Canister in CMBB: Realistic or Hollywood?

[Amedeo]

Eureka! I've found it

And it was clearly depicted in one of the pages of the 1938 vintage book on soviet artillery I posted above

If you take a look at this page and skip though the text until you find picture No. 89

You'll see that there was a position labelled "K" (for Картечь i.e. case shot) on the graduating ring of the time-fuze of the 76mm shrapnel. It was intended to set the timer to "zero" to enable the use of the shrapnel round as a canister ("на картечь").

So there was no separate canister round for the 76mm guns, but regular shrapnel rounds (as this one)

could be used that way, after proper setting of the fuze.

This should explain both the reference to canister usage for 76mm guns and the lack of information about dedicated canister rounds. In fact it's (a posteriori) obvious that the only guns to have canister-only rounds are the 45mm and 57mm AT guns that, being AT weapons had no need and were not issued shrapnel rounds. Field guns were a different matter and, for sure, it was practical and cost effective to have double-use rounds.

The use of shrapnel rounds fired "as canister", for close defence, is also referred to in this document (see note No. 13).

Regards to all,

Amedeo

[John D Salt]

Originally posted by Amedeo:

Eureka! I've found it

And it was clearly depicted in one of the pages of the 1938 vintage book on soviet artillery I posted above

[snips]

Excellent! Well spotted. That resolves the puzzle rather nicely, I think.

The text accompanying drawing no. 89 makes it clear that shrapnel fired "Na kartech'" bursts 10-20m from the muzzle. ISTM that this would reduce its effectiveness against tank-hunter teams close enough to attack a T-34 practically to nil.

It also resurrects the general question of modelling shrapnel shells, since it now appears that you can't have 76mm canister without also having shrapnel.

All the best,

John.

[Amedeo]

John,

for sure the effectivenes of 76mm shrapnel fuzed "as canister" should be reduced to nil in the 0-10m range (at least). It's not a coincidence, I think, that the accounts, in the same book, about field guns' canister usage during the '20s, said that generally fire was opened at 300m or so. This distance was possibly also selected because it enabled the best overlapping of fire "cones" when used by a deployed battery.

Even if the BFC guys don't want to model shrapnel, I think that they could still manage to implement a working model for canister rounds with a variable FP effect in front of the gun that increases with distance until reaching a cutoff. Thus a 76mm canister should have 0 FP at 1m increasing maybe to 500 FP at 200m then decreasing again to 0 FP at 500m.

Just my two Eurocents. I don't think this is the best way to model the whole thing but for sure one cannot expect big tweaks for v1.03.

Kind regards,

Amedeo

[John D Salt]

Originally posted by Amedeo:

Even if the BFC guys don't want to model shrapnel, I think that they could still manage to implement a working model for canister rounds with a variable FP effect in front of the gun that increases with distance until reaching a cutoff. Thus a 76mm canister should have 0 FP at 1m increasing maybe to 500 FP at 200m then decreasing again to 0 FP at 500m.

Just my two Eurocents. I don't think this is the best way to model the whole thing but for sure one cannot expect big tweaks for v1.03.

As Admiral Gorshkov is alleged to have had written up over his desk, "Best is the enemy of good enough".

I think it would probably be good idea, for this and other reasons, to have a simple minimum-range restriction of, say, 10m for all tank-mounted weapons (exempt NbW and, if you really must, pistol ports). This might a simple fix, or it might have horrific knock-on effects on the TacAI, I have no way of knowing.

All the best,

John.

[Lady Roxanne]

Excellent work, gentlemen! Something will be done to tone down "cannister" rounds now. I feel certain of that.

So, our CMBB T-34s are firing shrapnel rounds, with the fuze set to minimum range (10-20 meters), giving a "cannister effect". Can I assume then that barrel wear was not a concern because the T-34 76mm guns were not firing REAL cannister rounds?

[Redwolf]

Originally posted by John D Salt:

Finally, quite apart from the question of canister effectiveness, it seems to me that tanks in CM get off too lightly in close combat with infantry, as they do not seem to have any "blind" zone at extremely close range. The tank hunter's rule that the closer you are to the tank the safer you are is not reflected at all, and tank crewmen peering through their vision slits seem to have a preternatural ability to spot and shoot infantrymen dodging around within a few metres.

