DogDodger

Now give poor old delete some credit.
 
It DOES say something about the respective auto technologies... Just not what he thinks it does.
 
The Pershing worked specifically because american engineers were capable of engineering something that was within the limits of their automotive technology while the Germans couldn't even manage to not fuck that up!
 
Anyone Actually capable in their field would have known that the panther final drives wouldn't have even been satisfactory on something 15 tons lighter, like the Pershing, so they built final drives that would actually WORK with what they had!
 
Delete keeps trying to act like it's some sort of accomplishment to build a "medium" that's 15 tons heavier than it should be while having inferior fit out because he apparently doesn't understand that the goal is to get x set of capabilities with y mobility at the lowest weight and bulk possible.
 
It's a fundamental misunderstanding of what the purpose of tanks truly is at it's core.
 
Delete believes in the stat block over all else while sane people understand that AFV design is about striking the best compromise between all the competing factors and design considerations to come out with a system that does the most with the least so that you can make deploy and supply as many of them as possible.
 
These are not vegas air races aircraft delete. No points are awarded for the most sleek sophisticated and on the edge of your technological capabilities designs.
 
Your entire approach for deciding what is good is based in a fundamental misunderstanding of the purpose of afv's.

The 90 mm gun T54 was in response to the PITA of loading the separate projectile/propellant case of the 90 mm gun T15E2 found in the T26E4 Pershing. The 90 mm gun T15E2 was in response to the PITA of loading the unitary ammunition for the 90 mm gun T15E1, which was fitted to the first T26E1 pilot and sent over to Europe during World War II, and whose adventures can be read in Hunnicutt's Pershing and Irwin's Another River, Another Town. The T54 gun went back to a unitary round, but the propellant case was shorter and wider, which eased handling in the confines of the tank but kept the chamber volume and ballistics equal to the gun T15E2. Two M26 pilots were armed with the T54 and designated M26E1; forty-one 90 mm rounds were stowed, with five in the loader's ready rack and the rest in the hull floor bins. Tests were conducted from 1947-1949, and the T54 was deemed the best extant US tank gun. Then nothing else happened with it... MV with AP-T was 3,200 ft/s (4.9" RHA penetration at 1,500 yards and 30 degrees); HVAP 3,750 ft/s (7.7" RHA at 1,500 yards and 30 degrees).

You might be able to get close with extra normally-spaced road wheels, but then you risk getting into TOG- or T-35-sized length, which would itself affect maneuverability. Not suggesting that the Schachtellaufwerk is worth the effort (the caveats at the end of the post hint toward my opinion), but when comparing the Pershing and Panther, just wanted to point out that nominal ground pressure tells far from the whole story. Perhaps Schachtellaufwerk might be thought of as almost a sort of technology demonstrator: outstanding softer-terrain performance though not necessarily cut out for the ease of use desirable for a war machine.
 
Not the lifting capacity per se as I understand it, but as N-L-M said, more of an issue of the products which were presented. Armored Force commander MG Devers said in December 1942, "Due to its tremendous weight and limited tactical use, there is no requirement in the Armored Force for the heavy tank. The increase in the power of the armament of the heavy tank does not compensate for the heavier armor." Hunnicutt opines that the Armored Force would rather have shipped two medium tanks than a single heavy tank. But of course, the heavy tank that Devers was talking about was the M6, so it's no wonder...

Panther has this very weird double diff system (not triple, sorry) that is sort of like two Clectrac units hulksmashed together operating in a compound fashion.
 
Ignoring the wherbwank for the "outgun anyone" (laffs in 122mm), this does do a good description of how it works. It is IMHO a lame system overall, being a *slight* improvement over the Controlled Diff system but at literally double the expense and space.
 

You might be able to get close with extra normally-spaced road wheels, but then you risk getting into TOG- or T-35-sized length, which would itself affect maneuverability. Not suggesting that the Schachtellaufwerk is worth the effort (the caveats at the end of the post hint toward my opinion), but when comparing the Pershing and Panther, just wanted to point out that nominal ground pressure tells far from the whole story. Perhaps Schachtellaufwerk might be thought of as almost a sort of technology demonstrator: outstanding softer-terrain performance though not necessarily cut out for the ease of use desirable for a war machine.
 
Not the lifting capacity per se as I understand it, but as N-L-M said, more of an issue of the products which were presented. Armored Force commander MG Devers said in December 1942, "Due to its tremendous weight and limited tactical use, there is no requirement in the Armored Force for the heavy tank. The increase in the power of the armament of the heavy tank does not compensate for the heavier armor." Hunnicutt opines that the Armored Force would rather have shipped two medium tanks than a single heavy tank. But of course, the heavy tank that Devers was talking about was the M6, so it's no wonder...

The 90 mm gun T54 was in response to the PITA of loading the separate projectile/propellant case of the 90 mm gun T15E2 found in the T26E4 Pershing. The 90 mm gun T15E2 was in response to the PITA of loading the unitary ammunition for the 90 mm gun T15E1, which was fitted to the first T26E1 pilot and sent over to Europe during World War II, and whose adventures can be read in Hunnicutt's Pershing and Irwin's Another River, Another Town. The T54 gun went back to a unitary round, but the propellant case was shorter and wider, which eased handling in the confines of the tank but kept the chamber volume and ballistics equal to the gun T15E2. Two M26 pilots were armed with the T54 and designated M26E1; forty-one 90 mm rounds were stowed, with five in the loader's ready rack and the rest in the hull floor bins. Tests were conducted from 1947-1949, and the T54 was deemed the best extant US tank gun. Then nothing else happened with it... MV with AP-T was 3,200 ft/s (4.9" RHA penetration at 1,500 yards and 30 degrees); HVAP 3,750 ft/s (7.7" RHA at 1,500 yards and 30 degrees).

1976 comparative trials of T-80, T-72, T-64A and T-62 in primary archive sources.
https://www.tankarchives.ca/2021/03/the-ussrs-hungriest-tank.html

You might be able to get close with extra normally-spaced road wheels, but then you risk getting into TOG- or T-35-sized length, which would itself affect maneuverability. Not suggesting that the Schachtellaufwerk is worth the effort (the caveats at the end of the post hint toward my opinion), but when comparing the Pershing and Panther, just wanted to point out that nominal ground pressure tells far from the whole story. Perhaps Schachtellaufwerk might be thought of as almost a sort of technology demonstrator: outstanding softer-terrain performance though not necessarily cut out for the ease of use desirable for a war machine.
 
