
| Armored cars | |||||||||||||||
| Half-track and full-tracked vehicles | |||||||||||||||
| Other | |||||||||||||||
| Prototypes |
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