Tero

Lets not forget the way the current chain gang, spotting, suppression and evasion modelling affect the outcome of a firefight in CM at basic unit level.

<blockquote>quote:</font><hr>Originally posted by Treeburst155: Time to bump this for the weekend. All is going well I assume? Treeburst155 out.<hr></blockquote> Overall kill to loss ratio is acceptable (or better) BTW: any penalties for feet dragging ? The limit is 90 days and a disproportionate amount of games (mine at least) seems to be advancing at 1 turn a week at present time. [ 12-07-2001: Message edited by: tero ]</p>

Originally posted by Andreas: These guys simulate a four launcher battery firing four salvoes before PUFOing to avoid CBF. The RL reload cycle is what, 8 minutes. Your simulation was a simulation of 4 batteries firing. Could you do a control test with only one battery ? Did you spread the aim points or did you concentrate them to one spot ? British casualties: 102 (30 KIA) 2 Mortars 5 Vehicles (carriers) 1 gun 534 men okay IRL, I believe that this battalion would not have made it off the startline, due to the very heavy casualties. 4,7% KIA, 16% total casualties. I would not say the casualties were especially cripling. What was their morale status ? Bit arbitrary test, but it seems alright to me - based on the account of a Soviet infantryman in Lucas' 'War on the Eastern Front'. I think the Nebelwerfer works almost exactly like it says on the tin. Can you give specifics on the Soviet force ? How and where were they deployed ? How heavy casualties did the Soviets suffer ?

Originally posted by Andreas: No Hetzers, no Jagdpanthers, no Panzer IV/70, presumably few if any of the Stug 75L48, and/or the 75L43 variety in North Africa. IIRC Marders were present, especially the 76.2® armed ones. Also Jpz-I's were there. 0 maybe a bit of an underestimate, but I am not that surprised by it. Me neither actually. But the average is distorted if the number of SP's present is not taken into account.

Looking at the figures at http://rhino.shef.ac.uk:3001/mr-home/hobbies/loss.txt the writing should appear on the wall. There is one anomaly in the data I would like to point out: the North Africa data brings the SP kill average down considerably. Yet there were all sorts of SP guns present in Afrika Korps. [ 12-03-2001: Message edited by: tero ]</p>

Originally posted by Cauldron: At the risk of making this sound all too simple........ Rockets in CM are BOTH too inacurate and MOST DEFINATLY too "weak" on impact zone. Rockets in many ways were a terror weapon - you see whole trees fly over your head and most people think bad thoughts. NONE of this is indicated in CM. end of story eric You love being a wet blanket, don't you.

Originally posted by Treeburst155: What about the different sounds the various MGs make? That could give you away. Only for the Germans. The Soviet used the different versions of the DT in vehicles and as LMG.

Originally posted by Jeff Duquette: This may be of some interest to folks following this thread. Some reference material I have laying around here. A Military Intelligence Report circa-March 1945 regarding German Rocket Artillery. Of particular interest are the final two pages that discuss accuracy. http://www.geocities.com/jeffduquette/stuff2/rocket.html Interesting. I found some interesting insights at http://riv.co.nz/rnza/tales/raskin1.htm It seems this might evolve into a debate of the SMG proportions. Just because the US Army said they were inaccurate (without any specifics about how inaccurate they were) there is a need for the German POV and specs on the firemissions themselves. How often were the incendiaries used ?

