Panther's and KT's turrets are too slow

[willys]

I agree with Juha and Ari on this one. The point of revving engines to DECREASE temperatures does make sense. For instance, my Pontiac gets hotter sitting in idle than it does while I'm moving and the RPM's are up (increases coolant flow). Also, I think anyone can see how proper modeling of traverse speed is highly critical in modeling each tank. Still, when you consider these guys actually considered it in their program design at all when most games don't seem to shows the great effort that was put into this piece of software.

[Guest Germanboy]

<BLOCKQUOTE>quote:</font><HR>Originally posted by willys:

For instance, my Pontiac gets hotter sitting in idle than it does while I'm moving and the RPM's are up (increases coolant flow). <HR></BLOCKQUOTE>

I am not a mechanical engineer (and if I go to try it with my stinky old Volvo I will get prosecuted), but I always thought that the cooling effect when moving comes from the air passing the radiator. In which case revving while standing would be a very bad idea. Can someone enlighten me?

But quite apart from that, with the noise and fuel supply problems, I can not imagine German tanks sitting with high rev in an ambush. I read somewhere that one of the big advantages of German tankers over US tankers in Normandy was that they tended to rev less, thereby decreasing the likelyhood of sound spotting.

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Andreas

[Jeff Heidman]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Germanboy:

But quite apart from that, with the noise and fuel supply problems, I can not imagine German tanks sitting with high rev in an ambush. I read somewhere that one of the big advantages of German tankers over US tankers in Normandy was that they tended to rev less, thereby decreasing the likelyhood of sound spotting.

<HR></BLOCKQUOTE>

The point is that the tank does not need to sit there with the engine racing. The driver just has to twist the throttle on command from the gunner to rev the engine and rotate the turret.

The crew would practice this in training. It only takes a moment to get the engine from idle to 2500rpm.

Jeff

[Ari Maenpaa]

<BLOCKQUOTE>quote:</font><HR>Originally posted by PzKpfw 1:

Which also points out some negative aspects of the Panther turret, Ie, the traverse drive could not turn the turret or hold it in place on on inclines of 20^.<HR></BLOCKQUOTE>

As Guachi pointed out, this wasn't/isn't Panther's problem only. Other tanks can suffer from it too. At least those with big guns.

And because I haven't the needed resources to look up by myself, it would be nice to hear how well Sherman's turret handled the big 17 pounder used in Fireflies. Could it really be that fast?

Also Pershing's fast turret with the gun that big is impressive. Seems that the western allies had extremely good turret traversing engines. Surely they had their own turret problems too.

Some facts from the other side of the hill (pros and cons) could give more perspective to the main topic.

Although at this point of the discussion I'm much wiser than when writing my original message (Thank You all who have replied), I still feel that Panther's and King Tiger's current turret rotation speeds are too slow.

And as a newbie here (Actually I registered last year, but haven't been very active since that), I also regard this forum as one of the best places to get accurate information about WW2 and of course about CM. Killer game and an amazing forum

Ari

[M Hofbauer]

"I am not a mechanical engineer (and if I go to try it with my stinky old Volvo I will get

prosecuted), but I always thought that the cooling effect when moving comes from the air

passing the radiator. In which case revving while standing would be a very bad idea. Can

someone enlighten me?"

I think you are right. the bypassing air cools the cooling liquid runnig through the radiator. there is a small fan positioned behind the radiator to aid suckiong air through it while the vehicle is standing, but it will not compensate/is at a loss at helping to cool sufficiently when you are far above idle rpms.

tanks however are a different story. I have yet to see the tank that is aided in it's cooling by the airflow pressed through it's front-mounted radiator due to it's high speed

let's face it, even on the Autobahn a Tank never atains such a speed, nor are the coolant systems in any way designed to be supported by the airflow from vehicle movement.

as regards rpm helping rotation while sitting still, I can attest to that, when I have my coupé sitting on the street, and push up the rpm's to 5000 in an instant, it really helps the wheels to rotate very fast with the vehicle itself remaining stationary

[Sitting Duck]

So...I might be mis-interpreting, but does it boil down to a choice by the crew?

Do I risk burning up the motor (and become a <u>real</u> Sitting Duck)?

