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DogDodger

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  1. Tank You
  2. Tank You
    DogDodger got a reaction from Jeeps_Guns_Tanks in The M4 Sherman Tank Epic Information Thread.. (work in progress)   
    Ah, if it was converted from an M32B3 then it's an M74B1.
  3. Tank You
    DogDodger got a reaction from Clan_Ghost_Bear in The M4 Sherman Tank Epic Information Thread.. (work in progress)   
    Ah, if it was converted from an M32B3 then it's an M74B1.
  4. Tank You
    DogDodger reacted to Clan_Ghost_Bear in The M4 Sherman Tank Epic Information Thread.. (work in progress)   
    @DogDodger According to Infodefensa, they received a pair of M32s in 1945 as Lend-lease aid.
    https://www.infodefensa.com/latam/2016/07/19/opinion-venezuela-actualizacion-parque-medios-blindados.php
  5. Tank You
    DogDodger reacted to Clan_Ghost_Bear in The M4 Sherman Tank Epic Information Thread.. (work in progress)   
    The Venezuelan army has restored an M32 recovery vehicle to service.


  6. Tank You
    DogDodger got a reaction from delete013 in What the Hell is the Point of Interleaved Road Wheels?   
    M26 was rated for 60% (31 degrees) as well.
  7. Tank You
    DogDodger got a reaction from Jeeps_Guns_Tanks in What the Hell is the Point of Interleaved Road Wheels?   
    M26 was rated for 60% (31 degrees) as well.
  8. Tank You
    DogDodger got a reaction from Jeeps_Guns_Tanks in StuG III Thread (and also other German vehicles I guess)   
    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).
    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.
  9. Tank You
    DogDodger got a reaction from Beer in StuG III Thread (and also other German vehicles I guess)   
    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).
    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.
  10. Tank You
    DogDodger reacted to Beer in StuG III Thread (and also other German vehicles I guess)   
    My three cents. 
     
    Things are much more complicated than what can be conculed by looking at non-scaled pictures. 
     
    Panther has higher engine output than Pershing. Panther has 4 tons higher weight than Pershing. Panther's transmission is subject to more shocks than that of Pershing (the torque converter combined with the planetary geabox must have eased the shocks in the transmission a lot). All points worse for panther but that's only the base factors. 
     
    The main point IMHO is that Panther's final drive housing was designed very opened and thus weak (there is very little material mainly from the inner side due to the space taken by the double gears and their bearings) while Pershing assembly is basically a fully enclosed massive box which means it must be much more rigid. It is well known that one of the major problems with Panther's final drive was its weak housing and its fixation to the hull which deformed and caused oil leaks damaging the gears. Another result of such deformation was the gear misalignments further worsening the situation. In my understanding the resulting defects were also very often related to the breaking of the screws from the resulting shear stress. The September 1944 modification is not related to the gears but instead to the housing strength and its fixation. You are searching for the wrong thing. Anyway it looks like it never solved the problems completely which seems logical because there is no way to add material from the inner side or in the return roler area. 
     
    As for the gears alone inside the final drive assembly there is one gear more in Panther while the completele assembly isn't larger. I dare to say it looks even smaller especially in gear depth (considering there is a space used for the return roller on it as well) which logically means that the two gears in Pershing are larger than those three in Panther but without being able to determine torque on each gear it may be misleading (but I doubt the torque processed by Panther final drive was smaller especially considering the shock peaks which must have been flatten a lot by Pershing's torque converter). Straight-cut gears didn't help too. The herringbone gears like on Sherman would help for sure. Centurion final drive assembly is clearly much larger even judging just by the naked eye.  
     
    As for the material IMHO the situation with it is relatively the easiest to establish. Even if you have bad material you know what you use for the design or at least you shall have some quality control which guarantees that you get material which is equally bad every time. In short it means that with worse material you simply end having things larger and heavier but having worse material does not prevent design of a reliable machine unless the issue is non-existent material quality control and the defects coming from quality differences in material supplies. Nothing seems to point in that direction though. Of course designing a complex shape of a final drive housing without simulation SW is difficult but they had experience and were able to do that with proper and in-time given inputs. 
     
    Having things larger isn't always easy. In case of Panther it simply looks like the tank weight grew so much that a larger final drive simply couldn't fit on the vehicle without a radical redesign. How that could have been prevented is also rather easy to establish - the most obvious way is to stick with the design specifications and not to throw tons of additional armor on it late in the development phase. The other option is to start the design anew with new specifications but that takes time. Then there is the third option and that is to pray...  
     