This doesn't seem to be true, at least nto for weapons. While viewing seems to work at arbitrary close range, the weapons do not. I recently had a StuG attacked and it was showing "out of range" when using the target tool on squads nearer than 15 meters.

The question of vision is moot anyway with the absolute in-turn spotting we have now.

[Lady Roxanne]

I'm sure I read somewhere, perhaps in the manual, that there is a blind spot for tanks to the rear of the vehicle, at least if there is no cupola. Within 15 meters I think it was, but I'm not sure.

Anyway, as long as the uber-cannisters are de-uberized, the spotting issue is tolerable IMO. Tank crews in CM are just real alert.

[moneymaxx]

I don't claim to have understood everything that was said in this thread since I'm no weapons expert. But what I did understand is that the Russian canister-round in CMBB is in fact a shrapnel round with a special fuse setting.

Now my question, doesn’t that mean that the shell would be very effective against infantry in foxholes IF the fuse was set right, letting the shell explode just above the foxhole? The same, but maybe to a lesser extent, would be true if a shrapnel-round, with the right fuse setting, exploded INSIDE a building or woods.

I hope this question isn’t complete nonsense .

[Redwolf]

Originally posted by moneymaxx:

I don't claim to have understood everything that was said in this thread since I'm no weapons expert. But what I did understand is that the Russian canister-round in CMBB is in fact a shrapnel round with a special fuse setting.

The graphics and the short-range nature in the game clearly indicate it is a shotgun like round.

[rexford]

Originally posted by John D Salt:

In response to the following quote, go to the Panzer IV Universe site at http://ourworld.compuserve.com/homepages/willphelps/Specs-03.htm

and you'll find that 75mm L24 fired case shot with 960 9mm balls.

The German report on 76.2mm field gun ammunition that I have gives alot of data on schrapnel (Schr Patr) but nothing on cannister.

</font><blockquote>quote:</font><hr />Originally posted by John Kettler:

The apples appear to have become confused with the

oranges in this discussion. This is because shrapnel and canister are NOT the same thing.

[snips]

Indeed -- although Napoleonic people who still talk about "Major Shrapnel's spherical case" might claim that they are both kinds of case-shot.

I suspect that the confusion is somewhat assisted by the similarity between the Soviet designation letters Ш (Sh) for shrapnel (Шрапнель, Shrapnel') and Щ (Shch) for canister (Картечь, Kartech') -- quite why they use the latter letter I don't know, as it doesn't appear in the word Картечь.

Things are not helped by Valeriy Potapov's curious decision to transliterate Щ as "She" on his excellent Russian Battlefield site. Then again, as far as I can see, his artillery pages ( http://www.battlefield.ru/guns/project_1.html ) do not seem to list any canister rounds.

I anyone has a reference to a source giving the characteristics of the 76mm canister round, I'd be interested to know of it, Likewise I'd be interested in further information on the German canister for the 7.5cm L/24, a round I have not seen referred to outside the world of "Squad Leader" other than a fleeting reference in von Senger und Etterlin. Oh, and, while we're collecting them, can anyone think of any other canister rounds that are believed to have existed during WW2 (apart from the US 37mm ATk and 57mm RCL)?

All the best,

John. </font>

[rexford]

A very good find Amedeo!

Here are some tidbits from the German report on Russian 76.2mm field gun schrapnel (source of German data is a 1938 Russian report on 76mm Kanone 1902/30 L40, Kenn=Nr. 120, I. Teil, Ausgabe 1938):

"Nichtverfeuerte, bereita gestellte Dopp Z sind auf "K" (Transportstellung) zuruckzustellen.

Zur nahverteidigung (bis 400m) konnen die schrapnells mit zunderstellung "K" (kartasch) verfeuert werden. Jn dieser stellung ergeben die zunder sprengpunkte etwa 10m bis 20m vor der mundung.

