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Would a 75mm HE shell knock out a tank with 15mm of armour?


Oddball_E8

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I've been thinking about this a bit.

15mm is far from "thin" when it comes to the ability to stand up to small arms fire and explosions.

Now, a 75mm HE shell fired from pretty much any german tank would have the same amount of explosives in it right?

So would that shell do much damage to a tank with 15mm of armour like the SU76 for example?

And I mean a direct hit, not just explosions around it.

A direct hit right into the side of an SU-76 which has 15mm of armour IIRC, would that reliably kill it?

Or any other tank with 15mm of armour for that matter.

The reason I'm asking is because I've been having some discussions on another forum about the pzgr39's effectiveness against tanks with 15mm of armour since its fuse sensetivity is 25-30mm so it won't reliably go off when hitting a tank like that.

So in effect, it will be overpenetrating and largely acting like an APCR shell.

So would HE be more effective in that case?

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Even if 15mm withstood a 75mm HE blast, it probably Wasn't pleasant inside. Kinda be like being inside a metal garbage can and having someone toss M80s at you.

I don't know the answer, but wouldn't it also depend on the direction of the blast? Up and away from the 15mm vs directly down against the 15mm would make a difference?

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Well, it's hard to get information on the penetration values of HE, but I've looked at War Thunder Ground Forces (not the most realistic game, I know, but they do have historical values on penetration and armour for the most part) and the L43 and L48 guns have a pen of 14mm IIRC and the L70 has a measly 6mm (due to the low velocity of its HE shells no doubt, a measly 570m/s).

So the HE shells wouldn't actually penetrate the hull with those numbers, but on the other hand, if the shell has 14mm of penetration and the hull is 15mm, wouldn't that mean that, at least at the point of impact, the effective armour would only be 1mm?

This is all a bit too complicated for me.

I do know that in CMRT, the L48 gun will penetrate the side armour of the SU-76 using HE shells.

So maby BFC could shed some light on the penetration vaules of HE shells?

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One effect of HE, but a bit bigger, from 3AD site:

The 3AD had begun a four-pronged attack on the city, which was heavily defended. Division armor were finally able to enter the city slowly after numerous concrete tank barriers were destroyed. With 3AD tanks fanning out, and 36th Infantry riflemen following, the Super Pershing reached an intersection and began to round a corner to its right. Unknown to its crew, a King Tiger had apparently been waiting in ambush at a distance of two blocks or roughly 600 yards away, and in the same direction that the Americans were turning into.

At this distance, easily within its capability, the Tiger fired at the Super Pershing. But its infamous high-velocity 88mm shell, of the type that had destroyed so many American tanks and vehicles during the war, went high and was not even close. Gunner Cpl John "Jack" Irwin, only 18 years old, responded almost instantly with a round that struck the Tiger's huge angled glasis, or front plate. But the shot, a non-armor-piercing high explosive (HE) shell, had no effect. Ricocheting off the armor, it shot skyward and exploded harmlessly. The Super Pershing had been loaded with an HE only because Irwin had been expecting urban targets, such as buildings, personnel, and light anti-tank guns. "AP!", he shouted to his loader "Pete," which meant an armor-piercing shell would be next.

Maduri and crew then felt a concussion or thud on the turret. It was never known if this shot came from the Tiger, or from some other anti-tank weapon. In any case, no serious damage was done - probably a lucky glancing impact. In the next instant, Irwin aimed and fired a second time, just as the royal monster was moving forward and raising up over a pile of rubble. The 90mm AP round penetrated the Tiger's underbelly, apparently striking the ammo well and resulting in a tremendous explosion that blew its turret loose. With near certainty, the entire crew was killed.

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Very generally speaking, HE will penetrate an amount of armor (RHA) equal to 1/2 the shell diameter. CM models it a little higher than that, I think.

Hmm... so a 75mm shell would penetrate about 37mm of armour?

That sounds a bit high.

Wouldn't that penetrate pretty much mean that a sherman firing an HE shell into the side of a Pz IV would penetrate it with near 100% guarantee?

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Hmm... so a 75mm shell would penetrate about 37mm of armour?

That sounds a bit high.

The rule of thumb I mentioned comes from a guy who I would consider an expert in the field. That doesn't mean it is correct, but it does mean I need a specific reason to doubt it. I have never seen a penetration table for HE outside of Combat Mission.

Wouldn't that penetrate pretty much mean that a sherman firing an HE shell into the side of a Pz IV would penetrate it with near 100% guarantee?

At medium ranges, probably, but I've never tried it.

Pro tip: If you have a Tiger tank in LOS of the ground on which you know a T-34 is located, but the Tiger hasn't spotted it yet, a slightly gamey (but also risky) tactic you can use is to plot an area fire order onto that action spot. If any of the HE rounds hit the hull they will very likely penetrate, even from the front. The crew of the T-34 rarely survives. Don't ask me how I know this :D

Here are some of the HE penetration values used in the CMx1 games. I suspect they are about the same in CMx2.

Penetration @ 0°, range 500 meters

German

50mm L60 (Panzer III)

33mm

75mm L48 (Stug III, Pz IV)

47mm

75mm L70 (Panther)

61mm

88mm L56 (Tiger I)

78mm

U.S.

76.2mm L 52 (Sherman 76)

65mm

Soviet Union

76.2mm L42 (T-34/76)

52mm

152mm L29 (ISU-152)

69mm

85mm L55 (T-34/85)

78mm

122mm L48 (IS-2)

108mm

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The rule of thumb I mentioned comes from a guy who I would consider an expert in the field. That doesn't mean it is correct, but it does mean I need a specific reason to doubt it. I have never seen a penetration table for HE outside of Combat Mission.

