"So, what about an M6 "MBT" ?" Topic

"General Eisenhower ! you have to listen to me, the Germans will deploy incredibly powerful tanks and the M4 is going to be a complete disaster."

OK, so you went back in time and warned the US not to build the M4 Medium, or at least bulk up the specs into a more suitable combat vehicle.

This disrupts the whole M3/M4 design cycle. So instead of figuring out how to put a 75mm gun into a medium tank they have to scrap everything and start on a heavy tank.

Luckily the M6 is already chugging along and the first drafts of the T26 are being put on paper.

So you need a big upscaled version of the M6 with extra armour to resist 75L70 guns.

The first hurdle is an engine, of course it has to be a diesel engine, so they look for something suitable, and if necessary start work on upgrading an existing engine or go the troublesome road of dual engines.

Next it needs big broad tracks, VVSS doesn't work well with broad tracks, so you need to rework the suspension and because the tracks end up weighing nearly twice as much as the original ones the transmission has to be beefed up.

Next the front armour has to be beefed up to around 120mm and everything has to be sloped.

It then needs a gun, the 90mm is on hand, but of course you'll want a 120mm gun, big and long so that you can hit a King Tiger two miles away and still get the Panzer III hiding behind the Panther hiding behind the King Tiger …

So by now the US army has a 65-ton heavy tank that is impervious to frontal hits from a 75L70, but still vulnerable to flank shots.

It's huge so they have to be shipped in parts, taking up lots of room and tonnage (oh damn for ships to have only limited space and threaten to sink if you load too many tanks into them)

The corps of Engineers give you the stinkeye because bridges are not important in your reality. "Who needs to cross rivers if they can shoot enemy tanks in Germany from the Normandy beaches !!!"

Engines, tracks and transmissions are overburdened. From a volumetric point of view the extreme slope of the tank means the crew are packed tight without room to move and still have to handle heavy shells, everybody is cramped and miserable and know how Soviet crews feel.

The fight in North Africa goes bad because the British and US have to rely on old M3's instead of Shermans.

The first few M6 that arrive in time for Sicily need special transports, a few bog down trying to get ashore, more break down in the hilly terrain or find it hard to cross terrain. Even worse is the fact that they can't always follow the other units and those infantry divisions that receive them, leave their tank company behind. Without tanks integrated into every division, they have to fight the hard way as fewer, but heavier tanks are concentrated into the Armored Divisions.

The Tank Destroyers have been abandoned because they were a stupid concept and while each division gets extra AT guns and bazookas they are sorely missed since the M6 is too heavy to keep up. M6 plain suck and the US army has to do with light tanks for most of the fighting in Italy.

June 1944, Omaha beach still suffers since there is no way to convert them into DD tanks, as a result even the few M4 that did make it ashore are not there, so the death toll is even higher.

US tanks now enter the Bocage and it's a disaster, in our timeline the M4 with a 75mm had at least the advantage that the shorter barrel can still turn. The big 105mm gun is next to useless and US infantry again have to run the gauntlet with fewer tanks to support them.

Scandal !!! US tanks are unprepared for German tanks !!! The Germans with great effort managed to produce the Panther G armed with an 88mmL71 gun. They also bump into the Tiger B armed with a 128mm gun.

The Germans also deploy a 100mm panzershreck and an improved Panzerfaust.

Once they break the Germans the Falaise gap is not a problem since US forces are handicapped by their slow tanks.

"It's a very powerful tank, but it can't move like shit, ours are nearly half again as heavy as German tanks and need to be towed because they get stuck on anthills !!!!" Says a fuming Patton who finds that his offensive stalls just before Paris because his tanks use up even more fuel than he did in our timeline.

And today we write about how the US army went tank heavy crazy and should have built something simple and effective like T-34 …

Yeah, we get dramatic pictures of Tigers and Panthers with big holes in the front, but we get complaints from tankers that they were flanked anyway.

And Belton Cooper gets to blame it all on Patton for not understanding the concept of mobility ! And how he and his team still had to scrape dead tankers out of tanks that were too heavy to avoid being flanked and broke down most of the time and were a nightmare to tow back to the field repair stations and bemoans the more rational M26 which of course came too late to fix the problem.

