Is artillery too powerful against tanks?

[Olle Petersson]

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

Just curious, I thought the Patriot was effective as a point defense weapon, It was just the mispreception that it was supposed to defend WIDE areas (whole cities as opposed to a small HQ or something like that). What did the reports say and what do you think were the patriots failings?<HR></BLOCKQUOTE>

It's not an issue of point/area defence, it's the effectiveness on ballistic missiles.

The latest report I've heard cited stated that the Patriot was higly inefficient, with only about 20% kills on all Scuds engaged, most Scuds fired was not targeted at all.

That's still not a 20% hit probability, but 1.4% hits, given that 16 Patriots were fired at each of those Scuds. (The number 16 is a guesstimate of mine. It was definately more than one Patriot launced each time, and the standard SAM site has four launchers with four tubes each.)

Many of the news reels of "Scud debris causing damage" were actually the results of successful attacks.

I'm pretty sure the Patriot system works fairly well against regular aircraft, though.

Cheers

Olle

[Kingfish]

<BLOCKQUOTE>quote:</font><HR>I like this kind of magic. There’re enought kynetic energy to penetrate top armor but HE blast magically appears and probides some of that hard needed kynetic energy. Can I ask how did it?<HR></BLOCKQUOTE>

Well, it's not like you can ignore the effects. If you want to realistically question whether a HE shell can penetrate top armor then you must include it in the equation.

<BLOCKQUOTE>quote:</font><HR>If you are right then why didn’t the AP shells carry LOTS of HE explosive to improve their penetrative capabilities?<HR></BLOCKQUOTE>

Because the resulting explosion would disperse the energy of the AP shell (ever heard of reactive armor?), therby rendering it incapable of penetrating the armor.

[This message has been edited by Kingfish (edited 09-28-2000).]

[Fernando]

At this point it seems clear most artillery shells fired by guns in and indirect role lacked the kynetic energy to penetrate the top armor of most tanks. Some people think the penetration was helped or attained by the sheer impact of the exploding HE or the high velocity splinters produced during the explosion of the shell. It seems the shock wave produced by the explosion of high caliber shells could rip even a Panther hull and/or do extensive damage provided the shell was BIG enough and it hit at the right point but it also seems clear that the shock wave alone couldn’t penetrate armor. Can the splinters produced during the explosion penetrate a 16mm hardened steel plate? They must have a very high KE to do so. I’m sure they’ll fly at a very high velocity ( = high KE) but I think that their mass was MUCH smaller than that of an AP shell (= low KE) and their shape wasn’t the better one for attaining any penetration. I guess most of the splinters weren’t made of the same hardened metal the AP shots were made of. AFAIK the armor plates of the American and German half tracks were designed to resist small arms fire AND splinters, weren’t they?. The American half tracks armor was 7 mm all around, the German half track armor ranged from 15 to 8 mm . The M20 and M8 armor ranged from 19 to 10 mm and that of the German Puma from 30 (front) to 8 mm (side!). Panther top armor was 16 mm. Some people could think it wasn’t the same a near miss/hit than a close hit (whitin a few meters of the vehicle) but I think the KE of the splinters was about the same. I know that Panther wheels could be penetrated and track links broken in half by splinters but were they made of hardened steel plate or softer iron alloys? If splinter could penetrate Panther 16 mm armor plate then they could easily penetrate the American and German half track armor without need of a direct hit too. IMHO the KE of a splinter at the explosion point isn’t very different of the KE of that same splinter after covering 5 or 10 meters. Did the WWI half tracks die so quickly and easily to indirect fire? I don’t know. Are there people with some data about it?

[Fernando]

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

Because the resulting explosion would disperse the energy of the AP shell (ever heard of reactive armor?), therby rendering it incapable of penetrating the armor.

[This message has been edited by Kingfish (edited 09-28-2000).]<HR></BLOCKQUOTE>

I maybe wrong butI thought reactive armor was designed to stop hollow charge/HEAT hits (like WWII panzerfausts and bazookas or modern AT missiles) but isn't effective against conventional AP shells relying on KE. I thought spaced armor was used to stop "KE" shells

Anyway if the explosion disperse the energy of the AP shell as you say then the explosion of the HE shell will also disperse its energy thus reducing its penetrating power, not enhancing it.

[This message has been edited by Fernando (edited 09-28-2000).]

[PzKpfw 1]

I think maybe the question here should have been, does artillery hit tanks to often, in CM instead of the results. Historicly Artillery was effective & inefective vs tanks, as in it was ineffective as a means of destroying tanks, but effective in breaking up tank formations & splitting the accomanying Inf from the tanks. No Grerman tank attack in the West succeded when the Allied units had a competent FO present.

