I-Go Ko

I-Go Ko

Chi-Ha

I-Go Ko

Chi-Ha

Japan

I Rank

Battle rating:

AB	RB	SB
1.0	1.0	1.0

Class:

Light tank

Research:Free

Purchase:Free

Description

The Type 89b I-Go Ko 八九式中戦車 (乙型)「イ号」 was Japan's first domestic mass-produced tank, with the model B (otsu) being the world's first diesel-powered mass-produced tank to boot. Design started in 1925 as a light tank project planned on the FT-17, but the design based on the Vickers Medium C, the I-Go was adopted in 1929 as a light tank but shortly after reclassified as a medium tank for weighing over 10 tons. Well regarded in its early career against the poorly armoured forces of the Chinese, it couldn't keep up with motorized infantry and was easily outgunned at Khalkin Gol, and would be phased out by the 2nd generation of Imperial Japanese tanks, the Ha-Go and Chi-Ha.

It was introduced in Update 1.65 "Way of the Samurai" along with the rest of the initial Japanese Ground Forces Tree. While a slow infantry support tank, with little armour for tank combat, it comes equipped with a low velocity 57 mm cannon loaded with capable HEAT shells, able to lob high penetrating shells at close range and behind cover. Making for a challenging task for new tankers, it will serve as a trial by fire to learn positioning and shell trajectory with a glass cannon.

General info

Survivability and armour

Armourfront / side / back

Hull17 / 17 / 17

Turret17 / 15 / 15

Crew4 people

Visibility75 %

The armour on the I-Go Ko is lacking against contemporary enemies. With an armour thickness of less than 20 mm (aside from the spaced areas) all over, even large-calibre machine guns can penetrate the tank frontally. Not to mention, the front armour is only mildly sloped and presents a large target that can result in the vehicle being knocked out with a single penetration. It is recommended to not rely on your armour, nor advance on an enemy unless they are incapacitated (i.e. gunner or cannon knocked out).

Armour type:

• Rolled homogeneous armour

Armour	Front	Sides	Rear	Roof
Hull	17 mm (32°) Front glacis	17 mm Top 17 + 17 mm Bottom	17 mm (61°) Top 17 mm Bottom	10 mm
Turret	17 mm (9°) Turret front 25 mm (10°) Gun mantlet	15 mm (10-12°)	15 mm (11°)	10 mm
Cupola	15 mm	15 mm	15 mm	10 mm

Notes:

• Suspension wheels and tracks are both 15 mm thick.

Mobility

Speedforward / back

AB30 / 5 km/h

RB and SB27 / 4 km/h

Number of gears4 forward

1 back

Weight11.1 t

Engine power

AB225 hp

RB and SB118 hp

Power-to-weight ratio

AB20.3 hp/t

RB and SB10.6 hp/t

Game Mode	Max Speed (km/h)		Weight (tons)	Engine power (horsepower)		Power-to-weight ratio (hp/ton)
	Forward	Reverse		Stock	Upgraded	Stock	Upgraded
Arcade	30	5	11.1	183	225	16.49	20.27
Realistic	27	4		104	118	9.37	10.63

Much like the armour, the I-Go Ko leaves something to be desired in the mobility department. While the tank is reasonably mobile in close-quarters situations due to the good acceleration, the poor top speed will result in long trips across large maps and between capture points compared to other reserve tanks.

Modifications and economy

Repair cost

ABfree

RBfree

SBfree

Total cost of modifications3 620

167

Talisman cost190

Crew trainingfree

Experts1 000

Aces10

Research Aces80 000

Reward for battleAB / RB / SB

10 / 10 / 10 %

100 / 100 / 100 %

Modifications

Mobility	Protection	Firepower
Tracks Research: 440 Cost: 19 45 Suspension Brake System Research: 380 Cost: 17 35 Filters Transmission Engine Research: 720 Cost: 35 70	Improved Parts Improved FPE Crew Replenishment	Horizontal Drive Research: 440 Cost: 19 45 Adjustment of Fire Research: 380 Cost: 17 35 Elevation Mechanism Research: 540 Cost: 25 55 Artillery Support Research: 720 Cost: 35 70

Armaments

Main armament

57 mm Type 90 cannon

Shoulder stabilizer

Reduces the swing of the gun in one plane while moving

Ammunition100 rounds

Reloadbasic crew → aces

4.3 → 3.3 s

Vertical guidance-15° / 20°

57 mm Type 90					Turret rotation speed (°/s)					Reloading rate (seconds)
Mode	Capacity	Vertical	Horizontal	Stabilizer	Stock	Upgraded	Full	Expert	Aced	Stock	Full	Expert	Aced
Arcade	100	-15°/+20°	±180°	Vertical	14.47	20.03	24.32	26.90	28.61	4.29	3.80	3.50	3.30
Realistic					9.04	10.64	12.92	14.30	15.20

