Type 4 Chi-To (upcoming tier 6 medium tank)

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Author: Soukoudragon

Chi To photo

Development history

Japan expected that a new generation of tanks capable of tank engagements would be needed later in the war. In 1942, three medium tank classes were initiated. A 47mm cannon class, a 57mm cannon class, and a 75mm cannon class. These three classes were called Kou, Otsu, Hei respectively (something like A, B, C). It was soon considered that the 47mm cannon class medium would be obsolete before completion thus it was upgraded to a 57mm cannon class tank. The other 57mm cannon class medium merged with the 75mm cannon class tank. Thus these two, the 57mm cannon class tank and the 75mm cannon class tank, were respectively the Chi-To and the Chi-Ri tanks.

In the beginning plans were for a 20 ton tank with 50mm of armor with new features like an electrically driven turret. By February 1943, plans changed to 75mm armor, the 57mm cannon and top speed of 45kph.

For a bigger tank, a new engine started development by Mitsubishi and AL in 1943. The result was a air-cooled diesel 412 horsepower at 1800 rpm.

Multiple types of suspensions were examined such as the staggered road wheel layout from Germany (Chidori) and torsion bars. but the Japanese settled with what they were familiar with, the coil springs.

The 57mm cannon prototype was completed in March 1944. It completed testing and was officially named the Chi-To in May 1944.

57mm Chi-To prototype below.

Chi To 57mm 0003small

In the very same month, the Chi-To received the requirement to mount a high velocity 75mm cannon. The cannon would come for the Chi-Ri tank program. The single tray loader would be removed and the cannon was named the “model 2″ and was used for the Chi-To. There were delays in getting the new cannon on which eventually happened in early February 1945. A new turret and hull was designed and planned to enter production beginning in August 1945 (the “production version”). Plans were written up to create 170 Chi-To tanks by the end on 1945

Armor

Turret front: 75
Turret side: 50/35
Turret rear: 35

Hull front: 75
Hull side: 35/25
Hull rear: 35

Source:

日本の戦車 Japanese Tanks Hara 1978
グランドパワー Ground Power October 2012

Daigensui’s additional data on Chi-To:

Penetration Data/Expectation of Tank Guns Used in Service

75 mm Gun Type 3
Shell Weight: 6.615 kg
Muzzle Velocity: 668 m/s
Kinetic Energy: 1476 kj
Historical Pen: 90 mm (100 meters), 65 mm (1,000 meters)
Expected Pen: 103 mm

75 mm Gun Type 5
Shell Weight: 6.615 kg
Muzzle Velocity: 821 m/s
Kinetic Energy: 2229 kj
Historical Pen: 75 mm (1,000 meters) goal (met), 80 mm (1,000 meters) expected
Expected Pen: 130 mm + (137 mm possible)

Prototype Chi-To’s effective frontal armor is like this:
Upper frontal plate: 90 mm
Lower frontal plate: 80 mm

Production Chi-To’s effective frontal armor is like this:
Upper frontal plate: 106 mm
Lower frontal plate: 80 mm

Prototype on the left, production version on the right

Chi To proto and produc

Production schematics of Chi-To:

Chi To production0004

Chi-To prototype:

Chi To 00003

Chi To0044

37 thoughts on “Type 4 Chi-To (upcoming tier 6 medium tank)”

          • well i’m marine engineer so i have “some” knowledge but i never seen any solution of air cooled Diesel. it’s just very weird for me. u say that over 2500 RPM we have problems ? cool tell me about it in slow speed 2 strone Diesles

            • You should consider that almost all japanese tanks uses air-cooled diesels, so it obviosuly works. But yes, their lack of power is one of the reasons that japanese tanks are so lightly armored.

            • Well i admit my knowledge of Japanese tanks engines is very low that’s why i started it cuz it was confusing

            • i’d rather say it’s because they have minimum 80 Bara = 8000kPa pressure on each cylinder and power range starts from round 300kW and ends at 96000kW

          • Air cooled systems are more robust as they use a ready supply of working fluid, air. A leaking hose or a puncture in the system of liquid cooling system means the engine is going to die if run much longer. All you need in a air cooled system is multiple fans or a fan driven directly from the engine.

          • Those aren’t exactly extraordinary pressures there, and 96k kW beats the current record by circa 19.8k hp (14.8k kW).

            • that record of 96kkW is already 5 or 6 years old and i belive the old record was also set by Sulzer Wartsila

  2. for all those interested and not so scared of slightly older games.

    battlefield 1942 has a mod called “forgottenhope secret weapons” that mod is more or less realistic and features alot of the upcoming japanese vehicles. ofc you can also find other nice things like gasturbine powered jagdtigers going 50kph or haunebu UFOs but its realistic and really fun to play most of the time. it also seems like they were heavily influenced by WOT in the last years (i know, the latest news are quite old as well now :( )

    but still, no other game gave you the chance to try Chi-Nu against an american invasion :)

    • Do you see any definitive ingame values published anywhere ? Also they have to extrapolate from the pen values given at 1000m to what would it be like in WoT terms (100m).

  5. I like this one. It has such a definitive tank shape. I also like my T34/85 but I’d love a med with better depression, and this one also has good looks. Very business like.

    I guess the initial weight limit of 20t changed with 50% additional armor, so … how heavy did it get in the end ? 30-35t ?
    With 420hp, 30t is still acceptable. I’ll definitely try the jap med line.