As to its ability to kill tanks, well I have posted the data from the British anylss of examination of over 300 captured German tanks from June 44 - 1945 & Artillery was responsible for the destruction of maybe 1%. But 105mm & above HE was very effective vs the Panthers running gear etc, so maybe more imobes.

The US found in Sicily & Italy that 8in fire impacting 10 - 20yrds from an Panther would flip it, and any hits closer would destroy it, but this was not an economical way to kill tanks but it was often what they had to resort to, due to their tank & AT weapons innefectiveness.

Regards, John Waters

------------------

Notice: Spelling mistakes left in for people who need to correct others to make their life fulfilled.

[Philistine]

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

At this point it seems clear most artillery shells fired by guns in and indirect role lacked the kynetic energy to penetrate the top armor of most tanks. Some people think the penetration was helped or attained by the sheer impact of the exploding HE or the high velocity splinters produced during the explosion of the shell. It seems the shock wave produced by the explosion of high caliber shells could rip even a Panther hull and/or do extensive damage provided the shell was BIG enough and it hit at the right point but it also seems clear that the shock wave alone couldn’t penetrate armor. Can the splinters produced during the explosion penetrate a 16mm hardened steel plate? They must have a very high KE to do so.

{snip}<HR></BLOCKQUOTE>

I think there are three seperate issues that are getting all rolled up into one here. I don't know the answer to the questions (although my suspicions are somewhat different than yours, I think ) and I'd appreciate it if anyone who did know the answers could pipe up.

For artillery fire against tanks, there seems to be 3 different mechanisms for damage on a direct hit:

1. Kintetic energy from the shell itself (without consideration of the explosive) This seems to be fairly high (higher than certain small-caliber guns which do cause penetration on top or flank shots). However, this is ameliorated somewhat by the fact that the shell is not designed to pentrate armor. On the other hand, 16mm of armor isn't a whole lot...

2. Splinters. No idea here. I think though, this is more appropriate for airburst or near misses. Again, 16mm isn't a whole lot, but it could be enough.

3. Explosive effect. Look at it this way. What would be the effect of putting a couple of pounds of TNT on top of a tank's hull or turret? Isn't this essentially what Gammon Bombs and satchel charges were? (a bit lesser and greater amounts of explosive, respectively, I think). No idea though what the effect is.

I would think that surviability of tanks from mid-sized artillery is more a function of the difficulty of scoring a direct hit on a tank (even in a sustained barrage) than the ability of the thin top armor to withstand the shell. But I could be totally wrong here.

--Philistine

[Kingfish]

<BLOCKQUOTE>quote:</font><HR>I maybe wrong butI thought reactive armor was designed to stop hollow charge/HEAT hits (like WWII panzerfausts and bazookas or modern AT missiles) but isn't effective against conventional AP shells relying on KE. I thought spaced armor was used to stop "KE" shells<HR></BLOCKQUOTE>

Yes, you are correct. My goof.

<BLOCKQUOTE>quote:</font><HR>Anyway if the explosion disperse the energy of the AP shell as you say then the explosion of the HE shell will also disperse its energy thus reducing its penetrating power, not enhancing it<HR></BLOCKQUOTE>

Correct again, but consider that the HE shell is hitting the relativly light top armor. I agree that a 50mm or 60mm mortar round should not penetrate the Panther's top armor, but we are discussing a 25lbr.

[Jeff Duquette]

Olle Petersson:

<BLOCKQUOTE>quote:</font><HR>A well known design flaw with the early german 12cm mortars were that they did

hit the same crater with all rounds...the dispersion was only one or two metres.

This was subsequently corrected.<HR></BLOCKQUOTE>

Interesting. I have seen (somewhere) a similar impression of the 4.2 inch chemical mortar. Can't recall if it was something anecdotal or actually a US ARMY or USMC sanctioned study or FM. Anyway, I reckon given testing conditions, and reducing the influence of potential systematic errors, anything is possible. The nasty habit of hitting the same point could simply be eliminated by reducing or increasing charge. If a mortar platoon were employing say an open sheaf pattern, the depth of the impact area might be on the order of 100 to 200 meters and width around a 140 meters (assuming an 81mm Mortar platoon of 4 tubes). To cover the depth required 3 separate fires might be performed, successively increasing or decreasing charge to insure some coverage over the target area.

But back to your original point, what could be termed as a relatively small accuracy influence at a range of 2,000 or 3,000 meters really becomes a considerable influence over a range of 10,000 to 12,000 meters. That's really what we're talking about when trying to compare mortars to field artillery.