Originally posted by JasonC: Um no. It is pure math. One of them refers to a 50% line, whereas one standard deviation is about a 68% line. The distribution is assumed to be normal (Gaussian) in both cases. Your lack of knowledge of what the terms you are confidently citing even mean to begin with is not exactly inspiring. I was talking about the consistency, not the math. According to you there are precious little variables that can be manipulated so their affect is minimized to a degree where the barrage 100% zone for the battery is 100m by 50m. And no, the 50% zone is not "quaranteed" (sic). Nor does it mean "at least that many" will land there; if it did, and more landed within it, they would just increase the value slightly and still have it be true that half land inside a somewhat larger area. What it means is that on average, half of the rounds will land within that area So, on average the 50% zone contains 50% of the hits, but the number of hits can be greater ? The difference between my statement and yours is what ? - just like a fair coin does not ensure 50% heads, only that on average half the flips will be heads. If you really think this is relevant I must reevaluate my opinion on the US arty and its esteemed accuracy. I trust you are aware of the Fininish research on the the phenomenon where the slice of bread almost always falls to the floor with the side with the butter on it facing the floor. It was established the slice indeed falls that way statistically and the reason is the placement of the center of gravity. They just use a 50% figure instead of standard deviations, because it is easier for planners to use without knowing much statistical math. The same reason is behind using mils (1/6400 part of a circle) instead of radians or degrees - because it makes miss distances easier to calculate, since the sine of 1 mil is 1/1000 (hence the name), for small angles. Also, at 5-10 km a degree is too big a value for corrections. As for shells landing where they aren't supposed to, can you have been in the artillery (any nation's artillery) and not know what a short round is? They should also know what is the propability for a round hitting that far from the target point. That is why you always double check for human errors first if the round hits a 1,5% propability grid instead of the 50% propability grid. Besides that, I already explained one way it happens, without FO "error" - the spotting round happens to go longer than the average shot from the battery, and the FO properly responds with "drop 100, fire for effect". The battery lowers the range 100 yards, and most of its shells fall 100 yards closer again (some, "short" by random variation, still closer), and that may put them too close. That is why you always fire spotting rounds with all the guns of the battery simultaneously and not single spotting rounds from a single gun. Tell your stories of infalliable redlegs to someone in the bloody infantry, not to someone who has seen the business end. And you can tell your "practically no ****ed up fire missions by the FO, almost all are technical or statistical faults, not attributable to human errors" to anybody who has not been in the service at all. The infantry does not order fire missions in every army as a part of procedure. The FO is a part of the redleg organization so the FO error falls in the lap of them, not the infantry (even if the infantry suffers casualties because of the error). The FO can give the infantry a pretty song and a dance about windsheer and of Mars being in the house of Venus during the eclipse but the truth is at least 90% of the short rounds are short because somebody ****ed up, not because the statististics played an unfortunate number on the service.

Which is just another way of saying that you can't make individual rockets very accurate so you have to shotgun a large, area target with them instead of hitting point targets with a smaller number of rounds. Which is what I've been saying and you've been objecting to. Now you've switched sides? Hell no. I have never maintained the rockets are ideal for point targets. But the thing is you just simply do not fire individual rockets. When talking about barrages. The single projectile 50% zone for (US) 105mm at 2740m is 33m x 3.6m, the 28cm Rocket Projector 50% zone at 1500m's is 120m x 60m. What is not taken into account is the fact that the 50% zone gives you the area where at least 50% of the rounds fired land. If we fire 20 rounds of 105mm and 280mm from one 4 mount battery and have an exceptionally good day and (assuming overlapping zones) both batteries land 90% of the rounds in the 50% zone then it would mean you have 18 105mm rounds in a 33m x 3.6m square and 18 280mm projectiles in a 120m x 60m square. At which point does a point target become an area target ? Regular field artillery is generally also directed at area targets. If you have an area target of 100m by 50 meters Rocket arty does NOT burn out in the tube. I always thought WWII rockets in particular expended their propellant before leaving the rail/tube. The German 280mm has a max range of 1925 meters. That would indicate the propellant is in fact burned out at the tube. If it did, it would have no more range than a bazooka. For some curious reason WWII rocket projectiles tend to be bigger than bazooka rounds. Surely you've seen video of MLRS firings from the Gulf War? Or footage of Nebelwerfer firings? Yes, both. And Katyusha too. And I am frantically trying to remember if the Nebelwerfer fired the same way MLRS fires. The number of tubes per mount is different (duh ! ) so the amount of dust from the back blast is bound to be different in favour of the Neberlwerfer. What about the propellant burn out. IIRC both the Katyusha and the Nebelwerfer burned out the propellant at or very near the mount. Anyway, combined, these effects eliminate the surprise factor of rocket bombardments. In modern times, I agree. But I am not sure about WWII. They also paint HUGE arrows in the sky leading directly to the launchers. This is why individual rocket batteries usually can't do sustained bombardments. They have to immediately move a considerable distance from where they fired or they'll get smacked with counterbattery. To get a sustained rocket barrage, you either have to have total air and arty superiority so there's no counterbattery threat, or you have to have skads of batteries firing in sequence from different positions. Thinking in WWII terms here: The Germans could use sustained rocket barrages in the first half of the war. The Soviets could use sustained rocket barrages in the latter part of the war. In the West in 1944-45 the Germans could not use sustained barrages. Yet the Nebelwerfers seem to have rated quite high in the Allied hate/notoriety list. The Western armies did not use rocket arty in the same scale the Soviets and the Germans did during the war. After the war it took some time to get them to accept the rocket as a viable supplement to the field arty. I can make it sound like the rocket arty was just like the SMG to the Western Allies, undervalued and misjudged. Arty OTOH has a much lower signature. Shells leave no towering trails of smoke, nor do they look like gigantic tracer bullets. So that leaves the gun itself. And this is very, very difficult to spot even when firing, which is why armies have dedicated counterbattery observation units with highly sensitive and specialized equipment. I wonder why ? Jason has made it sound like the fall of the shell is as random as the fall of a dice.