Ammunition

Penetration statistics
Ammunition	Type of warhead	Penetration @ 0° Angle of Attack (mm)
		10 m	100 m	500 m	1,000 m	1,500 m	2,000 m
Type 92 APHE	APHE	21	21	19	16	14	13
Type 3 HEAT	HEAT	55	55	55	55	55	55

Shell details
Ammunition	Type of warhead	Velocity (m/s)	Projectile mass (kg)	Fuse delay (m)	Fuse sensitivity (mm)	Explosive mass (TNT equivalent) (g)	Ricochet
							0%	50%	100%
Type 92 APHE	APHE	349	2.58	1.2	9	103	47°	60°	65°
Type 3 HEAT	HEAT	380	1.8	0.05	0.1	303.36	62°	69°	73°

Ammo racks

Ammo racks of the I-Go Ko

Full ammo	1st rack empty	2nd rack empty	3rd rack empty	4th rack empty	5th rack empty	Visual discrepancy
100	97 (+3)	61 (+39)	49 (+51)	13 (+87)	1 (+99)	No

Notes:

• Racks disappear after you've fired all shells in the rack.
• To minimize rack detonation, it is recommended to empty all the way to the 3rd rack with 49 (+51) shells.

Machine guns

6.5 mm Type 91 machine gun (coaxial)

Ammunition3 000 rounds

Belt capacity30 rounds

Reloadbasic crew → aces

3.9 → 3.0 s

Fire rate499 shots/min

The Type 91 machine gun is mounted in the hull with limited traverse. With a limited magazine capacity, slow traverse speed, and small calibre, this machine gun usually doesn't serve much use in combat except as a tool against open-topped SPAA or tank destroyers, or to ping enemies on the map for teammates to see. As is common with many Japanese tanks, the turret is not fitted with a forward facing coaxial machine gun, so this machine gun is the I-Go Ko's only other weapon option if the main gun is incapacitated.

6.5 mm Type 91
Mount	Capacity (Belt)	Fire rate	Vertical	Horizontal
Hull	3,000 (30)	499	±22°	±25°

Usage in battles

The Type 89b I-Go Ko, despite its rather tractor-esque look, is a mobile tank that could use its speed to get to an enemy's flanks and cause some serious damage. The 57 mm cannon is unfortunately rather pitiful even in Rank I, with a penetration value of between 20 to 30 mm with APHE at standard combat ranges. Therefore, it is usually best to catch enemies unaware and go for flanking shots against their weaker side armour by driving around, instead of directly toward them. The 57 mm low-velocity shell does have an advantage of a rather prominent parabolic trajectory so it is possible to lob shells over hills to hit unsuspecting enemies behind it.

The gun's poor penetration will change when using the High Explosive Anti-Tank (HEAT) shell. This shell has 55 mm of penetration at any range but still has considerable drop-off due to the low velocity of the gun. It's a good enough anti-everything shell that can penetrate most targets you will meet, especially those pesky French tanks, which tend to be quite well armoured. The Type 3 HEAT shell, fortunately, has just enough penetration to get through them, although it is generally recommended to try to aim for weak spots and be prepared for the shell to not penetrate. This shell will also most likely destroy any truck or open-topped vehicle with a good hit.

Specific enemies worth noting:

Pretty much everything is a threat to this vehicle due to its mediocre mobility and poor armour. Fast vehicles like the M2A4, BT-5, A13 Mk I, and AMD.35 in particular are a difficult encounter; the I-Go Ko is reasonably fast at close quarters, but not that fast. The tank's sluggish turret traverse makes tracking a close target difficult and at long range the slow shells are difficult to aim precisely at a moving target. The 45 mm 20-K gun that the commonly encountered BT series have can easily destroy you at any range with a well-aimed shot.

Vehicles with autocanons and heavy machine guns like the M2A2, GAZ-AAA (DShK), Pz.II C, and T-60, are the I-Go Ko's worst nightmare. Their high volume of fire and good mobility coupled with the I-Go Ko's lack of a coaxial or pintle-mounted MG puts the I-Go Ko at a large disadvantage. SPAAs generally should be considered by the I-Go Ko to be just as deadly, if not more so, than conventional tanks.

