DogDodger

Ah, if it was converted from an M32B3 then it's an M74B1.

M74, perhaps?

On 4/19/2021 at 3:41 PM, 2805662 said:

27 degrees or 27% (15 degrees) gradient?
If it’s a 27 degree gradient, that’s actually pretty good. 

 

Modern western AFV generally can do 60% (31 degrees), so 35 degrees (70%) is very, very good. 

M26 was rated for 60% (31 degrees) as well.

18 hours ago, delete013 said:

I wouldn't call it a bad design. Rather no other choice. I agree that from an engineering point of view the vehicle was not very suitable for the situation in 1944-45. That is, imo, the principal criticism of a panther.

 

Choosing the "right" type of vehicle would inevitably mean operating with inferior vehicles. The choice was therefore between larger share of vehicles stuck out of action due to repairs and larger share destroyed in combat. Both versions decrease battle performance and ultimately result in an undesired situation. I can't say to what extent. From a (German) military point of view, the former is imo preferable. It is much harder to replace good crews. Those can compensate for numbers as well as equipment attrition. Weaker vehicles require greater numbers, greater numbers consume more fuel and potentially more spare parts.

 

The question is then, whether Daimler Benz prototype wouldn't decrease performance as much. It could be a plausible choice for 1944, if it could compensate for a lack of artillery and air support on the battlefield. So this is my opinion, design was not a problem. Evaluating German choices, one comes faster to the conclusion that war shouldn't continue beyond 1943, than to a design change.

For the record, the design to which I was referring as poor was the final drives, not the Panther per se. Going over all of its inherent pluses and minuses would take a longer post.

8 hours ago, delete013 said:

From this I can conclude that most likely cause of final drive failures was weak material, rather that the design itself. The best working German design was one that was the least sensitive to material quality!

Now conjecture, warning. This explains for me, why no firm solution could be found. Mass produced vehicles would have to use poor material. It is likely that a vehicle with proper material would require no improvements, beyond those made after the field testing. It is also likely that the prototype version of a vehicle would show less problems due to better materials used. The incentives to the designers went without effect, likely because any design other than planetary would face similar fate. Germans maxed the limitations of resource scarcity and had to put up with material generally considered unsuitable. Without exact analysis of materials is direct comparison between German and Allied designs problematic.

As we discussed previously, the design itself was poor because it was known that the available materials were not up to the task. Spielberger says that a higher-strength steel was intended for the gears, but after this was "unexpectedly" replaced no alterations in the design were made (and depending on when this replacement occurred, alterations may have been impossible).

4 hours ago, Beer said:

Does anyone have Panzer Tracts No.9-3? This is alleged quote from there. It would be good know more info especially when that report was created.

 

 

The report was from  Hauptmann Noak, commander of s.H.Pz.Jg.Abt.654, and was written on 24 July 1944, before the final drive improvements, to be fair.

17 hours ago, N-L-M said:

That entire site of yours is an absolute goldmine. I even got my profile pic from there.

Ha, thanks! That's awesome, I didn't even realize until you said something.

8 hours ago, ZloyKrolik said:

They did. Pretty much every track extender had problems with them breaking/bending.

Unbalanced loads are hard on tracks: e.g., the weight imposed by the Tiger Ausf.B's overlapping Staffellaufwerk was biased to the inboard portion of the tracks, resulting in track pins bent to the point that they couldn't be pulled out of the link.

Definitely unexpected results! Interesting assertion about the reduction gear preventing the Pershing's torque converter from slipping and that the Soviets found it performed well on slopes. In Marine Corps Tank Battles in Korea, Gilbert says, "The M26 was a powerful vehicle, but as the tank crews soon discovered, if it stopped on a steep gradient the transmission would slip, and it was difficult or impossible to get it moving again. Help was needed and Eugene Viveiros, who, with one of the Headquarters Platoon [Sherman] blade tanks, attached himself to the 3rd Platoon, was ready to supply it. He was called upon 'to pat them on the butt end with the blade of the 'dozer tank to shove 'em up and get 'em going again. Once they got traction, then they were all right,' Viveiros explained." Although at least some Army Pershings arrived in Korea in need of repairs or overhaul, these USMC tanks were in decent working order (despite a shipborne flooding mishap en route), so this wasn't a maintenance issue: in a discussion on the state of Korean Pershings over on TankNet Ken Estes said, "...the USMC [Pershings] were drawn from depots, with no miles...all the USMC WWII flame tanks and postwar M26s went from storage through the depot line before being shipped to the units."

