"Why were German tank engines in WW2 terrible " Topic

….when it came to power to weight ratios? Specifically the panzer 4, panther and Tiger tanks.

Interesting thread here….

link

Amicalement
Armand

Excellent piece! Thank you, Tango.

R

Thanks for posting this.

Dave

Interesting and I did not know the Brits recycled aircraft Merlins that way, although it makes perfect sense

The big problem with the Tiger was that it was originally supposed to be 30 tonnes, then 45 tonnes and finally wound up weighing about 54 tonnes – but not with a bigger engine!

Soooooo much mis information in that thread one could spend days correcting it. But I'm glad you liked it my friends (smile).

Interesting and I did not know the Brits recycled aircraft Merlins that way, although it makes perfect sense

The recycle of Merlin engines was used in Meteor development. They weren't allowed to use new build engines as the RAF had a monopoly on Merlin production. It wasn't until RR did a deal with Rover where RR got the jet engine and Rover the Meteor that Meteor production started. Rover built a new factory to produce it.
Yes lots of mistakes in that piece. Had a quick look and realised it wasn't worth bothering with.

The Tiger was not slow, it may have been sluggish compared to lighter tanks, but there is the basic physics of trying to move a 55 ton mass versus 30 tons. One will be easier to move than the other.

There was no reliable feedback loop when it came to designing and evaluating German tanks as they were approved and essentially field tested in their first engagements and evaluations usually ended up being "It's better than nothing." which didn't really prompt the engineers to try and do better next time, especially when politics demanded bigger tanks and companies were more than happy to oblige, with the military being almost kept at arm's length of the whole process.

Not that the German military had any clear ideas of what they wanted. Nominally most commanders agree that they needed more of everything, and stronger if possible, but beyond that they didn't have a clue because procurement and planning was not the kind of base and vile endeavour a battlefield commander should dirty themselves with. General Thomas one of the few people with a solid grasp of the concept of wartime economy was pretty much considered a leper by his fellow generals.

When I see the maint. procedures, etc., on the later WWII German tanks. It amazes me sometimes they fielded as many as they did in some battles. They were not crew/user friendly, and in many cases very hard to repair. Meaning your deployable combat assets are attrited before you even rolled into combat.

Not that the German military had any clear ideas of what they wanted.

Wouldn't agree with that. Guderian was very clear on what he wanted and that included numbers and types of tanks. He blocked a move to stop production of the Panzer IV at a time when only Tigers were being produced as Pz III production had switched to the Stug and Panther was just coming online. He attempted as director general of Armoured troops to stop new types being fielded until sufficient testing had been done and they were available in numbers. He pushed for simplification of existing types to increase production and tried to curb the worst excesses of Hitler and Ferdinand Porsche in the super heavy tank department.

Happy you enjoyed it my friends!. (smile)

Amicalement
Armand

German tank engines were terrible? – Excuse me, but the basic unmodified Sherman had a power to weight ratio of 10 to 13.5 Hp per short ton. That's not a lot different from the Panther A at 13.8 Hp per short ton and the Panzer IV H with 10.7

German tank engines were superb pieces of design, but they tried to balance too much in trying to get as much power out of the lightest, most compact engine possible.

All this came at a price, especially in a war where the pool of skilled personnel is a dwindling reserve, everything is in short supply and industry isn't optimized for war-time production until it's too late.

I think like a number of German designs, some were "over-engineered" … When I look at the interwoven suspension on the Mk.V on up. That must have been a nightmare to repair ? And I'm sure there were a number of other things on AFVs, etc., that were just as difficult to maintain & repair.

I think the biggest problem tended to be the incredible increase in vehicle weight, without a corresponding change in engine or transmission.

Can't really say how dodgy the late-war German engines were, but the record is pretty clear that the biggest mechanical problem suffered by the Panther was its transmission & final drive – all supposedly due to the great increase in its weight from original design parameters to final product.

B

Power to Weight Ratio is always a factor in AFV design. But the "eternal" conundrum, is more armor and bigger guns makes the AFV heavier. And that influences mobility/speed

So it's a balancing act, a mix of mobility, lethality and survivability. To create the "perfect" Iron Monster" …

Add the ability to produce and deploy large enough numbers along with maintenance, repair and recovery capabilities. It is not a "simple" equation.

Depends on how you define good or bad. And yes I'm going to quote some TV shows here because a picture is worth 1000 words. Or BLOGs. I loved the series I believe was called Tank Overhaul. Got into the nuts and bolts of things. I recall several "clips" very clearly.

One was the M18 Hellcat. When they needed to work on the engine they simply opened two doors in the back and it slid out on rails! No such ease with the German Beasts. Another episode showed what I believe were final drive gears. The German ones were light to save materials and marvels of engineering being finely specced to just do the job needed.

