Operation Barbarossa - What if

[ShadesWolf]

Operation Barbarossa started in June 1941. What if Britain/ France etc had not declared war in 1939, and Barbarossa could have been in June 1940 ?

We all know that Russia had a problem with Finland, if Germany had not been fighting on as many fronts as it was might the outcome of the invasion have been different ?

[Kagemusha]

I believe that is very hard question. Soviet Army was at pretty bad state in spring 1940.Also without Western Supplies they got in 1941,they could have collapsed lot easier. But then Also without the experience of the France,Yogoslavian and Campaign in Creece the Wermacht wouldnt have possessed the experience it had.Also without new recruits from younger Generations the Finish army was almost out of fresh blood straight after Winter War.There is lots to speculate in this matter this can turn out to be very intresting thread.

[spmetla]

This is definately abig "what if".

Let's see, the Wehrmacht was fairly well sized and would have had the experience of their Polish conquest but on the other hand the elite Panzers were still very primitive. Lots of Pz Is, PzIIs and Pz35/38s and only a handful of undergunned and underarmored PzIIIs and PzIVs. The MP 40 had only just entered mass production and the MP 38 was still a fairly rare weapon. Most artillery was horse drawn and the same goes for most supply.

The Kriegsmarine though was at it's greatest strength for it's surface fleet at this time and the U boot arm was still small but very effective.

The Luftwaffe was also very large at this point and for the time very well equipped for blitzkrieg warfare.

Taking this into consideration the Germans would probably have done very well initially but the advance would have been a fare bit slower seeing as the Panzer forces hadn't had the opportunity to practice true breakthrough fighting as they did in France and the Lowlands so they'd be less experienced and the tactics still rather primitive. The Soviet forces had very few good tanks at the time but they were get their KV series and T 34s on line so once these appeared they would have had total dominace of the battlefield, at least where these tanks could appear. There would probably of still been the huge routs of the 1941 invasion but with a less effective panzer arm encircling would probably have been slower and less soviets would have been captured. These fast yet slower advances might not have made the moving of Soviet industry to the Urals nessasary.

The Luftwaffe with only a single front to cover would have been able to maintain it's air superiority much longer than in the 41 invasion and with german industry not threatened by allied bombing the quick replacement of llost equipment could have allowed air dominance instead of just superiority. Without the losses of Ju 52 transports in an invasion of Crete the Luftwaffe would also have had it's elite Fallshirmjaeger to deploy in advance of Wehrmacht units and to capture bridgeheads and other strategic locations which if done properly could have made up for the weakness of german panzer forces at the time and also have allowed for an effective abiltity to supply forward units from the air to keep the momentum going.

The Kriegsmarine would have again had dominance over the Baltic sea but without the losses of the Norway invasion would have been perhaps able to better support the advance of units near the shore and if done correctly to help in a siege or encirclement of Leningrad. And without the heavy losses the U boot arm took from British destroyers and convoys the Germans might have been able to spare more U IIs for transport to the Black sea in greater support of Romanian operations.

All in all I think the Germans would have achieved great initial success just like in 41 and with the Soviets morale having lowered do to their poor performance in the Winter War with the Finns the USSR might have actually collapsed like it was predicted in 41. On the other hand without the experiences learned in France the Germans would probably not have been near as daring as they were with their strategic objectives in 41 so perhaps they would have been prepared for the winter and had a successful spring offensive in 41 to take Moscow or perhaps this would have enabled the Soviets to retain more control strategicly and to put the war into a stalemate much sooner than 42-43

[Franconicus]

If Britain and France would have decided to give the Germans free hand in Poland then the Poles would have accepted the German requests. Parts of Poland would have become German; the bigger part, however, would haveremained Polish, although a German protectorate. There would have been a German dominated alliance between Germany, Poland, Hungary, Rumania and Yugoslavia. In the end this is what France and Poland would have had to agree with.

If we pretend they did it, then there would have been no tensions between Germany and its Western neighbors. I assume that at least the British would have supported the German invasion of the SU, because they were anti communistic. Maybe not with troops, but politically and with supply. Same for the US.