Fallengelassene zunder durfen nicht auf die patrone aufgeschraubt werden. Die tragbare fallhohe ist in den russischen vorschriften nicht angegeben. deshalb vorsicht! fallenge lassene zunder und patronen mit zundern sind, wenn die fallhohe mehr als 1.20m betrug, als blindganger zu behandeln und zu sprengen."

If someone could translate it would be appreciated.

Originally posted by Amedeo:

Eureka! I've found it

And it was clearly depicted in one of the pages of the 1938 vintage book on soviet artillery I posted above

If you take a look at this page and skip though the text until you find picture No. 89

You'll see that there was a position labelled "K" (for Картечь i.e. case shot) on the graduating ring of the time-fuze of the 76mm shrapnel. It was intended to set the timer to "zero" to enable the use of the shrapnel round as a canister ("на картечь").

So there was no separate canister round for the 76mm guns, but regular shrapnel rounds (as this one)

could be used that way, after proper setting of the fuze.

This should explain both the reference to canister usage for 76mm guns and the lack of information about dedicated canister rounds. In fact it's (a posteriori) obvious that the only guns to have canister-only rounds are the 45mm and 57mm AT guns that, being AT weapons had no need and were not issued shrapnel rounds. Field guns were a different matter and, for sure, it was practical and cost effective to have double-use rounds.

The use of shrapnel rounds fired "as canister", for close defence, is also referred to in this document (see note No. 13).

Regards to all,

Amedeo

[moneymaxx]

Here is a first rough translation, fine tuning is welcome:

Unused, readied Dopp Z fuses must be reset to “K” (transport-setting).

For close defence (up to 400m) the shrapnels can be fired with fuse setting “k” (kartasch). With this setting the fuse produces a bursting point about 10m to 20m in front of the muzzle.

Dropped fuses must not be screwed on. The acceptable drop height isn’t mentioned in the Russian regulation. Therefore, caution! Dropped fuses and shells with fuses, if dropped from a height that exceeds 1.20m, are to be treated as dud shots and must be blown up.

Some clarifications:

- Dopp Z seems to be an abbreviation, that I can’t translate without knowing the context/more about shells.

[ May 31, 2003, 10:17 PM: Message edited by: moneymaxx ]

[kenfedoroff]

How difficult is it to change the fuse settings on the Shrapnal shells in the heat of battle (inside a T-34)? Or would they be pre-set to be used as cannister and nothing else? Would the T-34 crew have time to change fuses to try and have a shell explode over a position 3-400 yds. away?

Sincerely,

Ken

[ June 01, 2003, 09:07 AM: Message edited by: kenfedoroff ]

[JasonC]

I'll bet "Dopp Z" means in effect "timed fuse" - the Z probably stands for "zeit". I say this not based on any knowledge of German, but on knowledge of artillery fuses. You need a variable time fuse for shrapnel shooting. Those typically have a dial set for the number of seconds before bursting, down to tenths of a second.

You'd set the dial to the nearest position to zero for a just out of barrel burst. At least with contemporary US fuses, though, the actual zero position tells the round to act as an impact fuse ("quick"), rather than exploding after zero time. That also acts as the "safety" position, used for storage, traveling, and when handling the fuze before use.

The 80 by 20 beaten zone mentioned is exactly what you'd expect from shrapnel. It is really a long oval oriented along the LOS. I previously figured the 76 rounds were shrapnel rather than canister because the Russian battlefield site listing for the rounds includes a bursting charge. Canister casings disintegrate from the force of firing. Shrapnel is meant to hold together until near the target so it obviously needs a bursting charge.

The WW I experience with true shrapnel was that is was only marginally more effective than HE against completely exposed troops, while HE was far superior against troops in cover. Large HE charges means smaller shell splinters traveling fast. And it turns out small is good enough, you don't need a large iron ball if the velocity is high. So lugging extra iron as secondary projectile was inefficient, compared to additional TNT to drive the splinters faster and create more of them.

Meanwhile, if there is serious dirt, sandbags, etc between the shell and somebody the HE still puts a serious blast wave through that material, while the tiny bursting charge of shrapnel does essentially nothing. The velocity of the balls inside a sharpnel round comes almost entirely from the muzzle velocity of the overall shell, indirectly from the powder fired in the barrel. The small bursting charge just gives spread.

