WWI Era Armor - Real and WHIF

[rickshaw]

I've been kinda meaning to ask about this ever since the asthetics of Command & Conquer series computer games stirred up the ideas.

For a country that needed an indigenous tank design but had no experience building or maintaining anything other than tractors or obsolete tanks (as in the likes of FT-17 and tankettes, if taking a WWII point of view), would it have been possible to merge, say, two chassis of such vehicles in tandem to support a hull that can accommodate a bigger turret (and, by extension, weapons)?

Question: How are you going to drive or synchronize the drive of two separate track-laying systems?

Perhaps the same way the 4x4 Mini-Moke which Leyland produced for trials for the Australian Army in the late 1960s?  The original Mini-Moke was front-engined and front-wheeled, two wheel drive.  Leyland simply cut two Mokes in half, welded them back together and reversed the gear box in the rear-engine.  It had two gear sticks which were linked together by a piece of steel and could be disconnected to run or idle the rear engine seperately, if necessary (such as on long road marches). Apparently the hare-brained scheme worked quite well but the Moke was simply too small and too low to really make it work properly as a military cross-country vehicle (although I have seen a bogged Moke literally lifted out of the mud by four diggers ). 

One of the main technical hurdles of tank design was creating a reliable transmission that could absorb and transfer the necessary engine power without destroying itself. Because of the mechanical realities combining more than one 'Chassis' (which most tanks don't actually have BTW) isn't really a simpler solution.

I see no more problem doing this than building a viable four or six wheel drive truck.  You have a transfer case and drive shafts to each set of tracks.  Works for trucks.  Would work for a light tank (emphasis on the word light!).

[dy031101]

Aahh , then you say the one below would never be made to work , even by the WW2 Germany  ?

Alright maybe you're right, but joncarrfarrelly is also right on his comment...... 

Would work for a light tank (emphasis on the word light!).

Although I previously said "tank", I think if and when I put it in 3D it'll be no more than a tank destroyer......  

Would I nevertheless have been able to concentrate the engine to the rear to make as much room for a fighting compartment and a turret of, say, an upgunned M18?

[rickshaw]

Aahh , then you say the one below would never be made to work , even by the WW2 Germany  ?

Alright maybe you're right, but joncarrfarrelly is also right on his comment...... 

Would work for a light tank (emphasis on the word light!).

Although I previously said "tank", I think if and when I put it in 3D it'll be no more than a tank destroyer......  

Would I nevertheless have been able to concentrate the engine to the rear to make as much room for a fighting compartment and a turret of, say, an upgunned M18?

Try something along the lines of the original 6 Pdr armed Firefly wheeled tank destroyer (with Molins auto-loader).  The 6 Pdr was a very effective gun until the end of the war, particularly once APDS was developed for it.  Unfortunately its much under-rated in the minds of most wargamers ("Bigger is better").

More than likely though, it would be easier to build it with a fixed gun and with the engine in the front compartment, the transfer case in the middle and the fighting compartment to the rear.  Rear fighting compartments offer all sorts of advantages in AFV design.  You can fit a bigger gun, a larger fighting compartment and have the engine offer improved protection.  The Germans worked that out with their Panzerjaeger such as the Marder III, the Nashorn, etc.

[jcf]

Question: How are you going to drive or synchronize the drive of two separate track-laying systems?

Perhaps the same way the 4x4 Mini-Moke which Leyland produced for trials for the Australian Army in the late 1960s?  The original Mini-Moke was front-engined and front-wheeled, two wheel drive.  Leyland simply cut two Mokes in half, welded them back together and reversed the gear box in the rear-engine.  It had two gear sticks which were linked together by a piece of steel and could be disconnected to run or idle the rear engine seperately, if necessary (such as on long road marches). Apparently the hare-brained scheme worked quite well but the Moke was simply too small and too low to really make it work properly as a military cross-country vehicle (although I have seen a bogged Moke literally lifted out of the mud by four diggers ). 

One of the main technical hurdles of tank design was creating a reliable transmission that could absorb and transfer the necessary engine power without destroying itself. Because of the mechanical realities combining more than one 'Chassis' (which most tanks don't actually have BTW) isn't really a simpler solution.

I see no more problem doing this than building a viable four or six wheel drive truck.  You have a transfer case and drive shafts to each set of tracks.  Works for trucks.  Would work for a light tank (emphasis on the word light!).

I'm well aware of the Twin-Moke, however one look at the power-train of an FT-17 or even a tankette shows how that 'simple' solution wouldn't work, or at least not for long or reliably. BTW from what I've read over the years the 'connected gear-changing' was a nightmare and they couldn't keep the engines synchronized (the truly critical requirement), the final solution was replacing the rear manual gearbox with an automatic, but it still wasn't very good. Prior to the advent of electronic controls, keeping two separate power-trains synchronized was problematic, at best.

Transfer cases were also one the most common failure points in armoured vehicle development, its that power transmission problem again. Also a tank is not a truck, and driving tracks is very different from driving wheels, the stresses and loads are not the same. Again you run into the problem of the tech and manufacturing level quoted in the original question and if the hypothetical country in question has the ability to manufacture robust transfers cases and the associated drive shafts, then there would be no need to cobble together old vehicles that one has on hand, they could just build something new.

Jon

[dy031101]

I was kinda thrown off (okay okay, maybe I didn't read the exchange of info hard enough); I'll read it harder again, but in the meantime...... would it be easier or harder to have the four sets of treads driven by one engine (either a more-powerful single type or a "coupled" type comprised of a few low-power ones geared together)?