Other countries, like Spain and Italy would have been involved directly in the military operations. Maybe even volunteers from all Western countries, including Britain and France; just like during the Spanish civil war.

German industry would have had no problems getting natural resources (not only oil!).

So we talk about an alliance of Germany, Spain, Italy, Finland, Poland, Slovakia, Hungary, Romania, Yugoslavia, probably Turkey, with support of Britain, France, the Netherlands, Belgium, Sweden and Norway.

Maybe Britain would have even invaded Afghanistan and the Caucasus republics.

No doubt that the SU would have lost the war.

[English assassin]

I'm not sure an invasion in 1940 wouldn't have been harder than in 1941.

The SU had a truly vast tank park, but of mostly obsolete models. But as Spmetla points out, the German tanks of 1940 vintage were not that superior. The extra years production of PZKFW III and IV may have been very important (though you'd need to compare it with the figures for the T34 and KV1).

Russian tactics would no doubt have been as poor in 1940 as in 1941, but the German Army would have lacked the battle experience it had in 1941.

Most fundamentally, on the political front, surely a large number of divisions would have had to be retained in Germany for fear that France and Britain would declare war in support of the SU (ie as they did in fact for Poland). I forget how many divisions the French fielded compared to the Germans but I recall that the French army was (rightly) perceived as a formidable force, and the fact that historically it fell quite quickly to a blitzkreig attack doesn't, IMHO, make an undefeated french army on the western german border in 1940any less of a threat.

So unless some sort of diplomatic scenario is being assumed whereby French and British neutrality is guaranteed I'd think the invasion was impossible.

[Louis VI the Fat]

What if Germany invaded the SU in 1940? The Germans would've penetrated deep into Russia. They would've penetrated deep into Russia before the winter. Severe cold and Soviet counterattacks would take their toll. In the spring of 1941, they would've advanced to the outskirts of Leningrad, Moscow and Stalingrad, stretching their supply lines and keeping the bulk of the German army occupied.

Then, on the first of may 1941, France crosses the Rhine, Britain lands at Bremen and Hamburg. Three days later, French and British troops play rugby underneath the Brandenburger Tor.

[Franconicus]

What if Germany invaded the SU in 1940? The Germans would've penetrated deep into Russia. They would've penetrated deep into Russia before the winter. Severe cold and Soviet counterattacks would take their toll. In the spring of 1941, they would've advanced to the outskirts of Leningrad, Moscow and Stalingrad, stretching their supply lines and keeping the bulk of the German army occupied.

Then, on the first of may 1941, France crosses the Rhine, Britain lands at Bremen and Hamburg. Three days later, French and British troops play rugby underneath the Brandenburger Tor.

Who wins?

[Louis VI the Fat]

France, with 31-6.

Oh, you didn't mean the rugby match but the war? Well, while the entire German army was engaged in a war on the eastern front, France / Britain occupied Germany in a textbook blitzkrieg. Dazed and confused, cut off from their occupied homeland, the German army goes 'uh, now what?' and decide to just run rampage in the Ukraine. They spend the rest of the year fighting a war of attrition on Soviet soil.

France and Britain spend the rest of 1941 in occupied Germany, waiting for the Germans and Russians to exhaust each other. By spring 1942, France / Britain attack from the west, America lands in Vladiwostok. Six weeks later, they meet at the Ural mountains. Having annihilated Nazi Germany and the Soviet Union, they now turn their attention towards Japan. In one swift overland campaign staged from occupied Russia, they drive them from mainland Asia. Under threat of the huge allied force ready to stage an invasion from Korea, Japan surrenders. By the summer of 1942, WWII is over.

[Kraxis]

Since the winter of 40-41 was comparably mild compared to 41-42 it wouldn't have had as hard an impact on the Germans.

In 1940 the KV-1 and T-34 hardly existed. A few trial vehicles existed of course, and I believe a few combat tanks as well. But not the 1000 each of 41. Thus the Germans wouldn't have had to contend with them, but would still learn the lessons when they faced the very few there were.