Not the lifting capacity per se as I understand it, but as N-L-M said, more of an issue of the products which were presented. Armored Force commander MG Devers said in December 1942, "Due to its tremendous weight and limited tactical use, there is no requirement in the Armored Force for the heavy tank. The increase in the power of the armament of the heavy tank does not compensate for the heavier armor." Hunnicutt opines that the Armored Force would rather have shipped two medium tanks than a single heavy tank. But of course, the heavy tank that Devers was talking about was the M6, so it's no wonder...

There were a few reasons why heavy tanks were considered to be more difficult to deal with, but none of those were strictly speaking enough to disqualify the concept; more so, the inability of the heavy tank projects to bring a product considered sufficiently better than a medium tank (or indeed uparmored mediums like the Jumbo) to justify all the hassle.

This discussion has actually given me a renewed appreciation for the M26.
 
It's lower and shorter than Centurion or Panther, has worse frontal hull protection than the latter (but better side, top, turret, rear protection) and is generally more comfy than either. It's gun is perfectly fine, and has decent HE capability (unlike the other two). The soft factors (crew comfort, lots of viewing devices, a low and high-magnification gun sight, roof MG mounts, raised driver's seat, duplicated driver's controls, large engine bay hatches, ammunition layout etc) are all nice.
 
Overall, I'd say that the common historical verdict on the Pershing is more or less correct: it was an interim vehicle, advanced in some ways over its predecessor but not fully developed and lacking in certain areas. Even so, I'd say that it's the most balanced and usable of the three late-war heavy mediums. A solid 6/10 to the Cent 1's 5 or the Panther's 4. The T-44, for reference, is more like a 6.5-7, while the first-run T-54 is more like an 8.

In a way it was indeed possible to reach such numbers but we can safely bet they were inflated - after all they were inflated for all sides as deep studies of particular engagements show. To be fair numbers of kills by US bomber crews are probably the most inflated and I guess it was done knowingly to raise morale of the gunners as well. 
 
The reasons why such disproportionally huge number of victories for German fighter pilots could be possible are mainly two. 
 
First they flew until they died while allied pilots were used to train newbies. As a result of this fly-till-death strategy Germany had smaller and smaller group of elite pilots followed by cannon fodder while Allied pilots became gradually better than common German pilots as the war went on.
 
Flying till death brough this disproportionally enormous numbers of combat missions. Hartmann flew 1404 combat sorties with 825 engagements. Kozhedub flew 330 with 120 engagements, in a quick online search unfortunately I didn't find numbers of sorties for Bong, Marmaduke, Albert or Urbanowicz but I guess they weren't higher than 300. By quick math for Hartmann 1404/352=3,99 and 852/352=2,42. For Kozhedub it's 330/62=5,32 and 120/62=1,93. If we took it as real numbers Kozhedub would have worse sortie/kill ratio but better engagements/kill ratio than Hartmann. Let's not also forget that Hartmann was 16x shot down, i.e. he was in a way also extremely lucky. After the war Hartmann was charged in USSR for various crimes including "destuction of 345 expensive Soviet aircraft". The trial was also more of a propaganda show I guess but interestingly it operated with Hartmann's offcial numbers.  
 
The second reason, why, is that to have huge number of kills you need to have someone to shoot down. We can see that the top fighter pilots of battles of France and Britain also scored plenty of kills in very short time because there was more than enough targets to shoot down and they flew non-stop in desperation. As the war went on the number of Germans flying around went so low in comparison to now overwhelming numbers of Allied planes that towards the end of the war some Allied pilots probably never even entered an aerial combat. Best scoring pilot of the Battle of Britain Josef František was credited with 17 sure+1 probable kills in 28 days. The elite French Groupe de chasse I/5 was credited with 71 kills with a loss of only one dead own pilot during the Battle of France (many were shot down but survived and fought again). I.e. in desperate situation against enemy with superior numbers top Allied pilots scored enormous number of kills as well (and their kills were of course also inflated). 
 
In the end I would say that the numbers of aerial kills could be proportionally correct but they were for sure inflated on all sides (that is normal in every war, US kills in Vietnam were grossly inflated too). 
 
 
What I don't believe however is tank kills of pilots like Erich Rudel. Various studies showed that armor losses to airforce were minimal during the WW2. The tests showed that destryoing a tank with WW2 aircraft was extremely difficult even on a static tank without AA fire.  

