"Hetzer" (Jagdpanzer 38) Armor Quality, allegedly 50% the value of RHA?

[Peasant]

Unless I am mistaken, the only projectiles that can 'reduce' effective armor thickness for slopes are either massively larger diameter shells, and APFSDS projectiles. The 85mm might overmatch the 50mm plate a lot, but for a 60-65mm plate I'm just not seeing it. Especially with Soviet quality control and shell design.

Isn't there a picture on this very thread which shows non-pens to the LFP?

Thats because it doesnt "reduce" the effective armour thickness. It's an illusion born from the inherently flawed concept that is the "effective armour thickness" that spawned a myth that soviet blunt tipped AP shells are much more effective against sloped armour than the conventional sharp tipped AP.
It's actually the other way around: the soviet shells are just less bad against thin plates at slope and penetrate about as much as an AP shell of their mass and caliber would. To put in into perspective: a 9,2kg 85mm APCBC shell fired at 800m/s would penetrate about 145mm/0° at 100m, if it had a more advanced design, similar to that of the shells of western nations. If we use this metric to measure how powerful a given gun is, it shouldnt surprise you that it can defeat relatively easily targets like the Panther's LFP.

About that picture: the original photo doesn't indicate from what "distance" those shot were taken, we have only the "artistic interpretation" of facts from the author, Yuri Pasholok, who's word I wouldn't trust farther than I can spit.

[Yoozername]

I don't like your tone.

[critical mass]

Thats because it doesnt "reduce" the effective armour thickness. It's an illusion born from the inherently flawed concept that is the "effective armour thickness" that spawned a myth that soviet blunt tipped AP shells are much more effective against sloped armour than the conventional sharp tipped AP.
It's actually the other way around: the soviet shells are just less bad against thin plates at slope and penetrate about as much as an AP shell of their mass and caliber would. To put in into perspective: a 9,2kg 85mm APCBC shell fired at 800m/s would penetrate about 145mm/0° at 100m, if it had a more advanced design, similar to that of the shells of western nations. If we use this metric to measure how powerful a given gun is, it shouldnt surprise you that it can defeat relatively easily targets like the Panther's LFP.

A good explenation. But I wouldnt say it "easily" defeated the PANTHERs LFP. It rather struggled to make a calibre sized hole at any distance (results cannot be dependet upon). With RHA armor plating, the amount of damage entering a vehicle can be quiete small until a calibre sized hole is formed through plastic deformation or, preferably, plug ejection.

At very high obliquity and thick plates, there were little differences in the performance as long as all projectiles broke up. However, at thin enough plating, the blunt nosed APBC could perforate intact at even lower velocity than pointed APCBC-HE-projectiles, both against vertical and sloped plate.
But then again, when looking into severe targets at low to moderate obliquity, requiring high enough velocity to break up the shell, soviet AP-technology choices perhaps reduced the effectiveness against German AFV.

[Peasant]

A good explenation. But I wouldnt say it "easily" defeated the PANTHERs LFP. It rather struggled to make a calibre sized hole at any distance (results cannot be dependet upon).

Yeah, I meant "easily" relative to the UFP.

With RHA armor plating, the amount of damage entering a vehicle can be quiete small until a calibre sized hole is formed through plastic deformation or, preferably, plug ejection.

You are making an Interesting point here. Are you suggesting that failure by plug ejection is somehow beneficial for the armour at high obliquity? Perhaps accelerating the ejected plug robs the shell of some it's velocity vector component directed towards the armor and turns it away from it's path? Just making a wild guess, I haven't seem much research done on this topic. Although I know that the optimum hardness level for the plate increases for a given T/D ratio as the obliquity increases between 0 and 45°, not sure if this relationship holds up at even higher obliquity.

[Yoozername]

Not sure where this specious thread is going.

Perhaps I can make some 'dots', and see if we can pull it all together, and connect them. {graphs!}

I think most people reject the notion that the armor on the upper hull of the 'Hetzer' was thick junk.

Most people might accept that photographic evidence shows that it is not easily holed. The side armor can peel away or even crack off in chunks.

Perhaps trying to compare the upper hull of the Hetzer, and the lower hull of a Panther could have went somewhere? Is the Hetzer viable with its upper hull vs 85 mm at 700 meters? Or is it pierced at most 'battlefield ranges' as one has said?

Inquiring minds want to know....

[Peasant]

Well, since they wanna know: my current best estimates suggest that the UFP on the Hetzer is a very tough target for this gun. The T-34/85 would probably need to close in at 500m or less to do any kind of damage behind the armour and to even shorter distances to pierce it reliably. Although at this point it might just opt to aim for the weaker LFP.

