Jagdpanzer E-100 vs. Modern MBT armor

[RaccoonEmpire]

Today in the mail arrived a model shop catalog from a company I do bussiness with, and on it's cover...a 1/35th scale Jagdpanzer E-100. This monster tracked mobile pillbox has a 170mm( or a 17cm for you sticklers) anti-tank gun. This got me to utter that famous Keanu Reeves line..."Whoa", and the nerd question then came up...could the 170mm brew up( destroy ) modern MBTs like the M1 or Leopard? Russian MBTs are pretty light and I'm pretty sure a 170mm will punch them and destroy them, so they aren't included in this question. Now I know modern MBTs have better sensors, movement, and gunnery systems so an actual battle would be a bit goofy and the Jagd E-100 could be made short work of by them. But, if the 170mm was firing at a suprised modern MBT(or just blasting away at one on a target range) could it score a kill and at what ranges?

[sultanbev]

Depends on the ammo.

If it was a modern 170mm gun with FSAPDS then it would have over 30% single shot kill probability even against chobham/DU armoured M1A1HA/M1A2, and would penetrate something like 120-130cm of vertical armour at 2km!

However with it's WW2 era ammo, APCBC, definitely not. The nearest gun we have data for is the 17cmL48 K18 gun, whose PzGr.73 APCBC round (an anti-shipping one really!) penetrated 29cm of vertical armour at 1000m. Which would do a Leopard 1, T-55, M60A1, T-62 or monkey model T-72, but nothing with Chobham armour. Even if we would expect a 1945 tank gun of 17cm to be better than a 17cm 1939 naval round, so something like 35cm at 1000m would be reasonable, that would still be insufficient against current tanks.
Even first generation chobham armoured tanks would have around 40cm equivalent.
Of course, in the side should be no problem at most ranges.

Fit it with a HESH round, and it would be on a par with the British FVF215B with 183mm gun of the 1950s, but again, of limited effect against Chobham/composite armoured tanks.

It would actually be more lethal just firing HE, a 200lb HE round that actually explodes on a tank would wreak havoc even if it didn't actually penetrate anything. In my own wargames rules a 170mm HE fired direct at a tank would have 85% of doing some damage, and have 33% of brewing up the tank or blowing the turret off, and another 33% chance of doing permanent damage (destroyed gun barrel, engine immobilised).

Of course, HE is less accurate than an AP round, which is the problem.

The E-100 SPG I have as 40cm armour including the slope, so it would be proof against 1970s era APDS, and only the 155mm T7 HEAT on the US T -30 heavy tank or Russian 122mm HEAT from 1948 would just penetrate, and perhaps the 130mm APCBC from 1954 at 100m or less if your Is-7 or ISU-130 could get that close!

So, putting it briefly, good to go up to anything to 1978, after that, against the best stuff it's on a loser, although at 120 tons will still be tough to knock out.

Mark

[piersyf]

I agree for the most part, but as in many of these discussions, the KE transfer is ignored. There are other ways to kill a tank than just penetrate its armour. 100kg of HE buried in the ground generates enough energy to roll an M1 onto its back. The vehicle may well be recoverable, the crew most likely to survive, but upside down it is not useful. A direct hit from a SAP round will not defeat composite laminate armour, but the shock of impact might well break the drive train and immobilize the vehicle. Total pressure across the face of the armour will also potentially damage the laminate structure beneath the steel skin, so a second shot to the front will have a measurably better chance of penetrating (if it can hit the same spot). A hit from an HE round of that size has a good chance of stripping laser rangefinders, comms gear and optics, potentially blinding the vehicle.
You might notice that the shock of impact across the front face argument also means that HESH can do the same thing. I have had it independently verified that HESH can damage the structure of composite laminates making them more vulnerable to ADFSDS.
In short, my guess would be that it will hit harder than you might think. Still not a fair match up, though.

[Noble713]

I agree for the most part, but as in many of these discussions, the KE transfer is ignored. There are other ways to kill a tank than just penetrate its armour. 100kg of HE buried in the ground generates enough energy to roll an M1 onto its back.

*nods* The SU-152 was known to rip the turret right off a Tiger. Proof that you don't need AP if your HE rounds are frickin' gigantic.

[TAMMY]

That was a possible result but it was not very frequent..It probably required a perfect hot on the turret and was the result of, the combined effect of the KE of the 50kg OF.540 shell and of its explosive charge.

With most other points of impact or with jagdpanzer (like the Ferdinand) there were no visible external effect of a KO as the damages were internal (crew shock, spalling, etc.). The usual tactics required to fire at least a second HE shot to be sure.

To obviate to this, the SU-152 got an AP BR-540 shell of 47kg (perforation 115mm at 1.000m) hoping to cause internal fire or explosion. It was not not much used.

This lack of use may be read as an indication that the use of the SU-152 as a tank hunter was not a standard practice.

[HKurban]

100kg of HE buried in the ground generates enough energy to roll an M1 onto its back.