But I think the Soviets had a number of Armoured divisions at this time, that only got broken up late in the year. Kind of ironic that they were broken up.

[Seamus Fermanagh]

I think the assessment of a May/June '40 offensive -- strong but falling short of a killing blow -- is accurate. Too many Pz I's and II's in the formations for the Germans and not enough PzG infantry -- they altered their mobile force significantly following their experiences in France. Advantages in air power and Fallschirmjaeger probably not quite enough to compensate.

The German army of mid 1941 was a finely honed sword that only fell short in Barbarossa because of mistakes at the high command level -- remember, the Russians never massed those KV-1s or T-34s until later and the Sov AF was dead until 1942 (suggested read Panzers East).

In a no-war in France scenario, the German attack should have come off in November of 1940. Prepared for, Winter is actually a great time to attack in Russia -- the real enemies of the Blitzkrieg were the muddy seasons in late Sept/Oct and Apr/May. Think about a solid winter offensive (which Germany hadn't done since Frederick, and which would have probably caught them off guard) Nov through Feb, followed by a June '41 through September strike.

[King Kurt]

Since the winter of 40-41 was comparably mild compared to 41-42 it wouldn't have had as hard an impact on the Germans.

In 1940 the KV-1 and T-34 hardly existed. A few trial vehicles existed of course, and I believe a few combat tanks as well. But not the 1000 each of 41. Thus the Germans wouldn't have had to contend with them, but would still learn the lessons when they faced the very few there were.

But I think the Soviets had a number of Armoured divisions at this time, that only got broken up late in the year. Kind of ironic that they were broken up.

Not many KV1s and T34s - but plenty of BT5s and 7s - more than a match for Mk1s and 2s and 38Ts which made up a significant proportion if not the majority of the German armour. From memory the Mk3s would only have had 37mm guns in 1940 and Mk 4s short 75mms - so there is a case to say the russian armour - in performance as opposed to doctrine - is better in 1940 than 1941 in comparison to the germans.
The most critical factor would be that the Russian army is still recovering of the purges of 1938 - is was a major problem in 1941, so I assume that 1940 would be worse.
Another factor would be the lack of the low countries and france as a captive source of money and resources - other people have covered the need to cover the possible threat of France/ GB intervening militarily when the German backs are turned - especially as they would not need to cross the water.

[discovery1]

Hmmm. I belive the pzIII was supposed to have a 50 mm gun, not a 37, but for some reason(uniformity of supply?) used a 37 mm. If they see action in Russia before the are produced in numbers, maybe this won't happen. Course, it probably won't if the 37 mm is enough to handle the likes of the Bt-7. Although if the sovs use their few combate t-34s, the inadequecies of the 37 mm probably would be apparent. Thus when the Mk III appears in numbers, it is far more effective without the need for upgunning. Capable of taking out a t-34 anyway.

http://en.wikipedia.org/wiki/Panzerkampfwagen_III
Wiki agrees on the gun, for what its worth

[Brenus]

Interesting points of view, but I am not so sure about the initial German Success. In 1941, Stalin was so sure it was a mistake that he order his army not to resist, his fighter not to engage the German planes. Without the invasion of France, USSR would have been ready for the shock. And, yes, the T34 an KV85 were ready. Without the French experience, the panzers invading SU would have been Pz IV (75mm short barrel), but the majority would have been the T35…

[Kraxis]

I agree that the BT-7s were not bad tanks at all, they were just superceeded by the T-34, so they never managed to show their full capability. But the fact is that the German infantry AT-guns could very easily deal with them due to two things. Their horrible armour and lousy tactics. The T-34 used the same lousy tactics, but it's strong armour at the time made up for it, and its gun was also good against soft targets unlike the 45mm of the BT tanks.