This, of course, assuming that there are no issues with armour quality on that particular vehicle.

[Yoozername]

Also, assuming the Hetzer would be so kind as to show its LH. One thing people do miss when critiquing the Hetzer is that it had a very good gun depression (albeit narrow traverse). Minus 8 degrees it seems. This would allow it to use ambush positions that used hull down and the ability to pull back also.

Looking through images of destroyed Hetzers, it would probably be best to just have access doors through the side 20 mm armor. That armor wouldn't stop much even with oblique hits. And having a means to exit the AFV quickly (and take a peak outside) would have raised spirits. I would not want to be the driver, assuming he is the last man out.

[Mobius]

Regardless of the Yugo tests vs hard or soft armor there is also
In other test where small caliber tests show that 230 BHN was only 89% of the resistance quality of 280 BHN.
https://apps.dtic.mil/dtic/tr/fulltext/u2/492002.pdf
In other firing tests it was 95% of the resistance compared when struck with 3" M62 APHE.
But certainly not 50%.

[Yoozername]

Regardless of the Yugo tests vs hard or soft armor there is also
In other test where small caliber tests show that 230 BHN was only 89% of the resistance quality of 280 BHN.
https://apps.dtic.mil/dtic/tr/fulltext/u2/492002.pdf
In other firing tests it was 95% of the resistance compared when struck with 3" M62 APHE.
But certainly not 50%.

Thanks ole' bud. I have never seen that before.

And, BTW, Mobius was a big part of the Panzer Command wargame. A very under-appreciated product IMO.

[Contender]

Well, since they wanna know: my current best estimates suggest that the UFP on the Hetzer is a very tough target for this gun. The T-34/85 would probably need to close in at 500m or less to do any kind of damage behind the armour and to even shorter distances to pierce it reliably. Although at this point it might just opt to aim for the weaker LFP.
This, of course, assuming that there are no issues with armour quality on that particular vehicle.

With respect this seems a bit different than before:



I had this at hand The @ 30 degree angle chart:


How thick is the nose plate of the Panther is how was it exactly and did it change during its production?
The soviet test in the above posts quotes a figure of 60-65 mm on the Kursk era Panther D but I've come across other measurements that differ such as 50 mm.

[Peasant]

With respect this seems a bit different than before:



I had this at hand The @ 30 degree angle chart:


How thick is the nose plate of the Panther is how was it exactly and did it change during its production?
The soviet test in the above posts quotes a figure of 60-65 mm on the Kursk era Panther D but I've come across other measurements that differ such as 50 mm.

You shouldnt take any values in a sentence that also contains the word "estimate" as some absolute truth. My models evolve and change in light of my expanding knowledge of terminal ballistics as well as new historical data that comes into light.
I'm mostly sure only about two things on this topic: First, that the Hetzer UFP did not provide complete protection from the soviet 85mm gun and the second that it was a difficult target for this gun.

Another issue I've come across when converting the ballistic limits (m/s) into distances (m) is how slowly high caliber shells loose velocity. An uncertainty about the exact velocity of +-5% translates in this instance from 500m(750m/s) into 100 - 900m, a significant uncertainty from a tactical standpoint.

Spielberg in his book "Panther and it's Variants" reports that in the Panther G version the LFP was reduced to 50mm nominal. Although on some late war german vehicles we see plates 65/85mm instead of 60/80mm thick it's because some production plants had troubles with producing armour plates of adequate quality with the new molybdenum-free alloys introduced between 1943/1944 and were allowed to compensate by increasing thickness by 5 mm in order to not slow down production until these problems were resolved. In actuality most of these plates had effective thickness in between 60 and 65mm.

[Yoozername]

Spielberg in his book "Panther and it's Variants" reports that in the Panther G version the LFP was reduced to 50mm nominal. Although on some late war german vehicles we see plates 65/85mm instead of 60/80mm thick it's because some production plants had troubles with producing armour plates of adequate quality with the new molybdenum-free alloys introduced between 1943/1944 and were allowed to compensate by increasing thickness by 5 mm in order to not slow down production until these problems were resolved. In actuality most of these plates had effective thickness in between 60 and 65mm.

Do you have a source for this? My understanding is that the plates were specified as a nominal thickness of 8 cm, and the allowance is -0/+5 mm. I am sure if the manufacturers could make it 8 cm and -0/+0 they would. They would save on metal. In reality, the manufacturers would not want to have finished product that is rejected either. In the real world, almost everything has specifications. The Germans had QC and also acceptance people that tested out product before it could be used.

