Curtiss Sherman Tank

A small WI, what if, on viewing the M2 Medium Tank, decide that it's too tall and so seek a lower engine for the M3 and M4, and end up with a slightly updated version of the 1923 Curtis D-12. How do the M3 Lee and M4 Sherman tanks do when powered by a V engine rather than a radial engine?
 
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The D-12 was designed by Arthur Nutt, with 1145 cid, 693 lb dry wt. Purchasing this engine to power the Fairey Fox caused Fairey to be blackballed by the British Air Ministry for any engine business. Rolls Royce was asked to copy the design philosophy to develop a British engine. This was done. The Fox was purchased in only small quantity until the Hawker Hart was ready with the Rolls Royce Kestrel.

D12028.jpg
 
*Twenty pounds or so heavier, around 40 hp more (compared to the first model used in the M4, if I've read correctly), and a lower profile (judging by the pictures). Sounds like a minor improvement in what were already decent tanks. Not much of a game-changer, truthfully.

EDIT (for clarity) : The D-12 is the slightly heavier, more powerful and lower engine compared to the radial first used in the M4.
 
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The D-12 was designed by Arthur Nutt, with 1145 cid, 693 lb dry wt. Purchasing this engine to power the Fairey Fox caused Fairey to be blackballed by the British Air Ministry for any engine business. Rolls Royce was asked to copy the design philosophy to develop a British engine. This was done. The Fox was purchased in only small quantity until the Hawker Hart was ready with the Rolls Royce Kestrel.
Apart from the fact that we're talking about the same engine, how does any of that answer my question?

Twenty pounds or so heavier, around 40 hp more (compared to the first model used in the M4, if I've read correctly), and a lower profile (judging by the pictures).
Longer mind, so the weight will probably be about the same, or maybe a bit more.
 
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Apart from the fact that we're talking about the same engine, how does any of that answer my question?

Sorry. I'm not familiar with tank engine requirements. I am familiar with engines. I do know Thomas, the tank engine. I won't bother you again.
 
A better question might be what effect using the Rolls Royce Kestrel to power british tanks might be. At the verry least a Kestrel powered crusader would be more reliable that the origional liberty powered version.
 
A more reliable engine might help, yes, but not much, it also suffered from an underpowered gun, thin armour, heavy track wear, and bad ammunition handling. I picked the Sherman because it was a widely used tank, and the engine change would make it quite different-looking.
 
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Don't forget the Grant and Sherman were designed after the Fall of France and the early desert campaigns.

True the Crusader was a terrible design, a result of a poorly thought out prewar pollicy of tank development. The 2pdr and armour were on a par with other early war year tanks.

My thought on the Kestral as a tank engine is if Vickers negotiated a licence with Rolls Royce allowing them to build them and designed their private venture tank around it, leading to a faster and probably slightly larger Vallentine, with a three man turret and the ability to be up gunned to the 6pdr already in development. Come the disaster in France the Army would gladly accept all that Vickers could build, and after the faults of the Crusader are exposed in the desert Nuffield may find themselves ordered to switch production.
 
A more reliable engine might help, yes, but not much, it also suffered from an underpowered gun, thin armour, heavy track wear, and bad ammunition handling. I picked the Sherman because it was a widely used tank, and the engine change would make it quite different-looking.


The Sherman also had its faults. High silhouette, weak gun, tendancy to catch fire, difficult to bale out of.
 
The Sherman also had its faults. High silhouette, weak gun, tendancy to catch fire, difficult to bale out of.
The Silhouette will be solved by having a V-engine (the whole point of the thread), the gun is still acceptable for anti-light use (neither the 76mm nor the 17lbr had as good an explosive round), and the fire issue was due to bad ammunition handling, not actual bad design.
 

Hoist40

Banned
With enough V-block engines available the Sherman would probably look something like the T14 but with thinner armor.

http://www.flamesofwar.com/hobby.aspx?art_id=1337

There was another possible way to reduce the height of the tank and while still using the radial engine, that is putting a aux gear box in which would drop the drive shaft down to the bottom of the tank and allow the hull and turret to be lower. The M-18 tank destroyer had that arrangement so a Sherman would look sort of like a heavier armored M-18. Such a gear box was proposed for the M-3 light tank pre-war but the Army was so short of funds that they could not fund it and when the war started they did not want to waste time developing it before mass production of the M-3

http://en.wikipedia.org/wiki/M18_Hellcat
 
How do the M3 Lee and M4 Sherman tanks do when powered by a V engine rather than a radial engine?
:confused:Ah most Shermans were powered by V engines, no? A Ford V8, if I remember correctly.

Sure some were powered by radials and some by a kludged up 30 cylinder (5 blocks of 6 cylinders mashed together).

Given the shortage of engines, restricting it to a single engine would reduce the supply of tanks.
 
There was another possible way to reduce the height of the tank and while still using the radial engine, that is putting a aux gear box in which would drop the drive shaft down to the bottom of the tank and allow the hull and turret to be lower. The M-18 tank destroyer had that arrangement so a Sherman would look sort of like a heavier armored M-18. Such a gear box was proposed for the M-3 light tank pre-war but the Army was so short of funds that they could not fund it and when the war started they did not want to waste time developing it before mass production of the M-3
That's an option I hadn't initially considered, thanks for pointing it out.

:confused:Ah most Shermans were powered by V engines, no? A Ford V8, if I remember correctly.
About a quarter of the Shermans produced were given V8s, but they were the last quarter, so the engine had to be fitted to the existing housing.
 
That's an option I hadn't initially considered, thanks for pointing it out.

About a quarter of the Shermans produced were given V8s, but they were the last quarter, so the engine had to be fitted to the existing housing.
Hmmm... Wiki (ja, I know wiki) says
M4A3 - Ford GAA V-8 engine; welded hull; 75-mm, 76-mm, and 105-mm guns. Users: US, France (small numbers), Nicaragua (small numbers). The M4A3 was the preferred US Army vehicle.
Italics added. That last sentence had made me think it was a lot more than 1/4, but it doesn't give production numbers.
 
There were also versions powered by Cat diesels, the M-4A4 variants if I remember correctly, but I could be wrong on that.​
 
Hmmm... Wiki (ja, I know wiki) says
Italics added. That last sentence had made me think it was a lot more than 1/4, but it doesn't give production numbers.
Go to the engine page, it gives a list off all the vehicles the engine was used in, and the numbers of each vehicle. Subtracting those that aren't Shermans, you end up with a figure just shy of 12,600, which, measured against a production of just shy of 49,250, gives you a figure of 25.58%, or about 1/4.
 
There were also versions powered by Cat diesels, the M-4A4 variants if I remember correctly, but I could be wrong on that.

The diesel-powered variants were the M4A2 & A6; the M4A4 was the version with the weird Chrysler multibank engine. The main variants of the Sherman OTL are as follows:

  • M4- welded hull, powered by Continental radial engine
  • M4A1- one-piece cast hull, radial engine
  • M4A2- GMdiesel engine; not used operationally by US Army- some supplied to USMC, rest transferred abroad under Lend-Lease to Britain, Free French & USSR
  • M4A3- Ford GAA V-8, preferred variant of US Army, most subvarients in the Sherman family
  • M4A4- Chrysler multi-bank engine & lengthened hull; only made with 75 mm gun; not used by US operationally & transferred abroad under LL to Britain & Free French
  • M4A6- Experimental Caterpillar radial diesel, using M4A4 hull- only a handful built & all used for training & testing.
(The M4A5 designation was to have been used as an administrative placeholder for Canadian production)
 
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