Depends on what military leaders and which doctrinal publications one reads, I suppose. In October 1941 Armored Force commander Major General Jacob Devers was on the record saying the desired defense to have versus enemy tanks was more tanks, which echoed the viewpoint of the previous Armored Force commander, Major General Adna Chaffee. US medium tanks M2 and M3 and light tanks M2A4/M3/M5 were all topped by extant 37 mm antitank guns, and it was intended to arm the M4s (along with the 75 mm gun and 105 mm howitzer thanks to its interchangeable turret front plate) with the 3" antitank gun later found in the GMC M10 and heavy tank M6 (which was armed with both 37 mm and 3" antitank guns). The 3", of course, turned out to be too unwieldy for the medium tank turret, hence the 76 mm gun's genesis. But on the subject of doctrine, Armored Force field manuals consistently listed enemy tanks as potential targets for friendly medium tanks. In March 1942, FM 17-10 Armored Force Field Manual: Tactics and Technique directed, "Medium tanks...protect the light tanks against the attack of hostile tanks. When the enemy is composed of mechanized troops, a large medium tank component, if available, is held in the reserve." Referring to GHQ tank battalions, this manual advised, "[Medium tanks] are used offensively against hostile tanks...During the course of an attack GHQ tank units may be used offensively, in conjunction with other available antitank measures, to attack hostile mechanized forces threatening to break up or disorganize the main effort...GHQ tank units attached to army corps or divisions may be used in large numbers to break up hostile mechanized formations." The September 1942 edition of FM 17-33 Armored Force Field Manual: The Armored Battalion, Light and Medium included the "support by fire [of] the advance of light tanks, other medium tanks, or infantry in tank versus tank action" among the uses of medium tanks. The December 1944 revision of FM 17-33 asserted that medium tanks may be used "[w]hen necessary, against enemy tanks", and indeed one purpose specifically assigned to 76mm gun medium tanks was to "reinforce the antitank defense of a supported infantry unit." Similarly, technical manuals for the Sherman also evinced the intention of taking on enemy armor with both 75mm and 76mm guns. TM 9-731B Medium Tank M4A2 from January 1943 suggested that fully 40% of the 75 mm ammunition loadout should be armor-piercing, and TM 9-759 Tank, Medium M4A3 from September 1944 alleged that both the 75 mm and 76 mm guns were "employed chiefly against enemy tanks and other ground objectives." So while not all FMs said tanks were the primary antitank weapon, taking on enemy armor was a main mission listed in others. Indeed even the Tank Destroyers themselves recognized this: FM 18-5 Tank Destroyer Field Manual Organization and Tactics of Tank Destroyer Units from June 1942 says of TD battalions attached to armored divisions or GHQ tank groups: "Tank destroyer battalions with armored divisions are not the only units fitted for offensive engagement against hostile tanks as is the case with other types of divisions..." The July 1944 edition of FM 18-5 Tactical Employment Tank Destroyer Unit noted in the section describing TD attachment to armored divisions, "Since the armored division can meet strong armored attacks with effective organic weapons, tank destroyers may execute secondary missions on rare occasions, even when a hostile armored attack or counterattack is imminent."
 
During study and the extractions of lessons directly after WW2, the General Board of the European Theater explicitly stated in its postwar studies that "[t]he European campaign demonstrated that tanks fight tanks," and also that the "current thought is that the medium tank is the best anti-tank weapon." The January 1946 report by the War Department Equipment Board agreed with the General Board, saying, "The best antitank weapon is a better tank."
 
Re: the other mechanization proponents listed, there seems to be agreement that tanks are an important, if not primary, antitank weapon. In Tanks in the Great War, Fuller describes his view of future war: "The tank fleets under the cover of dense clouds of smoke, or at nighttime, move forward, not against the body of the enemy's army but against his brains...What is the answer to this type of brain warfare? The answer is the tank; the brains will get into metal skulls or boxes, the bodies will get into the same, and land fleet will maneuver against land fleet...If the enemy will not accept peace terms forthwith, then, wars in the air and on the earth will take place between machines to gain superiority. Tank will meet tank and, commanded from the air, fleets of these machines will maneuvre between the defended ports seeking each other out and exterminating each other in orthodox naval fashion." In Armoured Warfare, he says, "...the art of attacking will largely consist in establishing moveable strong points from which carefully directed fire can be brought to bear on the enemy's machines, whilst other forces of moving machines drive him towards them...In these battle tactics there is one minor point that requires examination, and that is--how wil tank engage tank? I think the eventual answer to this question is likely to be that normally tank will not engage tank, but instead that tank unit will engage tank unit." Indeed, Holden Reid says of Fuller: "Fuller's view of mechanized battles was...[t]he decisive act of battle would be the tank versus tank encounter or, depending on conditions, the tank verus anti-tank gun. Tanks should be armed, then, with small calibre armour piercing guns which could destroy their own kind."
 
In the Christopher Duffy translation of Achtung--Panzer!, Guderian says of tank-versus-tank combat: "Military literature tends to steer clear of this subject, invoking as an excuse our lack of experience. This attitude cannot be sustained over the long term. We will unfailingly be presented with the reality of tank versus tank action in the future, as we have already established, and the outcome of the battle will depend on the issue of that combat, irrespective of whether or not we are cast in the role of attackers or defenders...The tank's most dangerous enemy is another tank. As soon as a tank force identifies enemy machines, and is in a state to do battle with them, that force is duty bound to drop all its other missions and engage in combat. This also happens to be the best service we can render to our own infantry, since they will be in as much danger as our tanks if the enemy manage to break through with an armoured counter-attack...We cannot be content with training for individual combats of tank against tank. We must reckon on the appearance of large forces of tanks, and it is much more useful to work out how to manage combat on this scale." In Constantine Fitzgibbon's translation of Panzer Leader, he says of the equipment being discussed for the German armored forces, "Our opinion then was that for the eventual equipment of the Panzer Divisions we would need two types of tank: a light tank with an armour-piercing gun and two machine-guns, one in the turret and the other in the body; and a medium tank with a large caliber gun, and two machine-guns as before...We had differences of opinion on the subject of gun calibre with the Chief of the Ordnance Office and with the Inspector of Artillery. Both these gentlemen were of the opinion that a 37 mm. gun would suffice for the light tanks, while I was anxious that they be equipped with a 50 mm. weapon since this would give them the advantage over the heavier armour plate which we expected soon to see incorporated in the construction of foreign tanks."
 
Simpkin and Erickson quote Tukhachevsky's New Question of War: "...Decisive success in battle will go to the formation which has more gun tanks capable of destroying enemy tanks.
 
"Thus, for conflict with armies which have mechanised formations, our mechanised formations must be equipped not only with armoured personnel carriers and engineer and other specialist tanks, but with gun tanks--despite the fact that this is an unnecessary luxury for combat with infantry forces."
Once they became scared of German tanks they happily did, but this took until the invasion of France to occur. As above, tanks were more than cleared to engage enemy armor per Armored Force doctrine, and this was acknowledged in TD doctrine. In June 1944 it was intended to field 75 mm and 76 mm gun tanks in a two-thirds to one-third ratio, and they weren't employed at all until late July. By the time of the Rhine crossings in March 1945, however, experience had swayed this opinion so that approximately 40% of the Shermans in European Theater stocks were armed with the 76 mm gun. Indeed, production of 75 mm gun tanks totally ceased that quarter. Internecine politics may also have played a role in the 76 not being fielded until Cobra: Baily, for example, asserts that, contrary to the enthusiasm it showed for the idea in 1942, the Ordnance Department may have been opposed to the 76 mm Sherman in 1944 since it had the potential for interfering with the procurement of the T23...