(If I'm not mistaken from the exchange: is it where the transmission problem joncarrfarrelly brought up and for which rickshaw commented that the resultant vehicle still have to be light comes into play?)

Because of the mechanical realities combining more than one 'Chassis' (which most tanks don't actually have BTW) isn't really a simpler solution.

Do you mean...... even if I taking two FT-17s (or tankettes, or tractors, or whatever) worth of the tracks, road wheels, and suspension sets, I might as well really be mounting them on a new hull to begin with whether it's my original intention or not??

[rickshaw]

Question: How are you going to drive or synchronize the drive of two separate track-laying systems?

Perhaps the same way the 4x4 Mini-Moke which Leyland produced for trials for the Australian Army in the late 1960s?  The original Mini-Moke was front-engined and front-wheeled, two wheel drive.  Leyland simply cut two Mokes in half, welded them back together and reversed the gear box in the rear-engine.  It had two gear sticks which were linked together by a piece of steel and could be disconnected to run or idle the rear engine seperately, if necessary (such as on long road marches). Apparently the hare-brained scheme worked quite well but the Moke was simply too small and too low to really make it work properly as a military cross-country vehicle (although I have seen a bogged Moke literally lifted out of the mud by four diggers ). 

One of the main technical hurdles of tank design was creating a reliable transmission that could absorb and transfer the necessary engine power without destroying itself. Because of the mechanical realities combining more than one 'Chassis' (which most tanks don't actually have BTW) isn't really a simpler solution.

I see no more problem doing this than building a viable four or six wheel drive truck.  You have a transfer case and drive shafts to each set of tracks.  Works for trucks.  Would work for a light tank (emphasis on the word light!).

I'm well aware of the Twin-Moke, however one look at the power-train of an FT-17 or even a tankette shows how that 'simple' solution wouldn't work, or at least not for long or reliably. BTW from what I've read over the years the 'connected gear-changing' was a nightmare and they couldn't keep the engines synchronized (the truly critical requirement), the final solution was replacing the rear manual gearbox with an automatic, but it still wasn't very good. Prior to the advent of electronic controls, keeping two separate power-trains synchronized was problematic, at best.

The Russians put into production the T-70 light tank with two separate engines, one running each track.  Yes, they had problems, just as they did with the BTR-60 and BTR-70 with two separate engines.   The Australians used three truck engines running through a transfer case to power the Sentinel.  The UK used two separate bus engines for the early Mathilda. The US used two separate engines to run the LVT-4.  They also built the Chrysler Multi-Bank engine for the Sherman which used five engines.  These examples worked.  Some better than others.  It is not the optimum method but there are examples of where it was used and it worked.

Transfer cases were also one the most common failure points in armoured vehicle development, its that power transmission problem again. Also a tank is not a truck, and driving tracks is very different from driving wheels, the stresses and loads are not the same. Again you run into the problem of the tech and manufacturing level quoted in the original question and if the hypothetical country in question has the ability to manufacture robust transfers cases and the associated drive shafts, then there would be no need to cobble together old vehicles that one has on hand, they could just build something new.

Jon

Again, I agree it is sub-optimum.  However it has been done in the past and it has worked.   I purposefully suggested a light tank because I was well aware of the power train problems associated with heavy weights.  One of the reasons why its harder than with trucks to make them robust is the rolling friction problem that tracks have compared to wheels on hard surfaces.

One should be very careful about assuming that only an optimal solution will be suitable.  Necessity is the mother of invention and all that.  You make do with what you've got.

[tahsin]

Aahh , then you say the one below would never be made to work , even by the WW2 Germany  ?

Alright maybe you're right, but joncarrfarrelly is also right on his comment...... 

Would never doubt it , but the Internet sez lots about German WW2 engineering , right ? Not that I claim the UFOs but these guys had 60 cm mortars on tracks , and those tracks do look like ship lenght , what were they thinking on this one

How about many engines , many generators and one single fuse box that disperses electricity to many transmissions .Simple not but people might have lots of copper

[ysi_maniac]

Turreted Mark IV female

[NARSES2]

Now that's interesting 

There were some French heavy tank projects which looked quite similar although the turrets were farther forward.

[Dizzyfugu]

Indiana Jones prop...? 

[scooter]

Indiana Jones prop...? 

That was a Mark VIII, with a turret.  (And built around an excavator )

Turreted Mark IV female

That's got some serious deflection issues...and the driver and TC pillbox is gonna have some blast damage every time the main gun fires. 

[PR19_Kit]

That was a Mark VIII, with a turret.  (And built around an excavator )

Well, they needed something to dig them out of trouble. 

Yeah, yeah, I know. Hat, coat etc............

[Dizzyfugu]

I also wonder if a turret right above the engine (it was literally placed in the middle of the tank!) would be a good idea at all, and I doubt that there's be any space for it...? But it's whifworld, after all.  When there's one in an Indiana Jones movie, there's got to be something to it. 

[scooter]

Yeah, yeah, I know. Hat, coat etc............

Fedora & leather A2.  Don't forget the bullwhip and gas mask carrier. 

[PR19_Kit]

Yeah, yeah, I know. Hat, coat etc............

Fedora & leather A2.  Don't forget the bullwhip and gas mask carrier. 

I've got the fedora anyway, see my avatar. Can't afford the A2.