Which Is Better:"FDW" or "RDW"???

[Killjoy Ausf. B]

In the sagacitous opinion of the assembled luminaries of this foreum, which is deemed to be the superior arrangement of AFV suspension... ...That employing a front drive wheel, or that employing a rear drive wheel?
Please include if possible the pros & cons of each arrangement...

[cbo]

The important part is, I think, to have the drive sprocket in the same end as the engine and transmission in order to save space. So rear engine = rear drive; front engine = front drive.

Claus B

[Ralph A]

Interesting.

I just read something about this very topic, and it turned out to be a very interesting and complicated subject!

I think the pros and cons of the different configurations revolved around vibration affecting gunnery optics, tensions on the tracks, and horsepower-to-weight ratios.

I do know the Panzer III, at least, had the engine in the back, with a driveshaft extending forward to a transmission in the front, giving the thing a "transaxle" to the "front-wheel drive" sprockets.

I'll see if I can find the article for you. An interesting question.

[cbo]

Re: Interesting.

Originally posted by Ralph A
I just read something about this very topic, and it turned out to be a very interesting and complicated subject!

I think the pros and cons of the different configurations revolved around vibration affecting gunnery optics, tensions on the tracks, and horsepower-to-weight ratios.

I do know the Panzer III, at least, had the engine in the back, with a driveshaft extending forward to a transmission in the front, giving the thing a "transaxle" to the "front-wheel drive" sprockets.

I'll see if I can find the article for you. An interesting question.

I would be very interested to see it!

Btw, many WWII tanks had rear engine/front drive, including most US and German vehicles.

Claus B

[Killjoy Ausf. B]

Re: Interesting.

Originally posted by Ralph A
I do know the Panzer III, at least, had the engine in the back, with a driveshaft extending forward to a transmission in the front, giving the thing a "transaxle" to the "front-wheel drive" sprockets.

I believe all German tanks had "rear-mounted" engines, while specialized/modified chassis like the Geschutzwagen III/IV which was used for the Nashorn had the engine mounted "amidship" - ie: at the center of the chassis.
The StuGs and Jagdpanzers had rear mounted engines...
All had forward drive sprocket/wheels
The British used rear drivewheels except for the Churchil, but I believe all had rear-mounted engines...
All American tanks had front drivewheels, all rear-mount engines...
All Russian tanks had rear drivewheels, save AFAIK, the T-70, with all rear engines. Not sure what mods their SP guns' chassis may have had...
(I use the aforementioned examples as the "major players"... Italians favored Foreward DW...French Char had rear; Renault front...usw, usw...)

Would also like to see the article you mentioned.
Seems to me Rear engine/rear drivewheel would be best, but who knows?

[Tiger II lover]

Front drive Tigers

Awesome thread. The giant Tiger II had a very high front drive sprocket and very good climbing and trench crossing capabilities. Anyone with some expert analysis please post it for us to see.
















Odin Zone Refugee

[cbo]

Re: Re: Interesting.

A couple of nits....

Originally posted by Killjoy Ausf. B
The British used rear drivewheels except for the Churchil, but I believe all had rear-mounted engines...

The Churchill had rear-drive as well. The front idler was toothed and could be confused for a driving sprocket.

Originally posted by Killjoy Ausf. B
All American tanks had front drivewheels, all rear-mount engines...

The M26 Pershing had drive and engine in the rear.

Claus B

[Killjoy Ausf. B]

Sorry!
The apparently cheesy tome I was looking at for depictions of the tanks contains comparatively little technical data. (Which I was ignoring, anyway, taking my "info" from the drawings/paintings therein)
Oddly enough, it also doesn't even mention the Pershing, which I completely forgot about...

[Astérix]

Balance

Gearboxes were somewhat bulky.
Question is: were can it be placed? If put on the back after the engine, it must be balanced by the turret (à la T34): gun is moved forward, tank is longer. this can lead to worst performances in rough terrain or turning capabilities in cities streets or small roads. It can be placed under the engine , leading to a higher silhouette.It can also be replaced by an hydraulic or electric transmission, but it may be difficult to gain access to the parts.
If put on the front, it adds protection on the front (this is specially interresting for light tank) and separates driver from radio, stopping bouncing shrapnels of penetrating AP rounds.
On the other hand, a hit on the front, even if not penetrating, or on the drive sprockets can stop the tank.
What is the best?