<BLOCKQUOTE>quote:</font><HR>I think most of it was field artillery. The Russians had a habit of placing their 76mm field guns in direct firing positions, just as the Brits did with their 25pdrs in the desert. The 76mm field gun had a fair anti-tank capability.<HR></BLOCKQUOTE>

Agreed. Regarding the 25 pounder firing solid shot in a direct fire mode…I have already provided a reference to this in a previous posting on this thread. As with most artillery units during the war solid shot or HEAT type munitions were typically available for firing in direct fire mode. Lets not forget part of the idea behind Blitzkreig was penetration of armour to the rear of enemy combat formations in order to destroy artillery assets. Blizkreig was really somewhat of a continued evolution of German Stosstruppen tactics developed in late war WWI (i.e. highly trained assault infantry teams would avoid strong points with the intention of penetrating to the rear of enemy formations in order to get at a defending formations artillery assets). An infantry division without its artillery has really been reduced considerably in its overall combat effectiveness. It would therefore seem somewhat naive not to outfit WWII artillery with a means of self-defense against being over-run by tanks….thus the availability of AP and HEAT munitions to field artillery.

Regarding the Soviet 76mm…agreed again. With the exception that I suspect the Soviet 76mm was employed much more often in a deliberate anti-tank mode relative to that of the British 25 pounder. But again I think we are talking about the 76mm employing solid shot while being employed in an anti-tank role.

[Jeff Duquette]

Sorry, couldnt resist.

From: Bill Mauldin’s “Up Front”

[Banshee]

<BLOCKQUOTE>quote:</font><HR>Originally posted by PzKpfw 1:

I think maybe the question here should have been, does artillery hit tanks to often

<HR></BLOCKQUOTE>

Because CM simulates the FEBA I think you would see a higher % of arty hits vs general wartime. Because a higher % of arty is under direct observation. In many of the books I read I was surprised at the amount of unobserved fire went on vs "suspected" positions. Or adjusting fire by sound, and various things like that. If you have an area under direct observation by an observer you would have a much greater chance at an accurate hit.

So I would say "Yes" that tanks get hit at higher % in CM than in General war. But only because in CM your always playing a battle on the front lines.

------------------

Veni, vidi, panzerschrecki

[Philistine]

I think in determining hit probability of tanks by artillery, for a rough guideline you'd need to know:

The surface area of the tank, the CEP of the artillery, the amount of shells per unit of time and the amount of time the tank is within the fall of shells. This'll at least give you a rough estimate of hit probabilities.

Sadly, I don't know any of the numbers. I do kind of suspect (as John pointed out) that the real problem might not be the ability of artillery to take out a tank on a direct hit in CM, but rather its frequency.

It just seems that a standard CM barrage of even 50-70 shells is giving too many hits (but I have nothing to base this on except a gut feeling).

--Philistine

[Fernando]

<BLOCKQUOTE>quote:</font><HR>Originally posted by PzKpfw 1:

. But 105mm & above HE was very effective vs the Panthers running gear etc, so maybe more imobes.

<HR></BLOCKQUOTE>

I agree it could be effective but I think we’d read the following German report (Oct. 43) before thinking about too much Panther immobilizations:

“Suspension and Track: No failures have ocurred with the new reinforced roadwheels. Almost all Panthers heve dameged running gear due to near misses by high explosive shells (splinters). One roadwheel was perforated, three others damaged and several track links broken in half. When 45 and 76 mm (note: Russian guns) armor piercing shells penetrate the track they do not cause further damage or immobilize the panther. In every case, the Panther could still leave the battlefield”

It seems it was easy to damage Panther roadwheels and tracks but it seem it was not so easy to immobilize them. Anyway I think CM medium artillery should have less top armor penetrations and/or substitute most of them for gun damage or imobilization.

[Fernando]

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

Sadly, I don't know any of the numbers. I do kind of suspect (as John pointed out) that the real problem might not be the ability of artillery to take out a tank on a direct hit in CM, but rather its frequency.

It just seems that a standard CM barrage of even 50-70 shells is giving too many hits (but I have nothing to base this on except a gut feeling).

<HR></BLOCKQUOTE>

I think so. In a scenario my opponent's veteran forward observer fired about 50 shells to a group of armored vehicles (they weren't stationary) and got two direct hits (a Wespe and a Panther). I don't know if I was just unlucky or the frequency of direct hits in CM is too high.

[This message has been edited by Fernando (edited 09-28-2000).]

