US tank design and philosophy

[Markus Becker]

9 hours ago, Stuart Galbraith said:

Thats quite curious, Id always assumed the small size was to help it in places like Burma. But it makes sense.

The IJA wasn't looking south or east but north to the USSR and west to China. 

[Markus Becker]

8 hours ago, bojan said:

I am not sure if there would be capability to make decent HEAT. US and Soviet postwar HEAT ammo benefited tremendously from their nuclear program, in particular explosive lens formation theory, and even then it took until mid-late '50s to get useful tank HEAT.

Well, the Germans came up with 75mm HEAT penetrating ~100mm. I'd rather not be in a Tiger I when that hits the frontal armour. 

[R011]

2 hours ago, Murph said:

I want to say you are correct in this.

Except for the autocorrupt on "Stuart" which I went back and fixed.🙂

[futon]

5 hours ago, Murph said:

That is a very valid point, but putting the 90mm turret on the Sherman would have made a huge difference from 1944 onward.

Seems very doable. Maybe the turret swap adds only about 1.5 tons. 

[futon]

3 hours ago, Markus Becker said:

Well, the Germans came up with 75mm HEAT penetrating ~100mm. I'd rather not be in a Tiger I when that hits the frontal armour. 

The Japanese got some HEAT tech from Germany. 

In April 1944, the Australians captured a Japanese 75mm mountain gun and had some Type 2 HEAT with it. They test fired it on a Matilda II and it penetrated. 

That bit somewhat in the middle of the wiki article.

https://ja.wikipedia.org/wiki/タ弾

[Argus]

21 hours ago, R011 said:

Stuarts were decent recce vehicles which was how the British used them once they had enough medium tanks to replace them as cruisers.  Being light and comparatively plentiful, they served reasonably well in the Pacific until enough Shermans were available.

<snip>.

There's an M3 in the AWM that looks like a colander with all the 20mm holes punched though it from a Type 97.  The Japanese gunner even had enough time and skill to group his shots neatly in the crew locations. I'd be the first to agree that any tank is better than no tank, but I'd have rather been in a Matilda

[Ssnake]

7 hours ago, Murph said:

That is a very valid point, but putting the 90mm turret on the Sherman would have made a huge difference from 1944 onward.

What's your definition of a "huge difference"?

There was the logistics concern, having two types of tank gun, two incompatible types of ammunition. A rushed production would have come with the old turret design, hence slower loading speed, and possibly more tankers dying in slower evacuations. Yes, the rounds were better, but volume of fire would have been lower, and the armor was still not a good match for either 88mm or 75mm; they still would have had a bit of a glass chin, despite the heavier punch. Would that have been a worthwhile trade-off?

You had at least have to equip certain formations with those tanks. That means taking them out of the fight, reequip and retrain them. Wouldn't they have been missed in other battles? And, which formations would you equip with them? Those still in Britain , preparing for D-Day? In which case no difference would have been made until July '44. Or have them deployed in Italy where they might not have made a big difference?

Arguably, better training in infantry-tank coordination would have made a much bigger difference in early Normandy dates than issuing Shermans with the 76mm gun. And between breakout from Normandy and the battle in the Ardennes, I don't think the US Army needed a lot of help during the liberation of France. So then, this leaves the Battle of the Bulge right at the end of '44 where the better guns might have killed more German tanks faster than they were running out of fuel and spare transmissions. As it was, the German assault collapsed anyway (and I'm not sure if it had ever a realistic chance to succeed). Even if Hoth had turned right rather than left, found the fuel depot he was so desperately after, and actually made it to Arntwerp harbor: At that point he would have been out of fuel again, even more out of ammo, under clear skies.

 

So, what is the huge difference that this gun in earlier Sherman tanks would have made?

Some tank-on-tank tactical engagements could have been more in the US favor. Tank-on-infantry engagements - there was no good anti-infantry ammo for the 76mm gun initially - might have gone the other way. I think this question is given more weight than it deserves.

[R011]

2 hours ago, Argus said:

There's an M3 in the AWM that looks like a colander with all the 20mm holes punched though it from a Type 97.  The Japanese gunner even had enough time and skill to group his shots neatly in the crew locations. I'd be the first to agree that any tank is better than no tank, but I'd have rather been in a Matilda

A Stuart is way better than a Carrier, but yeah, a Matilda or Valentine were much better still.  Even better, at least for Australia, would have been de-bugged Churchills in enough quantity to be deployed to SE Asia a year or two earlier.