OR

Do I risk getting shot by that Firefly (and become a Dead Duck)?

As the representative of all sitting ducks, everywhere in the world, I'd risk the engine.

Quack!

[This message has been edited by Sitting Duck (edited 08-21-2000).]

[Guest Germanboy]

<BLOCKQUOTE>quote:</font><HR>Originally posted by M Hofbauer:

tanks however are a different story.<HR></BLOCKQUOTE>

That was my point, actually.

<BLOCKQUOTE>quote:</font><HR>Originally posted by M Hofbauer:

as regards rpm helping rotation while sitting still, I can attest to that, when I have my coupé sitting on the street, and push up the rpm's to 5000 in an instant, it really helps the wheels to rotate very fast with the vehicle itself remaining stationary <HR></BLOCKQUOTE>

LOL.

Jeff, you are right, I wasn't thinking.

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Andreas

[Mikester]

I'm not a thermo expert, but I do have a Mech. Engr. degree.

Is the Panthers cooling system liquid based or air based? I believe most tanks have the former if I'm not mistaken.

If it's liquid based as I'm assuming I believe the fans (fan belt driven off pully attached to drive shaft) were actually mounted facing up and pulled (or perhaps pushed) air through the tanks rear deck (I believe these are the two circular features you see on the Panthers rear deck) down through the radiator (i.e. heat exchanger core) where the heat is pulled out of the water/anti-freeze liquid by the air passing over the exchanger surfaces thus cooling it. The fluid is then pumped by a water pump back through internal chambers around the engine hot spots such as the cylinders where they pick up heat from the engine combustion which is then carried out of the engine and back to the heat exchanger. IIRC, typically about 1/3 of the heat generated by the combustion process driving the engine is carried away by the cooling fluid system.

Point here is that the fan blowing air across the exchanger is directly linked to the engine output shaft so it spins faster providing more air flow as the engine turns at higher rpm's. Also, the fact that the fan/exchanger combination is mounted vertically vs. horizontally (like in your car) means there is really no "ram air" effect of the vehicles forward movement/velocity contributing to increasing airflow across the heat exchanger. So whether or not the tank is sitting idly vs. moving is probably immaterial.

Willys,

The fact that your car runs hotter when idling is mostly due to the fact that you are not receiving the benefit of your cars velocity forcing airflow across the heat exchanger surfaces, not that the fan attached to the drive shaft is turning faster. This of course varies with speed, but at some point probably around 25-35 miles per hour the velocity of the vehicles contribution to the total air flow vs. that of the fans is probably starting to dominate the equation in terms of cooling. Also, everyone needs to keep in mind that revving the engine to spin the fan faster while no air is being forced across the heat exchanger due to vehicle movement (which as I said before is always the case for the tank whether its moving or not) really does not provide additional cooling. Granted, it increases the airflow (due to fan turning faster) across the heat exchanger which does in fact increase the convective heat transfer (cooling), but revving the engine means you are also increasing the number of explosions in each cylinder in direct proportion to the rpm's generating tons of heat. So you really are not cooling the engine off any better by revving the engine while you are sitting still and in fact if the cooling system is not designed to sit w/ vehicle not in motion and remove this additional heat you create by revving the engine at high rpm's you might very well be heating the engine up more by doing this.

Mike D

aka Mikester

[This message has been edited by Mikester (edited 08-21-2000).]

[willys]

Cooling of tank motors of any size would almost have to be liquid based. Although, of course, after the war Germany did produce the famous Volkswagen, with it's revolutionary air-cooled system. The idea was that it helped cold start conditions in chilly environments. It also was one of the reasons the VW didn't have a very effective compartment heater.

[M Hofbauer]

I agree fully. But one minor point: I was surprised at your 1/3 ratio. I would have guessed that more than 80 of the heat would be carried away by the hot gas residue of the combustion itself, exiting out of the exhaust auspuff. Don't misunderstand me,I am not questioning your fact, I am just expressing my genuine surprise.

while we are talking fans and turrets, wasn't there also this thing about the german tanks' air-conditioning applets being inadequate for prolonged fire exchanges and consequently parts of the firing gases building up inside?