That also addresses the question, what if a shrapnel round bursts e.g. inside a building. The answer is, less happens than if HE bursts inside a building. The oval of balls in a shrapnel burst is concentrated along the line of flight. The "sideways velocity" is small, compared to shell splinters from an HE round, because the bursting charge is only a small fraction of ordinary HE. Even the shell splinter pattern from HE is oval, longer in the direction of flight. But it is more circular (eccentricity closer to 1) than the oval of shrapnel.

Going back to the other round John was calculating things for, a quick and dirty "stepwise" bell would be to take the spread mentioned as roughly 2 SDs - 2/3s of the balls in the first half the radius (which is 1/4 the side to side area), the other 1/3rd in the remaining half the radius (which has 3/4 of the area).

Then at 50-100-200m, you'd have 1+2, 1+4, 3+6 targets "centered" or "edge". The former are 2.68 times as likely to be hit as previously calculated, while the latter are only 44% as likely (1/3rd in 3/4 of the area, vs. 2/3rds of the balls in 1/4). The previous "level" averages from the previous table were 96, 54, 18%.

Those become "hit the guy aimed at, 50 and 100m, 48% chance for the middle 3 guys at 200m". So the expected "center casualties" are 1, 1, 1.5. The center of the cone is "overkilled" at the closer ranges.

Meanwhile the "edge" personnel are hit only 44% as often, producing hit chances against them of 42%, 25%, and 8% at 50-100-200. There are 2-4-6 of them, so the "edge" hits expected become .84, 1, and .48. The result is you expect 1.8, 2, and 2 hits at 50-100-200. Much more nearly a constant "2".

The expected casualties are not sensitive to the range, because more personnel enter the cone at longer range, but the chance against each is falling. At first that fall is unimportant along the center-line, because it is still nearly everyone hit. By 200m or more, though, even the person most directly aimed at, in the densest part of the cone, has a significant chance of not being hit.

As for the Napoleonic era question, it was true caseshot, not grape. They used two types, "heavy case" with a moderate number of large balls (over .50 caliber) at ranges out to 300-500 yards, and "light case" with a large number of balls smaller than musket balls, more like ball bearings or buckshot, at closer range.

A quarter of the typical ammo load (which ran 60 to 150 rounds per gun, typically) was case. Howitzers (less common, but typically 2 per battery) had shell for the rest of their ammo load (fused, powder charge, bursting a hollow iron sphere at the right range - only the Brits added ball inside as "Colonel Shrapnel's spherical case").

For the guns (3/4 of the pieces) the rest of the ammo was solid shot. So if you assume 1/4 howitzers, the typical overall ammo load for a whole Napoleonic era artillery park works out to around 55% solid shot, 25% case, 20% shell (or shrapnel, for Brits).

The case shot balls were held in a light tin casing (which disintegrated on firing) only marginally smaller than bore diameter, so the entire powder charge could drive them. True grape (buckets of nails, bolts, loose iron tossed down the barrel almost at random) was a field expediant if case shot ammo gave out, but was limited to short ranges because it did not block the barrel ahead of the powder charge efficiently, giving very high "windage". Most of the talk of "grapeshot" in the Napoleonic era is about case, not the true grape.

[ June 01, 2003, 10:36 AM: Message edited by: JasonC ]

[JasonC]

As for the question about changing fuse settings in battle, if more recent US experience is anything to go on it is not particularly hard and does not take long, but is still the kind of thing you'd rather do while not in combat if possible. You are just twisting a dial on the fuze on the end of the shell, rather like screwing the fuze in. There is typically a special wrench for it, to avoid random movements changing the setting.

This is an "ammo prep" job, and in the artillery anyway is done after a fire mission order, just before and during the shooting, by men away from the actual gun operators. For vehicles, you try to have all the ammo in the vehicle itself already prepped as it will be used in action. Which would mean timed rounds fused for various common shooting ranges, the loader then just selecting the right one out of the set for the range called out. If he had to adjust the fuzes too, it would delay reloading, by roughly a factor of 2.

