Bazookas/Panzerfaust vs. stone buildings

[Keith]

I stand corrected from an earlier post and in fact these weapons were used frequently against infantry. However, I do think they should have limited effectiveness against STONE buildings as pointed out by the reference below from a U.S. Army publication:

"Then he kicked holes in the embankment until he could stand on it, got in behind a tree and opened fire with the bazooka. He fired seven rounds and all of them exploded through the barracks roof; as he saw it, there was no use firing at the walls because they were much too thick."

As I recall from the original Squad Leader board game, bazookas and faust were ineffective against infantry in stone buildings.

[Guest Username:]

Unless he is shooting at a castle with several feet of stone in the walls a hollow charge weapon will do wonders to a concrete bunker or stone wall.

[Guest Robert/1]

Not have them be able to distroy bilding no that would be like going bake to WWII and saying "You cant shoot at bildings,"

Robert/1

[This message has been edited by Robert/1 (edited 05-23-2000).]

[Bullethead]

Lewis is right, shaped charges do great on concrete. I've never shot one at a solid stone but I'd expect it'd be less effective. Concrete almost always has water in between the grains and when this flashes to steam, it shatters the concrete. I don't think all building stone would have this weakness. So just off the top of my head, I'd say a shaped charge would do better against a pillbox than a stone house. OTOH, pillboxes are usually much thicker than house walls.

Still, panzerfausts at least had considerable macho. There are documented cases of Shermans being hit on one side and the lance of flame exiting on the other side. Going through both thicknesses of side armor isn't surprising. But for the flame jet to maintain its integrity through the open air between is impressive to me.

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-Bullethead

jtweller@delphi.com

WW2 AFV Photos: people.delphi.com/jtweller/tanks/tanks.htm

[This message has been edited by Bullethead (edited 05-24-2000).]

[Mattias]

In one PBEM game I fired a bazooka at a StuG in LD. The rocket missed the StuG but hit the church, which promptly collapsed

It had been well pounded before that but it was definitely the bazooka round that was the final straw for the building.

Bullethead, with regards to the effect of the shaped charge. The reason it retains it integrity is mainly because it is no flame and not really what one would usually picture as a "jet", well, at least not me.

The part that penetrates the tank is called a jet but it really is solid metal.

It is not melted, vaporised or pulverised, it is quite solid. However it can behave like a liquid when it’s motion is interfered with, but that’s only because of the high speed with which it moves.

the HEAT jet really is a metal penetrator just like an ordinary AP round. The difference lies in the method with which it is delivered, the speed of it and how it interacts with the armour when penetrating.

M.

[TankDawg]

hi,

Since some one used the "Squad Leader" word.... HEAT weapons in that game can only be fired vs. Infantry in Buildings, Bunkers or behind walls.

Jeff

[Bullethead]

<BLOCKQUOTE>quote:</font><HR>the HEAT jet really is a metal penetrator just like an ordinary AP round. The difference lies in the method with which it is delivered, the speed of it and how it interacts with the armour when penetrating.<HR></BLOCKQUOTE>

I disagree. I think you're confusing shaped charges with explosively forged penetrator rounds. They are very similar in concept and operation but in the SC, the principal penetrating effect is from the flame of the explosive itself, whereas in the EFP it's the liner of the charge cavity, which is much thicker and less concave than in an SC.

True, the right lining material in an SC round DOES increase the penetration capability. However, this is a bonus, not an enabler. The usual liner is copper, which is quite soft and melts at a low temp; thus, the explosion completely melts it. Because SC rounds explode very close to the target surface, the liner is still quite molten when it hits. It thus seems to give a sort of sandblasting effect as well as adding some mass to the plasma. It all gets packed into the forward part of the jet so if the SC doesn't penetrate, it solidifies at the bottom of the hole into a "carrot". This gives the impression of having a solid slug during operation, but I'm very sure this isn't really the case.