One more vehicle type to worry about is aircraft. Due to the tank's roof being thin, aircraft with anything more than a heavy machine gun will be able to penetrate the I-Go Ko. Some examples of these include the 12.7 mm-armed P-26A-34 M2 and F3F-2, and the 20 mm-armed He 112 A-0 and D.500.

Pros and cons

Pros:

• Decent forward speed and good acceleration
• Parabolic trajectory lets you lob 57 mm rounds over hills
• APHE has a huge amount of explosive mass, especially for the calibre
• Type 3 HEAT shell has good damage output and can go through most tanks rather easily
• Great gun depression
• Shoulder-stabilized main gun which allows for stable shots at low speeds

Cons:

• Very poor armour layout
• APHE shell struggles to penetrate many of the tanks it will face, even from the sides
• Slow turret and hull traverse speed
• Tall for a Rank I tank
• No coaxial machine gun in the turret, the bow machine gun only fires forwards in a limited arc
• Tight crew spacing, which can result in the I-Go Ko being knocked out in one shot

History

Development

Japan's early pioneering into the concept of armoured warfare began as early as October 1918 during the first World War. They were able to acquire a few tank samples from the European governments, ranging from a British Mark IV tank, Medium A Whippet tanks, and Renault FT tanks. These tanks would make up Japan's first tank units in 1925. Their experiences with these tanks led to the eventual development of their own domestic tank design. The requirement for this new tank was given to the 4th Military Laboratory under the Imperial Japanese Army's jurisdiction and was mainly in charge of land vehicle development. In the summer of 1926, the first prototype was completed with the design of three turrets, one main in the middle and two smaller ones in the front and rear. The design was deemed too heavy at 18 tons and so development restarted, the initial design carrying on in the failed Type 91 and 95 tanks. During this time, a trial with a British Vickers Model C tank had the tank's gasoline engine catch fire. This prompted the Japanese to fit their tanks with a diesel engine instead. The development led to a new design in 1929, titled Type 89 I-Go. Though it is considered to be a light tank, the designation changed to a medium tank due to its weight of 10 tons.

The Type 89's construction was assigned to Sagami Arsenal, but it was subcontracted to private firms due to Sagami's lack in industry. One of the firms was Mitsubishi Heavy Industries, which developed a tank plant specifically for the Type 89. The Type 89 production officially started in 1931, with mass-production in 1933 and continued until 1939 with 404 tanks built.

Front 3/4 view of an Imperial Japanese Army Type 89a I-Go Ko.

Design

The Type 89 I-Go was Japan's first domestic tank design, yet it showed a lot of features that were revolutionary and would become a trademark of the Japanese tank designs. The Type 89 I-Go had a four-man crew in the tank with two in the turret. The turret held a 57 mm low-velocity gun meant for fighting fortifications due to the tank's role as infantry support. A peculiar feature on the Type 89 was the rear machine gun on the back of the turret. This machine gun was meant to enable the Type 89 to engage forward targets with a machine gun or its 57 mm gun and would be a design trend in future tank development.

The Type 89 design changed gradually over time due to troop experience and advances in technology. For example, a small change that occurred for the Type 89 was the change of the commander's cupola from a "top hat" or "lid" design to a split hatch design. A noticeable change was in the engine when the first models produced off the lines were powered by a 118hp gasoline engine, these tanks were labelled as Type 89A I-Go Ko. It wasn't until 1934 when a change to 120hp Mitsubishi diesel engine was made that the Type 89 was redesignated the Type 89B I-Go Otsu. This diesel engine made the Type 89 the first mass-produced tank that uses diesel as its fuel.

The Type 89 does carry its few flaws, however. The tank was quite slow at about 25 km/h (16 mph), a hindrance to mobile operations using motorized infantry that must wait for the tanks to reach the combat zone. The armour was quite thin at 17 mm and the 57 mm's anti-tank power was quite abyssal. However, against the Chinese troops from 1932 onwards, the armour and firepower flaws were small worries due to the lack of available tanks and anti-tank defences on the Chinese side.

Combat usage

The Type 89 was first used in 1932 in the 1st Special Tank Company after the Manchurian Incident. The company, armed with Type 89 along with Renault FT and NC tanks, took part in the conflict between China and Japan in the Shanghai Incident. The experience showed that the Type 89 performed well in comparison to the Renaults and soon the entire company was fitted with Type 89s, retiring the Renaults.