While this may be true, this is not an indicator of how effective an HE round of similar force would be. In this scenario, the explosives are buried under the tank, and when detonated, the energy only has one place to go: up. If a comparable HE shell was fired, the explosive force would not only blast toward the tank's armor, but in all directions as well, losing a large amount of the energy in the process. Plus it is a lot harder to flip a low sitting tank using force from the side, as opposed to from below.

Now that isn't to say that pure explosive force couldn't be effective against modern armor. The problem is, a successful penetration by post WWII guns would likely require multiple, repetitive hits on at least the same strike face, if not the same point area. Without autostabilization or advanced optics, and when faced against modern weapons supported by a robust high-tech ISR network, the post WWII tank would hardly stand a chance against its modern counterpart. It would have to rely on Sherman vs Tiger style cat and mouse games, but with a much higher casualty rate since modern tanks can outperform the older tanks due to newer and larger engines.

[Noble713]

Jam a turret ring, etc? Absolutely.

Rip the turret off? I think not. Quote your source for that one please.

I can't remember where I first read it, but it's stated on the wiki page for both the SU-152 and ISU-152. I don't personally have acess to a more scholarly source.

[piersyf]

Now that isn't to say that pure explosive force couldn't be effective against modern armor. The problem is, a successful penetration by post WWII guns would likely require multiple, repetitive hits on at least the same strike face, if not the same point area.

Now you are highlighting my point; at no stage did I mention 'penetration' other than after several HESH rounds impacting modern composite armour and softening it up for KE penetrators. This was from a previous discussion I had on another forum about the merits of rifled guns vs smooth bores; I argued that HESH gave an advantage over guns that could only fire APFSDS and HEAT, despite the complication of slipping bands, and was supported by someone who worked with the armour.

You don't need to penetrate armour to put a tank out of action, and a penetration of the armour does not equate to destruction of the vehicle. Ken Macksey's book "Tank VS Tank' describes an early encounter with a KV1, and after it was destroyed (by satchel charges) they determined that it had been hit and penetrated twice by 88mm rounds and not put out of action (p86).

As to HE tearing the turret off a tank, it very much depends on where the HE ends up; the Finns claimed that 6kg of explosives placed under the turret overhang would remove ANY turret (maybe any Russian turret), but 6kg would be around the HE content of a 152mm HE round, and about the content of a 5" or 6" rocket, and both of these were capable of removing turrets by force alone.

The point is that is is possible; whether it is statistically significant (ie; effective as an AT weapon) is a different thing. If you were a gunner on a 155mm howitzer and you had an enemy tank in your sights, would you fire, or just think you would have no effect? I was taught to shoot. (ex artillery guy here).

[sultanbev]

"The point is that is is possible; whether it is statistically significant (ie; effective as an AT weapon) is a different thing. If you were a gunner on a 155mm howitzer and you had an enemy tank in your sights, would you fire, or just think you would have no effect? I was taught to shoot......"

This is a very important point overlooked by most wargames rules. In the real world iIf tanks met tanks, they fired AP at each other (of whatever type) regardless of penetration (Other than running away, what option would you have?)

The gunners don't look up penetration tables then decide whether to fire or not! This is why in our rules we have fire priorities. Tanks have to fire at tanks first, even if they can't penetrate. They can't pick off the light APCs lurking in the background further away! We do allow the chance of a track hit, so even a Stuart can immobilise a King Tiger if it got lucky. We also allow that once your AP round has failed to penetrate, you can choose to fire HE subsequently (if you're still around!).

Close support vehicles like StuG 105, ISU-152, Su-122, sIG33, Sherman 105 are allowed to fire HE at armour at any time, as this is more akin to their role. An yes, field howitzers can fire HE at tanks if they come in range. You've probably already lost the battle if you 155mm howitzers are being attacked by tanks, but we know it can happen.

There is a survey from WW2 Normandy somewhere on the internet that showed that 65% of tanks of all protagonists were killed in the side. That's very significant. In other words, given a choice, any gunner whether in tank, SPG or towed ATG would attack enemy armour from a flanking position, for fairly obvious reasons. Something that doesn't appear to happen in most wargames, even ours. SOmething to think about.

Mark

[HKurban]

This is a very important point overlooked by most wargames rules. In the real world iIf tanks met tanks, they fired AP at each other (of whatever type) regardless of penetration (Other than running away, what option would you have?)

The gunners don't look up penetration tables then decide whether to fire or not!

\

That's why my partially-automated rules obscure the specifics of how much damage A's gun will do to B's Tank. Since my gaming group deals with many different periods, and not everyone knows the difference between an M829 APFSDS and an M82 AMR, I include a basic rating of the weapon, just so that unfamiliar players know whether their weapon is more of an effective anti-infantry weapon, anti-vehicle weapon, etc. It does not specifically show players whether the weapon would be able to penetrate a particular tank's armor.

A tank gunner may not avoid firing because he feels his gun might be too weak, but a rifleman would most definitely avoid firing an M16 at a tank because they really don't want to make themselves a target.