Funny to think that in 1940, the Matilda was cutting edge and a deadly menace to the Panzerwaffe.  By 1943, it was relegated to the Indo-Pacific because it was now useless in the MTO/ETO but still good against the Japanese.

[R011]

1 hour ago, Ssnake said:

What's your definition of a "huge difference"?

There was the logistics concern, having two types of tank gun, two incompatible types of ammunition. A rushed production would have come with the old turret design, hence slower loading speed, and possibly more tankers dying in slower evacuations. Yes, the rounds were better, but volume of fire would have been lower, and the armor was still not a good match for either 88mm or 75mm; they still would have had a bit of a glass chin, despite the heavier punch. Would that have been a worthwhile trade-off?

You had at least have to equip certain formations with those tanks. That means taking them out of the fight, reequip and retrain them. Wouldn't they have been missed in other battles? And, which formations would you equip with them? Those still in Britain , preparing for D-Day? In which case no difference would have been made until July '44. Or have them deployed in Italy where they might not have made a big difference?

Arguably, better training in infantry-tank coordination would have made a much bigger difference in early Normandy dates than issuing Shermans with the 76mm gun. And between breakout from Normandy and the battle in the Ardennes, I don't think the US Army needed a lot of help during the liberation of France. So then, this leaves the Battle of the Bulge right at the end of '44 where the better guns might have killed more German tanks faster than they were running out of fuel and spare transmissions. As it was, the German assault collapsed anyway (and I'm not sure if it had ever a realistic chance to succeed). Even if Hoth had turned right rather than left, found the fuel depot he was so desperately after, and actually made it to Arntwerp harbor: At that point he would have been out of fuel again, even more out of ammo, under clear skies.

 

So, what is the huge difference that this gun in earlier Sherman tanks would have made?

Some tank-on-tank tactical engagements could have been more in the US favor. Tank-on-infantry engagements - there was no good anti-infantry ammo for the 76mm gun initially - might have gone the other way. I think this question is given more weight than it deserves.

In the great scheme of things, probably not much difference.  Perhaps a few hundred fewer fatalities and permanent injuries, but not war-shortening.

[Markus Becker]

7 hours ago, futon said:

Seems very doable. Maybe the turret swap adds only about 1.5 tons. 

Absolutely doable. M36B1: M4 hull with an M36 turret. OK, the open TD turret but that could have been changed. 

[R011]

32 minutes ago, Markus Becker said:

Absolutely doable. M36B1: M4 hull with an M36 turret. OK, the open TD turret but that could have been changed. 

Besides an armoured roof, they'd need a coax and increased armour.  I don't know if that might prove problematic in service.

[futon]

 An M26 turret was actually experimented on the M4, summer 1944. Given that the M51 worked, this is also probably workable.

[LeeWalls]

13 hours ago, R011 said:

Except for the autocorrupt on "Stuart" which I went back and fixed.🙂

Ha I've always called it "autoincorrect" but I think I like yours better.

[futon]

8 hours ago, Ssnake said:

What's your definition of a "huge difference"?

There was the logistics concern, having two types of tank gun, two incompatible types of ammunition. A rushed production would have come with the old turret design, hence slower loading speed, and possibly more tankers dying in slower evacuations. Yes, the rounds were better, but volume of fire would have been lower, and the armor was still not a good match for either 88mm or 75mm; they still would have had a bit of a glass chin, despite the heavier punch. Would that have been a worthwhile trade-off?

You had at least have to equip certain formations with those tanks. That means taking them out of the fight, reequip and retrain them. Wouldn't they have been missed in other battles? And, which formations would you equip with them? Those still in Britain , preparing for D-Day? In which case no difference would have been made until July '44. Or have them deployed in Italy where they might not have made a big difference?

Arguably, better training in infantry-tank coordination would have made a much bigger difference in early Normandy dates than issuing Shermans with the 76mm gun. And between breakout from Normandy and the battle in the Ardennes, I don't think the US Army needed a lot of help during the liberation of France. So then, this leaves the Battle of the Bulge right at the end of '44 where the better guns might have killed more German tanks faster than they were running out of fuel and spare transmissions. As it was, the German assault collapsed anyway (and I'm not sure if it had ever a realistic chance to succeed). Even if Hoth had turned right rather than left, found the fuel depot he was so desperately after, and actually made it to Arntwerp harbor: At that point he would have been out of fuel again, even more out of ammo, under clear skies.

