Tiger-II front glacis vs AT guns

[delcyros]

To make it repeatable, I give my approximations for the D-10 ballistics:
gun: D10
nation: soviet
timeframe: mid-late ww2
Caliber = 3.9 inch (10.0 cm)
Shell weight = 35 lbs (16 kg)
Muzzle velocity = 2922 fps (891 m/s)
plate thickness in calibres = 1.8
Relative ballistic performance: 1.00 (my assumption, but soviet ballistic
projectiles were not bad in comparison to other. I might be wrong here)

Muzzle energy = 6.262 megajoules = 2307.6 foot-tons

Relative muzzle energy: 1.18

Elevation-----Range --------Time-----Velocity----Fall Angle--effect*:
0.0 deg-----~300 yards----0.1 sec--2896 fps----0.1 deg---1886 fps
0.5 deg-----1400 yards----1.6 sec--2561 fps----0.6 deg----1318 fps
1.0 deg-----2500 yards----3.1 sec--2295 fps----1.2 deg----676 fps
1.2 deg-----3100 yards----3.7 sec--2204 fps----1.5 deg----234 fps
1.3 deg-----3300 yards----4.0 sec--2161 fps----1.7 deg----plate holed normal plug punched out
1.4 deg-----3500 yards----4.2 sec--2134 fps----1.8 deg----no holing of the plate
1.5 deg-----3700 yards----4.5 sec--2094 fps----1.9 deg----no holing of the plate
1.6 deg-----3900 yards----4.8 sec--2055 fps----2.1 deg----no holing of the plate
2.0 deg-----4600 yards----5.9 sec--1925 fps----2.7 deg----no holing of the plate
2.5 deg-----5400 yards----7.3 sec--1783 fps----3.6 deg----no holing of the plate
5.0 deg-----8600 yards----13.4 sec-1360 fps----8.3 deg----no holing of the plate
7.5 deg-----10800 yards---18.9 sec-1140 fps----13.8 deg---no holing of the plate
10.0 deg-----12600 yards---23.9 sec-1014 fps----19.6 deg--no holing of the plate


(excluding fractions)

*) means effect on plate (holed or not), resp. the remaining projectile velocities in case the plate is defeated.
Assuming no hit on the bulge of the gunmount (in most cases the projectile would glance off anyway). Armour properties:
Q=0.95, E=15%, armour tends to be brittle, NO FACE HARDENED TYPE (?not sure in this?)
Thickness: 180 mm, no backing plate, inclined back by 10 degrees from the vertical

Conclusion: The D10 will achieve full penetration at distances up to 2870 m (normal) for direct impact angles and under assumption of no shatter. Records show that this shelltype is susceptible to shatter for greater impact velocities than 2200 fps. (at these direct impact angles nose shatter with only minor or no lower body damage)
Shatter would greatly reduce the ability of the projectile to penetrate, so I conclude that a terminal striking distance of ~1490 m for defeating of the turret face with >80% reliability. Keep in mind that perfect impact angles are rather uncommon. a difference in 20 degrees target angle for a net impact obliquity of 21.74 would result in a terminal striking distance of 2400 m without shatter and ~ 1330 m with shatter for >80% reliability. Higher impact angles sharply decrease the performance of this shell to penetrate due to a higher probability of lower body damage due to shatter.

-----NOTE that I (probably) slightly exagerated the D10 ballistic performance (guns with NO barrel wear) and understimated the armour properties in order to give a high degree of reliability for the immune distances, rather than a low degree of reliability for penetrating distances----- (edit)

-----NOTE that at ~3000 m +-20m a danger gap exists, when the impact velocity of the projectile allows a no shatter, so that at this distance the plate may be holed again, all under ballistic , armour and shell assumptions as above-----

 

[Soren]

Tiger Ausf.B's on the Eastern front were very frequently engaged by soviet 100-122mm AT guns, however NEVER did the Soviet AT guns, any of them, manage to penetrate in ANY area on the Tiger's frontal armor - and let me remind you that it was standard practice for the Tiger Ausf.B to ALWAYS have its front towards the enemy, almost never exposing its flanks. (And you can read Soviet reports about this as-well) Yet never, NEVER, was the Tiger Ausf.B's frontal armor ever penetrated in combat, it didn't happen, despite many Tigers taking extreme amounts of hits.