Any idea what "average technical speed" means? Too bad the off-road test was cancelled; didn't General Fedorenko know that people would be arguing about these things on the Internet 80 years later??

53 minutes ago, Lord_James said:

What is an M4A1E9? I came across it while bored, but the only information I saw is that it is “an M4A1 with spaced out VVSS suspension and extended end connectors”, but all the pictures that come up look like normal VVSS to me: 

 

 

If it doesn't count as spam, there are some pictures of the spaced-out suspension on a hybrid M4 here.

18 hours ago, Jeeps_Guns_Tanks said:

 

Damn, I was hoping you had heard something about it, now I'm going to have to search for it! I have no idea what book or if it might even be wrong, I mean, you really know your stuff!

 

 

Ha, thanks. Flattery will get you...well pretty far, I suppose.

2 hours ago, roguetechie said:

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.

Indeed. The state of German automotive technology was unprepared for mass-production of a 45,000 kg tank. As we've been over, and as Spielberger notes, "Since it was envisaged to produce the Panther in large numbers, production costs of various subassemblies would have to be kept to a minimum...If it had been possible to foresee what difficulties the final reduction gearing was to cause, it would have been a much better solution to have selected a more expensive final drive which provided a greater degree of reliability. In the end, the final drive proved too weak to handle braking with the Klaue disk break [sic] when steering through tight curves. The use of epicyclic gearing for the final drive hinged upon the bottleneck being encountered in the supply of gear cutting machines for producing the hollow gearing. When passing judgement on the double-spur final reduction gear it should be noted that the high-quality steel originally planned for the spur gears in the final drive was not available for mass production and was unexpectedly replaced by VMS 135 (today 37 MnSi5) tempered steel (not as suitable for this purpose)...

"The final drive (gear teeth and bearings) was the weakest part of the Panther. It was a risky proposition to use a spur gear system for transferring the drive power - especially considering that the available steel during the war did not have a particularly high stress tolerance. A better solution would have been to use an epicyclic gear system; a prototype final reduction drive using planetary gear reduction had already been tested and had performed flawlessly. However, as mentioned previously, a shortage of gear cutting machinery for the hollow gearing prevented this type of final drive from being mass produced. In order to bridge the gap a final reduction gear system was installed in front of the main gear drive, but due to installation restrictions its mountings were far too weak and could not be strengthened. Because of gear teeth breaking under too great a load and the weak mountings, the gears were pushed out of alignment  - virtually guaranteeing mount and tooth breakage.

"The general consensus in the industry was that inner-toothed gear wheels could not be produced due to a lack of proper machinery. This meant that a final drive using planetary gear reduction and pre-selector spur gearing - found to be reliable in company testing - could not be installed in production tanks. All attempts to improve the final drive met with failure, despite the offers of a special bonus as an incentive..."

To quantify this a bit, Ristuccia and Tooze in "Machine tools and mass production in the armaments boom: Germany and the United States, 1929-44" note that Germany did make strides in increasing the number of gear-cutting machines in service, going from at least 10,407 in 1939 to 28,621 in January 1945. Even with these increases, compared to the US there were only 0.74 gear-cutting machines per German metalworking employee in 1945.

15 hours ago, Jeeps_Guns_Tanks said:

 

 

Wasn't there also a flat car limitation? If I recall right, we did not have much rolling stock that could handle a M26 let alone anything heavier during WWII?

 

                                                                                                                                      

Could be, haven't read about that.

10 hours ago, TokyoMorose said:

 

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.

 

Interesting, thanks; what is this from? Ogorkiewicz differentiates between double-differentials and the Panther's steering system, and has a pretty high opinion of it:

...

9 hours ago, TokyoMorose said:

M48 always struck me as comically huge for how much armor and gun you get for it, (as might be reasonably expected from a literal cut-down heavy tank design) - and it is really quite a shame that they dragged their feet upgunning the things for so long despite the cavernous interior. So many upgrades designed and/or tested for the M48 that went nowhere in the rather chaotic 50s and 60s... and that mini-turret is one of the few things to go into production.