It would be really interesting to compare readiness rates for M26s in Europe versus the ones that went to Korea. It would also be interesting to compare the Army M26s sent to Korean to the Marines, since the Marine tanks had been purchased right after WWII and put in storage. 
 
I'm sure what little US Army had in funds for spares went to the units in Europe. The stories of the Army having to refurbish Gate Guard Tanks, just goes to show you have close to the bone the Army had been cut by the Truman admin. Korea came just at the right time to show just how unprepared the US Military under Truman was to fight even a minor war.  If I recall right, Truman cut the Defense Department back to Pre WWII levels. 

Of course, I took it as a figurative statement. What I was hoping to illustrate, though, was that despite being ~17,000 lb heavier than an HVSS M4A3 and having essentially the same engine, the T26E1 was a large improvement in cross-country mobility with just a single torsion bar supporting each road wheel pair. The Panther's system doubtlessly provided a good and stable ride, but should the improvement over a single-bar system have justified its implementation? Germany was never going to out-produce its enemies, so a strategy of "qualitative" enhancement was logical, but it still seems that discretion is the better part of valor in some areas, especially when your tanks are expected to fire from the short halt. Could you please expand on what you mean by Pershing was not a finished vehicle as a medium? Thanks.
 
Although tank maintenance was a struggle for all US tank types in Korea, especially in the first year of the conflict, the M26 still showed itself to be the least reliable in that theater. To be fair, many of the M26s shipped to Korea were in poor condition and some overdue for overhauls, so the M26's performance there may be an outlier...
 
One was designed, but it seems it was not possible to actually manufacture it in the numbers needed to install on the new medium tank. Spielberger notes an epicyclic final drive had been tested successfully, but "a shortage of gear cutting machinery for the hollow gearing prevented this type this type of final drive from being mass produced." So spur gears with weakish steel were used by necessity.

The reliability problems with the Pershing were solved fairly fast from what I've read, and the tanks on the Zebra Mission are not all that different than the ones that served in Korea. The only big item I can think of is the final drive housing braces.  The longstanding problem that was never worked out was a bad driver could cause fan belts to pop off.  US standards for reliability were so far ahead of the Germans, the M26 would have been considered almost impossibly reliable to them. 

Excellent reply!

Depends on what military leaders and which doctrinal publications one reads, I suppose. In October 1941 Armored Force commander Major General Jacob Devers was on the record saying the desired defense to have versus enemy tanks was more tanks, which echoed the viewpoint of the previous Armored Force commander, Major General Adna Chaffee. US medium tanks M2 and M3 and light tanks M2A4/M3/M5 were all topped by extant 37 mm antitank guns, and it was intended to arm the M4s (along with the 75 mm gun and 105 mm howitzer thanks to its interchangeable turret front plate) with the 3" antitank gun later found in the GMC M10 and heavy tank M6 (which was armed with both 37 mm and 3" antitank guns). The 3", of course, turned out to be too unwieldy for the medium tank turret, hence the 76 mm gun's genesis. But on the subject of doctrine, Armored Force field manuals consistently listed enemy tanks as potential targets for friendly medium tanks. In March 1942, FM 17-10 Armored Force Field Manual: Tactics and Technique directed, "Medium tanks...protect the light tanks against the attack of hostile tanks. When the enemy is composed of mechanized troops, a large medium tank component, if available, is held in the reserve." Referring to GHQ tank battalions, this manual advised, "[Medium tanks] are used offensively against hostile tanks...During the course of an attack GHQ tank units may be used offensively, in conjunction with other available antitank measures, to attack hostile mechanized forces threatening to break up or disorganize the main effort...GHQ tank units attached to army corps or divisions may be used in large numbers to break up hostile mechanized formations." The September 1942 edition of FM 17-33 Armored Force Field Manual: The Armored Battalion, Light and Medium included the "support by fire [of] the advance of light tanks, other medium tanks, or infantry in tank versus tank action" among the uses of medium tanks. The December 1944 revision of FM 17-33 asserted that medium tanks may be used "[w]hen necessary, against enemy tanks", and indeed one purpose specifically assigned to 76mm gun medium tanks was to "reinforce the antitank defense of a supported infantry unit." Similarly, technical manuals for the Sherman also evinced the intention of taking on enemy armor with both 75mm and 76mm guns. TM 9-731B Medium Tank M4A2 from January 1943 suggested that fully 40% of the 75 mm ammunition loadout should be armor-piercing, and TM 9-759 Tank, Medium M4A3 from September 1944 alleged that both the 75 mm and 76 mm guns were "employed chiefly against enemy tanks and other ground objectives." So while not all FMs said tanks were the primary antitank weapon, taking on enemy armor was a main mission listed in others. Indeed even the Tank Destroyers themselves recognized this: FM 18-5 Tank Destroyer Field Manual Organization and Tactics of Tank Destroyer Units from June 1942 says of TD battalions attached to armored divisions or GHQ tank groups: "Tank destroyer battalions with armored divisions are not the only units fitted for offensive engagement against hostile tanks as is the case with other types of divisions..." The July 1944 edition of FM 18-5 Tactical Employment Tank Destroyer Unit noted in the section describing TD attachment to armored divisions, "Since the armored division can meet strong armored attacks with effective organic weapons, tank destroyers may execute secondary missions on rare occasions, even when a hostile armored attack or counterattack is imminent."
 
During study and the extractions of lessons directly after WW2, the General Board of the European Theater explicitly stated in its postwar studies that "[t]he European campaign demonstrated that tanks fight tanks," and also that the "current thought is that the medium tank is the best anti-tank weapon." The January 1946 report by the War Department Equipment Board agreed with the General Board, saying, "The best antitank weapon is a better tank."
 