"If only they had focused on the M26 instead !!! It could have been built in larger numbers and more of them would have been available and the 90mm gun was enough to take on most enemy tanks, heck even the 3-inch or the unused 76mm could have been useful !!!"

And if we had throttled the M4 in the crib and used the M26 instead it would have been the same issue all over again : too big, too heavy, underpowered and not suitable for the job !!!

The M4 was not the most powerful tank in absolute terms, but as a mobile combat vehicle it was a good enough package for combined warfare where the sum total of the fighting elements make up for an individual weapon system's failure and US Divisions in the end would eat German Divisions alive with or without the help of the M4.

The M4 Sherman was the right tank at the right time. Was it perfect, No. It was the best compromise of the many factors faced to produce it and get it to the field.

The actual alternative heavier tank available in a realistic timetable – say, if there had been instant action in mid 1943 based on reports from Kursk of the existence and prevalence of Panthers – would have been the T23, would it not?

Which IIRC was to the M4 what the KV1 was to the T34. More armour, but as it only has the same gun, then in getting close enough to destroy the enemy tank, it gets so close as to be penetrable by the enemy's gun. So the armour is worthless, it is no more effective, but it is heavier and it is thirstier.

Interesting thoughts

In addition to the US Army problems, the Brits and Canadians used a lot of Shermans (more than 17,000) – in fact, as I recall the 4th Canadian Armoured Brigade (the tank brigade of the 4th Canadian Armoured Division) were all Shermans and Fireflies – so without the M4 they would have had to use something else (perhaps, in the Canadian case, the Ram tank which had many M3 components)

As well, the Russians received more than 4,000 as lend lease – again, while maybe not a tipping point were no doubt very useful

Your premise that the M 4 was a disaster is false. Everything else appears to he noise to support the premise.

Nicely put, Patrick R. But think of all the WWII US miniatures gamers, obsessing over every minor US variant, and winning all the tabletop games even if their side lost the war.

Well, if I was going to go back in time, I'd take an M1 (though an M60 would probably be good enough)

But then that would change the timeline, as they reverse engineered the future artifact, and appiled the future technology in the past. Eventually M1 (or M60) would just disappear at some point, as it would never have been designed in the first place, and we'd just end up with the M4.

Then I would tell them about Stalin's plan, and we would just go to war with the Soviets in 1945. They'd start to smash us with their numbers, we'd nuke them, create a nuclear winter and kill off humanity. I'd never be born, couldn't go backin time in the first place, and we'd still win with the M4.

Wonderfully put and a delightful read!

79th rather than indictment of M4 it is actually a terrific parody of the various arguments about why the M4 was a failure and how we could have had a much better tank.

Sounds like an American King Tiger…

Well … I'm still a proponent of the M26 being introduced sooner. Or even the M25 …

The first few M6 that arrive in time for Sicily

I didn't know any were ever fielded/saw combat ?!?

I understand that the Russians loved the M4 Sherman, primarily because we supplied a literally endless supply of ammunition and spare parts. Much easier for tankers to bail out if hit, as well.

Gdep

Patrick R what a pleasant and entertaining read. So nice to se humor and realism in one place.

Should have made Infantry Fighting Vehicles out of the Tank Destroyer chassis-running away furtively.

Now that was a fun read!

Two things being ignored here.

First, shipping space. As Hunnicutt pints out, two M6's took up as much shipping tonnage as five M4's.

Second, US tank doctrine. Tanks were not considered to be antitank assets. They were to assist infantry in the breakthrough, then conduct the exploitation of the breakthrough. Both things the M4 did quite well.

The obvious solution to the transportation problem is to stick wings on them. Christie tried it!
What could possibly go wrong?

US tank doctrine insisted on the offensive role of tanks, and as the tanker manual states, engaging enemy tanks was their business when executing their proper offensive task.

They were not going to act as "fire brigades" and be called upon to "rescue" other units whenever the enemy launches a mechanized assault.