 

Even a great many tank enthusiasts out there don't seem to be aware the M48 originally came with a perfectly reasonable vision cupola with a remote MG mount, only for that to be ditched for that damned tumor.

Seeing M48s in person, the gun seemed a bit unimpressive compared to the size of the vehicle to me as well. The original cupola was pretty slick, but couldn't be reloaded from under armor, of course, so the bad M1 cupola was a go.

4 hours ago, delete013 said:

Why did the radioman have a reserve steering set?

 

Commander's cupola is useless for observation. Those glass slits certainly don't offer good vision.

 

Mobility is obvious also an issue and a medium with poor agility is an easy target.

 

Turret form is sub par. It features plenty of nice vertical surfaces and the inverted heart form makes the cheeks quite vulnerable to hits from 30deg angles. Mantlet also features the panther's shot trap.

 

Because he's the assistant driver; the radio was in the turret bustle. Perhaps a better question would be: why was the assistant driver not provided with duplicated controls in all US designs? The TC's cupola has a rotating periscope in the hatch door, as well. As we mentioned earlier, trials at Aberdeen indicated that the T26E1 was better cross-country than the HVSS Sherman. We're lamenting the M26's near-vertical turret armor while comparing it to the Centurion?

4 hours ago, delete013 said:

Pershing engines burned out and died in Korea. This is akin to early panthers.

The M26's performance in Korea can be considered an outlier as far as reliability goes. MacDonald et al in "The Employment of Armor in Korea," vol.I, noted, "The M26 tanks were a later World War II development and were in a generally poor physical condition." And when discussing the cannibalization required due to spare part scarcity: "This situation was aggravated because many of the tanks brought to Korea had seen extensive service elsewhere or had deteriorated while in storage. One battalion with M26 tanks departed the US with all but 10 to 12 tanks in unsatisfactory operating condition. These tanks, in operation since 1946 in troop training, were in serious need of complete overhaul."

3 hours ago, delete013 said:

It would be nice to know that Soviet testing better. Link? So why did Americans have so many troubles? Poor off road mobility is but in every book on Pershing. Details are as usually scarce.

 

Scarce indeed. In Korea, the physical width of the tank precluded some routes, and the steep hills were taxing, but what issues were prevalent off-road?

3 hours ago, delete013 said:

Thanks for the links! Especially interesting is the Pershing test. It gives better impression on mobility. I am confused as to why the mobility is so emphasized in American literature. Seems fine, except that off road speed test was not performed and the agility was a problem.
The test about the panther is however seems quite positive. Apart from confirming the inability to neutral steer it has few of the British problems. It confirms my assumption that the British tests are quite lackluster. I don't know how you consider panther worse. Evaluated as a heavy tank, Pershing clearly didn't impress with firepower nor armour. Panther on the other hand seems good in this respect, even if it is medium. Plus it was nimble.

The Pershing wasn't really a heavy tank, as noted earlier. It was named a heavy for morale purposes for a couple years, but actual heavy tanks were in development.

2 hours ago, delete013 said:

With zero test info or anything beyond a prototype, I am fairly convinced that it didn't work. If ordinary pershing moved reasonably it couldn't with a few tons more.

 

GAF was good for a sherman. Let's be honest, it wasn't in the HL230 class, with or without regulator. Panther's steering was quite more advanced and an important part of tactical mobility. Dispensing with it makes the designer's life much simpler but that of a tanker worse. I think being able to have more free leg space is much less important than being able to turn and drive out of opponents sight.

 

The T26E5 was tested starting in July 1945 and performed well besides having to take it easy over rough ground to avoid suspension damage. World War II was over, though, so a prototype was all that was going to be produced. Panther's steering design was clever, but in practice the final drive design and material hindered this advantage since using the steering brakes caused the final drives to shear, no?

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).

11 hours ago, Jeeps_Guns_Tanks said:

 

 

I think I've seen charts talking about the same things, they may even be somewhere in these 89s pages! Surely it does not do enough to warrant the nightmare the Panthers Suspension was to deal with in every other way.  We could also really get into the weeds, and talk about Track and road wheel durability. Jentz mentions issues with the Panther tracks bending guide horns, are these problems aggravated off road, negating any advantage the suspension is going to give you. I don't recall the Pershing having similar suspension issues. The advantage the Panthers Road Wheel system offered must be minor enough no copied it on tanks. Surely you can get damn close with an extra normal size road wheel and shocks?