EFPs OTOH are designed to explode a good distance from the target (ex: modern submunitions like 50' in the air above the target). At this range, the explosive jet of the SC would have dissipated. So the liner and charge cavity are designed to result in at least a semi-solid slug moving at extremely high velocity. Thus, the effect on the target is essentially that of a conventional KE penetrator, even though the EFP comes from a cousin of the SC round.

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-Bullethead

jtweller@delphi.com

WW2 AFV Photos: people.delphi.com/jtweller/tanks/tanks.htm

[Guest Germanboy]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Keith:

However, I do think they should have limited effectiveness against STONE buildings as pointed out by the reference below from a U.S. Army publication:

"Then he kicked holes in the embankment until he could stand on it, got in behind a tree and opened fire with the bazooka. He fired seven rounds and all of them exploded through the barracks roof; as he saw it, there was no use firing at the walls because they were much too thick."

As I recall from the original Squad Leader board game, bazookas and faust were ineffective against infantry in stone buildings.<HR></BLOCKQUOTE>

Keith, two points. First this is a dodgy reference, if you don't mind me saying so. It relates not even experience but an impression by one guy. Did he try shooting the wall first? We don't know. Difficult to base anything on that.

Secondly, I have never played Squad Leader, but from what I have read here, BTS is not going to use the (apparently often incorrect) rules of SL or other games for CM. IIRC, what you get in CM is based on either original data or at least original reasoning and conjecture by BTS and the august group of beta testers. Those few, those happy few, that band of brothers... (sniff). Gentleman on the board do think themselves accursed for not being one of them etc. pp. with apologies to the Bard.

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Andreas

It is amazing what you can learn from a good book...

[Guest entec]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Bullethead:

I disagree. I think you're confusing shaped charges with explosively forged penetrator rounds.

<HR></BLOCKQUOTE>

No he is not confused, SC do form jets out of the metal liner, which is different from an EFP. Now this might be the current state of SC technology and it may not apply to liners made of copper.

[Kurtz]

I feel a compelling need to add to the confusion here.

FWIK, the penetrator of a SC (HEAT) round is liquid but since it is moving at a few thousand meters per second it behaves like a solid penetrator.

A HEAT will give you high penetration but low behind-armor effect and it is sensitive to the stand-off distance (distance between detonation of the round and the surface of the armor).

A EFP on the other hand has lower penetration but much more effect behind the armor. It is also less sensitive in variations in the stand-off distance. The penetrator from a EFP travels much slower than the penetrator from a HEAT, but both types form a penetrator out of the liner whose shape varies and determines the effect. A HEAT will make a small hole (finger-sized) whereas an EFP will make a hole you could put your fist into.

(Warning! Do not try this at home! )

This is the extreme cases, a HEAT round is usually a compromise between penetration and behind-armor effect.

A semantic question: shouldn´t both qualify as shaped charges?

[This message has been edited by Kurtz (edited 05-24-2000).]

[Bullethead]

<BLOCKQUOTE>quote:</font><HR>This is the extreme cases, a HEAT round is usually a compromise between penetration and behind-armor effect.<HR></BLOCKQUOTE>

Agreed. But the main thing re: the subject of this thread is that the HEAT round puts a lot of its fire down the hole in the target. In the case of concrete, this extremely hot type of fire causes good shattering in the area around the small HEAT hole when the water trapped in the concrete flashes into steam in a confined space.

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-Bullethead

jtweller@delphi.com

WW2 AFV Photos: people.delphi.com/jtweller/tanks/tanks.htm

[Guest Babra]

I'm with Kurtz. The penetrator in a shaped charge is the stream of molten liner, directed forward by the explosion of the charge.

[Bullethead]

The shaped charge functions by what is known as the Monroe Effect. This was discovered by a guy named Monroe, who noted that the letters stamped into blocks of explosive burned images of themselves into a steel plate when the explosive was set off against it. This was done solely by the shape of the explosive, which had no liner at all. The tiny grooves of the letters functioned as tiny shaped charges.

Like I said, the liner of a HEAT round helps but does not itself cause the penetration. If you took the liner out of a WW2 HEAT round, it would still penetrate a good ways into the target. The liner just makes the penetration a bit deeper. In modern HEAT rounds, this effect of the liner has been maximized, but it is still not the main penetrator. That's still the fire.