Remember with a front as wide as this one, the armour of the two sides wouldn't meet very much. It would mostly be armoured assaults on infantry. And the infantry of 1940 wasn't very different from that of 41, and we all know that besides the KVs and the T-34 they could handle Russian tanks at the time.
Also, while it was readily accepted that the PzI and PzII were outdated, the PzII proved itself capable enough in Russia (to warrent the continued development of it, ending with the 'Luchs'). When they passed enemy points of resistance and got into the rear, it was hardly a difference if the tank was a PzII or PzIV, they could wreck comparable damage (technically no, but in reality they could more or less). And this was what happened even with PzIIs in 41.

Germany wouldn't win this time, but she would learn her lessons much cheaper, much eariler and much faster. The 41 offensive would likely be able to win.
Don't forget that it wasn't just in terms of armour that the SU was 'lucky' in 41. The Il-2 had just become active as well. It proved vital as you must know. And they had also taken the first steps towards modern fighters, and were even outproducing the Germans in this regard. In 1940 they wouldn't have any proper attackplanes nor any modern fighters, not even any nearing finished designs. They would need another year for that. Meanwhile Germany would lack heavier tanks and some experience.

But don't forget that the reason the Light divisions were disbanded was because they were not strong enough against well equipped enemies. I'm not so certain that they would be inadequate against the Russian armies at the time. And this would in theory give the Germans superior mobile punch compared to 41 as they would have more mobile divisions (if somewhat weaker).

[Sarmatian]

It is not that simple. If britain/france were not involved in the war, the germans would still have to go through poland. Barbarossa came as a suprise because everybody believed that germany is going to attack england. With that out of the question, as it is in this "what if" scenario, russia would have been ready for war. Do not forget that SU had much more airplanes than germany (although not as advanced) and air superiority of the germans would be in question. German army achieved air superiority because it destroyed russian airplanes on the ground. That would not have happened if SU have been prepared.
Also, german tanks (panzer IV) proved ineffective against t-34. "Panther" came later, after they realised panzer IV ineffectiveness in russian campaign. But t-34 was more than a match even for a panther, and not to mention it was 4 times cheaper. Next improvement, the tiger tank, was to bulky and slow to carry out the offensive.
Therefore I think that the result of the campaogn would have been the same.

[spmetla]

Although the Soviet airarm was large it was hugely obsolete and ineffective. The Planes the Germans had in 1940 didn't differ too much from 41. The only differences would really be that 109 might not have had the F model until later and the 190 wasn't far along yet.
If the Germans had been able to maintain air superiority longer they would probably have been able to negate the value of Soviet armor longer as well, at least until German tank production and technology improved. One of the problems the Germans faced initially with the Luftwaffe was that witht he Luftwaffe having to divert so many of it's resources so far they couldn't give all ground forces the aircover they needed and later when other fronts of the war required more airpower they weren't able to fill these gaps of air superiority which allowed the Soviet Air Force to contest the Germans in 42. Now with a single front war the Luftwaffe would have been able to cover the Russian front much better, how complete I don't know but this could have been a key factor seeing as air superiority was one of the key factors in all the Germans historical successes of 39-42.

An interesting that was brought up was the involvement of the West. If Britain and especially the USA saw facist Germany attacking the Soviet Union they might have been content to encourage these two powers to engage in perpetual war and like Truman said, "if the germans are winning support the soviets and if the soviets are winning support the germans that way they can kill as many of each other as possible" or something to that effect.
Do you think that the west might have been happy to sell oil, ammunition, and other supplies to the Germans? I don't really think they would have supported the USSR because if they were neutral then they wouldn't have to risk their own ships to sell to Germany while supporting the USSR would have still required bypassing Uboats which might not be worth the profit to loss of life.

And another though, with the West neutral I'd guess that Mussolini would lend more support of the Italian navy to the Germans which could be very decisive in the Black Sea region where Italian dominance over the Soviet navy would probably have been assured and allowed the entire Black Sea coast line to be threatened from naval invasion and draw off more troops from the German front. If done correctly the Italians could have quickened the conquest of crimea and possibly have siezed important ports along the Eastern Black Sea allowing for a possible 41 assault in the Caucaus region and therefore oil.

Just some thoughts.

