Bouncing HE rounds (yes, again) ad Smoke

[RMC]

At the risk of starting another flamewar....

Since this board has served on several occasions to shed new light on some obscure subject matter (nahverteidugungswaffe, tanks spinning in place, sandbags as armor etc), I though I would resurrect two themes that have been discussed here before based on what i found today in a book I just got. I hope this time we can just discuss these themes without the personal attacks that have marred the threads from before.

“...Sie besaßen eine Aufschlagzünder mit einstellbarer Zündverzögerung (0,15 Sekunden), der es gestatte, die Geschoßwirkung optimal auf das Ziel auszurichten. Ein Beispiel: Zum Schießen von Abprallern wurde der Zünder mit Verzögerung verwendet. Das auf den Erboden flach aufsetzende Geschoß prallte ab und zersrpang erst, wenn die Verzögerung des Zünders beendet war. Mit Abprallern konnte gegen lebende, von oben nicht eingedeckte Ziele eine besonders große Splitterwirkung erzielt werden.” ....Wolfgang Fleischer Die deutschen Sturmgeschütze 1835-1945.

Translated:

“They had a delay fuze with a selectable (switchable) delay of .15 seconds that allowed the shell effectiveness to be optimized on the target. An example: the dealy fuze was used to shot richochets. The round striking flat ground at a low angle would ricochet and detonate after the delay ended. Especially good effect could be achieved against living target without overhead cover.”

Comment: Before Lewis' posts on the subject I had never heard of this at all. Now I am finding references to it in odd sources. For me it still doesn't quite pass the common sense test. I figure that the fragments from the exploding round would still have forward velocity at detonation and therefore the fragments would form sort of a cone in the direction of travel. Getting the round to detonate in the right spot must have been a real trick. Getting the round to be in downward motion (aimed at the target) must have been a feat of rare skill.

The other reference I've seen to this can be found in Waffen Revue 91 (fall 93) in a section on the fuzes used by most HE rounds in the wehrmacht Aufschlagzünder 23. it came in about 17 versions. version 3 had a delay time of .15 seconds after field experience suggested the .25 second delay of version 2 was too long for the "so called ricochet shots". Version 8 had two delay options (in addition to the no delay setting). One was .8 seconds for detonatin after penetrating heavy cover, concrete etc. the other was .2 seconds to achieve "effective detonation heights in conjunction with the ricochet shots."

And in regards to smoke rounds.....

“Zum Kampsatz der Sturmgeschütze gehörten weiterhin 7,5cm-Nebelgranatpatronen KWK 40. Deren mit Nebelstoff gefüllten Geschosse erzeugten nach dem Aufschlag weißlich graue Nebelwolken mit einem Durchmesser von 30 meter, die nach 20 bis 25 Sekunden ihre Wirkung verloren. Nebelgranatpatronen stellten 1943 den geringsten teil der 1. Munitionsaustattung in den Sturmgeschützabteilungen, Zehn Stück wurden für jede Kanone mitgeführt, in der Regel aber nicht auf dem sturmgeschütz. Sie befanden sich bei den Munitionsstaffeln der Batterie.” Wolfgang Fleischer, ibid.

Translation:

“Furthermore, the 7.5cm Smokeround KWK 40 belonged to the basic load of the Sturmgeschütz. Filled with smoke producing chemicals they generated a white-gray smoke cloud with a diameter of 30 meters that lost their effect after 20 to 25 seconds. Smoke rounds were the smallest portion of the ammo loads for the StuG battalions. 10 rounds were carried for each gun though as a rule not with the guns. They were carried around by the ammo sections in the batteries.”

Comment: IIRC it was unclear how many smoke rounds most AFVs would carry as part of their basic load. The StuGs in CE carry 3 each and this source suggests that this would be incorrect under most conditions.

[Guest Germanboy]

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

At the risk of starting another flamewar....<HR></BLOCKQUOTE>

Oh dear...

Two quick points.

Re: bouncing rounds, does Fleischer state anywhere how common this was or what gunners said about it?

Re: smoke, this is one unclear sentence (I am a native speaker of German). Does Fleischer mean that there were no smoke rounds as standard load-out on the Stug but that they were kept with the ammo stock at base?