 

[Soren]

delcyros,

The 100mm D-10 would penetrate 185mm of vertical 240BHN RHA at 1,000m with its APBC round, the best AP round available to the D-10. (Against FH armor however it wasn't the most effective, like most soviet projectiles)

- Results achieved at the Aberdeen proving grounds.

 

[delcyros]

I know the reports.
I made this calculations with a lot of assumptions, like 1) no gunwear
2) ballistic performance of soviet shells = average US ballistic quality
3) frontal turret armour beeing of inferior quality with high degree of britellness
4) no backing layers (I actually believe this is wrong but so far I have no idea what kind of construction steel was used for it)
6) homogenious instead of glacis (am not sure if this is correct) for turret front
7) soviet projectile beeing as resistable to shock damage as was the US M79 APC -which truly isn´t the case

As You see, I generally decided pro D10. The critical values for this specific projectile are, without doubt, lower than those I posted above. Nethertheless I must admit that the gun will reach penetration limit and at reasonable distance. The degree of inclination is too low in case of Tiger Ausf. B turret front.
Hope, this will cause some discussion here...

 

[delcyros]

delcyros,

The 100mm D-10 would penetrate 185mm of vertical 240BHN RHA at 1,000m with its APBC round, the best AP round available to the D-10. (Against FH armor however it wasn't the most effective, like most soviet projectiles)

- Results achieved at the Aberdeen proving grounds.

185 mm of 240 BHN equals to a Q: 0.98 and E:20%, which is of substantially tougher quality than the King Tiger´s near vertical turret front plate. So far, little difference exist between 1000 m and the 1490 m I posted above. The difference may reflect the different shell / plate properties. No doubt the D10 may defeat the turret front plate on this distance.

 

[Soren]

Yet the D10 never once achieved to penetrate the Tiger's front, eventhough engagements between this gun and the KingTiger were plenty according to Tiger crews ! (And hits weren't rare at all either)

Fact is Soviet AP projectiles were often of such low quality that the JS-2's 122mm L/43 D-25 armament even had a nasty and frequent tendency of bouncing off the "Tiger Ausf.E's" frontal armor, at close range ! Ofcourse this can be partly attributed to the Tiger Ausf.E's unequalled armor quality, but it nonetheless still says quite abit about the quality control of Soviet projectiles - cause the gun itself packed more than enough power to cut straight through the Tiger Ausf.E at close range if just the projectile was of sufficient quality.

 

[delcyros]

...worth mentioning.
The Tiger I E had plates of excellent quality, beeing highly resistent ductile (Q:1.0; E:20%). Possible that projectiles with soft AP-caps will ricochet off or suffer full shatter on distances when they physicly should achieve penetration.

 

[delcyros]

The last frontal area to be hit of the Tiger II is the lower, 120 mm inclined 50 deg. hullplate. The approximated necessary striking velocities are (assuming nose shatter but only minor lower body damage):
85mm D5: 3110 fps, exceeds muzzle velocity, no penetration possible
122mm D25: 2626 fps, exceeds muzzle velocity, no penetration possible
100mm D10: 2683 fps, full penetration achieved. Penetration possible up to 540 m at direct impact angles (with >80% reliability).
So far, only the turret front plate is a reasonable defeatable plate of the frontal layout of the Tiger-II against the best soviet AT gun, the 100mm D10. Note that the area to hit is rather small and most projectiles will glancing off from the "Blende".

 

[Soren]

Delcyros, just a minor correction - the Tiger Ausf.B's frontal hull armor is 100mm thick, not 120mm.

And regarding the Tiger Ausf.E's armor quality, relying purely on memory, the Tiger Ausf.E's armor was of 255-260BHN and of the RHA type ofcourse - The very best.