[English assassin]

Do you think that the west might have been happy to sell oil, ammunition, and other supplies to the Germans? I don't really think they would have supported the USSR because if they were neutral then they wouldn't have to risk their own ships to sell to Germany while supporting the USSR would have still required bypassing Uboats which might not be worth the profit to loss of life

Whilst I doubt there would have been any tears for Stalin, I don't think either the French or the British would have been willing to allow a huge German empire to have been created by conquests in the east. (Nor, taking the longer term view, would it be in their interests to see Germany destroyed and the Russians adjacent to western europe)

The only issue might have been, if 1940 went as well as 1941, whether the speed and scale of German (apparent) success would have been so great that the UK and France would have held back from declaring war. After all, Russia had collapsed in a war with Germany once before. As the UK and France did in fact declare war over Poland, when it was obvious that Poland could not resist the German invasion, I can't imagine they would have held back from declaring war over an invasion of Russia in 1940 even if that invasion was going very well for the Germans.

[Kraxis]

spmetla, about 40% of the Lufwaffe was placed in France and Germany at the time of the original Barbarossa.
Add to that the losses suffered over France and Britain.

Now the SU didn't so much contest the control of the skies in 42, as in it managed to sneak into the massive holes in the German airspace. Tere were not enough planes to cover the entire front. Similar to 41 actually. With fewer holes the Red Airforce would not be able to do it's interdiction of advancing German forces tothe same degree as it did in 41, especially not with no modern fighters on the way.
Special operations, such as the bombing of bridges would still be possible, as you simply can't stop that entirely.

[screwtype]

Hmmm. I belive the pzIII was supposed to have a 50 mm gun, not a 37, but for some reason(uniformity of supply?) used a 37 mm.

As I recall the German ordnance dept wanted to equip the PzIII with the 37mm gun simply because they had a lot of 37mm guns lying around. The field commanders however wanted the 50mm gun. A compromise was reached in that the tank was fitted with the 37mm but built to accomodate the larger 50mm should the need arise, which in retrospect was a wise decision.

But of course, not only the 37mm but also the 50mm was quickly found to be inadequate on the Eastern Front.

[Alexanderofmacedon]

Operation Barbarossa started in June 1941. What if Britain/ France etc had not declared war in 1939, and Barbarossa could have been in June 1940 ?

We all know that Russia had a problem with Finland, if Germany had not been fighting on as many fronts as it was might the outcome of the invasion have been different ?

I wouldn't be so sure. Stalin killed a lot of his best generals and disbanded his more elite units, for fear of treason in the ranks. If Germany invaded earlier, they would have had better generals and better troops to deal with. I'm not positive though, because a war on fewer fronts, would also free up great German generals and troops.

[screwtype]

It is not that simple. If britain/france were not involved in the war, the germans would still have to go through poland. Barbarossa came as a suprise because everybody believed that germany is going to attack england. With that out of the question, as it is in this "what if" scenario, russia would have been ready for war.

I don't think it would have made much difference whether the SU was "prepared" for a German invasion or not. They simply did not have the doctrine, the organizaton or the training to withstand the Blitzkreig. A more "organized" defence might simply have put more Soviet units in the front line and thus subject to encirclement.

Do not forget that SU had much more airplanes than germany (although not as advanced) and air superiority of the germans would be in question.

Yes but most of them were obsolete biplanes which would have been no match for modern German monoplane fighters. Also their airfields and their equipment would probably have been overrun quickly by the advancing Wehrmacht in any case.

Also, german tanks (panzer IV) proved ineffective against t-34. "Panther" came later, after they realised panzer IV ineffectiveness in russian campaign. But t-34 was more than a match even for a panther, and not to mention it was 4 times cheaper. Next improvement, the tiger tank, was to bulky and slow to carry out the offensive.
Therefore I think that the result of the campaogn would have been the same.

Sorry, but this is not correct. Firstly the Panzer IV was not "ineffective" against the T-34, it was a good tank and performed effectively against the opposition right to the end of the war. However the T-34 was a better tank in some respects such as mobility. The German Panther tank was an attempt to copy some of the good design features of the T-34, such as the increased mobility and sloped armour.