[gorilla]

Just thought I'd add one more thing. (thanks for the input bout the game, and the link to the other forum )

I poked around a bit, and found some interesting scientific stuff bout rounds. Check out: http://www.fas.org/man/dod-101/sys/land/index.html

but more specific to this particular topic: http://www.fas.org/man/dod-101/sys/land/bullets2.htm

I couldn't find anything about HESH tho. Hmmm.

[Jeff Duquette]

A quote from one of Gorilla’s above provided URLs. Should shed some light on the subject.

<BLOCKQUOTE>quote:</font><HR>

From: Military Analysis Network

When a high explosive detonates, it is converted almost instantly into a gas at very high pressure and temperature. Under the pressure of the gases thus generated, the weapon case expands and breaks into fragments. The air surrounding the casing is compressed and a shock (blast) wave is transmitted into it. Typical initial values for a high-explosive weapon are 200 kilobars of pressure (1 bar = 1 atmosphere) and 5,000 degrees celsius.

<HR></BLOCKQUOTE>

For normal folk an atmosphere is better understood as 14.7 psi (pounds per square inch). Sorry for the non-meteric presentation here. In America we are still using that backward English system of units and measurements. Anyway a compression blast from detonating High Explosive is capable of generating a pressure of (see above URL) 200 kilobars. That’s:

200 x 1000 x 14.7 = 2,940,000 psi.

To put that blast pressure into perspective, construction grade rebar (reinforcing steel used in concrete for you lay folk), and structural steel typically has yield strength in the range of 30 or 50 ksi…or 30,000 to 50,000 pounds per square inch (psi). This is the applied pressure at which mild steel moves from an elastic state to a plastic state. In other words failure of the steel is initiated at the yield strength. Construction grade steel doesn’t snap or rupture once yield strength is exceeded. Construction grade steel will creep along and deform plastically for awhile until rupture occurs. In buildings and bridges this is a good thing. Deformation and shift about before failure occurs gives folks time to get off the bridge or get out of the building before the thing collapses (or so the theory goes…doesn’t always happen that way in practice).

Now in the case of less ductile steel (hardened steel) which would tend to be employed in tank armor … From: Ballistic performance Maps for Thick Metallic Armour by Srivathsa Ramakrishnan (1998), Grade A steel armor plate is rated with a yield strength of about 3 times the yield strength of a mild steel. This equates to about 150,000 psi (that’s some seriously strong steel…take my word for it). The critical item to remember being that hardened steel does not really fail in a ductile manner ala. construction grade steel. It fails in a brittle manner…so as yield strength is approached catastrophic failure tends to occur (i.e. rupture or cracking) with little plastic deformation occurring prior to rupture.

So what’s this all mean: Well a compression blast from an exploding high explosive shell weighs in at about 2,940,000 psi. The yield strength for armor plating weighs in at 150,000 psi (and bare in mind the values in Ballistic performance Maps for Thick Metallic Armour, by Srivathsa Ramakrishnan are for modern armor…not WWII armor…and if you think there hasn’t been serious advances in metallurgy over the last 55 years, think again). A is really big compared to B. I leave the rest to your imagination.

[This message has been edited by Jeff Duquette (edited 09-29-2000).]

[gorilla]

Funny that you picked out that specific quote, cause thats the one that caught my eye. I didn't pay much attention to the pressure created (although I knew it was a lot) but thought that the heat created in an explosion was pretty interesting.

I'm guessing here, but I do know 5000 degrees is really hot. I'm assuming that would damage a tank as well (steel has the ability to conduct heat rather well as far as I know). What I don't know is the physics behind hot metal, and the effect it has on penetration. My assumption is that heated metal is easier to penetrate. I also don't know how much heat would be transferred to the armor (the explosion is rather instantaneous.) Would this be enough to ignite powder/fuel/cloth etc? By the way Jeff Duquette, what do you do for work? Ohh yea, I liked the demo of CM, and I'm gonna order it. I hope I don't loose, what some people may consider, my version of a life.

I noted when I played how closely arty (81mm mortars to be specific) landed together. I couldn't find the explosive radius of an 81mm HE round, but I did find the 40mm grenades explosive radius of 5m. So for arguments sake, lets just say that the radius for an 81mm mortar is 10m (which is, I'm sure, too small.) Anyway, I targeted an area which was dominated by a sherman. Now a sherman's (m4a2(76)) hull length is 5.92 meters. The diameter of the 81mm grouping was no more than 7 sherman lengths... so about 50m diameter. I don't know how many rounds were actually fired, but the sustained rof for a modern day 81mm mortar (m252 to be exact.) is 16 rounds per minute. I think that a battery of mortarts is 4 guns, and we'll say that they only fired for about half of a round (30 sec) so... we have 4x16/2 = 32 rounds.