Another way of handling it would be just to set the shrapnel fuses to "quick", give up on perfectly timed airbursts with innaccurate range estimates, and just live with the shrapnel spread given by an impact burst. Then the gunner only has to worry about getting the range right compared to his last shot, not absolutely.

This is probably what they did in practice most of the time. The perfection of going for timed bursts at the right height was probably left to true artillery, if not left behind on the firing range. Shrapnel was probably fired as westerners would fire "quick" fuse HE, at targets more or less in the open. While HE would be fired at targets westerners would use "delay" HE for - dug in positions.

[ June 01, 2003, 10:50 AM: Message edited by: JasonC ]

[Amedeo]

Originally posted by kenfedoroff:

How difficult is it to change the fuse settings on the Shrapnal shells in the heat of battle (inside a T-34)? Or would they be pre-set to be used as cannister and nothing else? Would the T-34 crew have time to change fuses to try and have a shell explode over a position 3-400 yds. away?

The graduating ring on the 76mm shrapnel's fuze could be set to K (canister) to UD (impact). Between those extreme settings there was the 'proper' scale for usage as a regular shrapnel with 50m increments from 0 (K) to 130 (thus the maximum flight distance, in airbust mode, would have been 130x50=7500m).

Some rounds were preset to "canister" directly at the factory.

This document states that at the beginning of the war, shrapnel usage by soviet artillerymen was very limited. This might imply that to use this kind of round properly would have required skills and presence of mind that are not to be found among ill-trained conscripts.

On the other hand the Combat Regulations for Tanks and Mechanized Corps of 1944 says that "The choice of weapons and the type of ammunition depends on the target and firing range. With cannon you can shoot [...] with shrapnel: against infantry as well as Stukas and dive bombers" :eek:

So I'd guess that the effectiveness of cannister usage depended on the quality and experience of the crew. A conscript crew would have barely managed to fire factory pre-set canister rounds, while a veteran crew would have been able to... shoot down Hans Rudel himself

Regards,

Amedeo

[edited for spelling]

[ June 01, 2003, 11:02 AM: Message edited by: Amedeo ]

[Amedeo]

Originally posted by JasonC:

I'll bet "Dopp Z" means in effect "timed fuse" - the Z probably stands for "zeit".

Wrong but close enough. Dopp Z stands for Doppelzünder, that is "double fuze": time and percussion.

Regards,

Amedeo

[Amedeo]

Returning on the effect of lead-anymony spherical balls fired by canister/shrapnel rounds against covers, helmets etc. it's worth noting that the soviet regulation for the 76mm infantry guns stated that the shrapnel rounds should be effective in piercing the armour of light AFVs.

Maybe a bit optimistic but I think this implies that an helmet will survive only the most favourable (geometrically speaking) hits.

Again, the canister limitations lie probably more in its narrow cone of fire than in the number or energy of its balls.

Regards,

Amedeo

[Jeff Duquette]

Nice bit of work Amedeo. This topic has been brought up before:

http://www.battlefront.com/cgi-bin/bbs/ultimatebb.cgi?ubb=get_topic;f=23;t=000233

I have long suspected that shrapnel and canister were being confused with each other in the case of the Soviet 76mm (see John Salts post on transliteration). The TCH and SCH letters in Cyrillic are very similar.

In addition, you will be hard pressed to find either circa-WWII drawings; photos; or firing tables for Soviet 76mm canister…i.e. if you dig through WWII Soviet Artillery manuals on the 76.2mm there are a fair number of references to shrapnel ammunition, but nothing that refers to canister. Translated Red Army AARs which refer to canister being employed by field guns with muzzle breaks simply reinforces the idea that shrapnel shells were being mistaken for some sort of canister round. Soviet Army tank manuals of the period discuss ammunition load outs for the T34/76. Typical load-out was on average five shrapnel shells...and again there is nothing that refers to a canister round being employed by the T34’s 76mm. Obviously typical load-outs can vary dependent upon numerous factors.