The TD doctrine involved keeping a whole branch of mobile AT assets in reserve and deploy them when the enemy launched such an assault, they would form a defensive line, digging in and/or flanking the enemy.

What the generals complained about was not the Tank Destroyers themselves since they performed well enough, but that they might as well have been tanks and keeping a fighting force in reserve is a silly idea, just up and integrate AT defenses into the divisions and do away with a whole branch which in practice already was forced to break its own rules.

I did address the problem of shipping briefly by stating that they would have to be shipped in parts, maybe removing the tracks, or even the turret before they could be loaded into a ship, taking up a lot of space and weight.

I borrowed from actual experience with tanks like the M103 and the T28 which was tested, but ultimately failed. It was underpowered with a 500hp gasoline engine, a huge no-no in traditional circles who hold that tanks should only have diesel engines.

My thesis was also based on experience with Soviet and German heavy tanks, which all had problems crossing bridges and having to reinforce existing ones or look for fords to cross. Even the Pershing "the only sensible US tank made in WWII" suffered the same problem on its spectacular debut at Remagen, offering good support to the troops, but then remaining stuck until the engineers build bridges because the Remagen bridge would not hold heavy tanks.

In a post made a few days ago we had a link to an article which was one big "GOTCHA !!!" which was in fact somebody flogging a dead horse. The article started from the POV that the US Army lied through their teeth about the M4 Sherman being a superior tank whereas in fact it was vastly inferior and that everyone since had kept up that horrible lie until today and the author was the only woke guy who understood what Belton Cooper was trying to say all along, that the Sherman was a death trap.

Cooper is not entirely wrong in this matter. There is no denying that if you found yourself on the wrong end of a Panther's barrel things didn't look good for you no matter what.

And the only answer we ever get from these woke guys attuned to the grim reality of war, whereas we are all under the collective delusion that the Sherman won the war, is that they should have fast-tracked the Pershing, ditch the M4 altogether and build it in huge numbers because a prototype was available in 1942, this left two whole years to crank them out in huge numbers by 1944, enough to drown all the Panzers in a sea of M26 Pershings.

But this narrative ignores the facts in favour of some simplistic narrative.

As I have stated before tanks in WWII were not like knights seeking each other out on the battlefield to duel with each other. Tanks support offensive actions, and engaging enemy tanks is one part of the job, they also have to coordinate with infantry and artillery, provide direct and sometimes indirect fire support.

If you insist on guns being only high velocity AP machines you paint yourself into a corner since any HE ammo needs much thicker casing to resist higher velocities, therefore reducing the explosive charge. It's a problem tanks still face today.

So while you get to appease the peanut gallery for finally having that all important at the expense of everything esle "better gun" ie, something that will shot straight through a King Tiger, you end up making the rest of the tank's job much harder, ie the 85% of shots fired, 11 shots to each AP shell, the HE fired at buildings, guns, troops and every target vulnerable to HE fire.

"MOAR ARMOUR ! MOAR GUN ! DIESEL ENGINES YA STOOPID !!"

To the historian who only knows about battles, generals and which SS division was involved in which battle, stuff like ground pressure, military production, logistics (that stupid joke everybody makes without actually understanding what it means) It's obvious they should go big or go home, after all we do have M1's so what's stopping them from fixing the issue in 1941 !!!

They were still figuring out how to put a 75mm gun in a turret in 1941.

Just because a prototype is available at some date doesn't mean they throw a large switch or hit a big red button and fire minutes later some factory cranks out the first production model. A prototype is a proof of concept which has to be tested to see if it works, and often there is a lot to correct. So from prototype to production model it takes about two years. To want the Pershing in production by 1942 ignores all the hard work they did right up until mid to late 1944 to get a more or less "battle-ready" vehicle. And the first models sent over needed their crews trained in their use, so they had ironed out most of the problems, trained their crews in a minimum amount of time between delivery in January 1945 and their first operational use weeks later. And in practice they were found to have problems, like bridges not being able to bear the load, underpowered and still needing tweaks.

The M26 would probably be quickly be tweaked to make it better and more reliable if it had been given the same lifecycle as the Sherman did after it was introduced in 1942.

