Panther Gets Too Much Love And Hate?

[Colin]

Interesting for a nation that is struggling with raw material shortage, double torsion bars seem to fly in the face of that issue. How did the Tiger's suspension differ?

[DKTanker]

Interesting for a nation that is struggling with raw material shortage, double torsion bars seem to fly in the face of that issue. How did the Tiger's suspension differ?

The tank still requires some type of spring suspension, the double bar suspension (much like the more modern tube over bar system) seeks to maximize travel while minimizing spring stress and thus failure rate.

[DogDodger]

The Tiger had a "normal" torsion bar suspension. Due to material reasons, the Panther II was going to have a single torsion bar suspension as well.

[cbo]

 

 

Speaking of the Panther, does anyone have any idea how they went about replacing broken torsion bars on that vehicle? The double torsion bar system of that tank does not look like it would be easy to access for repairs.

 

There are two holes in the hull for every wheel. One holds the arm for the wheel with one torsion bar attached. Assumingly, you could remove the wheel, then the arm and then you can pull out the torsion bar. The other hole is covered by a plug that seems to hold the yoke which holds the ends of the torsion bars for the wheels on the other side of the tank.It seems that you could remove the plug, dissemble the yoke and probably pull out the other (or both?) torsion bars through this hole.

You can of course acces the suspension components from the inside, but I don't think you could remove a torsion bar from the inside!

 

The problem - as always with the interleaved roadwheels - is that you need to remove up to four wheels to gain acces.

 

 

No, the real problem is that if a torsion bar is broken then you can't pull it out because if it's broken then it's in two pieces, and if you try to pull it out you will be leaving half of the torsion bar inside the hull.

 

On a tank with normal torsion bars you can push a busted bar out from the side of the hull opposite the swing arm it goes to. On a tank with bar-in-tube suspension you can pull on the bar if the tube is broken or pull on the tube if the bar is broken.

 

On a panther though, it is not obvious what you can do to get a broken torsion bar out of the hull short of pulling the turret (or alternatively changing the bars so often that they never break) because the bars only penetrate the hull in one place.

 

The Panther has two holes on each side, one for the swing arm and one for the yoke holding the other end of the torsion bars. So my assumption is that these holes could be used to remove the torsion bars from either end. I agree that removing the torsion bar would probably require access from inside the tank to detach the torsion bars from their attachments inside the hull. I'm not convinced that would require the removal of the turret though.

 

As DKTanker suggests, the very nature of the suspension may have reduced the number of broken bars. According to Spielberger, the issue did get som attention in the design phase, as the mounting of the torsion bars was designed to reduce breakage. Considering the number of flaws in the Panther design which had recieved due criticism over the years, I would be surprised if this was a major issue that had somehow escaped notice.

[Loopycrank]

 

Interesting for a nation that is struggling with raw material shortage, double torsion bars seem to fly in the face of that issue. How did the Tiger's suspension differ?

The tank still requires some type of spring suspension, the double bar suspension (much like the more modern tube over bar system) seeks to maximize travel while minimizing spring stress and thus failure rate.

 

 

Exactly. Panther had exceptional suspension performance that wouldn't be matched until well into the Cold War. That level of performance implies an extremely large amount of energy being loaded and unloaded into the suspension. The only way to store that much energy was to add more material to the torsion bars, since packing more energy into the same size of torsion bar would have simply resulted in broken torsion bars.

 

They can't make the torsion bar any longer; they're constrained by the width of the tank. The can't really make the torsion bars thicker either, because that would increase the force acting on the road wheels. If the torsion bars were made thicker and the swing arms were made longer (more leverage), this could work, but the road wheels are so densely packed together that this isn't workable either.

 

So they went with the double torsion bar design.

 

Modern metallurgy, in particular VIM/VAR steels allow single torsion bars to perform as well or better than the panther's double bars in tanks like the leo 2 and Abrams.

 

The Tiger had a "normal" torsion bar suspension. Due to material reasons, the Panther II was going to have a single torsion bar suspension as well.

 

Wasn't panther II supposed to have common running gear with tiger II in general? Same road wheels, and tiger II transport tracks were to be panther II combat tracks.