The mass production of the Type 89 from 1933 onwards allowed the formation of large tank groups in Japan, leading to the 1st and 3rd Tank Regiment in Kurume, Fukuoka with the 2nd Tank Regiment at Chiba Tank School. The 1st Tank Regiment would be deployed with the Kwantung Army in China, where it would carry the Type 89 tank in the conflict against China from 1937 onwards.

By 1939, the Type 89 was starting to be succeeded by newer Japanese tanks, but they still served on the frontlines such as the border conflicts between Japan and the Soviet Union. In the Battle of Khalkhin Gol, the IJA's 1st Tank Corps attacked the Soviet 11th Tank and 7th Armoured brigades in July with a mixture of Type 89s, Type 97 mediums, Type 95 lights, and tankettes in the 3rd and 4th Tank Regiments. Though the attack stirred up Soviet lines, there was no breakthrough in Soviet lines. The Soviets, armed with T-26 and BT light tanks, would soon push the Japanese back to Manchuria and have a cease-fire signed on 24 August.

Though the Type 89 was mostly withdrawn from service and replaced with the Ha-Go and Chi-Ha, the I-Go still served as far into the battles for the Philippines, Malaya and Burma. Some tanks saw further use as static pillboxes in the Japanese islands of the Pacific, but these tanks were vulnerable to newer anti-tank and tank technology of the Americans with their bazookas and M4 Shermans once they started their island-hopping strategy against Imperial Japan.

Even after World War II, some Type 89s were still seen in service of the French during the First Indochina War, using the captured Japanese armour in a unit known as 'Commando Blindé du Cambodge'.

Surviving Tanks

Restored Type 89b I-Go Otsu at Tsuchira tank museum open day.

Many Type 89 relics still are visible in the wild usually reduced to a wreck with a handful of tanks still being in a good condition. These in good condition are located in:

• The Ordnance Training Support Facility, Ft. Lee, VA, USA.
• The Japanese Ground Self-Defense Force base at Tsuchiura, Ibaraki, Japan.
• Sinbudai Old Weapon Museum, Camp Asaka, Japan
• Villa Escudero, Tiaong, Quezon Province, Philippines

Only 1 I-Go Otsu remains in running condition, which was restored at the JGSDF base at Tsuchiura together with the last Type 3 Chi-Nu to still exist. Both are stored on military ground so aren't at all times in public display. The I-Go Otsu usually makes an appearance during the open day of the Tsuchiura base. The vehicle can be seen in media still running after being restored by the JGSDF.

Media

Skins

• Skins and camouflages for the I-Go Ko from live.warthunder.com.

Images

• 

  Type 3 Chi-Nu & Type 89 I-Go on display, The first and last Japanese Army production medium tank.

• 

  Type 89 I-Go assaulting on White Rock Fortress.

Videos

TOP 5 Reserve Tanks discusses the I-Go Ko at 2:23 - War Thunder Official Channel

Type 89 medium tank - Imperial Japanese Army Armored Forces Exercise - September 1941 - kinsei1560

Type 89 tank Imperial Japanese Army - MrHofner5001

See also

Equipment of the same adoption year

• Type 89 (Disambiguation)

External links

• [Devblog] Type 89 I-Go Ko: First Series
• [Wikipedia] Type 89 I-Go medium tank
• [Tank Encyclopedia] Type 89 I-Go
• [Military Factory] Type 89 Chi-Ro

References

Mitsubishi Heavy Industries (三菱重工業株式会社)
Light Tanks
Type 95	Ha-Go · Ha-Go Commander
Medium Tanks
Type 89	I-Go Ko
Type 97	Chi-Ha · Chi-Ha Kai
Type 1	Chi-He · Chi-He (5th Regiment)
Type 3	Chi-Nu · Chi-Nu II
Type 4	Chi-To · Chi-To Late
Type 5	Chi-Ri II
SPGs
Chi-Ha Derived	Ho-Ro
Chi-He Derived	Ho-I
Chi-Ri Derived	Ho-Ri Prototype · Ho-Ri Production
Other	Na-To · Ro-Go Exp.
Captured	␗Chi-Ha · ␗Chi-Ha Kai
Note	Most tank designs would be contracted by the Army Technical Bureau to Mitsubishi
See also	Mitsubishi Heavy Industries Ltd. (Post-War)

Japan light tanks
Type 89	I-Go Ko
Type 95	Ha-Go · Ha-Go Commander
Type 98	Ke-Ni
Other	Ka-Mi
IFV	Type 89
RCV	Type 87 RCV (P) · Type 87 RCV · RCV (P)
MCV	Type 16 (P) · Type 16 (FPS) · Type 16
USA	▅M24 · ▅M41A1