     
    Pershing final drive: 
    http://afvdb.50megs.com/usa/pics/m26pershingfinaldrive1.jpg
    http://afvdb.50megs.com/usa/pics/m26pershingfinaldrive2.jpg
     
     
     
     
     
     
     
     
     
  11. Tank You
    DogDodger got a reaction from Jeeps_Guns_Tanks in What the Hell is the Point of Interleaved Road Wheels?   
    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??
  12. Tank You
    DogDodger reacted to ZloyKrolik in The M4 Sherman Tank Epic Information Thread.. (work in progress)   
    They did. Pretty much every track extender had problems with them breaking/bending.
  13. Tank You
    DogDodger reacted to N-L-M in The M4 Sherman Tank Epic Information Thread.. (work in progress)   
    That entire site of yours is an absolute goldmine. I even got my profile pic from there.
  14. Tank You
    DogDodger reacted to Beer in What the Hell is the Point of Interleaved Road Wheels?   
    Soviet evaluation of Pershing in summer 1945 gives some light to the previously discussed terrain speed of Panther and Pershing. The result didn't favour Panther... 
    http://www.tankarchives.ca/2018/03/pershing-heavy-by-necessity.html
     
    This is the measured average speed in comparison with other tanks on the same terrain track. Pershing was the fastest of them in this test mainly thanks to its torque converter. 
     
    T26E3 - 18,9 km/h
    T-44 - 17,5 km/h
    M4A4 - 16,5 km/h
    Panther - 15,8 km/h
    IS-3 - 14,6 km/h
     
    Fuel consumption on the same track however showed that the torque converter made it also very thirsty, basically same as Panther. 
    IS-3 - 373 l/100 km
    T-44 - 378 l/100 km
    M4A4 - 503 l/100 km
    T26E3 - 585 l/ 100 km
    Panther - 595 l/100 km
  15. Tank You
    DogDodger got a reaction from Beer in The M4 Sherman Tank Epic Information Thread.. (work in progress)   
    If it doesn't count as spam, there are some pictures of the spaced-out suspension on a hybrid M4 here.
  16. Tank You
    DogDodger got a reaction from N-L-M in The M4 Sherman Tank Epic Information Thread.. (work in progress)   
    If it doesn't count as spam, there are some pictures of the spaced-out suspension on a hybrid M4 here.
  17. Tank You
    DogDodger got a reaction from Jeeps_Guns_Tanks in The M4 Sherman Tank Epic Information Thread.. (work in progress)   
    If it doesn't count as spam, there are some pictures of the spaced-out suspension on a hybrid M4 here.
  18. Tank You
    DogDodger got a reaction from Lord_James in The M4 Sherman Tank Epic Information Thread.. (work in progress)   
    If it doesn't count as spam, there are some pictures of the spaced-out suspension on a hybrid M4 here.
  19. Tank You
    DogDodger reacted to Beer in What the Hell is the Point of Interleaved Road Wheels?   
    Already before WW2 Czechoslovak industry rutinely produced heavy extremely thick armoured cast pieces, especially observation cupolas and firing posts for the fortifications. To my knowledge at least three companies were supplying them in hundreds (Steel works in Vítkovice, Třinec and Škoda in Plzeň). They had a lot of experience from working on armoured parts for Austro-Hungarian fortresses and navy (basically all heavy machinery of A-H Empire was enherited by Czechoslovakia). 
     
    The mass-produced armoured cupolas for Czechoslovak interwar fortiffication had 150-300 mm thickness (per object resistance class), the weight was 20-65,5 tons (300 mm heavy cupola for twin-HMG). They were later largely removed and reused on Atlantic wall by the Germans. 
     
    Due to Münich treaty this thing was never installed but parts were built by Škoda including at least one turret. The Armor of the turret was 300-350 mm, the fixed armor around the turret is 175-450 mm thick. The weight is roughly 120 tons for the retractable turret and 180 tons for the surrounding armor (there are two full-size semi-automatic 105 mm howitzers inside hence why the size). 
     

    Source of the pixture is book of Eduard Stehlík: Lexikon tvrzí československého opevnění z let 1935–1938
     
     
    Here is something from a recent research done with one of one of the cupolas produced in Třinec in 1937 (200 mm thickness): 
    Chemical: C 0,28; Mn 1,15; Si 0,44; P 0,026; S 0,023; Cr 0,35; Cu 0,27; Al 0,01 
    Ferrite-pearlite structure with measured hardness 177 HV 30 which shall be equivalent to 169 HB, i.e. rather soft. It is not much known about the original requirements, incomplete sources say the steel had to have tensile strength between 550-700 MPa and ductility 14-17%. Based on that the steel used on this cupola was probably close to the lower strength limit. 
     