 

 

 

 

Speaking of the Panther, does anyone have any idea how they went about replacing broken torsion bars on that vehicle? The double torsion bar system of that tank does not look like it would be easy to access for repairs.

 

There are two holes in the hull for every wheel. One holds the arm for the wheel with one torsion bar attached. Assumingly, you could remove the wheel, then the arm and then you can pull out the torsion bar. The other hole is covered by a plug that seems to hold the yoke which holds the ends of the torsion bars for the wheels on the other side of the tank.It seems that you could remove the plug, dissemble the yoke and probably pull out the other (or both?) torsion bars through this hole.

You can of course acces the suspension components from the inside, but I don't think you could remove a torsion bar from the inside!

 

The problem - as always with the interleaved roadwheels - is that you need to remove up to four wheels to gain acces.

 

 

No, the real problem is that if a torsion bar is broken then you can't pull it out because if it's broken then it's in two pieces, and if you try to pull it out you will be leaving half of the torsion bar inside the hull.

 

On a tank with normal torsion bars you can push a busted bar out from the side of the hull opposite the swing arm it goes to. On a tank with bar-in-tube suspension you can pull on the bar if the tube is broken or pull on the tube if the bar is broken.

 

On a panther though, it is not obvious what you can do to get a broken torsion bar out of the hull short of pulling the turret (or alternatively changing the bars so often that they never break) because the bars only penetrate the hull in one place.

 

The Panther has two holes on each side, one for the swing arm and one for the yoke holding the other end of the torsion bars. So my assumption is that these holes could be used to remove the torsion bars from either end. I agree that removing the torsion bar would probably require access from inside the tank to detach the torsion bars from their attachments inside the hull. I'm not convinced that would require the removal of the turret though.

 

As DKTanker suggests, the very nature of the suspension may have reduced the number of broken bars. According to Spielberger, the issue did get som attention in the design phase, as the mounting of the torsion bars was designed to reduce breakage. Considering the number of flaws in the Panther design which had recieved due criticism over the years, I would be surprised if this was a major issue that had somehow escaped notice.

 

 

No. There are no holes to withdraw the pivoting blocks through, only holes for the torsion bars. Look at this picture of the Littlefield panther:

 

 

The suspension did not reduce stress within the torsion bars; it brought stress to acceptable levels in view of the exceptional performance of the suspension.

Edited January 18, 2016 by Loopycrank

[zaarin7]

I've been to Bovington twice. Once the turret to there Tiger I was out on a dolly. The other time the hull was out on it's tracks but with out any decking or internal parts. I remember looking and photoing over the hull side. I could the torsion bars and it was quite an instructive sight because though I'd read about torsion bars seeing them installed was great.

[DogDodger]

Wasn't panther II supposed to have common running gear with tiger II in general? Same road wheels, and tiger II transport tracks were to be panther II combat tracks.

Yep, Panther II was to use the Tiger II's transport tracks, final drives, steering gears, transmission, engine, road wheels, etc. Speaking of the Tiger I, its suspension design also did the maintenance crews no favors. Friedli quotes a June 1943 report from the Paderborn training school that says, "The exchange of an inner road wheel takes at least 10 hours even with a well-rehearsed crew." In August 1944, Major Hans-Joachim Schwaner of s.Pz.Abt.502 said of the Tiger, "The hard shocks make the torsion bars break especially frequently. Even when all spare parts are available, a Pz.Kpfw.VI damaged in such a manner needs 30-36 hours to repair. In the case of a broken rear torsion bar, the engine needs to be dismounted."

[Ken Estes]

Very true of most German tanks introduced in wartime, always rushed to the front too soon, and with parts provisioning lacking. The Tiger really bears similar critique as the Panther. Jentz' first volume on the Tigers posts an impressive list of items requiring replacement/redesign. Production startup was stillborn May-July42, only began to catchup in December. The premature dispatch of the first four vehicles to the Leningrad Front reportedly made further assembly impossible because of the resulting demands for parts and transmission overhaul, and so forth. The goal of submerged fording had to be abandoned and a host of revisions took place to counter engine overheating, brake seizure [not immediately resolved], and problems of transmission, final drive, exhaust, and so forth. A new transmission was placed on line Nov42, new steering device Feb43, the hydraulic brakes finally replaced with a mechanical system Mar43, asbestos covered oil lines Apr43, replaced main shaft steering gear with heavier part June43, added fuel filter [!!] Sept43, changed central drive gear from beveled to straight teeth [sound familiar?] Aug44. Throughout the history of Tiger I it appears to have leaked oil all over the place and suffered frequent engine fires. Many of these items are not minor.