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-Bullethead

jtweller@delphi.com

WW2 AFV Photos: people.delphi.com/jtweller/tanks/tanks.htm

[Mattias]

First of all, sorry if I repeat questions and answers that has already been given, I had to work through my head myself before answering and it's sort of late here

Well, Bullethead, perhaps it is a misconception on my behalf. The basic concept stems from a model working solely with the shaping of the explosive itself and the resulting direction of energy, correct?

I on my part have no doubt been influenced by the level of importance that has been placed on the design and composition of the metal liner in all weapon designs I have seen using shaped charge techniques. Because that is where the work is being done and advances in this field are nearly exclusively due to improvement in the precision in the liners shaping and centering.

What I would like to know is, how does the effect of an optimally shaped charge without a liner compare to one with an optimally shaped liner in it? If the liner is merely an improvement the difference couldn’t be that great, could it?

If there is a substantial difference favouring the charge with a liner I would interpret that as indicating that the liner is indeed critical and essentially the “enabler” in achieving armour penetration at the level needed for anti tank purposes.

When it comes to describing the actual workings of the shaped charge (with a liner as that is what is in use) there seems to quite a bit of differences in opinion and a lot of terms being applied loosely.

As I have understood it what happens is that the explosion collapses the liner. The kinetic energy imparted to the liners metal is such that it is virtually no longer coherent and will thus behave as an incoherent body, i.e. like a fluid.

However, the metal is still solid but it moves at such a speed that it can change it’s shape like a fluid. This has been proven by way of a simple experiment:

Several liners were sawn up into pieces, and these where then carefully reassembled and kept in place by melted explosive. The charges were then detonated into deep water tanks and the slugs recovered, subdivided into as many pieces as the liner had been cut into.

This, as far as I can see, disproves the mistaken description of the metals state as “melted”.

The jet itself however, can not be recovered as it is so thin that it disintegrates. Just as would, say, a knitting needle fired at 50.000 m/sec.

This latter fact seem to be the source of much of the confusion. It is however, in my view, the rapid flow of matter (from the metal liner) in the jet that is primarily responsible for the armour-piercing effect.

Now, things don’t exactly get less complicated once we get to the point of the actual workings of the interaction between the matter-jet and the armour.

I have in front of me an article describing this in detail (Georgio Ferrari, “The how’ s and why’ s of armour penetration”, Military Technology, Volume XII, Issue 10, 1988), but the only way to really describe it adequately would be to quote it in its entire length.

The short and extremely unfulfilling explanation is that the jet flows through the armour by way of hydrodynamic interaction. This interaction is not only influenced by, it depends on, the characteristics of the metal used in the liner (gold for example being superior to copper).

The slug, or carrot as you call it Bullethead, is simply the slower part of the liner that flowed in the other direction in the compression phase. The slower part that is used in the “alternative” type of shaped charges you mentioned.

The distinction between “Self Forging Fragments”, “Explosively Formed Projectiles” or “normal” HEAT rounds however, is mostly superficial as it all boils down to shaped charges that have been optimised differently. As has been noted the “flat charges” (SFF/EFP) uses the slug as its penetrator whereas the normal HEAT uses the jet as described above.

Using the slug instead of the jet gives the weapon two important advantages beyond larger behind armour effect, firstly, it is less dependent on optimal stand off ranges and, secondly, stabilisation by spin rotation can be used as the slug does not get disrupted the way the jet does.

Ah, well, take a bit of that and Ill get back to ya

M.

By the way, be glad if you boys could indicate some of your sources regarding the facts presented.

[Bullethead]

<BLOCKQUOTE>quote:</font><HR>If there is a substantial difference favouring the charge with a liner I would interpret that as indicating that the liner is indeed critical and essentially the “enabler” in achieving armour penetration at the level needed for anti tank purposes.<HR></BLOCKQUOTE>

These days, with thicker tanks and armor resistive to HEAT, I'm sure that's quite true. It probably wouldn't achieve the desired results without a lot of effort put into optimal liner design to increase penetration enough.

