Vulnerability of the Panther Glacis to 122 AP

[Contender]

"more susceptible"... relative to what might I ask?

T/D difference between the two calibers IIRC, Ty.

[Peasant]

Found some info, not on the 122mm but the 100mm:

The armour strength of the T-54 Mod.1951 was somewhat weakened compared to that of the Mod.1948. Reminder: the frontal hull plates were reduced in thickness from 120mm to 100mm. While the 120mm armour was immune to the domestic 100mm D-10T gun, the results of the firing trials made in 1950 showed that the UFP was defeated by the blunt headed shell from a distance of 470m and the lower from 1000m. With an additional 20° side angle the distances are reduced to 240m and 790m respectively.

Source: book "C.Устьянцев, Д. Колмаков, Боевые машины УРАЛВАГОНЗАВОДА. Т-54/Т-55. 2004"

Looking at how these values all fit nicely into the model it looks like they were already smoothed out and interpolated from actual firing results by using a model similar to one I'm currently employing.

In the Yugo tests the UFP of T-54A was immune down to point blanc. That model was in production between 1955-1957, so it appears that somewhere between 1950 and 1955 the ballistic resistance of soviet RHA was significantly improved in regards to overmatching attack at obliquity.

This is not offtopic btw I think building the most accurate picture of capabilities of soviet guns is essential for determining the effectiveness of german armour.

[Contender]

In the Yugo tests the UFP of T-54A was immune down to point blank. That model was in production between 1955-1957, so it appears that somewhere between 1950 and 1955 the ballistic resistance of soviet RHA was significantly improved in regards to over-matching attack at obliquity.
This is not offtopic btw I think building the most accurate picture of capabilities of soviet guns is essential for determining the effectiveness of German armour.

I think the soviets most definitely improved their armour in the post-war, even just the nature of peace time allows for more quality to be applied than in wartime but I think one should consider the following:
Did the Yugoslavian tests equip the PaK 43 with the newer PzGr. 39/43 using the 45 (?)degree standard or the older round?
The IS-2 was mainly cast the armor was supposed to give resistance equal to 90 mm @ 60 degrees however resistance may have been less due to lower quality. It also had a large hole for the view slit cut into the glacis & lots of welds on the glacis especially around the view slit which may have impacted its armor resistance (hits to weld seam).

[critical mass]

Found this. No source, but it looks like a page from a bigger document:



Translation:

Table No.15

Firing Trials on the hull of a "Panther" tank.

Shot No. 1
Shell type: AP.
Target: Turret.
Armour thickness( in mm): 45
Obliquity(in °): 28
Angle between the direction of firing and the hull( in °): 90
Distance( in m.): 1000
Damage to the target: "Hole through. A piece of armour, 120mm in diameter thrown from the back of the plate. Inside, breech of the gun badly damaged."

Shot No. 2
- same stuff -
Damage to the target: "Hole through. The shell went into the gun mantlet 100mm thick. There it made a deep dent with a crack through"

Shot No. 3
- same stuff -
Damage to the target: "Hit to the corner of the turret. Hole through. A piece of armour, 120x130mm thrown from the back of the plate"

Shot No. 4
Target: Front hull.
Armour thickness( in mm): 65
Obliquity(in °): 55
Angle between the direction of firing and the hull( in °): 90
Distance( in m.): 200
Damage to the target: "Hole through of size 170x190mm"

Shot No. 5
-- same --
Armour thickness( in mm): 85
--same--
Damage to the target: Dents 45 and 65mm deep.

Shot No. 6
-- same --
Distance( in m.): 400
Damage to the target: "Dent 45mm deep, size 100x170mm, cracks in the armour within this dent's area."

Shot No. 7
-- same --
Distance( in m.): 700
Damage to the target: "Dent 35mm deep, size 30x230mm"

Shot No. 8
Shell type: Subcaliber.
-- same --
Distance( in m.): 1000
Damage to the target: "Dent 30mm deep."

Shot No. 9
Shell type: AP.
-- same --
Armour thickness( in mm): 65
Damage to the target: "Breach 30x50mm. A piece of armour, 120x180mm thrown from the back of the plate"


Now, it doesn't say which weapon was used here but from the fact that it failed against the UFP at 200m and yet defeated the LFP at 1000m I believe it was the 85mm AA gun firing the BR-365( the one with a windshield) shell.

