Japanese Medium Tanks of WWII And All Their Derivatives

[dy031101]

I found something that sounded like an old news here.

Regardless those kits (though I'm sure they'd attract interest), a Type 3 Kai, Chi-Nu with the long-barrel 75mm gun turret from Type 4 Chi-To, was mentioned.

Another derivative of the Type 97 Chi-Ha I'm not really clear about: Type 2 Gun Tank Ho-I.  Model kits depicting both that built on the Type 97 Chi-Ha and that built on the derivative (and newer; I'm under the impression that it's a bit larger, too) Type 1 Chi-He (scroll down the webpage for about 1/4 length) exist.  I started with reading Wikipedia (for a lack of better resource immediately reachable) entries, and the English version states both the initial plan and the production vehicles were built on the Chi-Ha whereas the Japanese version of the story states that while the Chi-Ha was used as the basis of a preceeding prototype, it (that prototype, called the Experimental Type 1 Gun Tank in the article) was found to be less than satisfactory.

Two sets of questions:

• I don't know if this Type 3 Kai really existed at least in paper project form...... did it?
• Which chassis did the production Type 2 Gun Tanks use?  If they were indeed built on Chi-Ha, does it mean the choice of chassis was fundamentally a non-issue, or the Japanese were merely forced to accept the problems associated with utilizing Chi-Ha chassis?

[raafif]

a Type 3 Kai, Chi-Nu with the long-barrel 75mm gun turret from Type 4 Chi-To ...

Don't think that was possible as the Chi-To turret ring is much bigger (vehicle is 9.4ft wide vs 7.66ft).
Only 6 Chi-Tos were built, gun was a long-barrelled development of an AA gun.
Standard CHi-Nu gun was a licence-built 75mm French Schneider (WW1?).

Type 2 Gun Tank Ho-I ...

Type 1 Chi-He 47mm gun (1941) & Type 2 HO-I 75mm gun (1942) Tanks were on Chi-Ha chassis but were very slightly longer -- looking at photos this must all be in the tail (hull, not chassis) as they had a larger engine of 240hp (up from 170hp).  Not many HO-I tanks were built suggesting that 75mm gun wasn't much good.

The Chi-Ha (15tons) chassis had lots of development life as the longer, wider & much heavier Chi-To (30tons) & Chi-Ri (37tons) show.

[dy031101]

Don't think that was possible as the Chi-To turret ring is much bigger (vehicle is 9.4ft wide vs 7.66ft).
Only 6 Chi-Tos were built, gun was a long-barrelled development of an AA gun.
Standard CHi-Nu gun was a licence-built 75mm French Schneider (WW1?).

I wouldn't imagine any Chi-To turret would have been actually trial-fitted onto a Chi-Nu hull, either, given the very slow pace of the Chi-To project itself...... unless maybe they plucked one from the prototype......?

Type 1 Chi-He 47mm gun (1941) & Type 2 HO-I 75mm gun (1942) Tanks were on Chi-Ha chassis but were very slightly longer -- looking at photos this must all be in the tail (hull, not chassis) as they had a larger engine of 240hp (up from 170hp).  Not many HO-I tanks were built suggesting that 75mm gun wasn't much good.

So I take it that means the Wikipedia is wrong to claim the production vehicles as built in Chi-Ha, and that they were built on the slightly larger Chi-He is the correct notion?

My understanding is that attempt to mass-produce Ho-I started just in time for B-29s launched from Marianas Islands to mess it up, but then again WWII HEAT ammunitions, which constitute the mean for Ho-I's low-velocity howitzer to work in an anti-tank role, are said to be plagued with erratic performance as well.

[dy031101]

One probably needs forum membership to see the pics contained in there <<CLICKY>>, so in the meantime I'll summarize:

1. The Japanese were said in there to actually plan to arm the Chi-Ri with a rapid-firing high velocity 75mm gun...... with a belt-fed mechanism!  This is said to be the reason why the initial turret on the Chi-Ri is so big.  Although it proved too ambitious, a much-simpler autoloader design was still to be fitted to the mass-production Chi-Ri II (smaller turret, shorter chassis with seven pairs of road wheels per side, and no hull-mounted 37mm...... which would then have been pretty close to Chi-To, a possible reason of it not outright described as Chi-To being that it probably would have kept the 550hp engine).  It is in fact claimed that the Type 5 75mm gun with its autoloader can be modified to upgun the earlier Chi-Nu.

2. Turret ring sizes of Chi-Nu and Chi-Ri are 1.75m and 2m, respectively.

3. A 57mm high-velocity anti-tank gun (muzzle velocity of AP shot: 800~900m/s, depend on subvariant) was planned for evolution of Type 1 Ho-Ni I and Type 2 Ho-I guntanks.

EDIT: I just found out that I don't need to log into that forum to view the drawing, so...... click away and see!

[rickshaw]

They may have planned to but as the Great Bard once alluded, "there's many a slip betwixt cup and lip!"   Japanese plans by 1944 were pretty disconnected from reality.   Japanese industry was very hard pressed by 1945 to build very much at all in any large numbers, particularly something as complex as an autoloading tank gun.  Not even the Western Allies managed that (American plans to arm their tanks with autoloaded guns foundered on the complexity and unreliability of such equipment and the British who did manage quite well to build autoloaded guns up to 57mm in calibre decided going that one step further, deciding it wasn't really worth the effort).

[dy031101]

They may have planned to but as the Great Bard once alluded, "there's many a slip betwixt cup and lip!"   Japanese plans by 1944 were pretty disconnected from reality.   Japanese industry was very hard pressed by 1945 to build very much at all in any large numbers, particularly something as complex as an autoloading tank gun.

Guess I forgot to put the disclaimers up front. 

[NARSES2]

Very interesting - many thanks