The real weakness of the Sherman is that it has many of the virtues of a good tank design, but they are "invisible" to most people. They don't look at things like production, ergonomics, survivability, reliability, how well it integrates into a combined arms situation. The US army added them to their infantry divisions, a luxury none of the other combattants could afford, at best the Germans added a company of Stugs and many formations had to do without any armoured support of any kind.

I'll gladly grant that mistakes were made, but they are not madness and criminal negligence like some would love to believe.

Yes the Sherman was designed for a 1941 battlefield based on data gathered since 1939. And the US made a mistake when they appreciated the issue of Panzers in Normady. They assumed that Tiger and Panther were rare heavy tanks and that they would not be a major factor in combat.

They were right about Tiger, but completely wrong about Panther, which is a completely irrational design from the general point of view of the time. Nobody builds a 45-ton medium tank in 1942-1943 !!! It's one of those things Panzer fan boys always conveniently ignore : "At least the Germans got their tanks right !!!" Yeah, by making them 15-tons heavier and slapping a "medium" sticker on it. It's like sending Hafþór Júlíus Björnsson into a Welterweight MMA fight and declaring that his opponents are vastly inferior.

We're barely one or two years into seeing the first T34 with a 76 gun a huge leap forward in tank firepower. Yes in retrospect Panther seems unavoidable. What threw everybody off was the timetable and the rather baffling idea of using a heavy tank as a medium tank.

The Germans were simply ahead of the curve for a few years until the rest caught up with improved medium tanks and a new generation of heavy tanks. With dwindling resources Germany would never keep that lead, even if they magically could summon the resources to build all those paper panzers, without the fuel, they might as well have built them as bunkers.

There are reasons why the Sherman turned out as it was, and I'll be more than happy to admit that mistakes were made, but they could be fixed to some degree.

German tank superiority was a diminishing game, they were scary in Normandy and could still be devastating on the local level, but a few months later they had lost their edge and vastly underperformed at the operational and higher scale German armoured forces were no longer a factor.

We get these last hurrah reports like Jagdtigers killing 22 Shermans in the closing days of the war, proving the Germans were utterly dominant until the last day !!!!

Half those Shermans were back in service within days, the Jadgtigers were lost anyway. At the same time they won something relatively easy (a long range ambush with vehicles that are invincible to even a Pershing) they were losing entire cities, railway hubs and factories and whole armies were surrendering. It's not even a Pyrrhic victory, it's the equivalent of that shiver that does down your spine when you see somebody twitch one last time before they die ! By the time of the fight the US has about 10k Shermans in theater with more inbound and Pershing coming online, the Germans were down to less than 500 tanks and about twice as many AFV's. Their soldiers were suffering from severe malnutrition, some having to survive on less than 500 calories a day. They were a few lucky veterans, old men and children, propped up with Pervitin and gangs of SS thugs who were really good at hanging women and children, but turned into jelly as soon as somebody pointed a rifle at them.

People have said that the US government owed it to their tankers to give them "better" tanks. But what about the millions of guys who went into combat with just a steel pot and a U.S. Rifle, Caliber .30, M1. Didn't the government owe them their own personal tank ???

I'll gladly admit the M4 was far from perfect, but nothing you can claim or say will take away its intrinsic combat value. 30-odd tons of steel with a 75mm gun and several MG's, as the quote goes "A Sherman can give you a very nice… edge"

Marvelous comments, Patrick R! I shall print them and keep them in my WWII "forever file."

GdeP

Patrick,well said!

Yes, some good comments !

All very true and well said. The Pershing saw some service in Korea, but even then the Sherman seems to have been preferred (by then the M4A3E8 version, IIRC). The perfect is always the enemy of the good-enough, and vice versa. Delaying tank production waiting for a better design was not a viable option, and interrupting production to introduce a better model would have gummed up the works. So I don't think switching to the M26 Pershing was the best idea. Perhaps putting the M25 version into production would have been a better idea, but someone always wanted to hang more armor on the thing. (But no amount of armor is ever "enough".) It should have been possible, though, to put the 90mm gun on a Sherman (the Israelis did it a few years later, and even a 105), as the Sherman and the Pershing had the same size turret ring. That would have given both better AP and better HE performance.