Notice that hit #9 was not a perforation, but an Army BL (soviet PTP). The hole diameter is smaller than the caliber, precluding any passage of the shell through the plate. The plate failing by ejection of a disc probably facilitated the event.

[Contender]

Saw this in an aircraft forum:

[Peasant]

Saw this in an aircraft forum:

Yeah this table makes no sense. Even if some parts are based on real firings results there is no way to tell them apart.

[Contender]

I haven't translated the chart itself (time issue on my end) , I posted it right after I found it so idk about how they got these figures but I did translate the description which was as follows:

Предельные дальности стрельб при которых возможно разрушение немецких танков "Пантера"

Rough website translation: " Maximum firing ranges at which the destruction of German tanks "Panther" is possible"

[Peasant]

The impact of the 85mm AP shell on the 65mm plate at 55° with 705m/s is quite similar geometrically to an 122mm shell hitting 80-85mm plate.
Using DeMarre equation, this suggests that the 122mm shell would have the same effect(hole less than caliber wide) at striking velocity of around 686m/s, which is equivalent to a distance of 750m for the sharp tipped BR-471 shell and 1300m for blunt tipped BR-471B.

[critical mass]

Found some info, not on the 122mm but the 100mm:

The armour strength of the T-54 Mod.1951 was somewhat weakened compared to that of the Mod.1948. Reminder: the frontal hull plates were reduced in thickness from 120mm to 100mm. While the 120mm armour was immune to the domestic 100mm D-10T gun, the results of the firing trials made in 1950 showed that the UFP was defeated by the blunt headed shell from a distance of 470m and the lower from 1000m. With an additional 20° side angle the distances are reduced to 240m and 790m respectively.

Source: book "C.Устьянцев, Д. Колмаков, Боевые машины УРАЛВАГОНЗАВОДА. Т-54/Т-55. 2004"

Looking at how these values all fit nicely into the model it looks like they were already smoothed out and interpolated from actual firing results by using a model similar to one I'm currently employing.

In the Yugo tests the UFP of T-54A was immune down to point blanc. That model was in production between 1955-1957, so it appears that somewhere between 1950 and 1955 the ballistic resistance of soviet RHA was significantly improved in regards to overmatching attack at obliquity.

This is not offtopic btw I think building the most accurate picture of capabilities of soviet guns is essential for determining the effectiveness of german armour.

After ww2, the soviets succeeded in improving the properties of its 42-S grade medium hardness RHA. First by adding molybdenium (42-SM) to delay the onset of temper brittleness, allowing the heat treatment of the sloped glacis plates to lower hardness (without temper embrittlement), then by employing electrosteel for cleaner steel with less impurities and finally by cross rolling of the plate. They obtained good results.

[ThatZenoGuy]

I am a simple man who doesn't quite know advanced material science and ballistics and such.

In a nutshell for a layman, what is the vulnerability of the Panther's glacis to the various soviet rounds? Shape nosed, blunt nosed, HE, etc?

[critical mass]

Apart from heavy artillery HE strikes, only the 100mm and 122mm AP bullets guns are readily capable to beat the PANTHERs glacis over a meaningful range of distances. However, instead of discrete values, its best to figure this as a distribution of probabilities, changing with distance.

[ThatZenoGuy]

Apart from heavy artillery HE strikes, only the 100mm and 122mm AP bullets guns are readily capable to beat the PANTHERs glacis over a meaningful range of distances. However, instead of discrete values, its best to figure this as a distribution of probabilities, changing with distance.

Did both the earlier 122 AP and later AP shells penetrate about the same against the Panther, or did earlier shells struggle at decent ranges/additional angle?

[Peasant]

Seems accurate enough.

[Peasant]

I'm sure we're all familiar with this chart here, depicting penetration performance of the soviet 122mm AP shell:



It's been used a lot to argue that defeating a 200mm armor plate is within the capabilities of D-25T gun. Well, I have something to show you:



It's a snippet of report on ballistic trials of BL-9 gun. It's a 122mm gun firing the same projectile as D-25T at 1000m/s. Here are the results it achieved against a 203mm plate at 1000m distance: "One shell penetrated completely, 4 shells are stuck in the armour, 3 shells left dents." For the record: the striking velocity at 1000m is 925m/s. You can figure out yourself what chances this shell has at defeating this target at 781m/s.

Source: http://www.tankarchives.ca/2013/06/sovi ... -bl-9.html

[ThatZenoGuy]

Isn't TankArchives usually regarded as being a little propaganda'y?