Secondly, the Tiger came before the Panther if I'm not mistaken. It was already in service in 1942, the Panther did not see action until Operation Citadel in July '43 and even then it turned out not to be ready.

Thirdly, the Panther was a considerably superior tank to the T-34 in critical respects, even after the upgrading of the T-34 with the 85mm gun. The Panther's long barrelled 75mm gun had a considerably greater effective range and more penetration than either the Russian 75mm or 85mm gun. Also, German tank guns had superior sights which made their fire much more accurate. These were critical advantages for the Panther.

In most other respects, the tanks were pretty much on a par, but of course the Panther also had crews with far superior training and communications which put them even further in front.

[Pannonian]

Sorry, but this is not correct. Firstly the Panzer IV was not "ineffective" against the T-34, it was a good tank and performed effectively against the opposition right to the end of the war. However the T-34 was a better tank in some respects such as mobility.

Armour, gun, production...

The German Panther tank was an attempt to copy some of the good design features of the T-34, such as the increased mobility and sloped armour.

Secondly, the Tiger came before the Panther if I'm not mistaken. It was already in service in 1942, the Panther did not see action until Operation Citadel in July '43 and even then it turned out not to be ready.

Thirdly, the Panther was a considerably superior tank to the T-34 in critical respects, even after the upgrading of the T-34 with the 85mm gun. The Panther's long barrelled 75mm gun had a considerably greater effective range and more penetration than either the Russian 75mm or 85mm gun. Also, German tank guns had superior sights which made their fire much more accurate. These were critical advantages for the Panther.

Not enough to compensate for the advantages of the T-34-76/85, which were ease of manufacture and ease of maintenance. The T-34 was even better suited for mass-production than the M4 Sherman, with around 40000 of all makes produced during the war. Interchangeability of parts was also built into the design, so that parts from a broken tank could easily be cannibalised for use in another. Getting parts from one German tank to fit another of the same make was notoriously difficult. Also, just about anyone skilled in metalwork of any kind could fix a T-34, while you needed specialists to repair Panthers. Finally, the T-34 was very reliable, second only to the Sherman among MBTs.

In most other respects, the tanks were pretty much on a par, but of course the Panther also had crews with far superior training and communications which put them even further in front.

German tanks may have been better individually, but they were far too over-engineered to produce and use in sufficient numbers to win the war in the east. Soviet tanks were at least competent in their task, and were repeatedly redesigned for greater and greater simplicity.

[screwtype]

Not enough to compensate for the advantages of the T-34-76/85, which were ease of manufacture and ease of maintenance. The T-34 was even better suited for mass-production than the M4 Sherman, with around 40000 of all makes produced during the war.

Fine, but I was responding to Sarmation's comment that Panthers were "no match" for T-34's. On a tank v tank basis, the reverse if anything is true.

And while it's true that ease of manufacture was a major advantage of the T-34, it's also true that German tank production (and industrial production in general) should have been a lot better. It was quite disorganized for most of the war, for a variety of reasons. The Germans also had to cope with strategic bombing, which led to constant shortage of parts. The Soviets didn't have that problem.

So I don't think it was so much the "over-engineering" that caused the problem as it was the disorganization of the industry, which never rose to anything like the efficiency of that of the other major powers. And I don't think a better class of equipment is something to sneer at. After all, when the rule of thumb was five T-34's/Shermans to take down one Panther, one would hardly need to achieve anything like parity in production in order to still come out on top.

[Watchman]

One little detail is that AFAIK the fiascos of the early Winter War and the German demonstration of the full viablity of Blitzkrieg techniques (which the Soviets also knew under the name "Deep Combat", but hadn't implemented due to Stalin's internal scheming) prompet some serious reforms in the Red Army. A Barbarossa in -40 instead of -41 would naturally mean much less of them would have been implemented.