I have long suspected that setting the fuze to zero on Soviet 76mm shrapnel shell was being confused with an honest to goodness canister round. This was after going through US Army artillery manuals for World War One. Amedeo’s findings have pretty much cemented my own opinion on this subject. Shrapnel could be employed as a pseudo-canister round for self-defense of the gun\battery against infantry rushes. From: “Elements of Modern Field Artillery, U.S. Service” by Lt. Col. H.G. Bishop, copyright 1917” (Bishop was an artillery instructor at Leavenworth):

“The [shrapnel] fuse has two elements, time and percussion. The time element enables the fuse, when properly set to burst the shrapnel at any point along the trajectory in the air. If the fuse is not set for time fire, or, if so set and the time element fails, the percussion element causes burst upon impact.

The fuse may be set at zero, whereupon the shrapnel will burst at about 20 feet from the muzzle of the gun giving canister effect. The common shrapnel is essentially a projectile for attacking personnel and has little or no effect against walls or even light entrenchments. Used in an attack of a field work of even temporary type, its function is to keep down the defenders until our infantry can advance sufficiently to warrant a rush on the position.”

[ June 01, 2003, 12:28 PM: Message edited by: Jeff Duquette ]

[John D Salt]

Originally posted by JasonC:

[snips]

Large HE charges means smaller shell splinters traveling fast. And it turns out small is good enough, you don't need a large iron ball if the velocity is high.

Indeed, very small is good enough. Shrapnel shells offer the advantage of controlled fragment size, but the typical shrapnel bullet of the WW2 era is likely to be very much more massive than is needed for incapacitating effect against human targets. Uncontrolled fragmentation of HE (I believe all WW2 HE was uncontrolled-fragmentation) results in a few large fragments, a medium number of medium-sized ones and a huge number of tiny ones. However, as fragments much smaller than a typical shrapnel ball can incapacitate, I would expect this, other things being equal, to produce more effective fragments in a given weight of metal than shrapnel balls would.

Modern beehive rounds use very small flechettes, and so gain the advantages of both controlled fragment size and a huge number of fragments.

A pal of mine from Fort Halstead suggests that the spreading pattern of shrapnel would tend to be annular, rather than having a central tendency.

Originally posted by JasonC:

True grape (buckets of nails, bolts, loose iron tossed down the barrel almost at random) was a field expediant if case shot ammo gave out

Mr. Midshipman Picky thinks that grape-shot has larger balls than canister and is a kind of dismantling shot used in naval guns, as are bar-shot and chain-shot.

The "all kinds of junk stuffed down the barrel" ammunition I would call langridge.

All the best,

John.

[JasonC]

Useful corrections and additions, all. Thanks.

[John Kettler]

John,

If grape is dismantling shot, then it is dismantling shot for people, not ships! It takes its name from the shot clusters, which somewhat resemble a bunch of grapes. Grape, frequently in tandem with one or more cannonballs, was the close range weapon of choice to strip guns of their crews and was horrendous against men massed as boarding parties. I own an example, and the iron shot itself is about 2" in diameter. From what I can tell, the bigger the gun, the bigger the balls in the grape it fired.

Regards,

John Kettler

[JonS]

Originally posted by Amedeo:

... This document states that at the beginning of the war, shrapnel usage by soviet artillerymen was very limited. This might imply that to use this kind of round properly would have required skills and presence of mind that are not to be found among ill-trained conscripts. ...

That would be a very sound assumption as it is mirrored by the experiences of another army in another war. During WWI the British use of true shrapnel declined for a number of reasons, the two main ones being;

1)its lack of lethal effect against men in trenches (though naturally it retained its very high effectiveness as a suppressive tool), and

2) the idea that conscripted gunners wouldn't be able to cope with the intracacies of fuze setting on these shells (never mind that the conscripts were often better educated than the regular army ...).

See: Bidwell, Firepower, or Gunners at War. (I forget which exactly)

Regards

JonS

Edit: another reason, IIRC, was the cheaper per-round cost of HE compared to Shrap.

[ June 02, 2003, 09:09 PM: Message edited by: JonS ]

[JonS]

Originally posted by John Kettler:

If grape is dismantling shot, then it is dismantling shot for people, not ships!

What, then, is the collective name for those rounds designed to shred rigging and sails, and dismast ships?

Regards

JonS

[xerxes]

Chain shot and bar shot was what was used to take out the rigging.