I believe the early captured Panthers already had 85 mm UFH measured by the Soviets.

Another issue I've come across when converting the ballistic limits (m/s) into distances (m) is how slowly high caliber shells loose velocity. An uncertainty about the exact velocity of +-5% translates in this instance from 500m(750m/s) into 100 - 900m, a significant uncertainty from a tactical standpoint.

Again, this is the real world. A gun can have a nominal velocity when accepted after production. There was a thread here about this, where the Germans would use barrels to a certain minimal velocity. So a ATG might have a nominal velocity that is exceeded during tests with testing ammunition. I think 750 M/s might be the example. But it was still serviceable down to 704 M/s or something like that.

[Peasant]

Do you have a source for this? My understanding is that the plates were specified as a nominal thickness of 8 cm, and the allowance is -0/+5 mm. I am sure if the manufacturers could make it 8 cm and -0/+0 they would. They would save on metal. In reality, the manufacturers would not want to have finished product that is rejected either. In the real world, almost everything has specifications. The Germans had QC and also acceptance people that tested out product before it could be used.

I believe the early captured Panthers already had 85 mm UFH measured by the Soviets.

In theory it should work as you say, but in the wartime, where keeping an interrupted production of material is literally a matter of life and death, such petty economic considerations are secondary. If, let's say, a big portion (30-60%) of your production doesnt meet the specifications, you cant just send hundreds of tanks back to the factory for a months long overhaul until they are perfect when they are need as replacements at the front ASAP. You simply dont have the luxury of time, so you either accept substandard product or take steps in increasing its quality (here specifically it's protective quality) in a way that doesnt compromise production quotas.

This is my logic, so no, I dont have a quote from a famous historian to support my intuition. Only this quote here about the new steel alloys and the fact that the Panther captured by the british in 1944 had 80mm(not 85mm) and 50mm(not 55mm) thick UFP and LFP respectively.

Another issue I've come across when converting the ballistic limits (m/s) into distances (m) is how slowly high caliber shells loose velocity. An uncertainty about the exact velocity of +-5% translates in this instance from 500m(750m/s) into 100 - 900m, a significant uncertainty from a tactical standpoint.

Again, this is the real world. A gun can have a nominal velocity when accepted after production. There was a thread here about this, where the Germans would use barrels to a certain minimal velocity. So a ATG might have a nominal velocity that is exceeded during tests with testing ammunition. I think 750 M/s might be the example. But it was still serviceable down to 704 M/s or something like that.

Well, yes, and the ballistic of a gun also change with the temperature of propellant, so the mv drops in winter, also dense cold air slows the shell faster but the cold also make the steel armour more brittle... there are innumerable variables that influence the final result, but we cant account for every single one of them every time we have a discussion so let us play with idealized spherical tanks made from isotropic material of uniform density in a vacuum firing spherical shells at other idealized tanks. =)

[Mobius]

I had this at hand The @ 30 degree angle chart:


You shouldnt take any values in a sentence that also contains the word "estimate" as some absolute truth. My models evolve and change in light of my expanding knowledge of terminal ballistics as well as new historical data that comes into light.
I'm mostly sure only about two things on this topic: First, that the Hetzer UFP did not provide complete protection from the soviet 85mm gun and the second that it was a difficult target for this gun.

I used my data base of normalized and averaged penetration tables to look at the relative penetrations of the German guns vs T-34/85 UFH. It is interesting in that it shows a possible difference of armor effectiveness based on penetration criteria. The data base is compiled of various penetration tables from several sources and not calculated based on ballistics. (At least on my end.) Of course the normalization could be way off so take with a grain of salt.
The Russians tested the PaK 40 with 770 m/s vs the 790 m/s shown in the graph against the T-34/76 and found that it could be penetrated at 1000 meters. http://www.tankarchives.ca/2014/04/spar ... links.html

[Yoozername]

This is my logic, so no, I dont have a quote from a famous historian to support my intuition.

I asked for a source. Not a quote. We are allowed, here, at this website to do so.

Using the turret front of the late Tiger II turret and its LFP as the reference points, as well as some of the more arcane terminal ballistic knowledge I've obtained by means that shall be left unnamed, I've created this chart.

I can't ask you about these "more arcane terminal ballistic knowledge" you have 'Obtained'. But feel free to make graphs, or charts, as you say.

I am basically calling you out as posturing yourself beyond factually backed up data.