    Source is here.
     
     
    Anyway starting with early 50' the new armory in Martin, Slovakia was producing quality cas turrets for T-34/85 and later T-55 and T-72 in thousands. 
  20. Tank You
    DogDodger reacted to SH_MM in What the Hell is the Point of Interleaved Road Wheels?   
    NGP vs MMP
  21. Tank You
    DogDodger reacted to N-L-M in What the Hell is the Point of Interleaved Road Wheels?   
    It's rarely pointed out because it is an absolute load of bullshit, and most self respecting people have enough of a brain to not embarrass themselves in public by making such inherently absurd claims. Clearly you either have no brain or no sense of self worth if you are willing to put your name behind such an incredibly stupid line of thought.

    Let us take, as a starting date, the year 1943, as that is nicely mid-war.
    At that point in the war, the Western Allies were largely engaged in the Tunisian campaign, where other than defensive actions the entire battle of the Mareth line was decided via tactical maneuver, outflanking the defenses and thus rendering the line untenable and forcing an Axis retreat.

    The final battle of Tunis, in May, featured a classic tactical breakthrough on a narrow front followed by exploitation by armored and infantry forces. Following the taking of the city, roughly 240,000 Axis troops, who had been defeated by maneuver, surrendered to the Allied forces there. They had been quite firmly defeated by being outmaneuvered, cut off, rendered irrelevant to the Allies achieving their objectives, and left with the choice of either dying pointlessly or surrendering. In fact, more surrendered than were killed fighting.
     


    Following the Allied victory in North Africa, the invasion of Sicily was a 6 week affair, in which the Allies continuously advanced and took critical key objectives, forcing the Axis forces there to retire or be cut off, you know, as one does in maneuver warfare. Many times tougher than expected resistance was met, and rather than turn the battles into a slogfest, effort was shifted to where it could give the best results, and the results speak for themselves. The Axis were systematically and quickly evicted from the island.


    In Italy, the landscape precluded maneuver warfare to an extent, but even there, after concentrated attacks on defensive positions (which did also feature maneuver on the allied side, but on a generally smaller scale) what happened? yep, exploitation maneuver by infantry and armored units forcing the enemy to retreat or surrender. One would notice that despite being on the offensive throughout all these campaigns, the Allies suffered lower casualties on the whole than the Axis did. How did they achieve such low losses? By utilizing their combat abilities better than the Axis did, and by exploiting successes to force axis retreats and surrenders at all levels.
    By mid 1944, Italy had surrendered and was in allied hands, and it wasn't a result of sitting around with thumbs in uncomfortable places.


    What else happened in mid '44? The largest amphibious invasion of history. And how was this invasion used to further the Allied goal of cleansing the Continent of the Nazi menace? Though maneuver warfare, primarily. The whole reason we hear so much about the Bocage and the attempts to break out of it was that the Allies didn't  want to fight that kind of fight at all. Yes, they were better at it than the Nazis were, and yes their armored vehicles were better for such close range fighting as many big cat apologists like to point out to cover for the really sad showing the Nazi metal boxes gave in Normandy, but as far as the Allies were concerned it was a bad way of conducting war. And what happened when they broke out of the Bocage? again, again, maneuver warfare. The Falaise pocket was a result of highly effective maneuver warfare, and decisively kicked the ass of the Nazis at what they considered their own game. Even the Nazi troops who escaped the pocket did so without their heavy equipment, which was irreplaceable as Nazi production was entirely incapable of keeping up with war losses.


    The following high speed chase to the German border was, again, brought about by maneuver warfare of the highest order, capturing several more Nazi units in various pockets, such as the Mons pocket and the Colmar pocket.


    In addition to the maneuver battles, there were also some battles, such as Hurtgen, which were not battles of maneuver, but those were A. not as common, B. not preferred, and C. Occasionally unavoidable, as previously discussed. They were, however, followed by an exploitation, as a rule, where at this point in the war the main limits on the Allies rate of advance wasn't the German resistance, as much as it was the logistical hurdles of supplying fast armies across a country where most of the transportation infrastructure had been wrecked.

    Following the Nazi winter offensive, which failed to achieve any of its primary goals, the Allies proceeded to, you guessed it, maneuver their way into the low countries and the Rhine. Including taking cutting off pockets of Axis troops at many locations.

     
    To conclude, the idea that the Western Allies didn't use tactical maneuver as a tool is not only wrong, it is farcical, and paints you, personally, the person bringing this up as an idea, as an absolute idiot without a shred of common sense nor the brainpower to think before you open your mouth.
     