 

This is why I added the month to the original question. Operate a Battalion of Perishing's and Panthers under similar conditions, and even with similar supply systems, the Pershing Battalion will have more running, combat ready tanks at the end of the month. Working on the Pershing would be so much easier, it would give it the edge. 

 

Check out this guys Flickr

He has many car, plane and tank pics, and seems to be connected to a very cool tank restoration shop. 

 

(That funny feeling in the pit of your stomach, Wehraboos, is the feeling you get when you look upon good tanks)

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.

5 hours ago, Beer said:

 

By the way wasn't the reason why no real US heavy tank made it in mass production in WW2 mainly in the maximum lifting capacity of cranes used in seaports? I believe I heard that somewhere. 

4 hours ago, N-L-M said:

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.

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...

On 2/26/2021 at 3:17 AM, delete013 said:

Underpowered, too slow, bad off road. Ground clearance was too low.

Considering that it started as a medium and got steadily bigger it makes me believe that the designers exceeded the limits of their design. What they got was neither satisfactory heavy tank, nor a medium. Attempts to make it competitive against tiger B failed because the suspension was overloaded and the hull out of balance. Now, you mentioned those trials and I have nothing much to go with here apart from Hunnicutt and some public "truths". Might also have been a case of institutional inefficiency, who knows.

You have high standards for ground clearance. The Pershing was designated as a heavy for a short while, but was begat by a medium design; actual heavy designs were ongoing but didn't see service before the war ended. Hunnicutt and Yeide agree that the "heavy" nomenclature was mostly for morale purposes. I'm not sure it was quite as bad off-road as you make it seem, but I do find the T25 a tantalizing what-if.

On 2/26/2021 at 11:54 PM, TokyoMorose said:

 

Panther, but only just - and primarily due to a better and more efficient steering mechanism (Triple Diff versus good ole Cletrac steering on the M26).

 

On most terrain, the ground pressure difference is so marginal that it matters not (Panther of course has a more notable advantage in deep mud and the like) and while people love to factor in the full "power" of the HL230 once you factor in the actual *governed* net power, the Panther and M26 have almost exactly the same net HP/Ton.

 

So yes, the Panther is marginally more mobile when working but I cannot stress how slim the margin is. They are for all intents and purposes equal outside of specific terrain (i.e. bad enough mud/snow the ground pressure difference adds up) and yet everyone calls the M26 a slow pig, and the Panther's mobility tends to get highlighted.

 

I think the reason for this distinction is that M26 saw lots of service and use with the much, much faster post-war designs that made it seem like a slow pig in comparison while Panther was mostly used alongside/against wartime and even prewar designs so it seems very mobile indeed. If you compared the Panther to the same set of machines M26 usually gets compared to (even if the comparison is subconscious by a unit that say, transitioned from M26 to M46 or M47), the Panther is just as much of a slow pig.

On 2/26/2021 at 8:27 PM, Jeeps_Guns_Tanks said:

 

What had better mobility Panther or Pershing over a month of steady use.  

 

Probably the Pershing in both cases, because American Vehicles don't break in catastrophic ways that take a long time to fix.

 

You can swap a whole M26 power pack in a few hours. That's a day at least on a Panther, since the hull roof and a bunch of road wheels have to come off to pull the Panthers Final Drives and Tranny. The engine wasn't super easy either. 

 

Pershing was 12.8 psi versus Panther G 12.65. Close enough to be negligible.  Pershing was running 450 HP for 46 tons. The Panther had between 500 and 600, (no one lists what the governed rating was) for 44 tons. It only made its 700 HP rating when it could be spun to 3000RPM, but it was governed to 2500 RPM. Call it 550, giving the Panther the edge on paper, but I just read through Panther Wank, the quest for Combat supremacy by Jentz, and the whole book is a listing off all the shit that was wrong with these tanks and how they kind of a fixed them, but never really did.  They Never fixed the HL230 of blowing head gaskets and throwing rods. Though, the horrible cooling system could have aggravated this, overheating blows head gaskets. 