[Mikester]

The 1/3 number is rough and as I recall the number for a car engine. And yes, most of the heat goes right out with the exhaust. The main reason for the radiator is to take care of the heat absorbed by the cylinder walls from the combustion process (extremely hot, cannot remember the exact temperature range offhand) and prevent them and things like piston rings from melting down. Amount of heat pulled out by radiator cooling system also depends on whether the engine block is aluminum or steel (I'm certain all tanks back in WWII were steel by the way). Aluminum conducts heat way moreso than steel. So aluminum engine blocks probably can attribute a somewhat greater percentage of overall engine cooling to the radiator system vs. just being dumped out the exhaust. Of course they also need to do so as the melting point of aluminum is lower than that of steel.

Mike

[PzKpfw 1]

BTT

Regards, John Waters

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"Make way evil, I'm armed to the teeth and packing a hamster!"

[PzKpfw 1]

As an add on to my earlier post I realised I was incorrect on the gunner & driver cooperateing on the traverse by telling the gunner increase RPMs.

Ie, the Tiger II gunner had control of the traverse speed; independant of the driver, by useing an selector switch with an high & low setting. I can only assume it was the same design in the Panther with the planned standardisation w/o digging out more books.

Regards, John Waters

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"Go for the eyes Boo, go for the eyes!!".

[Doug Beman]

Mikester, I'm gonna play picky-picky here and say "the T34 had an aluminum diesel, and I'm sure it wasn't the only WW2 tank to have an engine crafted mostly/all of aluminum."

Also, I can attest to the dangers of revving automobile engines while the vehicle is sitting still; my father used to have a 1972 Plymouth Roadrunner, and if that car sat still for more than 20 minutes the TEMP light would blink on.

Also, I'm sure you all know it's not a good idea to run your car's air conditioning while the vehicle is sitting still. All the heat that gets pulled out of the car's passenger compartment gets dumped into the engine cooling system, and if you're not moving the radiator can't do its job and your vehicle will overheat.

DjB

[M Hofbauer]

Doug Benneman,

let me be pikipiki too

"Also, I can attest to the dangers of revving automobile engines while the vehicle is sitting still; my father used to have a 1972 Plymouth Roadrunner, and if that car sat still for more than 20 minutes the TEMP light would blink on."

ah, but you are talking AMERICAN cars. that's the kind of car that would lose oil simply from standing somewhere not doing anything, engine not runing ;p

"your car's air conditioning"

air conditioning - again a mostly american car feature. though heavy and being mostly for decreasing mileage, they are starting to appear here, too.

willy's: are you talking the Käfer? the KdF-Wagen was a prewar, typical third reich era design. most hippies with their Käfer seem not to be aware of that. just make a literal translation of Volkswagen, it was meant exactly that literal way.

[Mikester]

Hey Doug B,

Most interesting to find a WWII tank w/ an Al block engine. One of the major reasons you see it today in car engines is for weight savings (about 1/3 lighter than steel) which directly equates to better fuel mileage. I'd be interested in hearing more about this and other tanks that may have had Al blocks and what reasons the designers had for using them.

Mikester out.

[Ari Maenpaa]

Hey BTS !

Just read the 1.05-readme.

Could we get these turret speeds fixed in 1.06 ?

Isn't the statement of the reason enough?

Ari

[Guest Germanboy]

<BLOCKQUOTE>quote:</font><HR>Originally posted by M Hofbauer:

willy's: are you talking the Käfer? the KdF-Wagen was a prewar, typical third reich era design. most hippies with their Käfer seem not to be aware of that. just make a literal translation of Volkswagen, it was meant exactly that literal way.<HR></BLOCKQUOTE>

The 'People's Car'. I think they only produced a few hundred of the original version before they switched to producing Kübelwagens, the military version using the money KdF members had put down towards their cars. After the war the Wolfsburg plant was rescued by a British Major. I think the original plan was to ship it to England, but he convinced the military government that Germans with jobs are less likely to go invade Europe again. As a former owner of a Käfer (Beetle) I can attest to the inferior heating... Very nice cars though.

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Andreas

[Herr Oberst]

This whole thread sheds new light on the stories of Wittman's driver "hull steering" to assist in the firing procedure...

[Guest machineman]

From what I remember the Germans took great care to train their tank teams to work together and a great deal of care was taken to keep a 'team' together as they transferred from tank to tank.

