DIY Tank Thread

[dy031101]

Previously there's a DIY tank topic in the Panzer IV thread, seeking to recycle Panzer III and IV components to build into a new battle-worthy tank......

This, coupled with Arc3371's SYS tank  idea, brought back memories of an old computer game depicted in the enclosed picture.



The game, which is centred upon a spiced-up version of the 2nd Sino-Japan War, has the ROCA side given a heavy tank that's like a Tiger turret mounted on a different, low-profile hull.

Then I began to harbour this idea for modelling in 3DS Max- a DIY heavy tank or tank destroyer with enclosed turret for a country (WWII China) that, IIRC, managed just as far as building/converting truck chassis into armoured cars during WWII?

90mm gun, the intended armament, would probably still have to be imported.

Figured that it better have been easy to build and maintain, and I want to base its external appearance on that computer game screenshot- the turret of that heavy tank is placed rather to the rear, leading me to become inclined to think that the engine might be placed in front like many self-propelled artilleries or the modern time Merkava tank...... nevertheless, would the conventional layout as established by the French FT-17 still have been taken in pursue of a really simple tank, or would the engine-in-front layout actually have been better?

Would the suspension likely to have been based on that used by tanks already in service (in case of the ROCA, leaf spring suspension used by T-26 and Panzer I), or is there a suspension that is easier to master/build/maintain?  Would suspension be a factor affecting the hull height, or would having the sprockets closer to the engine be enough to keep the hull low-profile?  What other vehicles can I look at for reference and inspirations?

Thanks every much in advance.

[B777LR]

The heavy tiger-like tank shown might be a Chi-Ri, which was planned to mount an 88mm

[dy031101]

The heavy tiger-like tank shown might be a Chi-Ri, which was planned to mount an 88mm

Chi-Ri is a Japanese tank though.  Units depicted in that picture are supposed to be purchaseable by the ROCA side.

==========================

To give me something to start with next year after S-67 and SYS tank, I modded a Tiger I turret with a gun barrel I made for the WWII-era SYS tank.  For the story behind it...... say, the gun came from a trashed M36 tank destroyer and didn't have a muzzle brake, so one patterned off Tiger tank captured by the European Allies was fitted.

Should I slope the armour a bit to save weight?

[dy031101]

Would it be possible for this DIY tank to, like Canadian Ram and Australian Sentinel projects, use imported M3 Lee/Grant and later M4 Sherman parts for suspension- except that rather than having just three suspension arms each side, this one would have four?  (Either that with eight road wheels per side or a scaled-up leaf spring suspension with six larger road wheels, but part of my idea behind the DIY tank is to bring 90mm guns onto the battlefield as quickly as possible, so maybe imported parts would save some time......)

The VVS and HVS suspensions wouldn't contribute to a tank's high silhouette, would they?  I'm hoping that front-engine/front-sprocket drive would be sufficient to keep the hull height down.

[dy031101]

rickshaw opened this thread that got me so intrigued, too, that I want to see if it is potentially suitable to the topic as well.

Based on the wording, I got the impression that Col. (Ret.) Icks wasn't necessarily talking about steam turbines.  I suppose alternatively I can have multiple of, for example, truck engines combined...... although such details likely won't be visible from the outside and would be more applicable for backstory purposes.

I wonder if I should look at WWII Italian tanks for inspirations on how a tank was put together with low-tech techniques- even their most potent design had riveted hulls- because I don't know where on the Simple v.s. Sophisticated scale their suspensions would occupy.

[rickshaw]

Would it be possible for this DIY tank to, like Canadian Ram and Australian Sentinel projects, use imported M3 Lee/Grant and later M4 Sherman parts for suspension- except that rather than having just three suspension arms each side, this one would have four?  (Either that with eight road wheels per side or a scaled-up leaf spring suspension with six larger road wheels, but part of my idea behind the DIY tank is to bring 90mm guns onto the battlefield as quickly as possible, so maybe imported parts would save some time......)

The VVS and HVS suspensions wouldn't contribute to a tank's high silhouette, would they?  I'm hoping that front-engine/front-sprocket drive would be sufficient to keep the hull height down.