At medium ranges, probably, but I've never tried it.

Pro tip: If you have a Tiger tank in LOS of the ground on which you know a T-34 is located, but the Tiger hasn't spotted it yet, a slightly gamey (but also risky) tactic you can use is to plot an area fire order onto that action spot. If any of the HE rounds hit the hull they will very likely penetrate, even from the front. The crew of the T-34 rarely survives. Don't ask me how I know this :D

Here are some of the HE penetration values used in the CMx1 games. I suspect they are about the same in CMx2.

Penetration @ 0°, range 500 meters

German

50mm L60 (Panzer III)

33mm

75mm L48 (Stug III, Pz IV)

47mm

75mm L70 (Panther)

61mm

88mm L56 (Tiger I)

78mm

U.S.

76.2mm L 52 (Sherman 76)

65mm

Soviet Union

76.2mm L42 (T-34/76)

52mm

152mm L29 (ISU-152)

69mm

85mm L55 (T-34/85)

78mm

122mm L48 (IS-2)

108mm

Whoa! Those are WAY higher than the ones in War Thunder.

Wonder what the difference is there. Maby they only count the penetration of the blast and not the shell since the penetration stays the same at all distances?

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Regarding the CMBx1 HE penetration table:

88mm HE and 152mm HE shells penetrating more armor, than huge 152mm HE ? Well...

Typical tank HE shell would only be equipped with a nose fuse. If set to superquick action, it would detonate the shell on contact with armor so the penetrating effect is mainly from HE explosion against the steel plate.

Heavier the shell, more HE, greater the penetration (or rather break trough) potential

If the nose fuse was set to delayed action, I think fuse would be destroyed during the process of penetrating the armored plate (succesfull or not) and not detonate the shell later.

It's post-penetration effectiveness would be like of an inert shell (no explosion). Only if the armor was thin (10-20mm) the nose fuse could survive (and shell integrity be preserved) for detonation.

It's hard to imagine for me a nose fuse (and the whole 85mm or 88mm shell) surviving penetration of something like 78mm thick armored plate. Maybe it would work with 20mm plate.

Anyway, IMO:

IF those penetration table is for penetration by High-explosive effect - the larger and heavier 122mm and 152mm shells should have much greater penetration than 85mm and 88mm HE shells.

IF the table is for ballistic penetration by (inert) HE shells, then again - 152mm HE shell has so much mass, momentum and plate-overmatching effect that it would penetrate more armor than much lighter and smaller 88mm or 85mm shell.

P.S.

By the way, Russians tested 88L56 gun against slightly angled T-34 tank from 1500m.

APCBC penetrated and partially penetrated the glacis plate (depending on the place of hit).

88mm HE shell _deformed_ the whole 45mm glacis plate (it bent inwards a bit) and broke off the driver's hatch which flew away.

A mission kill, yes. But the shell did not penetrate, wasn't even close to this.

Russians tested also 122mm and 152mm HE shells against Tiger tanks - including 80mm side armor plates. With good effect - armor cracking and even breaking - but the effects varied, some hits did damage, some not. Second or third hit was much more likely to crack the armor than first one. Many of those hits were mission kills, but certainly not penetrations against 80mm armor. They didn't bother to test 85mm HE against Tiger side armor, as it was not very effective.

122mm and 152mm HE shells were penetrating (or rather destroying) side armor plates of PzIV tanks, and very effective against side armor of Panther tanks (40-50mm) (large scale cracking and even breaking of armored plates). I don't think 85mm HE shell would be reliably destrying Panther side armor by HE action (not talking about multiple repeated hits). So I guess 85mm HE penetration potential would be in order or 20-30mm rather than almost 80mm. Same for 88mm HE.

I have no idea, how much armor an inert 85mm/88mm HE shell could penetrate. But I think a 15cm 43kg shell going 650m/s would penetrate even thicker plate than 8.5cm 9.5kg 790m/s one.

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I looked at cross-sections of 75mm and 88mm HE shells - the nose fuses are buried quite deep into the shel's nose, the walls of the shell case are quite thick...

So after thinking again, maybe the fuse with delay setting could still work (even struck and deformed) after succesfull penetration if only the shell retains it's structural integrity and the fuse is still in contact with the HE charge. But for the shell to maitain structural integrity and shape, the penetrated armor can't be too thick and defeated by overmatching & plugging. So armor should be markedly thinner than shell's diameter. I don't believe in 88mm HE penetrating 78mm of armor. Maybe a 1000m/s one ;).

The photos of 88L56 against T-34/76 glacis test with results can be found in a book "Tigers on Eastern front" by Frontline illustration.

39932019418892327377_thumb.jpg

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By the way, Russians tested 88L56 gun against slightly angled T-34 tank from 1500m.

APCBC penetrated and partially penetrated the glacis plate (depending on the place of hit).

88mm HE shell _deformed_ the whole 45mm glacis plate (it bent inwards a bit) and broke off the driver's hatch which flew away.

A mission kill, yes. But the shell did not penetrate, wasn't even close to this.

Thickness of the T-34 glacis varied a lot, even on different parts of the plate. The hatches were thicker than the plate itself. Some T-34/76s had applique armor on the glacis, some did not. Plate thickness often varied +/- 5mm between vehicles of the same model due to manufacturing inconsistencies. Plate quality also varied.

I think there is good reason to question the numbers, but not enough evidence to declare them wrong. It would be good to know where the numbers came from but that's probably not going to happen.

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