 

[delcyros]

You are correct, Soren. There is something wrong in my books. Several contradicting thicknesses are given but I see the lower figure (100mm @ 50 deg) beeing dominant. Maybe Schwarzpanzer may help out here.
The revised estimations for this area are:
minimum striking velocity, necessary to achieve penetration (assuming nose shatter but only minor / no lower body damage):
D5 (85mm): 2809 fps, exceeds MV, no penetration possible
D10 (100mm): 2435 fps, Full penetration achieved, penetration possible at distances up to 1400 m for direct impact angles (~980m with >80% reliability)
D25 (122mm): 2308 fps, full penetration achieved, penetration is possible at distances up to 650 m for direct impact obliquities (~500 m with >80% reliability). Note that the minimum striking velocity needed for penetration is high enough to ensure full shatter of these specific projectiles.

 

[plan_D]

The Pz.Kpfw VI Ausf E had an armour thickness of 100mm. On the Gun Mantlet is was 100 - 110mm.

 

[mosquitoman]

Posted in wrong thread

 

[m kenny]

Tiger Ausf.B's on the Eastern front were very frequently engaged by soviet 100-122mm AT guns, however NEVER did the Soviet AT guns, any of them, manage to penetrate in ANY area on the Tiger's frontal armor - and let me remind you that it was standard practice for the Tiger Ausf.B to ALWAYS have its front towards the enemy, almost never exposing its flanks. (And you can read Soviet reports about this as-well) Yet never, NEVER, was the Tiger Ausf.B's frontal armor ever penetrated in combat, it didn't happen, despite many Tigers taking extreme amounts of hits.

I think what you mean is a TII was ever photographed with a glacis penetration. To say it was never penetrated (in combat because at least one was penetrated in the Russian tests) you would have to know the fate of every knocked out Tiger II.
How do you 'always' keep your front to the enemy when they are in front and on your flank?

Fact is Soviet AP projectiles were often of such low quality that the JS-2's 122mm L/43 D-25 armament even had a nasty and frequent tendency of bouncing off the "Tiger Ausf.E's" frontal armor, at close range ! Ofcourse this can be partly attributed to the Tiger Ausf.E's unequalled armor quality, but it nonetheless still says quite abit about the quality control of Soviet projectiles - cause the gun itself packed more than enough power to cut straight through the Tiger Ausf.E at close range if just the projectile was of sufficient quality.

I would think a hit by a 122mm projectile, even without penetration, would do so much damage to the turret and its mountings that the Tiger would be out of action.

 

[plan_D]

m kenny,

The Soviets were big on propaganda, any penertration of the glacis of the Tiger II would have been photographed and used to it's limit. The fact that no picture of this exists (aside from the Russian test) shows us the Soviets had no image to go with. Thus, no frontally penertrated King Tiger to go with.

The post-war Russian tests do no indicate combat ability of the Tiger II. That test was done with various calibre cannon shells at all ranges. By the time the glacis was penertrated, the Tiger II had been hit several hundred times. The cannon to finally do the job was the A-19 122mm artillery piece.

In answer to your question, while directed at Soren, the King Tiger crews tried to keep their front to the enemy. When they failed to do this, they could well be destroyed.

 

[m kenny]

British destruction/test of 2 Tigers.

 

[m kenny]

The Russians did no more than any one else did.
The last pic is a frontal penetration

 

[plan_D]

I don't believe I stated that the Russians performed more ballistics tests than others. But the only penertration of a King Tiger glacis plate is #502 Tiger II on a Russian proving ground, after being shot several hundred times.

More to the point, you're showing Tiger I images. The penertration ability of Allied guns against the Tiger I is not in dispute.

 

[Joe2]

The tank mueseum in Bovigdon has an impressive coolection of tank guns form 128mm down to 20mm. I recomend that people go there as it has the largest collection of AFVs in the world

 

[DerAdlerIstGelandet]

Went there a couple of years ago. Was really nice.

 

[Joe2]

they also have these little Weapon-thingymabobs wich are real WW2 weapons but modified to shoot electricly. The are a Bren gun, A lee-enfeild rifle, a vickers gun and a PIAT bomb projector