 

After reading through the Jentz book, reliability goes to the Pershing.  Pershing, a History of the T20 series documents far LESS problems than the Panther.  

 

Final Note, I had not looked through the Boo Bibles for years, and having read so many Hunnicutt books, I'm spoiled. They are just so much better than this Jentz and Spielburger garbage. They couldn't be bothered to put spec sheets in for the models. Trash, utter trash, but the pictures are nice.  

Panther used a geared steering system and not a triple-differential, no? The nominal ground pressures were indeed similar (and even favored the Pershing, depending on the source), but the Panther's mean maximal pressure and other off-road performance characteristics would benefit from its maintenance-unfriendly road wheel setup. Wong has some interesting simulations in Terramechanics and Off-road Vehicle Engineering between a baseline M113-type vehicle with 5 road wheel stations, the same vehicle with 6 road wheel stations, and the same vehicle with 8 overlapping road wheel stations. The simulations are run on snow and clayey soil, and the machine with more road wheels shows better performance in everything from wheel sinkage to drawbar pull to tractive effort to trim angle, etc. Panther weighed 6.9-8.6% more than the M26, but its tracks were 2-3" wider and it had 2 more road wheel stations per track in the same ground contact length and essentially the same track pitch (5.9" for the Kgs 64/660/150 vs. 6" for the M26's tracks). Double torsion bars were probably needlessly complex, the interleaved wheels required inordinate effort and time for maintenance, and the final drive was never adequately strengthened, but credit where due: the thing should perform quite well off-road.

5 hours ago, delete013 said:

It was meant figuratively, of course. As a medium, Pershing was not a finished vehicle. I usually exercise skepticism over prototypes good on paper but never reaching service (or being half useful in the opinion of the army)

 

It is, imo, still better to have armoured weapon platform assaulting strong points than nothing. Jumbo likely saved many already by being a hard rock, attracting fire.

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.

3 hours ago, Jeeps_Guns_Tanks said:

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. 

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...

1 hour ago, Toxn said:

The other, never-considered alternative apparently being to design a tranny and final drives suitable for a 45-48 tonne tank.

 

Also, btw, the French checked the metallurgy of the drives and found it was fine. They were underbuilt, plain and simple.

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.

21 hours ago, delete013 said:

Excellent reply!

Thanks

18 hours ago, delete013 said:

Really? Which one? The slow IS-2? The immobile M26? The suspension wrecking jumbo? Good luck maneuvering in those things. They were for a reason heavy and panthers medium tanks. Maybe you should consider why there is a difference in tank classes?

The Pershing was labeled a heavy tank from 29 June 1944 to May 1946, mostly for morale purposes. It was begat from a program to replace the M4 medium tank, and there were actual heavy tanks being concurrently developed. The M26, though more heavily armored than its T25 sibling, still weighed over 34,000 lb less than the heavy tank M6. In September 1944, i.e., two months before the 90 mm gun, 92,000 lb T26E3 emerged from the T26E1, the Ordnance Committee recommended the development of the 105 mm gun, 141,000 lb T29 and the 155 mm gun, 142,000 lb T30. These were the US heavy tanks. Production of 1,200 T29s was requested on 1 March 1945, but of course the war ended before this could occur.

Also, the passage of the post being replied to was referencing the suspension systems specifically, as I understood it? The M26's relatively low power:weight became an issue in the mountains of Korea, but cross-country its single-torsion bar suspension (and automatic transmission?) could be quite an improvement over even much lighter tanks: A race was held at Aberdeen Proving Grounds' Churchill cross country area involving T26E1, T25E1, HVSS M4A3, and VVSS M4A3. The T25E1, being torsion bar-sprung and having a pretty sprightly weight, came in first with a 23-minute time. The heavier T26E1 was second at 26 minutes. The M4A3s, with the same engines but ~13,150-17,750 lb less weight than the T26E1, crossed the line in 28 minutes 25 seconds for the HVSS machine and 30 minutes 40 seconds for the VVSS machine. So perhaps "immobile" is a bit unfair, and perhaps the double torsion bars were in fact a bit of luxury.