Re: the other mechanization proponents listed, there seems to be agreement that tanks are an important, if not primary, antitank weapon. In Tanks in the Great War, Fuller describes his view of future war: "The tank fleets under the cover of dense clouds of smoke, or at nighttime, move forward, not against the body of the enemy's army but against his brains...What is the answer to this type of brain warfare? The answer is the tank; the brains will get into metal skulls or boxes, the bodies will get into the same, and land fleet will maneuver against land fleet...If the enemy will not accept peace terms forthwith, then, wars in the air and on the earth will take place between machines to gain superiority. Tank will meet tank and, commanded from the air, fleets of these machines will maneuvre between the defended ports seeking each other out and exterminating each other in orthodox naval fashion." In Armoured Warfare, he says, "...the art of attacking will largely consist in establishing moveable strong points from which carefully directed fire can be brought to bear on the enemy's machines, whilst other forces of moving machines drive him towards them...In these battle tactics there is one minor point that requires examination, and that is--how wil tank engage tank? I think the eventual answer to this question is likely to be that normally tank will not engage tank, but instead that tank unit will engage tank unit." Indeed, Holden Reid says of Fuller: "Fuller's view of mechanized battles was...[t]he decisive act of battle would be the tank versus tank encounter or, depending on conditions, the tank verus anti-tank gun. Tanks should be armed, then, with small calibre armour piercing guns which could destroy their own kind."
 
In the Christopher Duffy translation of Achtung--Panzer!, Guderian says of tank-versus-tank combat: "Military literature tends to steer clear of this subject, invoking as an excuse our lack of experience. This attitude cannot be sustained over the long term. We will unfailingly be presented with the reality of tank versus tank action in the future, as we have already established, and the outcome of the battle will depend on the issue of that combat, irrespective of whether or not we are cast in the role of attackers or defenders...The tank's most dangerous enemy is another tank. As soon as a tank force identifies enemy machines, and is in a state to do battle with them, that force is duty bound to drop all its other missions and engage in combat. This also happens to be the best service we can render to our own infantry, since they will be in as much danger as our tanks if the enemy manage to break through with an armoured counter-attack...We cannot be content with training for individual combats of tank against tank. We must reckon on the appearance of large forces of tanks, and it is much more useful to work out how to manage combat on this scale." In Constantine Fitzgibbon's translation of Panzer Leader, he says of the equipment being discussed for the German armored forces, "Our opinion then was that for the eventual equipment of the Panzer Divisions we would need two types of tank: a light tank with an armour-piercing gun and two machine-guns, one in the turret and the other in the body; and a medium tank with a large caliber gun, and two machine-guns as before...We had differences of opinion on the subject of gun calibre with the Chief of the Ordnance Office and with the Inspector of Artillery. Both these gentlemen were of the opinion that a 37 mm. gun would suffice for the light tanks, while I was anxious that they be equipped with a 50 mm. weapon since this would give them the advantage over the heavier armour plate which we expected soon to see incorporated in the construction of foreign tanks."
 
Simpkin and Erickson quote Tukhachevsky's New Question of War: "...Decisive success in battle will go to the formation which has more gun tanks capable of destroying enemy tanks.
 
"Thus, for conflict with armies which have mechanised formations, our mechanised formations must be equipped not only with armoured personnel carriers and engineer and other specialist tanks, but with gun tanks--despite the fact that this is an unnecessary luxury for combat with infantry forces."
Once they became scared of German tanks they happily did, but this took until the invasion of France to occur. As above, tanks were more than cleared to engage enemy armor per Armored Force doctrine, and this was acknowledged in TD doctrine. In June 1944 it was intended to field 75 mm and 76 mm gun tanks in a two-thirds to one-third ratio, and they weren't employed at all until late July. By the time of the Rhine crossings in March 1945, however, experience had swayed this opinion so that approximately 40% of the Shermans in European Theater stocks were armed with the 76 mm gun. Indeed, production of 75 mm gun tanks totally ceased that quarter. Internecine politics may also have played a role in the 76 not being fielded until Cobra: Baily, for example, asserts that, contrary to the enthusiasm it showed for the idea in 1942, the Ordnance Department may have been opposed to the 76 mm Sherman in 1944 since it had the potential for interfering with the procurement of the T23...

Depends on what military leaders and which doctrinal publications one reads, I suppose. In October 1941 Armored Force commander Major General Jacob Devers was on the record saying the desired defense to have versus enemy tanks was more tanks, which echoed the viewpoint of the previous Armored Force commander, Major General Adna Chaffee. US medium tanks M2 and M3 and light tanks M2A4/M3/M5 were all topped by extant 37 mm antitank guns, and it was intended to arm the M4s (along with the 75 mm gun and 105 mm howitzer thanks to its interchangeable turret front plate) with the 3" antitank gun later found in the GMC M10 and heavy tank M6 (which was armed with both 37 mm and 3" antitank guns). The 3", of course, turned out to be too unwieldy for the medium tank turret, hence the 76 mm gun's genesis. But on the subject of doctrine, Armored Force field manuals consistently listed enemy tanks as potential targets for friendly medium tanks. In March 1942, FM 17-10 Armored Force Field Manual: Tactics and Technique directed, "Medium tanks...protect the light tanks against the attack of hostile tanks. When the enemy is composed of mechanized troops, a large medium tank component, if available, is held in the reserve." Referring to GHQ tank battalions, this manual advised, "[Medium tanks] are used offensively against hostile tanks...During the course of an attack GHQ tank units may be used offensively, in conjunction with other available antitank measures, to attack hostile mechanized forces threatening to break up or disorganize the main effort...GHQ tank units attached to army corps or divisions may be used in large numbers to break up hostile mechanized formations." The September 1942 edition of FM 17-33 Armored Force Field Manual: The Armored Battalion, Light and Medium included the "support by fire [of] the advance of light tanks, other medium tanks, or infantry in tank versus tank action" among the uses of medium tanks. The December 1944 revision of FM 17-33 asserted that medium tanks may be used "[w]hen necessary, against enemy tanks", and indeed one purpose specifically assigned to 76mm gun medium tanks was to "reinforce the antitank defense of a supported infantry unit." Similarly, technical manuals for the Sherman also evinced the intention of taking on enemy armor with both 75mm and 76mm guns. TM 9-731B Medium Tank M4A2 from January 1943 suggested that fully 40% of the 75 mm ammunition loadout should be armor-piercing, and TM 9-759 Tank, Medium M4A3 from September 1944 alleged that both the 75 mm and 76 mm guns were "employed chiefly against enemy tanks and other ground objectives." So while not all FMs said tanks were the primary antitank weapon, taking on enemy armor was a main mission listed in others. Indeed even the Tank Destroyers themselves recognized this: FM 18-5 Tank Destroyer Field Manual Organization and Tactics of Tank Destroyer Units from June 1942 says of TD battalions attached to armored divisions or GHQ tank groups: "Tank destroyer battalions with armored divisions are not the only units fitted for offensive engagement against hostile tanks as is the case with other types of divisions..." The July 1944 edition of FM 18-5 Tactical Employment Tank Destroyer Unit noted in the section describing TD attachment to armored divisions, "Since the armored division can meet strong armored attacks with effective organic weapons, tank destroyers may execute secondary missions on rare occasions, even when a hostile armored attack or counterattack is imminent."
 