The determinant of height in the US M3 and M4 mediums was a combination of a (originally) a radial aero engine for power and the use of front wheel drive.  The drive shaft running through the hull determined how deep the turret could be (in the M4).   IF the US military had been willing to accept the radial aero engine mounted horizontally and a right-angled transfer case, the drive shaft could have been much closer the hull bottom and that would have lowered the hull significantly and hence the turret in turn.  In themselves, the VVS and HVVS aren't necessarily all that tall.  One only has to look at the Sentinel's use of VVS in the French styled suspension units to see that.

[dy031101]

Thanks for the input, rickshaw.

Would it be possible for this DIY tank to, like Canadian Ram and Australian Sentinel projects, use imported M3 Lee/Grant and later M4 Sherman parts for suspension- except that rather than having just three suspension arms each side, this one would have four?

Answering my own question again, simply employing four pairs of existing M3/M4 suspension units will very likely make the DIY tank longer than even the M103 heavy tank at more than 700cm without a gun overhang...... (Guess adding road wheels is really something that should be attempted only on torsion bar or Christie suspensions......  )

Looks like this idea is going to evolve into a mostly if not entirely newly-built, steam-powered (intake fans on the engine deck) T25 with a Tiger-I-look-alike turret......

[Jacques Deguerre]

What I've always found interesting about the high silhouette of the Sherman is that the US later designed both the M18 Hellcat TD and the M24 Chaffee with rear-mounted engines and front-mounted transmissions and both were lower than the Sherman. And true, while the M24 used a pair of commercial GM car engines, the M18 used a 9 cylinder radial. Of course, unlike the Sherman, the transmission in the M18 was almost floor to ceiling but it does demonstrate that the problems with engine and drive shaft height are not insurmountable in a "front drive" tank.

This is something I've been battling with in my "neo-retro" medium tank project. A Sherman chassis with HVSS is a major part of the design but a lower hull is a must. A front mounted transmission would allow for a (theoretically) easier build but a rear mount probably makes more sense design-wise.
Now would a really good time for one of the plastic kit manufacturers to announce a series of kits based on the "other" vehicles in the the T-20 family (aside from the Pershing).

[rickshaw]

What I've always found interesting about the high silhouette of the Sherman is that the US later designed both the M18 Hellcat TD and the M24 Chaffee with rear-mounted engines and front-mounted transmissions and both were lower than the Sherman. And true, while the M24 used a pair of commercial GM car engines, the M18 used a 9 cylinder radial. Of course, unlike the Sherman, the transmission in the M18 was almost floor to ceiling but it does demonstrate that the problems with engine and drive shaft height are not insurmountable in a "front drive" tank.

Of course they aren't. If they'd been prepared to wait, no doubt other solutions would have been presented in it's stead.  Because they went with the simplest and one which was really originally designed for the M2 Medium and which had then been used in the M3 and finally the M4, they were stuck with what they had.   Its interesting that even when alternative powerplants were used it was deemed easiest to stick with the existing high hull and drive train than go for a redesigned, lower one.  They could IMHO have taken about 2 feet off the height of a Sherman if they'd wanted to.

Also remember, the M18 started out as a very different vehicle to what it ended up as!

This is something I've been battling with in my "neo-retro" medium tank project. A Sherman chassis with HVSS is a major part of the design but a lower hull is a must. A front mounted transmission would allow for a (theoretically) easier build but a rear mount probably makes more sense design-wise.
Now would a really good time for one of the plastic kit manufacturers to announce a series of kits based on the "other" vehicles in the the T-20 family (aside from the Pershing).

Easy enough to make.  Just take an M26 and splice in extra track sections until you get the required number of road wheels. 

[Jacques Deguerre]

The M26/46/47 style lower hull was a consideration early on but the T-23 hull would be better for what I have in mind because of its square cross section. The later hull uses the "flattened V" shape which makes mounting the HVSS more challenging at the least.

Besides, the T-23 done as an injection molded kit in 1/35 opens up all kinds of Whiffing possibilities!