7 hours ago, Beer said:

No, no and no. Tank is not a tank destroyer at least not in most of army doctrines. This is a misconception or an outright ignorance. In the doctrines you find terms like breakthrough, explotation, infantry support but nowhere it is written that tank is a primary anti-tank weapon. Fuller, Hart, Guderian, Tukhachevsky and others saw tanks as a primary tool to exploit breakthroughs to an operational depth capturing vital transportation and communication hubs and not as a weapon to be used in tank to tank brawl in WoT style. 

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."

7 hours ago, Beer said:

 

US didn't field 76 mm Sherman for quite some time not because it was not available but because the units resisted to it - because it was worse than 75 mm against everything except tanks and for fighting tanks there were M10 tank destroyers (which per the doctrine were to fight the tanks allowing the tank units to do their job). Don't you think that if they were scared of the German tanks they would happily take the tanks with 76 mm gun? 

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.

1 hour ago, heretic88 said:

 

Basically, another nail in the coffin of the "150km final drive" myth. The french report is valid and good, but it is totally clear for me that who typed it, made a mistake. Humans arent perfect, and mistakes occur. Such typos can appear anywhere, I actually met one in a soviet AFV manual too. 

But eventually, the correct (and in my opinion quite realistic) 1500km value can still be considered BAD and does NOT dispel the fact that the final drives were indeed the weakest point of the Panther. 

I've always leaned towards this as well.

1 hour ago, SH_MM said:

I also wasn't able to find the old article on the Soviet trials of the M4A4; not sure if it was deleted or I am simply mis-remembering things. As far as I am aware, Pasholok's articles are usually not based on the actual Soviet archives, but rather on Western sources such as the British sources mentioned by you. E.g. he cites the US National Archives Records Administration and R. P. Hunnicutt's book on the Sherman.

 

The A57 engine was rejected by the the Canadians (as option for the Ram tank), the US Army and the Soviets, which makes me really question the British data and methodology. When the A57 was first tested in the United States on Aberdeen Proving Ground, it performed well, but upon closer inspection it became apparent that it had overheated and damaged seals and bearings:

 

 

From "The Ordnance Department: Planning Muniitons for War" of the Office of the Chief of Military History, Department of the Army's 1955 series "United States Army in World War II".

The later 400 hours trials also held at Aberdeen Proving Ground are not really a valid representation of actual performance, at least according to Peter Samsonov, these tanks were essentially given unlimited maintenance and spare parts for everything that was not directly the engine, while the test conditions were mild.

 

 

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.

6 hours ago, SH_MM said:

 Oh, damn. I must have been thinking of the Tiger then. Still the loader had a hatch; the one in the back of the turret. Earlier tanks often had none for the loader.

 

This is based on Peter Samsonov's Tank Archives blog, in which he posted various summaries, snipplets and translation of documents taken from the Soviet archives. There are multiple articles on the lend-lease Sherman; in regards to the M4A4 variant of the Sherman there are aspects mentioned in multiple articles but the short summary is here. There is also an article describing the visit of a Soviet officer to the Chrysler tank factory and an article on the actual tests of the M4A4 (where overheating and leakage issues arose). 

 

I guess he goes into more detail in his book Sherman Tanks of the Red Army. The American vehicle in Soviet service, though I haven't read that one yet.

 

The Soviet opinion on the Sherman was quite a lot different from the opinions touted in various web forums and English-language books (aside of the beloved Emcha), so I am a bit sceptical about the mythical performance of the Sherman, specifically after the reasoning for the "wet stowage made the Sherman tank have the highest post-penetration survivability" story turned out to be a myth/an error.

 

E.g. according to Samsonov, the Soviets found several issues with the M4A2 (their main Sherman variant) such as the clutch breaking down often (even after just traveling 200-250 km; although these might related to less experienced users), poor visibility for the commander, a mediocre (gunner's ?) sight, "normal" ergonomics with an uncomfortable position for the commander and poor work distribution, which only illustrates of subjective these facts are, as they are based on different point-of-views how a "good" tank should look and what should serve as a reference for good ergonomics, reliability, etc.

 

The Soviets even also found that the Sherman had a too high ground pressure, was too height, too few optics, and that the installation and removal of components was unnecessarily complicated and difficult. They noted that the tank is hard to maintain/service, which goes pretty much against the mainstream opinion in the English-language literature and public discussions, because these are often only based on the American & British point-of-view.