     

    The hilarious thing here is that the Cletrac controlled differential on the Sherman, or the Merrit-Brown gearbox on what really is a wide range of British tanks, were hands down superior to what the Nazis were using in the vast majority of armored vehicles (Pz 3 and 4 and variants) they produced. And they had the reliability to go halfway across the continent on their own power, not break down after a measly few hundred km and need rail transport for any real movement.
    Likewise, your other point is wrong on not one but two counts.
    The first is that the idea of cruiser tanks and infantry tanks was confined to the British, not all or even most of the Western Allies.
    The second is that by the mid war even the British were mostly out of that line of thinking, what with them operating very large numbers of American medium tanks (M3s and M4s in various variants) and effectively abandoning the development of infantry tanks in favor of ever better protected and armed cruiser tanks - with the introduction of the Cromwell, they had a tank which was a medium in all but name, with sufficient armor and firepower to go up against the common Nazi vehicles and win, while also being much more mobile.
     
    dividing up the weight of the vehicle by adding roadwheel stations reduces MMP at the cost of more weight, which is an issue all Nazi vehicles suffered from extensively. As for taking bumps, the greater unsprung mass resulting from having more mass of wheels is a net detriment, and beyond 4 or so roadwheel stations per side there's damn near no extra ride smoothness to be achieved by adding roadwheel stations, the springs, whether torsion or something else, do that work.
    Also, as has been previously noted in this thread, words have meanings and you are misusing them.
     
    Faster off road speeds which never seemed to materialize owing to drivetrain unreliability, maneuverability which was forbidden in the manuals for fear of breaking the transmission, a general failure to use these theoretical abilities to do anything much, a repeated set of losses to allied maneuver operations, losing more vehicles than they could afford despite being on the defensive, all the way back to the Rhine. AKA, a piss poor combat record.
     
    There are several good reasons to believe the solution was not the best, for example the entire rest of the world examining it and deciding it wasn't a good idea. The French even went the extra step of building a few of them, before discarding the idea into the dustbin of history, where it rightly belongs.
    Everyone else was clearly capable of making tanks which weren't absurdly heavy for their combat ability and which could actually get to the battlefields and do their jobs. The extreme weight of the big cats is a detriment, not a positive. Also, by dint of not being excessively heavy, most Allied tanks had a much better power to weight ratio and could go faster, in addition to being much more reliable.
    As did literally everyone else, yes. Shitty German steel would be a reasonable excuse for accepting reduced performance, not for creating horrible monsters which were entirely unsuited for fighting the war they were in the middle of. That anyone can make excuses for a """medium tank""" with the size and weight of a heavy but none of the performance thereof is absurd.
     
    Usually, when one is guessing blindly, one shouldn't brag about being an absolute idiot who doesn't know what he's talking about, and listen to those who do.
    This statement is entirely false. The overlapping wheels offer reduced ground pressure, at the cost of a whole host of other deficiencies, which are the reason nobody uses them any more.
     
    Various napkin drawings of for the most part imaginary tanks do not imply they would ever have seen production. Especially not when such a change would require refitting entire factories to produce tanks which are only slightly different to ones already in production, and the need for said vehicles is acute.
     
    In general, the square cube law favors larger tanks, but that doesn't apply when your tanks are made needlessly huge and heavy for no good reason. The overlapped suspensions, especially that of the Panther, came at a net weight penalty compared to other simpler suspension types, which means they come at a detriment to payload capacity, not an improvement.
     
    lol. None of the operational analysis we have from WW2 supports this claim of yours. This is just pure fantasy on your part, which appears to be aimed at convincing yourself the Nazi tanks were superior... for some reason? One does wonder why you'd have such a fanatical devotion to the creations of the regime whose sole truly groundbreaking invention was the industrialization of mass murder.
     
    you really have no clue how torsion bars work, do you?
    Here's a hint: double length torsion bars and overlapping roadwheels are entirely independent design choices. Both of them are bad choices.
     
    The 8.8 was quite a good gun as ww2 tank guns go, 100mm vertical is approximately equivalent to the armor of most medium tanks of the time, nothing to write home about when your tank weighs twice as much as a medium and that's all you get for your troubles.
    Freezing mud and the like led to many big cats being flat out abandoned and not seeing combat, which means the combat effectiveness of those vehicles was a net negative. Again, hardly anything worth white knighting over.