The American gears were massive herring toothed affairs way more robust than required. So Panther final drives broke more often than Sherman's. And when you needed to fix it for the Sherman you unbolted the housing and replaced it at a forward area workshop. For the Panther you had to dismantle half the tank in a rear area factory.

So actually the German "engines" were better made if you were building sports cars, but the Anerican stuff was better suited to the demands of battle. Cheers!

IMO, it goes beyond the fact that the design parameters of the German final-drive/transmission were never upgraded to match the weight increase. It was also the fact that the tank maintenance arm was dramatically short-changed in terms of provision of spares due to a management decision to maximize production of new vehicles. And then there is that situation the Germans faced with regard to their repair and maintenance elements working in the field under great duress.

Interesting question – What might the Panther's serviceability rates looked like if it had been an American tank and its spare parts, wreck recovery and service and repair facilities were of American standard?

B

If that was the case the Panther would of had a much higher Operational Readiness Rate. And more would have been Fully Mission Capable to roll into combat/action.

But … that is not what happened … fortunately …

When they needed to work on the engine they simply opened two doors in the back and it slid out on rails!

Yes, a quick easy repair was/is a critical factor in keeping more AFVs at the front and not broken down. If it can't shoot, move or communicate. It's a very large paperweight.

And that held true then and even thru to today. E.g. One of our Maint. crews could replace an M1 MBT engine in @ 4 hours. And made it combat ready.

What price maneuverability. Tanks are best with lots of small wheel to spread the load out, like the Churchill BUT that hampers higher speeds. Interleaved road wheels gets more contact points but they are bigger wheels so better able to cope with higher speeds. The price is maintenance. As always a complex equation to balance the pro's and con's.

Mobility … firepower … protection … add ease of maintenance … this can be quite a challenging equation to solve.

Blutarski,
From what I've read the Germans would not have been able to build a Sherman.

The transmission was one reason: link

Most of the final drive problems were overcome in Sept 1944 and the G model.

Germany had a severe copper shortage and was one of the reasons that did not have an electrical motor for turret traverse. They also lacked an APU which meant they had to have the engine running to traverse the turret and charge the batteries. The Sherman had an electrical traverse motor and an APU.

The Sherman also had a commander override for turret traverse to get the gun on target for the gunner. I don't think any other tank had that in WWII.

Wolfhag

The Germans were not blind to the weight increase because they changed many other parameters like the thickness of the torsion bars. The problem is once again one of availability, engineering choices and not enough testing.

Like engines, companies producing transmissions didn't come in an endless variety, so the were stuck with what that company could provide, which was a beefed up version of a standard transmission designed for tanks in the 10-20 ton range.

The Germans briefly flirted with rear wheel drive, but when engineers came up with a lightweight compact transmission they choose that option and kept it and variants in service.

The bigger transmission should have been tough enough, but tests were inconclusive and the clock was ticking so they were rushed into production and it took a while to fix the problems, bearing in mind that everyone had transmission problems with heavy tanks for decades after the war.

Another additional problem is that earlier German tanks had access to the transmission with panels in the glacis plate. Because they were at a very steep angle from the horizontal they were only rarely hit and penetrated as most hits either hit the driver plate or lower glacis.

These access panels were removed in Tiger for fear that it would compromise the overall protection, given that Tiger was meant to be used only for breakthrough operations and then taken back to the factory for repairs, this was not seen as a major problem. In practice they had to be serviced in the field more often than not and a crash program to equip these units with additional cranes and other equipment to ease the task was initiated.

The way Panther was laid out favoured armour and structurel integrity at all costs, trying to have as few weak spots as possible. They had a fix, which was to have a separate rooftop plate through which they could access the transmission. And while this was more labour intensive than replacing the transmission on a Sherman, they also had special tools and cranes to quickly lift those parts and a good crew could get a transmission replaced overnight or in a day or two. Compared to earlier tanks this was not a significantly slower method to maintain or replace a transmission, especially in 1943 and early 1944 when parts were still nominally in good supply. Later in 1944 and 1945 repairs took significantly longer and tanks often had to be cannibalized to fix those deemed most reliable.

There was method to the madness and most work was done to usual established specifications which had worked so far, it's just that Americans were far better at making a bunch of engineering features that made their tanks both more reliable and flooded their support units with spare parts, resulting in a much faster maintenance turnover that German units could only dream of.

it's just that Americans were far better at making a bunch of engineering features that made their tanks both more reliable and flooded their support units with spare parts, resulting in a much faster maintenance turnover that German units could only dream of.

Was watching a video from The Chieftain the other day and he was suggesting that the M4 wasn't anymore reliable than the average WW2 tank it was just easier to maintain/repair. Couple that to a well equipped, supplied and staffed workshop and that accounts for the high availability rates of US tank units.