Type 89 Medium Tank "Yi-Go"

Model Ko (A)

Introduced Year : 1929

Weight : 11.8 ton

Dimensions: 5.75 x 2.18 x 2.56(h) m

Armor (max) : 17 mm

Speed (max) : 25 km/hr

Engine : Gasoline Engine 118 HP/1800 rpm

Armaments : Type 90 57 mm x 1, Type 91 6.5 mm x 2

Crew : 4

Production Qty : 278

Model Otsu (B)

Introduced Year : 1935

Weight : 12.1 ton

Dimensions: 5.75 x 2.18 x 2.56(h) m

Armor (max) : 17 mm

Speed (max) : 25 km/hr

Engine : Diesel Engine 120 HP/1800 rpm

Armaments : Type 90 57 mm x 1, Type 91 6.5 mm x 2

Crew : 4

Production Qty : 126

Type 89 was used for infantry support mainly in China before WWII, but some were also used in the Philippines and Burma during WWII.

Model Ko and Otsu

The distinction of model Ko and Otsu is based on the engine type. IJA called Type 89 with gasoline engine as Ko and Type 89 with diesel engine as Otsu. But, engine type cannot be distinguished from outside. So far, Type 89 on the above photo has been regarded as model Otsu. However, according to recent study, this type of Type 89 had a gasoline engine. So, it is not Otsu, but Ko. The true Type 89 Otsu is one which is displayed at Tsuchiura JGSDF Ordnance School Museum. They are different in the following points.

1) fuel tank caps on sponsons
2) a cover of engine intake
3) grills on the engine deck
4) rear fenders

Compare Tuchiura Type 89 with one at Aberdeen below.

Now, Type 89 is classified as follows in Japan.

Type 89 Ko
- Prototype
- Early version
- Transitional version
- Late version
Type 89 Otsu

Type 89 at the top of this page and one at Aberdeen are the late version of Type 89 Ko.

Type 89 Otsu is not found in China or Pacific. It is believed that Type 89 Otsu was deployed only in Manchuria and Japan homeland. The battle of Nomonhan will be only example that Type 89 Otsu was used in combat.

Early version of Type 89 Ko

Transitional version of Type 89 Ko