Originally posted by JasonC: Deterministic is in contrast to statistical. You know this; don't play dumb. You started with the fancy footwork. Dance the jig out. The issue is whether each variable can be forecast exactly, or only within tolerance limits, giving only a statistical distribution as a prediction. The latter is the case, and the former is not. There is no way to state absolute certainties when statistics are involved. But you can work out the procedure so that you can forecast the results with acceptable accuracy. Take the statement The relative difference between standard deviation and propable deviation is r = 0,675 s. for example. Somebody must have done a lot of firing and statistics to find this consistency and correlation out. The fall of a die is deterministic physics, but the face that comes out upright is statistically random - indeed, is the basis of the idea of practical randomness to begin with. The wobble of a rocket after it leaves the tube is every bit as random as the fall of a die. Yes. However, to be able to calculate and verify the existence of a 50% zone there needs to be consistency. And the 50% zone is a zone where at least 50% of the shells/rockets land. The number can be anywhere up to 100% but the quaranteed number of hits in the zone is 50% of the shots/rockets fired. P.S. normally distributed and Gaussian mean exactly the same thing. By deviation effects I meant also propable deviation. P.P.S. no, claiming I "obviously" have no "practical" experience with artillery won't help your case. I was in the US field artillery, on 155mm and 8 inch self propelled. It does not help my case. But your adherence to the mathematical purity and seeming disbelief in the human mind and its ability to overcome or counter the established systematic effects of deviations made me think you never dabbled with the tools of the trade. Oh, and try telling the guys up front that every artillery friendly fire incident was their fault, and it was never the red-legs that screwed it up. Ever. I repeat: How many of those incidents were results of human errors on the FO's part (known also as "****ed up fire mission") rather than simple cases of shells flying in totally unexpected directions ? Granted, an individual gunlayer can make a mistake. Or an isolated case of mechanical malfunction. But for an entire battery to make a mistake that places the entire fire mission in a totally wrong place the mistake has to be either in the coordinates given by the FO or in the math of the direction/conversion team at the battery site. [ 11-28-2001: Message edited by: tero ]</p>