 

A modern-day tanker would not have appreciated these weaknesses. Just imagine the impact had the Porsche Tiger been fielded!

 

However, Henschel trumpeted in Feb45: "Without conjecture or overstatement, it may be stated that the Tiger E chassis and its components not only fulfilled but exceeded expectations. The unavoidable teething problems encountered at first did not belong to the chassis design but occurred mainly in components which were ordered and procured by Wa Pruef 6,"

 

Such blame evasion and doublespeak compares well with Chrysler Corpn at its worst. Jentz listed this without comment as he was a compiler not a historian. Equally without comment were the reports of sending the first prototype to Hitler on his birthday in Apr42, where the engine overheating and brake failures were apparently concealed. The first production vehicle chassis was sent, without turret, to Kummersdorf for evaluation on 17 May 1942, having been driven by Henschel a total of 25 kilometers! Is there any wonder at the rush to production with such criteria?

[zaarin7]

"Throughout the history of Tiger I it appears to have leaked oil all over the place..."

 

There ya go with them negative waves again! The main point I got from Jentz was if your going to do something like the Tiger I once you've got all those issue's fixed why do you stop production in favor of something like Tiger II?

[Ken Estes]

When did Jentz state that the Germans had 'all those issues fixed'?? It is significant that the last 54 or so Tiger I were ordered made from battlefield wrecks evacuated to Germany but beyond nominal repair.

 

The answer to your question? Once again, the Hitler effect. Hitler was convinced other countries, chiefly the USSR, had bigger and better tanks under development, was pressuring the army to equip heavy tanks with the 88mm/L70 at the same time Tiger I was in production, Panther on the horizon. Then in January 1943, he spoke to Speer and insisted that Tiger I and Panther could only be expected to remain dominant for a year, and in 1944 Tiger II and Maus would be required. He ordered 150 Maus to be built at that time. The next month the army ordered a tank destroyer based upon the Tiger II chassis built carrying the 128mm gun. In the end, the army was only interested in more Tiger II and Panther production, but as late as Jan45 H was ordering the army to increase and accelerate Jagdtiger production.

[alejandro_]

Very true of most German tanks introduced in wartime, always rushed to the front too soon, and with parts provisioning lacking. The Tiger really bears similar critique as the Panther. Jentz' first volume on the Tigers posts an impressive list of items requiring replacement/redesign.

Is there any wonder at the rush to production with such criteria?

My impression is that Hitler believed these wonder weapons could be decisive, thus the rush to introduce them everywhere. After Kursk (*) Panthers and Ferdinands were sent to Italy, which is not the greatest tank terrain.

(*) Which was delayed so more Panthers could be fielded.

[Ken Estes]

There is new scholarship from Germany that has changed the previously accepted reasons for the delays of Citadel, but I don't have them at hand at the moment. Essentially, numbers of Tiger and Panther tanks were not the only shortages, and intelligence on the expanding Russian defenses caused considerable worry, resulting in more delays for specialized mineclearing units [Goliath] and other reinforcements, none of which could improve the declining ratios in infantry and guns. Model sensed the buildup to his rear at the Orel Front. OKW wanted the assault called off in order to form mobile reserves for expected Allied attacks in both East and West. Even OKH had many doubts, and Hitler himself referred to it as a 'gamble.'

 

No Panthers were encountered in Italy until the Anzio landings, as I recall. Ferdinands/Elephants were in trouble wherever employed.

 

One usually reads criticism of the Germans sending the first Tigers to the Leningrad front, because of poor terrain. However, such notions ignore the transfer of Manstein's 11th Army and the siege artillery there after Sebastopol for Operation Northern Light, the capture of Leningrad. Thus, the demand for a breakthrough tank would have taken place then in late 1942, called off when the Russians began their own offensive to break the siege and later, of course, when Stalingrad worsened.