    The Allies, I would remind you, won the war. And they did so, on the whole, with lower casualties than the Axis suffered (in the West at least), and the general consensus among all of them was that there was very little to be learned from the Nazis about tanks. Before you go crying "victors", remember that the Allies were not above Operation Paperclip'ing any and all scientists they thought would be useful, and the Nazi tank designers didn't make the cut. The Allies didn't think they were worth stealing.
     
    With overlapping wheels, you either get horrible track torsion loads or the maintenance nightmare of interleaving wheels. The only alternative is this:

    The above also applies, in general, to the entire Nazi war effort.
    For a Panther aficionado, you are extremely poorly informed about it. All Panthers had that 4 row interleaved roadwheel setup, with the outer wheels and inner wheels on opposing swing arms. While this layout is slightly better than that of the Tiger, it still requires the removal of an awful lot of roadwheels to get to any inner one, and still allows freezing mud to immobilize the vehicle.
     
     
    wrong again. Even today, interleaved roadwheels would help reduce ground pressure, which for MBTs is reaching rather extreme values. But unlike then, nowadays everyone has the good sense to not mess around with unworkable ideas like that. Single torsion bars with dampers and bump stops gave a very good accounting for themselves in WW2, so your second point is also wrong.
     
    Or, in other words: The Nazis correctly identified that vertical travel is important for high cross country speed, but instead of being sensible about how much vertical travel they needed they went with a value far in excess of what was actually useful at the time, and paid a horrendous price in design terms in order to achieve it.
    There is a reason that even the postwar fast MBTs didn't have a vertical travel as large as that of the Panther, which was only done on the later NATO box tanks with much more powerful engines - below that point, it's just not very relevant.
     
    Improvising by creating the most overcomplicated and resource intensive solution is not a very sensible answer when your problem is lack of resources.

    Funny how even with very heavy tanks being used nowadays, many of which exceed 60 tons by a wide margin and have since they were designed, and in a wide range of extremely heavy engineering equipment, not only does nobody use overlapped or interleaved wheels, but literally nobody is even considering it as an option. perhaps, just perhaps, it is because the whole world knows it is a terrible idea?
     
    Fortunately, this forum has an abundance of mechanical engineers, at least some of whom have experience with automotive systems.
    Perhaps you should cease being so aggressively wrong when you yourself admit you have no clue what you're talking about.
     
    If you made any, sure. For a start, you must first read the relevant literature, because as of now your arguments from ignorance only serve to accentuate your stupidity.
     
    The T30 heavy tank features the CD-850 crossdrive transmission, which is a triple differential unit capable of both pivot turns and neutral turns. It also features a fuckoff huge torque converter, which allows a much easier driving experience as one only needs 2 gears forwards and one reverse to cover the entire range, and is in fact still in service today on a variety of vehicles. Which is more than I can say for any Nazi WW2 equipment.
    I would like my million bucks, along with a punitive extra 1 mil for you shifting the goalposts from suspensions to transmissions yet still being horribly wrong.
    and yes longer vehicles are harder to steer, but the magic number for tread-to-length is 1.5-1.8, and all Allied tanks of the late war period were perfectly fine in that regard. As Beer rightly notes.
     
    You've gone straight into denialism. Tell me, do you also not believe the Allied reports on what they found in certain camps in Poland?
    Regardless of what you choose or do not choose to believe, the Allies pretty much plowed through the Nazis in Europe, with the Nazis not achieving any great successes for all the divisions of brand spanking new tanks they threw into the grinder.

    In conclusion, you are a total idiot blindly "defending" the products of a tyrannical regime despite lacking some very basic knowledge on the subject in general and of your specific favorites in particular. I diagnose you with a extremely bad case of Dunning-Kruger, the only known cure to which is this:



    Your SNR is a net negative and the only reason you haven't yet been kicked off the forum for being a waste of electrons is that some people here still find your brand of idiocy amusing.
  22. Tank You
    DogDodger got a reaction from Toxn in StuG III Thread (and also other German vehicles I guess)   
    Ha, thanks. Flattery will get you...well pretty far, I suppose.
    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.
  23. Tank You
    DogDodger got a reaction from Stimpy75 in StuG III Thread (and also other German vehicles I guess)   
    Ha, thanks. Flattery will get you...well pretty far, I suppose.
    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.
  24. Tank You
    DogDodger got a reaction from Beer in StuG III Thread (and also other German vehicles I guess)   
    Ha, thanks. Flattery will get you...well pretty far, I suppose.
    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.
  25. Metal
    DogDodger got a reaction from Jeeps_Guns_Tanks in StuG III Thread (and also other German vehicles I guess)   
    Ha, thanks. Flattery will get you...well pretty far, I suppose.
    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.
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