Originally posted by JasonC: First you want to make out every variable of the firing process to be deterministic and forecast. Which of the variables does not comply with the laws of propability ? If the variable complies with the laws of propability then it must have elements that can be determined and forecast. You can not control barrel wear but by monitoring it you can determine and forecast the shell flight path in all conditions. Any variable you can determine and forecast you can incoroprate into the firing solution. Then you need to bring in a backdoor concession, downplayed as much as possible, that actually the targeted area has to be larger for rockets. No. The firing method of the WWII rocket arty has not been revealed. What is the difference betwwen the number of rounds a rocket battery can deliver in 10 seconds compared with the number of rounds a tube arty battery can fire in the same time ? Round for round the tube arty is more accurate. But if both fire at exactly the same target area the rocket arty can, with the proper firing method, get the same results as a regular arty battery can, only faster. You try not to notice that the two contradict each other. I have not assumed bigger area for the rocket arty target. An area target is an area target is an area target. It is you guys who assume you can only target a larger target area with rockets. The rocket is an area weapon. But so is any field arty piece. The reality is that every term effecting the firing has not only a value but an error bar. Yes. But careful peparations, solid database on all the HW and associated variables and solid working methods the effect of the variables can be minimized. But not weeded out alltogether. Says so in my arty manual. The pretended value is really just a mean or expectation. The error bars are the practical reality. Yes. But is the first ranging shot fired a "virgin" without any regard to the known, determined, forecast and expected variable deviations ? The FO just gives a heading and range and the calculations are done according to where the round lands ? No battery site preparation is done, nothing. Each factor winds up more or less normally distributed about the mean expectation. Actually the Gauss curve applies to the deviation effects. The size of all the error bars multiplies out to one overall error bar, which is far larger than the bar for the ballistic properties of the gun system alone, since that is not the only factor with error involved. Sorry, lost me there completely. No, you cannot reduce all of these error bars to nothing by knowing things beforehand. But you can minimize their effect. When you try to hit a target you deliberately aim off according to how the known variables affect the equation. Each shot in actually different from all of the others, and where is lands is not deterministic beyond the placement of the error bars. Yes. But can you explain how you can take down a bridge with indirect fire with only one gun ? HINT: Luck has very little to do with it. As for the confusion about what the battery is really pointing at, it is really pointing at an *actual* aim point, which is distributed somewhere around the *intended* aim point because of the error bars of the FO and the spotting rounds. You obviously have no first hand experience with arty. There is no confusion. The firing method is a way to determine how the individual fall patterns overlap (or not as the case may be) and what kind of density is gotten as a result. What you are talking about is true. But a barrage is not just a bunch of individual shells flying willy nilly and impacting totally at random all over the place. As for the idea that there never is any significant difference between those, tell it to men who lost limbs to friendly fire. Hmmmmmm.... how many of those incidents were results of human errors on the FO's part (known also as "****ed up fire mission") rather than simple cases of shells flying in totally unexpected directions ? And the ballistic properties of the rockets themselves are far less accurate than tube artillery shells, as the original figures showed clearly enough. I am not contesting that. But being statistics the results are cumulative. "They are pointed in the same way" does not remove a lick of that extra dispersion. But "they pointed at the same spot" puts the center of the dispersion pattern in the same location for each mount, making that the epicenter of all 4 (or what not) mounts and their respective 50% zones. "They are pointed in the same way" disperses the 50% zones across the landscape. It occurs due to random variations in the actual flight of each rocket, as each wobbles about its fins, tosses this way and that, has a motor that burns for a slightly different length of time, facing in slightly different directions over the course of the burn due to the aforementioned wobble, etc. Yes. And you are wrong that accuracy (well below 50-100m that is) is the be-all of indirect artillery fire to begin with. You better contact the Finnish army in that case so you can correct the erroneous experience and doctrine. If the target is of an appropriate size (a battalion, a regiment, a division), the accuracy only has to exceed a threshold level, and all of the rest can be accomplished just by dumping in enough rounds and letting the random spread of the fall of shot do the rest. Making the fireworks a typical US Army display. Armies with less resources have to device more economical methods. Like concentrating all fire to a tighter area and hitting the enemey where it hurts, not making the entire scenery suffer for its transgressions. Missing a 10m grid square doesn't mean diddly when you are aiming at a battalion deployed over a square kilometer, and are throwing total numbers of shells with 3 or 4 digits. Which means most of your fire is ineffective if the battalion is concentrated to one or two key terrain locations. Which is what rockets were meant to do, and did. The idea that they are ineffective in CM is due entirely to people expecting to hit single platoons with them. Which would be a waste, because most of the blast thrown would do nothing. But it is equally true that the tightest sheaf and most accurate fire is a waste against large targets, because most of the blast again does nothing, because the center-point of the barrage is already dead. This is why most people call for limited round barrages. The way CM models barrages is totally unrealistic, if adequate. Did people sometimes use concentrations with that in view in the real deal? Of course. US field artillery sometimes fired 200 guns at a single spot in time on target shoots. From wide angles, up to a full semicircle (which results in a circular impact of overlapping "long-short" lines). But what were the targets of such industrial strength shoots? Not a platoon position, whole enemy-held villages. Some "point target". They certainly called them that, but they are nothing like what a point target means in CM - a single MG. Don't you wish you could break up a tight SMG force rush with a short, well timed and and concentrated arty barrage ?