The U.S. intentionally went with gasoline-powered engines in tanks instead of diesel for the very good reason that they didn't want to complicate their supply situation by having different kinds of fuel for the tanks that what everything else used (having a separate grade of gasoline for aircraft was bad enough).

"A Sherman can give you a very nice… edge"

Woof ! Woof !

The Easy 8 Sherman was preferred in Korea because the 76mm gun could kill a T34 just fine and the Pershing was much less mobile (having the same engine as the Sherman and much more weight).

The big challenge with putting a 90mm into a Sherman was ammunition stowage. While the 90mm shells are about the same length as the 76mm, they are much bigger in diameter:

Actually, were one to be able to go back in time the option to have suggested would have been one of the T-20 series (T-20, 22, 23) with a better transmission.

With essentially the same weight, length, and width as the M-4 but armed with the 76mm gun and a good foot shorter with somewhat better protection it would have been a significant improvement from Normandy on.

There should have been no difference in loading plans for shipping them overseas.

As to disruption of Sherman production, the variations/modifications introduced to the Sherman during ranged from engine changes to switching from cast to welded hulls and even to the adoption of the T-23 turret for the Easy Eight.

With the number of plants involved producing Shermans retooling facilities should not have impacted overall production any more than the retooling necessitated by the production changes to the Sherman.

changes to switching from cast to welded hulls

There was no switch from cast to welded hulls. For a number of reasons the cast hull was preferred but few foundries could do such large one piece castings. As a result, given the need to field quickly and with expected needs, the welded hull was accepted at essentially the same time.

Three companies produced the cast hull (M4A1) Sherman:
Lima Locomotive Works which had its last batch of M4A1s accepted in 3rd quarter of 43
Pacific Car and Foundry which had its last batch of M4A1s accepted in the 4th quarter of 43
Pressed Steel Car which produced the M4A1 until the end of the war.

Of those only the Pressed Steel Car company produced any welded hull M4s. Due to initial need they produced the M4 for about a year. They were able to do this due to excess production capability. They produced the M4A1 prior to the M4, while working on the M4 and after so no disruption. So it is accurate to state none of the three switched over from cast to welded hull.

None of the welded hull factories produced cast hulls.

because the 76mm gun could kill a T34 just fine

That is the bottom line, IMO. But a 90mm would be good as well …

Don't forget that the M6 had the unique advantage of featuring a 37 mm coaxial gun, while the rest of the US tanks had merely .30 cal coaxial MGs that were pretty useless against any sort of armoured target.

Germans may have heard of this clever design and copied it when coming up with plans for the Maus, though with typical Teutonic cunning they decided to go for a 75 mm coaxial gun, which would have given them a distinct advantage in a duel with M6 tank.

Good thing that the NKs did not receive any JS3s

;-)

B

Bad source on the hull changes, but there were still enough changes being made that retooling a line to produce M-27s would not have significantly impacted production numbers.

Actually in Korea, IS-IIs would have been a major problem for the M4A3E8s let alone IS-IIIs. From sources not sure if the Chinese committed any of theirs.

Of course the British had the Centurion III which had exceptional mobility and the excellent 20 pdr gun.

Good thing that the NKs did not receive any JS3s

Very true … until M26s got there in large numbers. The JS3s would have been a challenge much more so than the T-34/85s. Which was hard enough to deal with at least initially.

From sources not sure if the Chinese committed any of theirs.

I have not heard of them deploying an JSs in the Korea. But there was talk about possibly deploying them in French Indochina. With the rumor the French were thinking about sending Pz Vs. To combat them.

And IIRC, later the USMC had a Bn of M103s on Okinawa, for the same reason.

Now I am thinking of Devil's Guard scenarios with French Panthers and ex-SS Foreign Legionaries, versus North Korean JS3s….

It should have been possible, though, to put the 90mm gun on a Sherman (the Israelis did it a few years later, and even a 105), as the Sherman and the Pershing had the same size turret ring. That would have given both better AP and better HE performance.