[shep854]

I was having a bit of difficulty visualizing how the Panther's suspension worked, but I came across this video that uses a model to illustrate.

It's also a prime example of raising daughters right!

https://www.youtube.com/watch?v=Dzlkb0-CQx4

[Loopycrank]

 

Wasn't panther II supposed to have common running gear with tiger II in general? Same road wheels, and tiger II transport tracks were to be panther II combat tracks.

Yep, Panther II was to use the Tiger II's transport tracks, final drives, steering gears, transmission, engine, road wheels, etc. Speaking of the Tiger I, its suspension design also did the maintenance crews no favors. Friedli quotes a June 1943 report from the Paderborn training school that says, "The exchange of an inner road wheel takes at least 10 hours even with a well-rehearsed crew." In August 1944, Major Hans-Joachim Schwaner of s.Pz.Abt.502 said of the Tiger, "The hard shocks make the torsion bars break especially frequently. Even when all spare parts are available, a Pz.Kpfw.VI damaged in such a manner needs 30-36 hours to repair. In the case of a broken rear torsion bar, the engine needs to be dismounted."

 

 

Fascinating stuff! Which book is this in? I'd love to read it.

 

I wonder why the tiger I needs the engine dismounted to change rear torsion bars. You would think they could push them through the same as usual.

 

I have a picture at home showing littlefields and it appears most be be somewhat accessed from inside. I think they had a puller they used.

 

 

Thanks. Was this an original wartime puller design, or something they rigged up for the restoration?

[DogDodger]

Fascinating stuff! Which book is this in? I'd love to read it.

Both quotes came from vol.2 of Repairing the Panzers.

[Przezdzieblo]

nvm

Edited January 21, 2016 by Przezdzieblo

[lastdingo]

I was having a bit of difficulty visualizing how the Panther's suspension worked, but I came across this video that uses a model to illustrate.

The second torsion bar appears to be stressed not only by torsion, but also by bending in this video, so it's no pure torsion spring system..

Edited January 21, 2016 by lastdingo

[Mikel2]

 

I was having a bit of difficulty visualizing how the Panther's suspension worked, but I came across this video that uses a model to illustrate.

The second torsion bar appears to be stressed not only by torsion, but also by bending in this video, so it's no pure torsion spring system..

No different than a coil spring.

[DB]

Real engineering solutions are rarely "pure".

 

The concentric tube and bar solution is less subject to a bending moment, and the outer tube can be supported by bearing surfaces if that's a serious concern.

[Mikel2]

This is worth posting again. I would love to have seen a T34 thrown into the mix as well.

 

https://www.youtube.com/watch?v=SmXEly5_u38

Edited January 21, 2016 by Mikel2

[Loopycrank]

 

I was having a bit of difficulty visualizing how the Panther's suspension worked, but I came across this video that uses a model to illustrate.

The second torsion bar appears to be stressed not only by torsion, but also by bending in this video, so it's no pure torsion spring system..

 

 

Yes; Technology of Tanks notes this.

 

I'm not sure what the implications for the life of the second torsion bar are, but probably not good.

[sunday]

I do not see how the two torsion bar would bend differently. I mean, if the second bar bends and moves that intermediate part upwards in its side, the opposite end of that part would move downwards, thus also bending the first bar.

 

Am I missing something?

[richard g]

Apologies if what follows has been already posted but the transmission problems of the Panther are directly related to a shortage of suitable machine tooling which meant straight instead of stronger helical gears had to be used. That may be related to a shortage of tungsten.

 

I have a drawing of the Panther's transmission but it's too big to upload. I also have a Soviet test of a captured Panther with notes comparing it to their tanks. They were reasonably impressed except with it's armour distribution, some good features like maintenance reducing centralised track lubrication and automatic engine fire supressor systems were mentioned.

 

.

 

 

[Burncycle360]

Had the panther been 30 tons (just about sherman weight) would have that made things better despite the reduced armor?

[Olof Larsson]

This is worth posting again. I would love to have seen a T34 thrown into the mix as well.

 

https://www.youtube.com/watch?v=SmXEly5_u38

 

or a late war M4A3 (76), being lighter, stronger and with wider tracks than the Firefly.

 

The Firefly was after all, probably among the worst M4-versions as far as mobility goes.