32 rounds in a 25 meter radius each exploding with a 10m radius.

Thats some good shootin as far as I can remember.

Next time I poke at the demo, I'll make sure to measure things more exactly.

Is this game to scale? And, if the bigger guns drop in a similar sized radius, no wonder why the tanks get messed up so easily.

[This message has been edited by gorilla (edited 09-29-2000).]

[Jeff Duquette]

Gorilla:

First off thanks for the research\digging and posting the above URL. I have the URL booked marked now. I am glad you are enjoying the CM DEMO. I was not sucked into CM initially by playing the DEMO. On the contrary I couldn’t figure out what all the fuss was about. But I stuck with it, bought the full blown version…now unfortunately I’m hooked. I can’t wait for CM2 East Front to rear its head.

I’m a civil engineer by profession. And, although I’m not technically a materials engineer, I do know a fair bit about construction materials and construction material engineering (comes with the territory). I have some military background, but that time was spent in Armour back in the early\mid 80’s. Trained on the old M60A1 and M48A5’s (M48A5 was basically uprgraded to carry a 105mm). I’m guessing from your comments, that you have a fair bit more hands on experience in the handling of artillery than myself…so I will try to limit my answers to your questions via references to Army Field Manual information.

Regarding the heat effect of the blast I suspect that your second premise on blast heat being enough to start engine fires, ingnite fuel, etc is probably correct. I am guessing that the time of the blast is such that melting -- or a phase change in the steels structure -- would only occur at the very surface of armor plating. Scorching and blackening of the surface would probably result.

With respect to mortar ROF (and hopefully you are on DSL or have a cable modem…the images are really going to slow this thread down) the following table is contained in FM 23-91 MORTAR GUNNERY. I suspect WWII mortar ROF’s were very similar.

Mortar Rates of Fire

Some of the basics of mortar fire (again derived from FM23-91 Mortar Gunnery

<BLOCKQUOTE>quote:</font><HR>SHEAVES

The term sheaf denotes the lateral distribution of the bursts of two or more weapons firing at the same target at the same time. The distribution of bursts is the pattern of bursts in the area of the target. Normally, all weapons of the platoon/section fire with the same deflection, charge, and elevation. However, since targets may be of various shapes and sizes and the weapons deployed irregularly, it is best to adjust the pattern of bursts to the shape and size of the target.

When mortars fire an open sheaf, the distance between impacts of rounds is half again the distance between mortars. Normally, 120-mm mortars are 60 to 75 meters apart, 81-mm and 4.2-inch mortars are 35 to 40 meters apart; thus, in an open sheaf, rounds should land about 60 meters apart. For the 60-mm mortars, which are normally 25 to 30 meters apart, rounds should land about 45 meters apart. All mortars fire using different deflections. The open sheaf is used when the target is slightly wider than the area a standard sheaf would cover.<HR></BLOCKQUOTE>

So to a very great degree sheave size seems to be a function of burst radius or lethal radius around the impact point.

Open Sheave

Standard Sheave

The following is a table detailing ideal sheave geometry for Final Protective Fire type missions (FPF for us laymen). It’s based upon burst radius, mortar caliber, and unit size (i.e. number of tubes firing).

Normal FPF Dimensions

Firing a 100 meter or 200 meter zone would ideally appear something like the following for burst distribution. Presumably this would entail firing three successive sheafs, with either an increase or decrease in charge to cover the target area.

Firing a 100meter Zone

Firing a 200meter Zone

Hopefully some of the above poop will answer some of your questions.

[Jeff Duquette]

Sorry, forgot to finish with Bill Mauldin

[Fernando]

To Jeff Duquette,

Please bear in mind I’ve got as degree in Early Modern History (from late fifteenth century to the French Revolution) but not in Late Modern History or Engineering.

Some questions:

1. I thought thick plates can resist pressure better than thin plates. It doesn't matter the thickness of the steel plate? In other words, does a 80 mm plate have the same resistance to pressure than a 8 mm plate? If they don’t have the same resistance then do you know what’s the expected resistance of different thickness plates? If so, what’s the expected resistance of a 16 mm reinforced steel plate?

2. Where are the initial pressure originated by the detonation applied? Inside the shell or just outside the shell and after shattering it. I guess the correct answer is after shattering it but I’m not sure. IIRC the same text states “Approximately 30% of the energy released by the explosive detonation is used to fragment the case and impart kinetic energy to the fragments”. Does the energy released by the detonation affect the strenght of the generated shock wave? In other words, does 1 Kg of a given explosive produce the same shock wave (and same temperature) as 5 Kg of the same explosive?