 

So, what is the huge difference that this gun in earlier Sherman tanks would have made?

Some tank-on-tank tactical engagements could have been more in the US favor. Tank-on-infantry engagements - there was no good anti-infantry ammo for the 76mm gun initially - might have gone the other way. I think this question is given more weight than it deserves.

I think obe thing that could be said is that during the design stage, the designing should not relax parameters on expectation in being able to rely on other parts of the service to deliver advantageous tactical situations, such as air superiority, superior artillery support, etc. The tank should be intended to measure up on its own to the adversary's tank. So the 75mm M4, clearly doing very well in '42 and '43, as naturally expected in the fast evolution trend of tank tech and capabilities, the 75mm M4 starts to age. 

So if taking the M26 turret cobbled onto the M4, the the hull armor is still the same but with a much stronger gun, engagement distance evens out the full formula. The M4 benefitted from air superiority. But what if it could not have been achieved? What if the SU was less successful in its counter offensive? Then the 75mm M4s would be pitted in a more leveled battlefield against panthers.

Edited January 7 by futon

[bojan]

16 hours ago, Markus Becker said:

Well, the Germans came up with 75mm HEAT penetrating ~100mm. I'd rather not be in a Tiger I when that hits the frontal armour. 

Only 450m/s muzzle velocity. US also developed similar performing HEAT for 75mm M20 RCL, even fielded it, but tank HEAT fired at any reasonable velocity had to wait until '50s.

[futon]

I had to have a little fun ... (^^)

On the easy 8 hull, it looks more balanced than on an earlier M4A3 hull like in that photo. 

[Ssnake]

4 hours ago, futon said:

The tank should be intended to measure up on its own to the adversary's tank.

I disagree.

Production capacity and logistics play as much if not a bigger role. The Sherman played to the American strength of mass production. Germany had a lot of shortages in raw materials so the fewer tanks had have some technological advantage. At some point better protection was needed, so the E8 was introduced, which was "good enough" in a sufficiently large number of duel situations with the Panthers.

 

The question must be asked if a different design was

a. feasible

b. substantially better

c. would have resulted in an equal or higher number of tanks in theater

Only if all three categories are met we're talking about something war-shortening. And all three would require to have been recognized on the basis of available information at the time.

 

The suggested "feasible" candidates don't convince me in the b. or c. category. I'm not ruling out that the Americans could have pulled it off, but it might have required a bit of a gamble to see if it would work out. And here I say, Hitler had to gamble. The Americans could rely on methodically grinding down the Wehrmacht, so each risky decision taken could just as well have backfired. In short, I'd like to see a lot more evidence presented for a Sherman-replacing tank to convince me that the replacement really would have made a huge difference.

[DKTanker]

13 hours ago, Ssnake said:

There was the logistics concern, having two types of tank gun, two incompatible types of ammunition.

With the rest of the myths, can we put this one to rest as well?  The US Army and Marines were already using two incompatible types of tank ammunition, 37mm and 75mm.  Moreover, with the introduction of the 76mm there would be three types.  The Brits managed, apparently with success, to have both 75mm and 17pdr ammunition in the same unit not to mention yet another flavor of incompatible 17pdr ammunition in the guise of 77mm floating around the logistics train.  

 

[R011]

7 hours ago, futon said:

 An M26 turret was actually experimented on the M4, summer 1944. Given that the M51 worked, this is also probably workable.

It fit.  How well it worked doesn't seem to be documented.  By then, any available M26 turrets were intended for M26 hulls,so there likely weren't  enough to refit Shermans.

[Markus Becker]

7 hours ago, bojan said:

Only 450m/s muzzle velocity. US also developed similar performing HEAT for 75mm M20 RCL, even fielded it, but tank HEAT fired at any reasonable velocity had to wait until '50s.

So an intense emotional event could be delivered in a second to a target 500 yards away? Not bad. 

That's the lesser issue. Wikipedia now not only has the actual pen data for armor sloped 30° but also estimated estimated ones for vertical plates. 75, 81, 92 and 95mm with AP/APC. 

So even good HEAT is not that much better or just marginally so. 75mm APCR would have wrecked a Tiger doing 117mm at 500yd/30°. 

[Tim the Tank Nut]

It's important to remember that the US had to figure shipping into everything they did.  That Atlantic and Pacific ocean thing...

The other thing to consider is just how much lead time really was available.  Finding out in '43 that the Germans had the Tiger and fielding the first Easy Eights at the tail end of 44 isn't terrible.