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Andreas

The powers of accurate perception are often called cynicism by those who do not possess them. (forgot who said it)

[RMC]

No Fleischer doesn't talk about how common this bouncing tactic was. I would tend to believe that it was rare because before Lewis' brought it up I had never heard of it being done. That coul be because it was rare or because most of my books are concerned with the vehicles themselves and not their tactical usage. I imagine that it took quite a bit of practice to get right and that it couldn't always be done in the heat of battle.

I understood fleischer to mean that "normally" a StuG would carry 0 smoke rounds but the ammo section at each company (battery) would carry (was supposed to have) 10 for each StuG in the company. It can't be that they were never used, but it would appear that their use had to be somehting planned ahead to make sure the vehicles had the rounds available. I would think this would be in a situation like last defence and not in CE.

[Guest Germanboy]

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

No Fleischer doesn't talk about how common this bouncing tactic was. I would tend to believe that it was rare because before Lewis' brought it up I had never heard of it being done. That coul be because it was rare or because most of my books are concerned with the vehicles themselves and not their tactical usage. I imagine that it took quite a bit of practice to get right and that it couldn't always be done in the heat of battle.

I understood fleischer to mean that "normally" a StuG would carry 0 smoke rounds but the ammo section at each company (battery) would carry (was supposed to have) 10 for each StuG in the company. It can't be that they were never used, but it would appear that their use had to be somehting planned ahead to make sure the vehicles had the rounds available. I would think this would be in a situation like last defence and not in CE. <HR></BLOCKQUOTE>

Thanks for the quick answer. That is how I understood him, just wanted to make sure.

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Andreas

The powers of accurate perception are often called cynicism by those who do not possess them. (forgot who said it)

[:USERNAME:]

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

....Wolfgang Fleischer Die deutschen Sturmgeschütze 1835-1945.

Comment: Before Lewis' posts on the subject I had never heard of this at all. Now I am finding references to it in odd sources. For me it still doesn't quite pass the common sense test. I figure that the fragments from the exploding round would still have forward velocity at detonation and therefore the fragments would form sort of a cone in the direction of travel. Getting the round to detonate in the right spot must have been a real trick. Getting the round to be in downward motion (aimed at the target) must have been a feat of rare skill.

<HR></BLOCKQUOTE>

I am a motion control engineer and am wondering about your "common sense test" (No insult intended..just realize that there are pitfalls to non-scientific analysis).

As I see it, it is a case of related rates and vectors. The vectors of the fragments have a component that is "added" to them. Lets take the case of the "front piece of shrapnel" of the shell, the velocity of the moving shell and velocity imparted by the explosion would be additive. For the sides of the shell, the velocity of the moving shell puts a forward component on the shrapnel so that "flies forward".

Now, the question is then related rates. Is the shell rate (velocity of the shell) comparable to the frag rate (velocity of the fragments)? I would venture a guess it depends on fragment size because smaller fragments would have a higher escape velocity and the shells velocity would not matter much.

BTW, this is not peculiar to a shell bouncing, it would happen in the case of a point detonating shell also.

I have seen xray photos of shells exploding. The breakage of the body of the shell is mostly lenghtwise (the cylindrical nature causes the body to bulge as the ends hold strong) causing the fragment effect to almost be like a "ring" or toroidal in shape about the sides with large "chunks" heaved forward (additive) and to the rear (where they would have subtractive velocity effects if I am not completely wrong). The point being, that having the sides of the shell "facing" the enemy on the ground pays off nicely.

I can imagine that EXPERIENCED gunners would logically aim in front of a target, naturally, and guage the results. Shell seems to be tearing up the ground behind the target area (you WILL see the nastiness of shrapnel hitting the ground)? Decrease time setting or try ricocheting at a closer range.

Lastly I would like to remark that 1835 seems a bit early for StuGs. (I believe that you mean 1939-1945.. I have the same book).

Lewis

PS The spinning also has an effect it just occured to me. Again, it has to have a related rate.

[Guest Big Time Software]

If there's one thing I've learned about tankers (and self-propelled gunners, and assault gunner) it's that whatever ammo load they're supposed to have doesn't necessarily match what they actually have.

Case in point: the 76mm Sherman. American HVAP ammo was supposed to be reserved for the tank destroyer units. But did Sgt. J. Q. Public, commander of your average M4A3(76)W say, "Oh, OK, I think I'll pass on that kickass ammo. It's not my job to knock out tanks anyway."? Nope! With a little ingenuity and, er, a liberal interpretation of supply requisitions, the Sergeant tried to acquire a few of those rounds, "just in case".

