Sunday, 10 March 2013
IS-2 vs. the German Big Cats
I have written a great deal about the D-25's accuracy (combat and test) and penetration, but what happens when you combine the two, and have some captured Tigers and Panthers laying around? Let's find out!
"Photo # 33. "Panther" tank turret. Hits from armour piercing shells from the 122 mm gun.
1. Penetration. Breach 130 mm by 180 mm. Side armour plate of the turret is torn off.
2. Penetration. Breach 130 mm by 230 mm. Turret torn off the turret ring and displaced to the rear by 500 mm.
Distance: 1400 m.
Photo #34. Turret fragment torn off my penetration #1."
Now, for the Tiger.
CAMD RF 38-11377-12
These tests use the "Corps level 122 mm gun model 1931", more commonly known as the A-19, the precursor to the D-25. With the BR-471 shell, shooting at 1500 meters, the following was observed:
"Shot #1. The shell passed through a previously made opening in the front armour, went through the tank, and penetrated the rear. The entrance hole is 140 mm in diameter. The exit hole is 225 mm in diameter. Three cracks formed at the penetration point, 240 mm, 300 mm, and 220 mm in length. Three bolts holding armour screens were torn off.
Shot #2. The shell tore off a piece of armour off the turret 580 mm by 230 mm. The turret was torn off its turret ring, and displaced backwards by 540 mm.
Shot 3. Shell ricocheted off the turret roof. A dent 25 mm deep formed. Cracks spanning the thickness of the armour formed, 330 mm, 230 mm, and 210 mm long."
Tiger tank after testing. The displaced turret can clearly be seen.
With this Tiger, you can see the armour crack as it is hit. This is really bad, since cracking armour is indicative of the plates being too brittle. While brittle plates are more likely to shatter a kinetic penetrator, they are also likely to shatter themselves, sending armour fragments into the crew and the tank's internal components.
Now, let's take a look at the Tiger II. This report is much more detailed than the previous ones, so I won't be posting pictures. However, you can grab the report here, courtesy of litl-bro. Also, here's the picture of the Tiger II after the penetration trials, which adequately communicates what happened.
"Shot #1. Target: upper front plate. Shell: 122 mm HE-fragmentation.
Result: spalling across an area 300 mm by 300 mm. The welding seam between the upper front plate and the machine gun port burst on 3/4 of its circumference. Internal bolts holding the machine gun ball were torn off. The welding seam between the upper front plate and the right side burst, and the right side was displaced by 5 mm. The tank caught fire internally."
Here are those German welding seams, causing trouble again. If an enemy shell literally tears your tank apart without even penetrating it, that's bad news for you. The spalling and machine gun bolts flying around mean that the driver and radio operator would be dead. Let's read on.
"Shot #2. Target: upper front plate. Shell: 122 mm AP flat type. Propellant: reduced. Distance: 2700 m. Result: dent 165 mm by 260 mm, 60 mm deep. The shell ricocheted."
Well, looks like shooting at nearly 3 kilometers out with a reduced propellant charge won't do you any good. Let's consider a more realistic scenario.
"Shot #3. Target: upper front plate. Shell: 122 mm AP flat type. Distance: 500 m.
Result: dent 310 mm by 300 mm, 100 mm deep. On the rear side, a piece of armour 160 mm by 170 mm and 50 mm deep cracked off. The welding seam between the upper front plate and hull roof burst. All seams between the upper and lower front plates burst. The seam between the lower left hull and the left side of the hull burst. The driver's observation device was torn off."
Here, we see the perils of overly hard armour again. Even though the shell did not penetrate, the large chunk of armour that flew off the other end effectively carried out the shell's job, killing crew members and destroying tank components. The driver now has his observation device embedded in his skull, which doesn't increase his effectiveness any. More welding seams fail throughout the tank.
"Shot #4. Target: upper front plate. Shell: 122 mm AP pointed type. Distance: 600 m.
Result: penetration, hole is 180 mm by 250 mm. A piece of armour is torn off the rear side, 580 mm by 500 mm, 80 mm in thickness. The shell struck close to the non-penetrating hit from shell #3. The shell remained in the tank."
This is some pretty massive damage. The piece of armour that fell off further indicates the rapidly decreasing quality of German armour as the war went on.
"Shot #5. Target: upper front plate. Shell: 122 mm AP pointed type. Distance: 700 m.
Result: dent 200 mm by 250 mm, 90 mm deep. A crack all the way through the armour, 150 mm long. The welding seam between the upper front plate and the lower front plate burst from the inside."
The perils of overhardened armour show themselves yet again.
"Shot #6. Target: lower front plate. Shell: 122 mm AP flat type. Propellant: reduced. Distance: 2500 m.
Result: dent 290 mm by 130 mm, 60 mm deep. The opposite side shows a cracked bump. The right welding seam burst on its entire perimeter.
Shot #7. Target: lower front plate. Shell: 122 mm AP flat type. Distance: 600 m.
Result: hit the point where the upper front plate and lower front plate meet. Dent 180 mm by 120 mm, 35 mm deep."
Ironically, the effects of the 122 mm gun on the lower front plate were not as effective. However, shots to the upper front plate from any reasonable distance harmed the tank greatly. Let's see what happens when you shoot at the turret.
"Shot #34. Target: turret front. Shell: 122 mm AP pointed type. Propellant: reduced. Distance: 2500 m.
Result: A piece 700 mm by 220 mm was torn off the turret front. The shell penetrated completely. The roof of the turret is missing a piece 460 mm by 300 mm. The rear of the turret has two cracks through its entire thickness, through the welding seam of the roof and left turret side, 1100 mm in length, and on the turret roof, 1350 mm in length."
For a change of pace, this time the turret didn't fall off. However, it might as well have. It's missing massive chunks of armour, and is cracked significantly. Another demonstration of overly brittle armour.
Now, the testers are getting a bit overconfident.
"Shot #35. Target: turret front. Shell: 122 mm AP flat type. Propellant: reduced. Distance: 3400 m.
Result: a dent 200 mm by 230 mm, 90 mm deep. The rear side of the armour had a bump with cracks. The welding seam between the turret front and the bracing strut has a 200 mm crack."
Again, shooting at ridiculous distances using a reduced propellant charge doesn't do you any good. However, it has been demonstrated that the IS-2 can take out a Tiger II at over 2500 m by penetrating the turret, and does not even have to penetrate the upper glacis plate to incapacitate the tank and its crew.
Edit: The effects of the D-25 on the Ferdinand are explored in a separate article.