This was, in fact done. Hunnicutt's Sherman book has a photo of just such a tank. To make a long story short: it was rejected as mounting the Pershing's turret on the M4 hull would not get any more 90mm gun tubes into service, as compared to just shipping over M26 Pershings. Post-war it didn't matter so much to the US, who had the Pershings re-designated as medium tanks, started the conversion process to the M46 in '47 (altogether much better tank), with the M47 & M48 only a few years out…there was no need to rebuild Shermans with the Pershing turret.

Damon.

Germans may have heard of this clever design and copied it when coming up with plans for the Maus, though with typical Teutonic cunning they decided to go for a 75 mm coaxial gun, which would have given them a distinct advantage in a duel with M6 tank.

The Germans had already experimented with this setup in the Neubaufahrzeug, which mounted a 37mm cannon coaxially with a short 75mm cannon. If anything, the M6 resembled the Neubaufahrzeug, than the Maus resembling the M6…

Damon.

The Germans had already experimented with this setup in the Neubaufahrzeug, which mounted a 37mm cannon coaxially with a short 75mm cannon.

I had not taken that into account, just goes to prove how cunning the Huns were already in mid-30's.

Let's try a revised timeline:
1.) Germans build the Neubaufahrzeug to demonstrate what a brilliant concept 37 mm coaxial gun is.
2.) Impressed by the performance of Neubaufahrzeug in 1940 blitzkrieg, the US military also decides that they want a vehicle with a 37 mm coaxial gun (though preferably with a name that is easier to spell), leading to M6 development.
3.) Germans hear of the M6 design and decide to start a coaxial gun arms race by introducing a 75 mm coaxial to their Maus designs.

Soviet designers in the meanwhile are well behind the loop, only managing to put together a tank with 12.7 mm coaxial MG in the post-war years.

Because of course a 37mm will be a useful antitank gun in 1943… *eyeroll*

Because of course a 37mm will be a useful antitank gun in 1943…

My understanding is that it was still moderately useful against many Japanese tanks at that time.

Besides, there was also a canister shot available, which could be used for turning the gun into a gigantic shotgun – possibly useful for pounding at opponents hiding in shrubbery or for hunting ducks.

Now I am thinking of Devil's Guard scenarios with French Panthers and ex-SS Foreign Legionaries, versus North Korean JS3s….

Here ! Here ! Sounds like a fun scenario ! Or Chinese JS-3s crossing the border of French Indochina to support the Vietminh!

My understanding is that it was still moderately useful against many Japanese tanks at that time.

Yes, the IJF's AFVs were very generally lightly armored, with rivetted hulls in most cases. The 37mm would do the job.

Besides, there was also a canister shot available, which could be used for turning the gun into a gigantic shotgun

I had heard that the 37 with cannister was very effective vs. Infantry.

I'm not so sure the inclusion of a coaxial 37mm to deal with Japanese tanks or shotgun infantry is the wisest design choice you could do. Especially when considering it had a 3in cannon with 75rnds already. The 37mm just took up space that could be used for more 3in rounds. Regardless, it was an antiquated design that very few tanks took up after it was introduced (IIRC around 100 M6s were produced & entered service, though not for combat). Besides the armament issues, the M6 was generally antiquated in design features overall, so its not surprising it wasn't successful in service. The 3in cannon would have been useful, but the 76.2mm M1A1 cannon had identical performance & could be fit on a Sherman, so little advantage there either…

Damon.

Well, Matilda IIs with either a 2 pdr (40mm) or a 3 in howitzer served thru VE day in the Pacific.

I have also seen a Matilda II still on the active list in one of the Soviet fronts in 1944.

Of course the Soviets were also still fielding light tanks with 20mms in 1945.

I'm not so sure the inclusion of a coaxial 37mm to deal with Japanese tanks or shotgun infantry is the wisest design choice you could do.

Generally I'd say, an MG would be a better choice, especially in the PTO. However, if the M6 or even M26 was deployed in large numbers. The PTO would probably not need either and the M4 would be fine. As I had heard the M4 was sometimes called the "Panther of the Pacific". Albeit tank on tank engagements in the PTO were very, very, rare …