Out of 54 rounds carried in a StuGIII, it's very difficult to believe that the commander wouldn't sock away 2 or 3 smoke rounds "just in case" - especially if they were available in reasonably quantity back in the ammo trailers.

Plus, from a game standpoint, it would be quite unfair to preclude StuGs from using smoke, just because "usually" the 10 rounds weren't with the vehicle. However, if a scenario author considers it important to restrict the smoke laying capability of any unit, he can edit its ammo layout in the scenario editor.

Charles

[:USERNAME:]

Charles

You can extend your argument to the amount of ammo carried also. I have read of almost double for the StuGs. The crew must have been literally sitting on them.

US 57mm ATGs would suddenly have sabot rounds when US and British units traveled near each other (and the british suddenly had whiskey).

I believe loadout on a vehicle like a StuG would be highly mission driven. More AT rounds for tank busting and more HE and Smoke for sturmartillerie duties with the infantry.

Lewis

[Mark IV]

"... we received instruction in the 75mm antitank gun [spring, 1942] and how to fire mixed ammunition. Anyone being fired on by regular artillery rounds had a 50/50 chance of survival, if they hit the dirt. We were issued antitank shells tipped in steel and regular [HE] antipersonnel rounds. On the head of every HE projectile there was a screw-activated delayed fuse. With the screw turned in, or out, the HE projectile hit the ground and deflected into the air, spraying its blast downwards and forwards rather than expending its force upwards." -from "Panzerjaeger", William Folkestad (personal memoir of Bernhard Averbeck). Excellent read, and too short. No mention of how commonly it was used.

I was just reading about Korea, where tanks were often used for preparatory bombardments as a poor man's artillery. The back decks of the tanks were stacked with ammo for use in the bombardment role; once the offensive got underway, the tanker reverted to the as-yet-untouched full load-out in the racks. I have heard of this in WWII but can't think of a single reference at the moment... it certainly makes sense.

[Formerly Babra]

I love this board. I've been reading war-related crap for nigh on twenty-five years and I've never heard of this round skipping tactic... coolness incarnate I say

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When I die I want to go peacefully, like my grandfather, in his sleep -- not screaming, like the passengers in his car

[Guest Big Time Software]

Lewis,

Oh so true about overloading. CM does not allow this for vehicles at the moment, but perhaps it should. You can simulate UNDER supplied units, like a StuG being engaged after a previous encounter but not yet having a chance to go restock ammo.

Whenever I think about what you just said about overstocking ammo, I think to the movie Das Boot. Remember all the extra stuff they crammed into that boat? So much that it affected crew readiness, but they figured they would consume a good portion of the food before they got into their first scrape I suppose.

Steve

[This message has been edited by Big Time Software (edited 06-05-2000).]

[Formerly Babra]

If you allow overloading, be sure there is some inherent penalty attached. Otherwise we are going to see a whole boatload of scenarios with mega-ammoed tanks, to an ahistorical degree.

Chance of brew-up should be dramatically increased (and I mean dramatically) at the very least.

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When I die I want to go peacefully, like my grandfather, in his sleep -- not screaming, like the passengers in his car

[RMC]

Lewis good catch on my typo, but it is supposed to be 1935 not 1939.

Interesting points on the explosive dynamics. Maybe BTS should do a test like they did with the MGs. ;p

As regards the smoke, I agree that soldiers would tend to carry whatever they could get their hands on and in some instances might have smoke rounds left over from previous actions. Still it seems to me that in at least the case of the StuG it would reasonable to exclude smoke rounds from the "standard" game loadout and make their availability scenario dependent. Like I said before a situation like CE would suggest they didn't have them where as perhaps something like Last Defence they would have made it a point to add smoke to their load.

Fleischer also mentions overloading of ammo and particularly with the StuG I can see why this would be popular. In CE they usually run out of ammo while the Shermans won't. I was always a great SL/ASL fan of the StuG. Once I started with CC, I didn't like them so much anymore. The big problem is the lack of MG ammo. Anyway Fleischer comments that the crew would remove the ammo retaining devices to allow more rounds to be stuffed in the bins. This would imply that they tried to keep them off of the floor.