A rather important factor would however be if Stalin would be in similar denial in -40 as he historically was in -41. A military force's ability to oppose an invasion is obviously greatly hampered if it's told to not fire on the invaders come what may... A Soviet senior officer reputedly commented that what saved the USSR was the poor discipline of the troops, who would return fire regardless of orders.
'Course, I can't think of any particular reason why Stalin would be making his decisions any more lucidly than he did in -41.

So I don't think it was so much the "over-engineering" that caused the problem as it was the disorganization of the industry, which never rose to anything like the efficiency of that of the other major powers.

Oh, the Germans "over-engineered" their stuff all right. Not only did they have a definite flair for "bells and whistles" designs and downright odd experimentations, they had a bad habit of not designing their tanks in particular with future upgrades in mind. They pretty much just designed a wholly new vehicle every time, which was really a bit reinventing the wheel all over again. In comparision the Soviets for example could get by with a few solid base designs which they updated throughout the war, and I know the Brits built several of their late-war series fully expecting to have to for example eventually design bigger turrets to house larger guns.

It's not that the German propensity for sophistication and "high tech" didn't have its good points, rather one gets the strong impression they enageged in way more of it than their resources actually allowed for...

[Kraxis]

Actually the Panther was built with plenty of capacity for upgrading.
The Panther II which the Allies should be happy never got into production was a most impressive vehicle. A slim turret as that of the King Tiger, with the long 88 (the 75mmL100 was abandoned as being too impractical), integrated IR sights. Simplified engine and suspension and superior armour for better speed, mobility and survivability.

But the simple fact was that Germany was hard pressed, and the Panther was good enough for the job. So why divert its production for an upgrade that was unneeded, or rather would have been problematic while production was too low for current needs.

Also the Jagdpanzer IV got upgraded to the long 75. And the StuG III (and IV) could have carried the long 75mm, but the Germans took the chance to create purposedesigned vehicles rather then upgrading vehicles that were already being too slow/weakly armoured. The reason why they never got the long guns in any case, can likely be attested to the same problem of the Panther. They were just needed that much to allow the assembly lines to change too much.

[Pannonian]

Actually the Panther was built with plenty of capacity for upgrading.
The Panther II which the Allies should be happy never got into production was a most impressive vehicle. A slim turret as that of the King Tiger, with the long 88 (the 75mmL100 was abandoned as being too impractical), integrated IR sights. Simplified engine and suspension and superior armour for better speed, mobility and survivability.

But the simple fact was that Germany was hard pressed, and the Panther was good enough for the job. So why divert its production for an upgrade that was unneeded, or rather would have been problematic while production was too low for current needs.

Also the Jagdpanzer IV got upgraded to the long 75. And the StuG III (and IV) could have carried the long 75mm, but the Germans took the chance to create purposedesigned vehicles rather then upgrading vehicles that were already being too slow/weakly armoured. The reason why they never got the long guns in any case, can likely be attested to the same problem of the Panther. They were just needed that much to allow the assembly lines to change too much.

They should have done what the troops on the ground told them to do in 1941, reverse engineered a captured T-34 and given them large numbers of a good, reliable tank and let superior German doctrine do the rest. Up until the end of the war captured T-34s were a favoured prize for panzer crews, powerful, reliable, fast, easy to use. The Soviets reputedly had crews drive the finished tanks from factories straight into battle, so simple were they to understand. This simplicity meant it was never difficult to find replacement crews in the roles the Soviets meant for their tank armies, exploitation of breakthroughs. Of course, the relatively inexperienced Soviet crews meant that the average T-34 was mincemeat for defending Tigers and Panthers, but that wasn't their primary purpose. By the time Panthers were available in numbers, Soviet SUs (nicknamed animal killers for their effect on Tigers, Panthers and Elefants) were also available for specialist anti-tank work, armed with 152mm guns (!!!).

[Watchman]

The "from the factory into combat" story is AFAIK true, but happened in Stalingrad where the Sovs ditched everything for expediency for obvious reasons. The "Tank Factory" was one of the more contested locales, wasn't it ? I've read the tanks often weren't even fitted with even the simple sights they normally had, and the gunners had to aim through the holes...