3. What’s the expected area where the maximun shock wave effect is applied? What’s the point of application of the shock wave? Right on the steel plate surface or a point inside the detonating shell? If the point of application of that shock wave isn’t in the plate surface then does the reflected shock wave (“If the shock wave impinges on a rigid surface oriented at an angle to the direction of propagation of the wave, a reflected pressure is instantly developed on the surface and the pressure is raised to a value that exceeds the incident pressure. The reflected pressure is a function of the pressure in the incident wave and the angle formed between the rigid surface and the plane of the shock front”) interfere with other portions of the original shock wave? Unfortunately I don’t understand the reflected pressure concept Where’s it applied? Over the surface? or is it a reflected pressure wich could interfere with portions of the shock wave?

Thanks

[This message has been edited by Fernando (edited 09-30-2000).]

[Jeff Duquette]

Your not really reading my posts are you Yield stress is yield stress. It makes no difference weather a steel beam has plate thickness of 2 inches or 2 feet. If the yield stress is 50ksi than its 50ksi. A 50ksi No. 4 rebar has the same yield stress as a 50ksi No. 8 rebar. You seem to be confusing “force” with “stress and pressure”.

I will try another tack, but as we are fond of saying in America "You can lead a horse to water, but you can't make him drink" .

An Excellent Article on the subject at hand has been written by: Richard C. Anderson, Jr. for T.N. Depuy Journal, and is conveniently entitled: Artillery Effectiveness versus Armor.

<BLOCKQUOTE>quote:</font><HR>The TDI search found that an average of 12.8 percent of tank and other armored vehicle losses' were due to artillery fire in seven cases in World War II where the cause of loss could be reliably identified. The highest percent loss due to artillery was found to be 14.8 percent in the case of the Soviet 1st Tank Army at Kursk (Table II), The lowest percent loss due to artillery was found to be 5.9 percent in the case of Dom Butgenbach (Table VIII).

The seven cases are split almost evenly between those that show armor losses to a defender and those that show losses to an attacker. The first four cases (Kursk, Normandy I, Normandy II, and the "Pocket” (sic The Falaise Pocket)) are engagements in which the side for which armor losses were recorded was on the defensive. The last three cases (Ardennes, Krinkelt, and Dom Butgenbach) are engagements in which the side for which armor losses were recorded was on the offensive.

Four of the seven cases (Normandy I, Normandy II, the "Pocket" and Ardennes) represent data collected by operations research personnel utilizing rigid criteria for the identification of the cause of loss. Specific causes of loss were only given when the primary destructive agent could be clearly identified. The other three cases (Kursk, Krinkelt, and Dom Butgenbach) are based upon combat reports that—of necessity—represent less precise data collection efforts. However, the similarity in results remains stricking.

The largest identifiable cause of tank loss found in the data was, predictably, high-velocity armor piercing antitank rounds. AP rounds were found to be the cause of 68.7 percent of all losses. Artillery was second, responsible for 12.8 percent of all losses. Air attack as a cause was third, accounting for 7.4 percent of the total lost. Unknown causes, which included losses due to hits from multiple weapon types as well as unidentified weapons inflicted 6.3% of the losses and ranked fourth. Other causes, which included infantry antitank weapons and mines, were responsible for 4.80% of the losses and ranked fifth.<HR></BLOCKQUOTE>

Now if we assume that your premise of indirect artillery fire being ineffective against AFV’s is correct, how do you account for the above statistics?

[This message has been edited by Jeff Duquette (edited 09-30-2000).]

[Fernando]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Jeff Duquette:

Now if we assume that your premise of indirect artillery fire being ineffective against AFV’s how do you account for the above statistics?

B]<HR></BLOCKQUOTE>

I don't say indirect fire is ineffective. I say it can be effective (as US army says) but I guess there were few direct hit penetrations against closed top vehicles, if Guderian report was right, that is. To lose a vehicle to artillery fire doesn't means its top armor has been PENETRATED. It wasn't very difficult to do some damage to tanks. For example on Jentz's book there's a report wich stated that the tracks and/or wheels from every Panther of a German unit sustained damage from artillery fire but most of the time it didn't immobilized them. I fully accept that artillery can score gun damages and/or immobilizations forcing the crew to abandon the vehicle but I'm a bit suspicious about its capability to penetrate top armor. BTW If artillery shells are so powerful and can penetrate most armnor plates why did armies use the kynetic energy shells during WWII and not the HE ones only. You can use the AP shells for an antitank role only so they it seems they're less efficient than HE ones wich can also use them against soft targets.