The faults lie in the US not considering their enemies' own advancements.  If you have a shell that is good enough then it is time to start working on the better one, NOW!

If the Russians could manage to produce more, better, and bigger tanks while being invaded then the American forces don't have a whole lot of excuse.

At the end of the day forty Shermans is better than two Tigers and that is what happened.  Better shells were the thing that could've happened and needed to happen.

I'm with Murph on McNair but Rich seems to think he was okay.  I believe we've sparred on that before.  If one must defend McNair you can say that the pre-war Army was small and there was a lot going on.  Nobody could get it all correct...

[futon]

4 hours ago, R011 said:

It fit.  How well it worked doesn't seem to be documented.  By then, any available M26 turrets were intended for M26 hulls,so there likely weren't  enough to refit Shermans.

Yeah because it was the same turret ring. The gun in the manlet has to be balanced on its own. The hull is not relevent. The turret itself has to be balanced on its own. The hull doesn't matter in this regard.

What could be problematic is whether or not the little knick knacks on the hull can gave clearance to the turret. If not, probably not hard to adjust. This is the country that pushed out so many Shermans of variations. 

Another possible problem may be crew arrangment. While the turret ring size matching probably does ball-parks crew layout in the turret within acceptable range, but perhaps turret basket depth could be something. 

One other point is whether or not 90mm storage amount is sufficient in the M4 hull. If less than M26, perhaps not remarkably less and still acceptable amount. 

 

 

[R011]

12 minutes ago, futon said:

Yeah because it was the same turret ring. The gun in the manlet has to be balanced on its own. The hull is not relevent. The turret itself has to be balanced on its own. The hull doesn't matter in this regard.

What could be problematic is whether or not the little knick knacks on the hull can gave clearance to the turret. If not, probably not hard to adjust. This is the country that pushed out so many Shermans of variations. 

Another possible problem may be crew arrangment. While the turret ring size matching probably does ball-parks crew layout in the turret within acceptable range, but perhaps turret basket depth could be something. 

One other point is whether or not 90mm storage amount is sufficient in the M4 hull. If less than M26, perhaps not remarkably less and still acceptable amount. 

 

 

More weight or more weight higher up could certainly have serious effects on the stability of the vehicle and its performance.

[futon]

2 minutes ago, R011 said:

More weight or more weight higher up could certainly have serious effects on the stability of the vehicle and its performance.

Height of center of gravity.. that's true too.

[futon]

8 hours ago, Ssnake said:

I disagree.

Production capacity and logistics play as much if not a bigger role. The Sherman played to the American strength of mass production. Germany had a lot of shortages in raw materials so the fewer tanks had have some technological advantage. At some point better protection was needed, so the E8 was introduced, which was "good enough" in a sufficiently large number of duel situations with the Panthers.

 

The question must be asked if a different design was

a. feasible

b. substantially better

c. would have resulted in an equal or higher number of tanks in theater

Only if all three categories are met we're talking about something war-shortening. And all three would require to have been recognized on the basis of available information at the time.

 

The suggested "feasible" candidates don't convince me in the b. or c. category. I'm not ruling out that the Americans could have pulled it off, but it might have required a bit of a gamble to see if it would work out. And here I say, Hitler had to gamble. The Americans could rely on methodically grinding down the Wehrmacht, so each risky decision taken could just as well have backfired. In short, I'd like to see a lot more evidence presented for a Sherman-replacing tank to convince me that the replacement really would have made a huge difference.

Well to your bottom point, the Pershing turret M4 probably still be considered a "Sherman". It would be in consideration as to whether to introduce the whole M26 was the way to go. So on your point, instead of sending a few M26s to Europe to test it, it would make more sense to go with the M26's turret on M4 -- on the basis that this design passes all testing. Doing so reduces risk to logistics. M4 hull parts, training, familarity was already in system. 

If the M26 had a better engine, then maybe it would cross the threshold of substantially better. But it was pretty much the same engine as M4. Both were working with same engine power. 

With all that said, if hell broke out with Operation Downfall.. the 90mm would actually be overkill for most things. And slower M26 speed wouldn't be an issue with the type of warfare that would have occured. It would be more of the same kind of slow close quarters fighting like it was on Peleliu, Iwo Jima, Okinawa.. the tank crews would likely greatly appreciate the M26's front and side hull armor. If no M26s, they'd probably want 75mm or short 105mm armed Jumbos over Pershing turreted M4s.

Edited January 7 by futon