 

I am not sure how the American trials running 12 different, well-kept M4 tanks with the various engines along the same static course at the Aberdeen Proving Grounds is a real indication to reliability in field...

 

 

Thanks; Samsonov's blog is a valued bookmark, and I have his Sherman book pre-ordered. In a cursory search of his blog, I failed to find the articles complaining of the M4A4 overheating and leaking. Indeed, in this article Pasholok says of the A57, "This monster had its upsides as well. The design worked quite reliably and had sufficient power for a medium tank," "The experimental tank travelled for 6500 km. Trials showed that the experimental engine needed a little more work, but overall it performed well," "The tanks turned out to be quite reliable, but service turned into a nightmare for its crews. Each engine had its own water pump with its own linkages" [this was changed with the 1304th engine produced for the M4A4, where a single water pump served all engines], "The British became active users of the M4A4. Why would they use a tank that the Americans rejected? Short answer: reliability. According to data given to the GBTU by the British, the M4A4 (Sherman V) was the most reliable tank from the M4 family. The mean distance between refurbishments was 3200 km for the M4A2 (Sherman III), but 4000 km for the Sherman V. This explains why the British were not fazed by difficulty of servicing the engine." Pasholok relates that during Soviet trials of the M4A4, "The only advantage of this engine was that it worked flawlessly. The only problems during the trials were with the running gear and oil filter. The oil consumption was much less than the gasoline: only 2 L for 118 hours of work."

I mentioned Exercise Dracula in addition to the APG tests, where the M4A4 gave no issues beyond fuel thirst.

34 minutes ago, SH_MM said:

Certainly that is a good design, huh? Having gunner, loader and commander all escape from the same hatch onto which usually an machine gun was mounted.  Good luck getting out of this thing when it burns, but let me guess, its still "the best"? The Panther's loader also could escape the tank through the rear hatch of the turret, if necessary (which mean that he actually could exit the vehicle under cover...). The rear hatch might even have been the primary exit for the loader by design.

 

Even the Sherman was not the reliability wonder that people love to make it seem. The M4A4 variant was rejected as lend-lease tank by the Soviet Red Army due to reliability concerns, and the US Army also only took a few hundred (with the bulk of the ~7,500 M4A4 tanks made being sent to the UK, who had issues making competent tank designs on their own). But hey, we only count reliable variants (for which there often is very limited data)...

 

The rear hatch for the loader may very well have been his primary egress method, since there was no loader's hatch on the roof... The Sherman indeed had no loader's hatch until October 1943, and a small hatch is better than no hatch.

Where can we read of reliability issues of the M4A4? Thanks! G. Macleod Ross, a member of the British Purchasing Commission, says of engine testing when there was discussion of dropping the A57 from production: "...four engines of each type [Ford GAA, R975, GM 6046, Chrysler A57 were] being run in their respective tanks. Only four engines completed 400 hours when the trial was stopped. Of these four, three were Chrsyler A57 engines, while the fourth Chrysler entrant logged 339 hours to failure." Likewise, the M4A4 seemed to give no undue issues during Exercise Dracula.

On 2/3/2021 at 6:48 AM, Toxn said:

- The transmission is completely inaccessible short of pulling the turret.

FWIW...

On 9/29/2019 at 9:59 AM, Beer said:

The English one is for example here. I don't know if the content of the English version is same as Czech one. The original has also an attachment of dozens of factory drawings for both serial vehicles and some paper designs which never got even into the prototype.

Definitely the best book I've seen on Czech AFVs of that era. The English version has drawings as well--both apparently from the factories and from HL Doyle--but they are regular pages that aren't removable.

Also, a couple hundred pages of Kursk left, and then I'll move this to the front of the line.

Is this what you're talking about? Not 100% legible but I think it's the closest I have. Taken at the Memorial Day event at Ft. Knox on 26 May 2007. Link to original: click

That's exactly right Jeeps. Here's a comparison between this vehicle and an M74 (since I don't have a direct comparison handy of an HVSS tank). Lord_James, the M4A1 was the cast-hull variant, so it wouldn't have the sharp edges on the upper hull.