BTW some horses can drink. I began studying for a Chemical Engineering degree at Barcelona's University about 20 years ago but I left it in my second year there and began studiying for my degree in History afterwards. Please notize I didn't learned anything about explosives and very few about Materials technology. The knowledge learned during the first two/three years are VERY theoretical in the Spanish technical colleges. It's the problem of the Spanish university in fact. Too much theory and too few practice. Unfortunately I've forgot almost all the knowledge I learned there. Anyway I wasn't good at Physics. Please, bear in mind that I don't command English and it's a bit difficult for me to fully understand a very technical languague like yours.

I didn't want to be sarcastic or offensive. I was impressed by your previous answer and I fully realize that I don't have the knowledge about the subjet so I thought it was right to ask you about some points. If you ever ask something about Early Modern History I'll be glad to help you but I'll never repply you're a horse which can't drink.

I think you don't command Spanish. If you did then you could have read my repply to a message from Wild Will Wilder. I said him that it doesn't matter if some people with the technical knowledge demolish my arguments. I don't want to win an argument but to try to help to make CM better like I try to do with my mods (hope you've downloaded them). It seems you could demolish my thoughts and give me the definitive answers I'm looking for but unfortunately you've prefered to repply "that horse can't drink".

It doesn't matter.

Thanks anyway, Jeff.

[This message has been edited by Fernando (edited 09-30-2000).]

[Jeff Duquette]

Well I think we can still be friends even if we disagree about artillery vs. tanks. I did read your last message as being sarcastic, I see now I misinterpreted the content. Please except my apologies for being terse. I felt you we’re being overly stubborn\obstinate on this subject.

I have played the Chamois Scenario…and low and behold I managed to Knock out a vehicle cluster consisting of a Panther, MKIVh, and a halftrack. Did this all with a Polish 25 pounder barrage. Coincidence? Perhaps.

Having played that scenario and seen this effect was what originally brought me into your thread. I agree with your original assessment that artillery is not as potent in the real world relative to how it is being represented in Combat Mission. As you have indicated an exploding artillery round can do a lot of damage to a tank even without penetrating armor.

This is seemingly consistent with historical accounts I have read, and I agree with your assesment. However, we seem to disagree on why real world artillery was not as effective as what is portrayed in the game.

My feeling is that inaccuracy of indirect fire is the reason we dont see more HE kills. Your argument is that HE is very ineffective against armour. I suspect the real truth lies somewhere in between my extreme and yours.

[Fernando]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Jeff Duquette:

Well I think we can still be friends even if we disagree about artillery vs. tanks. I did read your last message as being sarcastic, I see now I misinterpreted the content. Please except my apologies for being terse. I felt you we’re being overly stubborn\obstinate on this subject.

I have played the Chamois Scenario…and low and behold I managed to Knock out a vehicle cluster consisting of a Panther, MKIVh, and a halftrack. Did this all with a Polish 25 pounder barrage. Coincidence? Perhaps.

Having played that scenario and seen this effect was what originally brought me into your thread. I agree with your original assessment that artillery is not as potent in the real world relative to how it is being represented in Combat Mission. As you have indicated an exploding artillery round can do a lot of damage to a tank even without penetrating armor.

This is seemingly consistent with historical accounts I have read, and I agree with your assesment. However, we seem to disagree on why real world artillery was not as effective as what is portrayed in the game.

My feeling is that inaccuracy of indirect fire is the reason we dont see more HE kills. Your argument is that HE is very ineffective against armour. I suspect the real truth lies somewhere in between my extreme and yours.<HR></BLOCKQUOTE>

You’re right. Most of the time the truth lies between the extremes and I also suspect it lies in a point between both extremes in this case. We can still be friends

I don’t say artillery’s ineffective . I say it’s mostly ineffective for knocking closed top tanks down through top armor penetrations. I don’t have any problem with artillery knocking down open top vehicles like Wespes or half tracks thought it seems it happens more often than not. To know that one of my scarce Panthers, King Tigers or Jumbos could get an immobilization or gun damage by artillery fire scares me a lot and makes artillery effective for disrupting my tank attacks or defenses.

I think it should be harder to get direct hits and top armor penetrations against closed top vehicles with artillery fire and/or substitute most of them by gun dammage or immobilization, taking into account the different vehicles, that is. It seems Panthers were strong enought to withstand some damage to their tracks without being immobilized.

No one has post hard data about top armor penetrations so I thought we had to guess it using disperse information sources and deductions. I was very happy when I read your post because it was a technical one and it was exactly what I was looking for.