During study and the extractions of lessons directly after WW2, the General Board of the European Theater explicitly stated in its postwar studies that "[t]he European campaign demonstrated that tanks fight tanks," and also that the "current thought is that the medium tank is the best anti-tank weapon." The January 1946 report by the War Department Equipment Board agreed with the General Board, saying, "The best antitank weapon is a better tank."
 
Re: the other mechanization proponents listed, there seems to be agreement that tanks are an important, if not primary, antitank weapon. In Tanks in the Great War, Fuller describes his view of future war: "The tank fleets under the cover of dense clouds of smoke, or at nighttime, move forward, not against the body of the enemy's army but against his brains...What is the answer to this type of brain warfare? The answer is the tank; the brains will get into metal skulls or boxes, the bodies will get into the same, and land fleet will maneuver against land fleet...If the enemy will not accept peace terms forthwith, then, wars in the air and on the earth will take place between machines to gain superiority. Tank will meet tank and, commanded from the air, fleets of these machines will maneuvre between the defended ports seeking each other out and exterminating each other in orthodox naval fashion." In Armoured Warfare, he says, "...the art of attacking will largely consist in establishing moveable strong points from which carefully directed fire can be brought to bear on the enemy's machines, whilst other forces of moving machines drive him towards them...In these battle tactics there is one minor point that requires examination, and that is--how wil tank engage tank? I think the eventual answer to this question is likely to be that normally tank will not engage tank, but instead that tank unit will engage tank unit." Indeed, Holden Reid says of Fuller: "Fuller's view of mechanized battles was...[t]he decisive act of battle would be the tank versus tank encounter or, depending on conditions, the tank verus anti-tank gun. Tanks should be armed, then, with small calibre armour piercing guns which could destroy their own kind."
 
In the Christopher Duffy translation of Achtung--Panzer!, Guderian says of tank-versus-tank combat: "Military literature tends to steer clear of this subject, invoking as an excuse our lack of experience. This attitude cannot be sustained over the long term. We will unfailingly be presented with the reality of tank versus tank action in the future, as we have already established, and the outcome of the battle will depend on the issue of that combat, irrespective of whether or not we are cast in the role of attackers or defenders...The tank's most dangerous enemy is another tank. As soon as a tank force identifies enemy machines, and is in a state to do battle with them, that force is duty bound to drop all its other missions and engage in combat. This also happens to be the best service we can render to our own infantry, since they will be in as much danger as our tanks if the enemy manage to break through with an armoured counter-attack...We cannot be content with training for individual combats of tank against tank. We must reckon on the appearance of large forces of tanks, and it is much more useful to work out how to manage combat on this scale." In Constantine Fitzgibbon's translation of Panzer Leader, he says of the equipment being discussed for the German armored forces, "Our opinion then was that for the eventual equipment of the Panzer Divisions we would need two types of tank: a light tank with an armour-piercing gun and two machine-guns, one in the turret and the other in the body; and a medium tank with a large caliber gun, and two machine-guns as before...We had differences of opinion on the subject of gun calibre with the Chief of the Ordnance Office and with the Inspector of Artillery. Both these gentlemen were of the opinion that a 37 mm. gun would suffice for the light tanks, while I was anxious that they be equipped with a 50 mm. weapon since this would give them the advantage over the heavier armour plate which we expected soon to see incorporated in the construction of foreign tanks."
 
Simpkin and Erickson quote Tukhachevsky's New Question of War: "...Decisive success in battle will go to the formation which has more gun tanks capable of destroying enemy tanks.
 
"Thus, for conflict with armies which have mechanised formations, our mechanised formations must be equipped not only with armoured personnel carriers and engineer and other specialist tanks, but with gun tanks--despite the fact that this is an unnecessary luxury for combat with infantry forces."
Once they became scared of German tanks they happily did, but this took until the invasion of France to occur. As above, tanks were more than cleared to engage enemy armor per Armored Force doctrine, and this was acknowledged in TD doctrine. In June 1944 it was intended to field 75 mm and 76 mm gun tanks in a two-thirds to one-third ratio, and they weren't employed at all until late July. By the time of the Rhine crossings in March 1945, however, experience had swayed this opinion so that approximately 40% of the Shermans in European Theater stocks were armed with the 76 mm gun. Indeed, production of 75 mm gun tanks totally ceased that quarter. Internecine politics may also have played a role in the 76 not being fielded until Cobra: Baily, for example, asserts that, contrary to the enthusiasm it showed for the idea in 1942, the Ordnance Department may have been opposed to the 76 mm Sherman in 1944 since it had the potential for interfering with the procurement of the T23...

Indeed, during ODS crews found that the engine air filters of the Abrams required cleaning after as little as 6 hours of desert operation, and daily even when the engine was not started. As a result, 2/2 ACR, for example, went to battle with three times the normal stock of engine air filters.
 
While we're on the subject, TM 9-759 for the M4A3 from September 1944 says of dusty conditions: "Even when the above precautions [avoiding other vehicles' dust clouds as much as possible and not exceeding speed specified for whatever gear being used] are taken, it may be necessary to clean the carburetor air cleaners and the air cleaner on the filter pipe as often as every two hours. If the air cleaners are kept clean and their oil level is maintained, little damage to the engine will result. It is possible to wear out the engine in one hour or less if the air cleaners are neglected." TM 9-731B from January 1943 for the M4A2 says, "The frequency of servicing air cleaners depends on the dust and sand conditions encountered. Under extreme dust and sand conditions, service air cleaners every eight hours to prevent premature engine wear." TM 9-754 from January 1943 for the M4A4 also advises, "The air cleaners should be cleaned daily when the vehicle is operated over dusty terrains..." TM 9-731A from December 1943 for the M4 and M4A1 says the air cleaners should be drained, cleaned and refilled "[d]aily, when operating on dirt roads or cross country, or every 250 miles, when operating on paved roads or during wet weather..." And for completeness's sake, TM 9-756 from December 1943 for the M4A6 instructs that air cleaners are serviced "[e]very 5 to 60 hours of operation, depending on dust conditions..." and that they are to be drained, cleaned, and refilled daily. Also, "Every 100 miles, remove air cleaners, wash all parts, and reoil."
 