[Killjoy Ausf. B]

Speaking of "..hydraulic or electric transmissions..." this reminded me of a "factoid" I read claiming that the Panther gearbox was supposedly not to be repaired in the field, but removed and sent to a "rear-area" for maintenance...
Anyone know if this was actually the case, and if so, was it because of either of the aforementioned designs being employed?

[cbo]

Originally posted by Killjoy Ausf. B
Speaking of "..hydraulic or electric transmissions..." this reminded me of a "factoid" I read claiming that the Panther gearbox was supposedly not to be repaired in the field, but removed and sent to a "rear-area" for maintenance...
Anyone know if this was actually the case, and if so, was it because of either of the aforementioned designs being employed?

The Panther transmision was a straightforward mechanical device, albeit somewhat impractical to remove from the vehicle.

IIRC dissembling, repairing and reassembling transmissions is something normally left to specially trained personel?

Claus B

[Astérix]

Russian British tanks

It reminds me that I read somewhere that Russians repaired in the field British tanks gearboxes, while there were supposed to be replaced and sent back to the factory for repair.

[Killjoy Ausf. B]

Originally posted by cbo
The Panther transmision was a straightforward mechanical device, albeit somewhat impractical to remove from the vehicle.

IIRC dissembling, repairing and reassembling transmissions is something normally left to specially trained personel?

Claus B

Ach!
I guess "in the field " was too vague...
By that I meant more in the way of the rear-area maintenance depots of the sort characterized by those wheeled cranes/gantries used to hoist turrets, engines, etc, but which were still technically within the theater of operations...
Also, I believe you are correct concerning the maintenance being done by personel other than the crews... Again, apologies for being vague and implying that the crews were doing the work.
Mentioned several times in Schiffer Publications vol44 Tiger I is the abbreviation "I Trupp", translated as "Repair troop" ( perhaps Instandhaltungstrupp ? ie - maintenance troop[s])
The gist of my earlier statement was that the repairs were apparently not performed by the I Trupp, but required more elaborate facilities.
Alas - curse me for a fool - my initial combing of reference material did not turn up anything refering to this notion. I shall attempt further to track down the source & elaborate then...

[cbo]

Originally posted by Killjoy Ausf. B
Ach!
I guess "in the field " was too vague...
By that I meant more in the way of the rear-area maintenance depots of the sort characterized by those wheeled cranes/gantries used to hoist turrets, engines, etc, but which were still technically within the theater of operations...

I didn't think you meant the crew - disengaging and removing the gearbox and steering drive would require the use of cranes etc. and would involve maintenance personell. But I think gearboxes and such were replaced as a unit and possibly shipped "heim ins Reich" for repairs.

Originally posted by Killjoy Ausf. B
Mentioned several times in Schiffer Publications vol44 Tiger I is the abbreviation "I Trupp", translated as "Repair troop" ( perhaps Instandhaltungstrupp ? ie - maintenance troop[s])
The gist of my earlier statement was that the repairs were apparently not performed by the I Trupp, but required more elaborate facilities.

I-Trupp is probably Instandsetzungstrupp. I'm not sure at what level these were operating, but in the Panther Abteilung there was a Versorgungskompanie (supply company) with an Instandsetzungsstaffel with a number of Instandsetzungsgruppen that were attached to the Panther companies. furthermore, the Abteilung had a Panzerwerkstattzug which, among other things, had a 16-ton portal crane.

But I would suspect, that the main purpose of these units would be to keep the tanks running while refurbishing gearboxes and engines would be done in factory workshops back in Germany (as was the refurbishing of gutted tank wrecks).

Claus B

[Killjoy Ausf. B]

Interesting!

Have you any idea of the proportion of knocked out German tanks which were actually repaired & returned to operation?
I've read repeatedly that one thing the Germans lacked was sufficient recovery vehicles to tow disabled AFVs - not surprising, considering the difficulty they had attempting merely to match Allied tank production. I know their were "recovery" versions of the Panther and Tiger, but I get the impression not a lot were in service basically because as many combat versions as could be produced were needed on the front lines, especially in the east...