However, the fire itself WILL penetrate significant amounts of armor or concrete by itself. I've seen decent performance from improvised charges in a demonstration that used only cardboard for the liner. So I figure in WW2, this was probably enough for the job. Besides, back then the whole idea of using the Monroe Effect as a weapon was brand new so there hadn't yet been all this research on liner and cavity design.

But in any case, this is all irrelevant to the basic point of this thread, which is that HEAT rounds send lots of very hot fire down the hole because they are right on the target surface (plus necessary standoff) when they go off. This fire creates instant steam inside the concrete, forcing the water to expand like 1700 times and shatter the concrete in that area.

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-Bullethead

jtweller@delphi.com

WW2 AFV Photos: people.delphi.com/jtweller/tanks/tanks.htm

[Guest Babra]

Well, *actually* ... The effect was first noticed by miners who frequently noticed that the name brand of the explosives, which was stamped onto the blocks of plastic, could be read (in reverse) on the bits of blasted rock. It was many years before anyone did any tests to discover what principle was at work there.

But my only point was that in the milliseconds between detonation and penetration, there is not time for the jet to solidify into a solid penetrator. It is neither the metal nor the "flame" as you describe it, which does the damage. It is the directed energy of the blast.

[Lt Bull]

Just wondering how many of you have seen the footage included on the CC2 CD of the panzerfaust being fired at a what appears to be a brick building and at open ground.

Its amazing when you compare the speed of a AT projectile from an AT gun to the speed of a panzerfaust and consider the penetrability of both against tank armour. Gives you an appreciation for the theory behind shaped charges and why they can be so effective.

Panzerfaust 30 30m/s, approx 30m range

Panzerfaust 60 45m/s, approx 60m range

Panzerfaust 100 60m/s, approx 100m range

75mm AT-gun 790m/s, approx 2000m range?

The apparent velocity of the gases (which do all the penetrating) is typically 8000m/s resulting in a penetrating pressure somewhere between 118000 MPa and 981000MPa!!!

(or 1200 - 10000 metric tons per cm^2).

These are absolutely ENORMOUS pressures when you compare it to the higher surface strengths limits of hardened steels (typically 1300 MPa).

I'm not sure if this site has been posted up before but it's one of the best I have seen that has got info on the panzerfaust, the theory behind spaced charges and other German WW2 weaponry.

http://www.geocities.com/Augusta/8172/panzerfaust.htm#intro

Lt. Bull

BTW don't go to www.panzerfaust.com expecting to see info on panzerfausts...it will probably be a big disappointment for most of you.

[This message has been edited by Lt Bull (edited 05-25-2000).]

[Guest Big Time Software]

<BLOCKQUOTE>quote:</font><HR>I'm not sure if this site has been posted up before<HR></BLOCKQUOTE>

Hehe... probably the single most referenced link on this BBS Just something about these PFs keeps us coming back to this link time and time again.

Steve

[Mattias]

Friends,

I could get in here with another round of facts and arguments but it seems a tad bit, well, over the top as we apparently discuss this from quite different standpoints.

Suffice to say we would probably have to go through this very slowly and in great detail to sort this issue out, this not being the place to do it.

Or is anyone intensely interested

There is more than meets the eye as far as this subject goes and the picture given in passing in many a book just doesn’t stand up to close scrutiny. Doesn´t even have to be that close coming to think of it...

M.

[This message has been edited by Mattias (edited 05-25-2000).]

[Lt Bull]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Big Time Software:

Hehe... probably the single most referenced link on this BBS Just something about these PFs keeps us coming back to this link time and time again.

Steve<HR></BLOCKQUOTE>

Hehe...doh! I couldn't beleive I hadn't ever seen it before as I usually check out all the sites which get referenced and usually bookmark them.

But hey, it seems to be one heck of a site and worth ANOTHER mention in case you are one of the few (like me) who haven't seen it.

Is the info on that site generally regarded as being accurate (esp the panzerfaust info)? The type of info given looks like it has been taken from some "official" source.

Lt. Bull