"A well-trained crew is like a family and should be kept together at all costs"

A good driver was considered to have a great deal to do with the success of a tank commander as he not only had a lot to do with aiming at times but also with keeping the tank under as much cover as possible. I remember a british comment that in the western desert that the German tanks were much more difficult to kill that the Italian in part because of the skilled driving that took more advantage of the cover of the terrain.

This of course was even more important for the Stugs, in which the driver HAD to be closely involved in the aiming of the gun.

"The biggest advantage over a conventional tank was its low, squat shape. A good driver could take advantage of the low silhouette against the skyline and use the countryside - like shallow depressions, ridges, or anything offered by nature or man-made, to minimise the risk of becoming a target."

In this way the Stugs, which had no turrent at all, could function fairly well against turrented armour.

"One such unit was the 244th Assault Gun Brigade, which distinguished itself by destroying 54 American tanks for the loss of only two assault guns" (Ardennes, 1944).

I believe Wittman and his crew came from assault guns before they got into Tigers, which would probably make them especially adept at commander-driver cooperation.

[:USERNAME:]

John Kettler recently posted a site where there was some great shots of Jgpnz IVL70. Also in that site are panther pictures including one where a german is adjusting a fan! The caption says that is was run off a power takeoff from the engine. So, it was variable with engine speed (not fixed electric is my point) and would have variable cooling. Therefore, aside from the revs wearing out the bearings over time, overheating SHOULD have not been a problem. I know the panthers had combustability problems with sloshing carbs but was boiled over radiators really a problem?

Given the panthers rotate in place capability, fast turret, excellent gun/optics, no wonder it was such a killer.

Lewis

[:USERNAME:]

<BLOCKQUOTE>quote:</font><HR>Originally posted by machineman:

This of course was even more important for the Stugs, in which the driver HAD to be closely involved in the aiming of the gun.

"The biggest advantage over a conventional tank was its low, squat shape. A good driver could take advantage of the low silhouette against the skyline and use the countryside - like shallow depressions, ridges, or anything offered by nature or man-made, to minimise the risk of becoming a target."

In this way the Stugs, which had no turrent at all, could function fairly well against turrented armour.

"One such unit was the 244th Assault Gun Brigade, which distinguished itself by destroying 54 American tanks for the loss of only two assault guns" (Ardennes, 1944).

I believe Wittman and his crew came from assault guns before they got into Tigers, which would probably make them especially adept at commander-driver cooperation.<HR></BLOCKQUOTE>

Where are these quotes from? Its true about Whittman, he even kept his sissor optics from his stug days. If you have ever seen a cutaway of a stug (theres one at that parola museum) the crew can literally kick the back of a drivers seat. left cheek kick means turn left, right kick etc.

Lewis

[Guest machineman]

Just thinkin' a Tiger must have seemed like a dream machine for Wittman and his crew , with the advanced transmission and turn in place capability PLUS having a turrent. Must have felt like Christmas for them getting that kind of an upgrade. No wonder he raised hell.

The first is a quote from p75 of 'German Tanks of World War II' by George Forty, who himself takes it from the writing of Max Fleming, a Stug driver of Fallschirmpanzerkorps Herman Goring. The second is from p68 of another book of the same name, this by Dr S. Hart and Dr R. Hart.

[mfred]

Originally posted by Fionn:

Question...

Given the heat buildup problems with the Panther engine just how often do you think crews had their engines running at 2500 rpms when sitting in a defensive position?

--------------------------------------------

Well I would believe only when necessary to target. The engines would idle, than the driver would apply full RPM to turn turret and hull for defensive, as this practice was employed.Ever seen film footage of this, interesting comparison to CM practice.

If I had a tank in my sights, the last thing I would worry about was the warranty on the engine?

With this in CM, the battles between Allie and Axis tankers might start to reflect history, and not propaganda.e.g M5 Stuart,the Allies should have just made them, such mighty mice.

[This message has been edited by mfred (edited 08-27-2000).]

[:USERNAME:]

The cooling is engineered for when the tank is under load ie moving its own mass up a hill. To be sitting still and revving an engine should not overheat it period! The tank gets no forward movement benefit like a car.