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Collimatrix

What the Hell is the Point of Interleaved Road Wheels?

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On 6/10/2016 at 7:26 AM, Collimatrix said:

Great find legiondude!

 

I'm actually pretty partial to the E-series suspension concept, as it appears to solve or at least ameliorate the big problem with interleaved/overlapping road wheels.

 

Dv3tczO.jpg

 

There are horizontal tubes filled with belleville washers pressing against a piston.  The piston is attached to the swing arm via that rack and pinion toothed mechanism.  This would probably work fine for the E-10 and E-25, but surely I am not the only one who thinks that those teeth would strip right the fuck off if E-50 or E-75 hit a bump.  Especially with late-war German metallurgy.

 

Anyway, to pull a bad road wheel you pull the bogie of two road wheels off.  Even if they're in fully overlapping configuration, you only need to tilt the bogie off diagonally to get it off the hull without disturbing the other road wheels.  This does mean that you have to take the road wheels off as pairs, and with their associated springs, but this is basically the same procedure for changing a road wheel on a tank with Horstmann suspension:

 

gMROQTX.png

 

And you'll see paeons to the centurion raving about how much easier it was to swap out busted centurion suspension units than it was to change out road wheels and torsion bars on the M48.

So is the E-50 suspension independently sprung? How does it compare to torsion bar suspension of Panther and Tiger II (smoothness and pitching issue)?

I am worried about its pressure on tracks since E-50 only has 6 wheels (3 pairs) per track while the Panther has 16 and Tiger II has 18 wheels.b0a5256b0d77b37c.jpg

I mean look at the wheels - they are so thin and few it makes me cringe.

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44 minutes ago, Thomas Zhang said:

So is the E-50 suspension independently sprung? How does it compare to torsion bar suspension of Panther and Tiger II (smoothness and pitching issue)?

I am worried about its pressure on tracks since E-50 only has 6 wheels (3 pairs) per track while the Panther has 16 and Tiger II has 18 wheels.b0a5256b0d77b37c.jpg

I mean look at the wheels - they are so thin and few it makes me cringe.

 

To quote Jentz and Doyle in Panzer Tracts No. 20-1:

Quote

 


The suspension was an entirely new design. The individual roadwheels were mounted in Schrittanordung (step arrangement). The crank arms for each pair of roadwheels acted through ratchets and wedge gear segments on a large parcel of Belleville springs contained in a housing with the shock absorbers. The E 50 had three suspension units  on each side, and the E 75 had four suspension units. The combat track for the E 50 was to be used as the transport track for the E 75.
 

 

 

It should be worth noting that this model above is probably not 100% to scale.  The road wheels on it do look noticeably thin, but that seems to me to be a result of the model designers.  They should be more similar, if not the same, as those found on the King Tiger.

King-Tiger-Wheels.jpg

 

 

World of Tanks' E-50 model has the suspension units modelled (and can be viewed here), so that should give an idea of what it would have looked like.

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On 6/23/2016 at 5:26 AM, Collimatrix said:

Forczyk mentioned in his T-34 vs panther book that there was some loon in the German armor development bureaucracy who was completely obsessed with torsion bars and interleaved road wheels, and would basically reject any design that didn't have them.  This is apparently why the DB panther design gained them later in development.  But it's not clear to me why this guy had so much say in tank design, and why everyone around him didn't point and laugh.

 

I know I am late here, but the loon wouldn't happen to be Ernst Kniepkamp would it? I know with the half-tracks and Panzer III he was directly the guy responsible for those elements - and the Tiger I work at Henschel was also his pet project of the time.

 

And wait, I have Forcyk's book.... and yep it is Kneipkamp. Head of all tank projects at the Wehrmacht, and had been the chief army engineer even before the Nazi takeover when it was the "Military Automotive Department". Even the tiny Kettenkrad has the interleaved wheels, and yep the patent on that is "E. Kneipkamp".

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Funny that nowadays everybody likes to bash ww2 german stuff. Yes, interleaved road wheels had problems, but it wasnt that bad actually. What about the mythical Christie suspension? In my opinion that was far worse. Took lots of space inside and was a nightmare to repair, much worse than interleaved german suspension. Also the ride quality... I once had the opportunity to ride on a T-34, that thing has horrible,  I felt almost every bump on the road. Compared to it, the T-55 (that I drove lots) has a luxury car quality suspension.

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I don't know why you think it was a nightmare to repair, replacement of springs was something that could be done at company repair workshops without much difficulty. As for taking up room inside the vehicle, the British actually praised this solution because it did not increase the height of the tank or require skirts like their own tanks had. Although the British always had a pretty complicated relationship with suspensions.


Actually I wonder, there is nothing stopping one from making a tank with both interleaved road wheels and a Christie suspension...

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That "i felt almost every bump on the road" doesn't look like a Christie suspension problem, more like "not having any shock absorbers" problem.

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6 hours ago, EnsignExpendable said:

I don't know why you think it was a nightmare to repair, replacement of springs was something that could be done at company repair workshops without much difficulty. As for taking up room inside the vehicle, the British actually praised this solution because it did not increase the height of the tank or require skirts like their own tanks had. Although the British always had a pretty complicated relationship with suspensions.


Actually I wonder, there is nothing stopping one from making a tank with both interleaved road wheels and a Christie suspension...

 

If they could figure out a way to make a tank suspension out of Beleville washers, anything is possible.

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18 hours ago, EnsignExpendable said:

I don't know why you think it was a nightmare to repair, replacement of springs was something that could be done at company repair workshops without much difficulty. As for taking up room inside the vehicle, the British actually praised this solution because it did not increase the height of the tank or require skirts like their own tanks had. Although the British always had a pretty complicated relationship with suspensions.

Yes, definitely not as time consuming (at least on T-34) as in the case of the Tiger or Panther, but still not an easy task, far harder than changing a bogie on a Sherman or on a Panzer IV, or changing a torsion bar on a tank without interleaved road wheels. Some springs are more or less trouble free, but some are nasty. In case of the british tanks, well, suspension repair is horror, surely worse than interleaved stuff (tracks off, wheels off, side armor plate off). Brits liked all kinds of weird stuff :D

So yes, you can bash the interleaved suspension, it indeed had problems. But it is unfair if you bash only that, when at the same time, there were other similarly less successful designs, like the Christie suspension. (in fact, you can still find some prototypes after the war with interleaved wheels, but absolutely nothing with Christie suspension)

 

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15 hours ago, Pascal said:

That "i felt almost every bump on the road" doesn't look like a Christie suspension problem, more like "not having any shock absorbers" problem.

Well, yes you can have shock absorbers with Christie suspension but that makes things more complicated, like on british tanks. 

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2 hours ago, heretic88 said:

Well, yes you can have shock absorbers with Christie suspension but that makes things more complicated, like on british tanks. 

Yeah i know about the british tanks, i just noted that the bumpy ride was on the fault of missing shock absorbers in a t-34 not the suspension.

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