The Germans tended to enjoy rather better communications and sighting aids (not to mention training), which resulted in the Soviets trying to compensate by turning tank fights into close-range melees whenever possible. This was naturally a bit of a challenge in itself every now and then on the steppes...

[Pannonian]

The "from the factory into combat" story is AFAIK true, but happened in Stalingrad where the Sovs ditched everything for expediency for obvious reasons. The "Tank Factory" was one of the more contested locales, wasn't it ? I've read the tanks often weren't even fitted with even the simple sights they normally had, and the gunners had to aim through the holes...

It certainly wasn't ideal, but it just shows how simple they were to man (in many cases woman). That kind of tank crew wouldn't stand a chance against another tank, but tank armies were supposed to break into the rear, not fight other tanks. A classic instance of Deep Operations in action occurred when T-34s broke into Tatsinskaya airfield, far, far beyond the front line. They shot up any planes that didn't manage to escape, and made the airfield unusable for the Luftwaffe from then on. No tank to tank combat, just lots of mobility and independence taking them far into the enemy's rear, where they severely disrupted the enemy's communications. No need for experience or finesse when the enemy can't harm you.

Experienced crews would naturally be given the best equipment and would be on a level par with enemy tanks. Less experienced crews would either learn from their experience or die and be replaced.

The Germans tended to enjoy rather better communications and sighting aids (not to mention training), which resulted in the Soviets trying to compensate by turning tank fights into close-range melees whenever possible. This was naturally a bit of a challenge in itself every now and then on the steppes...

The usual tactic was to open up with Katyushas and artillery before probing with infantry, followed by a combined infantry-armour attack (with additional artillery) if needed. Those were the Shock Armies, designed to punch a hole in the enemy lines. The bulk of the armour and mobile infantry would be concentrated in Tank Armies, ready to go through that hole and deep into the enemy's rear. The destruction of the enemy's communications would lead to the crumbling of the enemy front, which were mopped up by following, more conventionally organised formations. That was Deep Operations as envisaged by Mikhail Tukhachevsky before he was purged by Stalin and his ideas with him.

The KV was upgraded to the SU-152 after Stalingrad showed the need for bunker destroyers. It was first used in numbers at Kursk, where it proved itself against the heaviest armour the Germans had (able to destroy Tigers from over 1km). Kursk also saw the introduction of the Panther. So the Soviets always had specialist Panther and Tiger killers whenever they suspected large formations of them were about. As Tigers and Panthers were specifically designed to counter the T-34, so the King Tiger was later designed to counter the ISU (formerly SU) tanks.

[Watchman]

I'm not wholly certain what the KV series of heavy tanks has to do with the SU/ISU series of assault guns/tank destroyers (which AFAIK initially carried 122mm guns, but...). Weren't the Klim Voroshilovs more the conceptual basis for the Iosif Stalin series of heavy "breakthrough" tanks ?

It's another thing if the SU/ISUs were built on modified KV hulls, though.

Oh yeah, and the Germans get the prize for the most sodding obscenely phallic main gun ever - the 380mm "rocket gun" of the Sturmtiger.

[Pannonian]

I'm not wholly certain what the KV series of heavy tanks has to do with the SU/ISU series of assault guns/tank destroyers (which AFAIK initially carried 122mm guns, but...). Weren't the Klim Voroshilovs more the conceptual basis for the Iosif Stalin series of heavy "breakthrough" tanks ?

It's another thing if the SU/ISUs were built on modified KV hulls, though.

Oh yeah, and the Germans get the prize for the most sodding obscenely phallic main gun ever - the 380mm "rocket gun" of the Sturmtiger.

My bad. The various vehicles were related, but there were 2 lines of descent. The Russians played around with the hulls and eventually built the IS tanks and ISU assault guns (different vehicles) on the same hull. The Germans eventually learnt the same trick, but much too late - the Soviets standardised from 1942 onwards, while the Germans only started doing so in 1944.

I read somewhere that some M4s were adapted to fire rockets. It didn't catch on, as they were inaccurate, dangerous to accompanying infantry, and left a lot of smoke and trails behind.