So for the CIA engineers to complain that the T-34-85's oil bath air cleaners needed to be serviced daily in dusty conditions to provide decent protection seems strange. When the report says of the subject's "wholly inadequate engine intake air cleaners", "Several hundred miles in very dusty operation would probably be accompanied by severe engine power loss" or "The cleaners were of such low efficiency and low dirt capacity that, in dusty operation, they should have been cleaned at least once each day and preferably several times if any appreciable engine protection were to be obtained", one wonders if they had read manuals for their own country's vehicles. The T-34-85's air cleaners may well have been inefficient and of low dirt capacity, but the fact that they needed servicing at least daily in dusty conditions does not per se seem to be good supporting evidence. Some type of quantification would have gone far in supporting that assertion.

Indeed, during ODS crews found that the engine air filters of the Abrams required cleaning after as little as 6 hours of desert operation, and daily even when the engine was not started. As a result, 2/2 ACR, for example, went to battle with three times the normal stock of engine air filters.
 
While we're on the subject, TM 9-759 for the M4A3 from September 1944 says of dusty conditions: "Even when the above precautions [avoiding other vehicles' dust clouds as much as possible and not exceeding speed specified for whatever gear being used] are taken, it may be necessary to clean the carburetor air cleaners and the air cleaner on the filter pipe as often as every two hours. If the air cleaners are kept clean and their oil level is maintained, little damage to the engine will result. It is possible to wear out the engine in one hour or less if the air cleaners are neglected." TM 9-731B from January 1943 for the M4A2 says, "The frequency of servicing air cleaners depends on the dust and sand conditions encountered. Under extreme dust and sand conditions, service air cleaners every eight hours to prevent premature engine wear." TM 9-754 from January 1943 for the M4A4 also advises, "The air cleaners should be cleaned daily when the vehicle is operated over dusty terrains..." TM 9-731A from December 1943 for the M4 and M4A1 says the air cleaners should be drained, cleaned and refilled "[d]aily, when operating on dirt roads or cross country, or every 250 miles, when operating on paved roads or during wet weather..." And for completeness's sake, TM 9-756 from December 1943 for the M4A6 instructs that air cleaners are serviced "[e]very 5 to 60 hours of operation, depending on dust conditions..." and that they are to be drained, cleaned, and refilled daily. Also, "Every 100 miles, remove air cleaners, wash all parts, and reoil."
 
So for the CIA engineers to complain that the T-34-85's oil bath air cleaners needed to be serviced daily in dusty conditions to provide decent protection seems strange. When the report says of the subject's "wholly inadequate engine intake air cleaners", "Several hundred miles in very dusty operation would probably be accompanied by severe engine power loss" or "The cleaners were of such low efficiency and low dirt capacity that, in dusty operation, they should have been cleaned at least once each day and preferably several times if any appreciable engine protection were to be obtained", one wonders if they had read manuals for their own country's vehicles. The T-34-85's air cleaners may well have been inefficient and of low dirt capacity, but the fact that they needed servicing at least daily in dusty conditions does not per se seem to be good supporting evidence. Some type of quantification would have gone far in supporting that assertion.

Indeed, during ODS crews found that the engine air filters of the Abrams required cleaning after as little as 6 hours of desert operation, and daily even when the engine was not started. As a result, 2/2 ACR, for example, went to battle with three times the normal stock of engine air filters.
 
While we're on the subject, TM 9-759 for the M4A3 from September 1944 says of dusty conditions: "Even when the above precautions [avoiding other vehicles' dust clouds as much as possible and not exceeding speed specified for whatever gear being used] are taken, it may be necessary to clean the carburetor air cleaners and the air cleaner on the filter pipe as often as every two hours. If the air cleaners are kept clean and their oil level is maintained, little damage to the engine will result. It is possible to wear out the engine in one hour or less if the air cleaners are neglected." TM 9-731B from January 1943 for the M4A2 says, "The frequency of servicing air cleaners depends on the dust and sand conditions encountered. Under extreme dust and sand conditions, service air cleaners every eight hours to prevent premature engine wear." TM 9-754 from January 1943 for the M4A4 also advises, "The air cleaners should be cleaned daily when the vehicle is operated over dusty terrains..." TM 9-731A from December 1943 for the M4 and M4A1 says the air cleaners should be drained, cleaned and refilled "[d]aily, when operating on dirt roads or cross country, or every 250 miles, when operating on paved roads or during wet weather..." And for completeness's sake, TM 9-756 from December 1943 for the M4A6 instructs that air cleaners are serviced "[e]very 5 to 60 hours of operation, depending on dust conditions..." and that they are to be drained, cleaned, and refilled daily. Also, "Every 100 miles, remove air cleaners, wash all parts, and reoil."
 
So for the CIA engineers to complain that the T-34-85's oil bath air cleaners needed to be serviced daily in dusty conditions to provide decent protection seems strange. When the report says of the subject's "wholly inadequate engine intake air cleaners", "Several hundred miles in very dusty operation would probably be accompanied by severe engine power loss" or "The cleaners were of such low efficiency and low dirt capacity that, in dusty operation, they should have been cleaned at least once each day and preferably several times if any appreciable engine protection were to be obtained", one wonders if they had read manuals for their own country's vehicles. The T-34-85's air cleaners may well have been inefficient and of low dirt capacity, but the fact that they needed servicing at least daily in dusty conditions does not per se seem to be good supporting evidence. Some type of quantification would have gone far in supporting that assertion.