A neat little coastal artillery game I found at http://www.susi.ysakk.fi/~aolpekmu/Coastgun/coastgun.htm

Originally posted by machineman: I see the Finns went to much greater lengths, adding concrete as well to the mantlet plus logs to the sides. Actually also the Germans and the Soviets used logs as an ad hoc ad on protection on the vehicle sides.

Originally posted by Jeff Duquette: I had considered mentioning this earlier, but thought it might be interesting to see where he went with this. Yeah, right. I then would have been on your case for getting all those X's on the zero width lines of Y meters lenght but not getting an X on the O. Let alone on the intersection of these two infinitely thin but long lines. [ 11-27-2001: Message edited by: tero ]</p>

Originally posted by Bullethead: There is no way to compensate for random inaccuracies, which is what rockets have. Increased weight of fire is one compensatory measure. A degree or 2 off at launch corresponds to dozens of meters off at the target. I doubt the tubes or rails allowed full degree deviations. And the shortness of the launch tube or rail gave it less chance to minimize this effect. IIRC the Nebelwerfer tube was as long as the round itself. The Katyusha rail is a few times the lenghth of the rocket. The Katyusha was also fin stabilized while the Nebelwerfer was not (IIRC). Which is why rockets have to have multiple launchers and/or submunition warheads to be effective--you need to shotgun the target area because they can't hit a point target. They are area weapons by design. Nope. First, regardless of quality, it's easier to obtain consistent burn conditions in a gun tube than a rocket. Not if the propellant itself is defective. Second, shell propellant can ONLY affect a shell's velocity, whereas imperfections in a rocket can affect both velocity and direction. True. But as I said the deviation in tube arty is more dramatic statistically speaking. Third, because arty is usually adjusted by an FO, any problems with the propellant will be taken into account before FFE begins. True. Yes really. There is no way to eliminate the inherent inaccuracies in rocketry to the same extent that you can in arty. Only if you are fire single rockets at point targets. When firing at area targets with sufficient amount of rockets the same basic rules apply to both tube arty and rockets. There is no surprise of targets involved with rockets. When the first rocket impacts you need to be in cover as they all will land within seconds in the general area. Rocket launches in the day make HUGE clouds and trails of smoke Which model where you subjected to ? and at night make bright flames in the sky. Then again so does regular arty. If the rocket propellant burns out in the tube then there is less flames in the sky. Also, if the terrain is not open steppes or desert then the horizon will mask most of the smoke and flames anyway. Incoming rockets also make much more noise for a longer time than shells do. How much longer ? All these factors give personnel at the target more time to react than they get with shells. Then you just have to duck for the 1 big impact because, unless multiple rocket batteries are firing in sequence, there won't be any more for some time. ÜberFinns at least disliked the Stalins Organs because they all impacted virtually simultaneously. They were less dangerous than regualr arty if you were in cover. And when used they were almost invariably used in greater numbers than the guys in the receiving end would have cared for. With arty, you never know when they'll stop shooting so need to say in cover longer. IIRC the Red Army used ploys like switching from regular arty to Katyushas (or vice versa) when their infantry was getting nearer the enemy positions so the enemy would keep their heads down that much longer. Plus, the rocket fire will be over a wide area, without fail. Arty can be fired in a variety of patterns. It could be you want all your firepower delivered more or less to the same point. You can do this with arty but you can't with rockets. I am not convinced. The rocket launchers can be pointed the same way a regular arty piece can. They can use the same firing methods the regular arty. To me it seems it is only a matter of dispersion and density and how you want to deploy it. Warts and all.