The problem is to know how did a HE shell knock an armoured target down. They have lower KE than AP shells and it seems artillery shells lack enough KE to penetrate most top armor. We need to know the maximun height a an artillery shell trajectory and the expected impact angle to be sure about it but no one has posted it yet. If the maximun height is 500 or 1000 meters then the KE of the shell is small but if the maximun height is 5000 meters (I guess it isn’t) then it could have a lot of KE and be able to penetrate most top armors. We calculate trajectories at school in Spain before studiying in the University. We took into account the air ressistance, gravity and initial muzzle velocity and angle. It’s the typical test problem about forces for elementary Physics students. I remember that it was fairly easy to calculate them but I don’t remember the formulas and I don’t have the books to look at.

If artillery shell don’t have enough KE then their splinters could penetrate it but I think it isn’t true most of the time. They have a lot of KE but they are small, made of softer materials than hardened steel armor plates and have an inefficient shape for penetrating armor. If I’m right this leaves the effect of the HE detonation (shock wave and temperature) as the main cause of most armor penetrations. You did post a nice answer but I notized it wasn’t taken into account the armor thickness and energy unleashed in the detonation but I did an elementary mistake. Please correct me if I’m wrong. Bars made of the same material have the same yield stress so they crack/deform when under the same pressure but higher diameter bars are better because you need to apply stronger forces to attain the same pressure (F/S) to crack/deform those bars. If HEs produce always the same shock wave pressure and temperature then it seems clear it can penetrate armor so it doesn’t matter what thicness it has but I also guess that shock wave, temperature and splinters KE are function of the energy unleashed during the detonation so different amounts of explosives get different results, don’t they? I DON’T know the answer so I applied an indirect approach. If HE shock waver is so effective cracking armor plates then why didn’t WWII or modern armies get rid of the AP shells, very ineffective against infantry, and began using HE shell for antitank purposes?

I know that HEAT/hollow charge projectiles are a kind of AT “HE” shell wich apply most of the detonation energy in a given point. They’re good because they concentrates that energy in a very effective way. An artillery shell doesn’t concentrate it so they use HE energy in an inefficient way (for antitank purposes, that is).

Fernando

[:USERNAME:]

Oh boy so much hooey here.

Someone asked about descent angles for arty. A arty shell will always fall at a steeper angle than at what it was fired. On the moon or anyplace without an atmosphere it will be the same. Here on earth, They come down steep. So mortars virtually land on their noses.

I hate that data that was printed in talonsofts east front II manual. I am talking about the 300 some tank study by the british. First off it was late in the war and I would imagine that german arty supplies were getting scarce. Second it was a battle off movement at that stage.

In normandy, there wasnt great sweeping movement and tanks were arty targets. If a tank was immobilized and under directed arty attack, he would get hit. A tanks best defense against arty is to just move. Mines and arty took out a lot of tanks in Normandy.

Its been discussed to death on every wargame forum and tanks are susceptible to all kinds of non-penetrating damage. Radios blink off because the concussion destroys tubes. Carburators slosh fuel around the engine compartment. Antennas are neatly sliced off. Shrapnel ricochets into engine compartments destroying cooling fans and radiators. Vision blocks crack, periscopes break, guns get out of alignment, etc.

Even if a 24 pound shell didnt crack the armor plate above you, do you think it would be very pleasant to have the shock wave come through the metal and crack blood vessals in your brain? Ive read of guys spitting blood from bleeding lungs in tanks because of concussion. Ive read of broken arms because someone was leaning on a plate that got hit. You dont have to make that magical hole to effect a tank's occupants.

Velocity DOES make a contribution to HE effectiveness and BTS models this. I was in a big discussion with a bunch of genius' about this.

Lewis

[Henri]

It's incredible that with all the mesages here, no one has mentioned the ONLY knows statistical study of the effect of artillery on tanks; the US Army did a similar study, but it doesn't distinguish between AP and artillery.

The study in question was "A survey of tank casualties amongst armored units in Northwest units", by the British. "Dmaged" in the report means being made unable to continue participating in the battle, so I presume that it would include disabled guns and track hits when on the offensive.

The study shows that only about 3% of tanks casualties were due to artillery. From this it is clear that artillery in CM is much too effective against tanks: in some battles, I have had more than half of my tanks immobilized or suffering gun hits, and I would guess that overall, the ratio is certainly over 25% in CM. This is certainly one of the most unrealistic aspects of CM

A photograph and discussion of the above report is found in the Talonsoft West Front manual.

Henri