Indeed, during ODS crews found that the engine air filters of the Abrams required cleaning after as little as 6 hours of desert operation, and daily even when the engine was not started. As a result, 2/2 ACR, for example, went to battle with three times the normal stock of engine air filters.
 
While we're on the subject, TM 9-759 for the M4A3 from September 1944 says of dusty conditions: "Even when the above precautions [avoiding other vehicles' dust clouds as much as possible and not exceeding speed specified for whatever gear being used] are taken, it may be necessary to clean the carburetor air cleaners and the air cleaner on the filter pipe as often as every two hours. If the air cleaners are kept clean and their oil level is maintained, little damage to the engine will result. It is possible to wear out the engine in one hour or less if the air cleaners are neglected." TM 9-731B from January 1943 for the M4A2 says, "The frequency of servicing air cleaners depends on the dust and sand conditions encountered. Under extreme dust and sand conditions, service air cleaners every eight hours to prevent premature engine wear." TM 9-754 from January 1943 for the M4A4 also advises, "The air cleaners should be cleaned daily when the vehicle is operated over dusty terrains..." TM 9-731A from December 1943 for the M4 and M4A1 says the air cleaners should be drained, cleaned and refilled "[d]aily, when operating on dirt roads or cross country, or every 250 miles, when operating on paved roads or during wet weather..." And for completeness's sake, TM 9-756 from December 1943 for the M4A6 instructs that air cleaners are serviced "[e]very 5 to 60 hours of operation, depending on dust conditions..." and that they are to be drained, cleaned, and refilled daily. Also, "Every 100 miles, remove air cleaners, wash all parts, and reoil."
 
So for the CIA engineers to complain that the T-34-85's oil bath air cleaners needed to be serviced daily in dusty conditions to provide decent protection seems strange. When the report says of the subject's "wholly inadequate engine intake air cleaners", "Several hundred miles in very dusty operation would probably be accompanied by severe engine power loss" or "The cleaners were of such low efficiency and low dirt capacity that, in dusty operation, they should have been cleaned at least once each day and preferably several times if any appreciable engine protection were to be obtained", one wonders if they had read manuals for their own country's vehicles. The T-34-85's air cleaners may well have been inefficient and of low dirt capacity, but the fact that they needed servicing at least daily in dusty conditions does not per se seem to be good supporting evidence. Some type of quantification would have gone far in supporting that assertion.

Indeed, during ODS crews found that the engine air filters of the Abrams required cleaning after as little as 6 hours of desert operation, and daily even when the engine was not started. As a result, 2/2 ACR, for example, went to battle with three times the normal stock of engine air filters.
 
While we're on the subject, TM 9-759 for the M4A3 from September 1944 says of dusty conditions: "Even when the above precautions [avoiding other vehicles' dust clouds as much as possible and not exceeding speed specified for whatever gear being used] are taken, it may be necessary to clean the carburetor air cleaners and the air cleaner on the filter pipe as often as every two hours. If the air cleaners are kept clean and their oil level is maintained, little damage to the engine will result. It is possible to wear out the engine in one hour or less if the air cleaners are neglected." TM 9-731B from January 1943 for the M4A2 says, "The frequency of servicing air cleaners depends on the dust and sand conditions encountered. Under extreme dust and sand conditions, service air cleaners every eight hours to prevent premature engine wear." TM 9-754 from January 1943 for the M4A4 also advises, "The air cleaners should be cleaned daily when the vehicle is operated over dusty terrains..." TM 9-731A from December 1943 for the M4 and M4A1 says the air cleaners should be drained, cleaned and refilled "[d]aily, when operating on dirt roads or cross country, or every 250 miles, when operating on paved roads or during wet weather..." And for completeness's sake, TM 9-756 from December 1943 for the M4A6 instructs that air cleaners are serviced "[e]very 5 to 60 hours of operation, depending on dust conditions..." and that they are to be drained, cleaned, and refilled daily. Also, "Every 100 miles, remove air cleaners, wash all parts, and reoil."
 
So for the CIA engineers to complain that the T-34-85's oil bath air cleaners needed to be serviced daily in dusty conditions to provide decent protection seems strange. When the report says of the subject's "wholly inadequate engine intake air cleaners", "Several hundred miles in very dusty operation would probably be accompanied by severe engine power loss" or "The cleaners were of such low efficiency and low dirt capacity that, in dusty operation, they should have been cleaned at least once each day and preferably several times if any appreciable engine protection were to be obtained", one wonders if they had read manuals for their own country's vehicles. The T-34-85's air cleaners may well have been inefficient and of low dirt capacity, but the fact that they needed servicing at least daily in dusty conditions does not per se seem to be good supporting evidence. Some type of quantification would have gone far in supporting that assertion.

Pasholok's original article linked at the bottom of the English-language version cites Материалы ЦАМО РФ among its sources, presumably for the Soviet tests he went over where the engine performed "flawlessly?"
 
Canadian consideration of the A57 for the Ram sounds interesting. Production of the Ram, of course, was well underway before any A57-engined tanks entered service (fifteen Rams  were ready for shipment by January 1942 and 39 more were awaiting accessory installation; 22 Ram IIs were produced by that March), so had it been offered to Canada significant redesigns of the Ram would presumably have been necessary. Such a redesign scheme may have been deemed not worth it as in February 1942 the Director of Mechanisation Colonel MacFarlane recommended that Canada change over to Sherman production ASAP; a tripartite subcommittee recommended the next month that Montreal Locomotive Works and Canadian Pacific Railways' Angus shop change to Sherman production in 1943.
 
The tests referenced in Planning Munitions for War, occurring in February 1942, were likewise performed before the M3A4 was first accepted for service in June 1942. As that book goes on, "Except for the weight problem, none of the reported difficulties proved insurmountable..." and concludes, "...after several improvements the engine ultimately gave a remarkable account of itself." If during the APG tests referenced by Ross the A57s were provided with lavish maintenance, it would follow that the other engines were as well, and the A57s still excelled compared to them. FWIW, I tend to agree with Toxn that the pendulum of online opinion seems to be swinging past the centerpoint of the Sherman bad-Panther good/Panther good-Sherman bad continuum. All I've read, however, indicates the A57 was not the problem child, and the radials, for example, were more of a pain.