Originally posted by JasonC: Err, because it is a mathematical point, and thus has dimension zero, and thus has no area, and thus every shot falls at some distance from it, however infinitessimal. Well, in the metaphysical level even the shell impact point is a zero dimension entity with no area. Besides, the O's in his example represent lines of zero width but X meters lenght. The MPI is the intersection of these lines. Being a mathematical calculation the MPI can be said to be the origo in hex grid of the equation. Surely it can be calculated how many instances hit grid reference 0.0. Obviously, if you want to know about "direct hits" you have to define them such that they can occur. Which means specifying the size of the target. Misses from the point of aim smaller than half the size of the target directly hit the target - obviously. But there is no such animal as the "hit probability" for a mathematical point, without specifized size. I have never heard of an area target that was 0x0 meters. As for the idea that rockets can be "just as accurate" as rifled, tube artillery rounds "if you just know enough", that is simply false. You can know as much as you like about the statistics of the fall of shot, and the dispersion is still there. Are you sure ? Of course the dispersion is still there. Even I would pick a cannon over a rocket when trying to take out a single tank woth stitch fire from a single tube. But since it is field artillery we are discussing here and the area of the target is xxx meters by yyy meters and most errors are systematic there is no reason why a battery of rockets can not be made to hit the same target as a battery of howitzers. Sure, you can call howitzer fire on a point target more readily and more accurately. But there is absolutely no reason why a rocket battery can not be made to hit a wider target area just as accurately as a regular arty battery. The whole idea is to clobber an entire area. A target 1 km on a side is adequately hit by innaccurate rockets. Does anybody actually know which firing method the rocket artillery used in WWII: all mounts pointing at the target (each mount use a different bearing and the lines of fire intersect at the target point), mounts pointing at the target point by the section (each mount in the section points use the same bearing and the lines of fire of the sections intersect), all mounts in the battery pointing at the target zone using the same bearing (lines of fire of the individual mounts of the battery do not intersect). ? If they all cluster around the aim point, you gain nothing - to get good coverage you'd just have to widen the sheaf to make up for it. Which is what tube artillery does when firing such missions. Putting all the rounds on one point just wastes blast in overkill. Not in the überFinnish experience. In the summer of 1944 short, powerful, ACCURATE hits at point targets broke off many Red Army assaults when they were assembling. Spreading the fire around the landscape was a waste of resources. For one thing, because in indirect fire the battery is not actually aiming at the target to begin with. Where is it aiming then ? In CM, we place a point-target on a continuous map exactly where we want it, and then the shells fall in a distribution around that point. This is why I aim the fire off deliberately. That is not what actually happens. The FO has only an approximate sense of where the center of the distribution (the point of aim) is to start with, because he only sees a limited sample of spotting rounds, which are themselves randomly "disturbed" away from the actual point of aim. And he only estimates their distance from his chosen target, typically in 50m to 100m increments. Are you discussing RL or CM here ? Greater accuracy than that is not realistically possible with indirect, observed fire. Not true. The increment is usually 50 meters. But you can use smaller increments if need be. The gun laying appartuses are graduated so that this is possible. When a spotting round lands 100m beyond the target, it could have been because it landed in the left far quadrant of the oval of the firing gun's dispersion pattern, and the point of aim is already quite close. This is why you need to see spotting rounds fired by the entire battery, not just a single gun. When the entire battery fires the FO can see the dispersion pattern as well as the fall pattern and adjust the fire by the battery, not by the gun (which you can also do). Or it could be because the point of aim is 200 meters too long, and the particular spotting round landed 100m short. Highly unlikely. Possible human errors mostly associated with poorer quality crews that can cause errors of this magnitude include gun layer error in reading the dial, calculation error at the conversion table. Successive shots will reveal this. If the spotting rounds were from an entire battery and a single shot went this wild off the battery pattern then the human error is the most likely suspect. What you do is this: first you get the grouping for the whole battery as tight as possible and then all the guns are directed in unison. If care is taken the battery shot grouping should be tight to begin with. The spotter may think it actually landed 50m beyond the target, or 200m - all he sees is that the plume doesn't conceal the target from his view. Then he should not be an FO. Or he needs new glasses. Perfect spatial vision is one of of the prequisites an FO has to pass before becoming one. And of course, the line of sight to the target (where the FO's "side to side" error is smallest) is not the same line as the line of fire from gun to target (where the gun's "side to side" error is smallest). This is not a serious obstacle. If the army employing the FO knew its trade then the difference in the angles should be already taken into account. The individual gun's, the sampling error created by a few samples from the gun's (difference between battery aim point and fall of spotting rounds), The individual guns are all rated for accuracy. When the firing solution is calculated individual characteristics are calculated in. Systematic sampling errors should not occur if the gun log book is up to date. and an additional statistical dispersion from the FO's merely estimated "sensing" of the location of the shots, They do get training in it. and last small variations in where each gun in the battery is pointing, which can easily differ by a single "mil" (1/6400 of a circle), which can add ~10m of dispersion in both angle and distance. Again, parring gun layer error, if this kind of error creeps in the battery site preparation has been sloppy. All of those variations from a single direction just "add up" statistically into a wider fall of shot around the *intended* aim point. Which is what you try to minimize with careful preparations.

Originally posted by Jeff Duquette: Interesting. Please elaborate. I'll try. The specs on each caliber and gun are known. The barrel wear is known and monitored for each and every piece. The effect of athmospherics is known and monitored . The specs on specific charges are known and monitored. If a batch of propellant is known to be of outright uneven quality or of suspect quality it is known. Assuming of course proper storage at the front lines is and can be observed. Specific range to target you know, questimate or find out with ranging shots. The burn time of the propellant and any systematic deviations in it you know to get the shell flight time right. The shell flight time is known. Flight path deviation due to rotation of the shell in flight can be calculated in. Prevailing athmospherics you know (duh ! ) The shell fall pattern with which you hit the target point itself is determined by the firing method: all guns pointing at the target (each gun use a different bearing and the lines of fire intersect at the target point), guns pointing at the target point by the section (each gun in the section points use the same bearing and the lines of fire of the sections intersect), all guns in the battery pointing at the target zone using the same bearing (lines of fire of the individual guns of the battery do not intersect). The deviation between the target point elevation in relation to the barrel horizontal line is known and calculated in. This is known in Finnish as maastoviiva (terrain line) and maastokulma (terrain angle). I must point out that the WWII Finnish arty had developed this aspect further than most artillery arms by developing before the war a special camera for terrain elevation survey. The camera took two photos simultaneously, one from the terrain below and one from the horizon. Flying altitude was printed on the photo to get the terrain elevations in line with recce/survey photos from adjoining areas. This procedure is often remarked in sources as the entire country being preplotted. Not exactly true but IRL any "unknown" potential combat terrain could be mapped and surveyed for arty purposes within 48 hours, or faster depending on how up to speed the cartography service was. If there were existing recon/survey photos of the area the work went faster. An interesting detail: all existing cameras were ordered destroyed by the Soviets as a part of the peace treaty in 1944. Only one camera survives today. Questions ?

Originally posted by Bullethead: This is incorrect. May be. As I said it seems] the fall density and fall patterns are linked to the ordnance caliber. You just do not get the same density with the 155mm as you do with the 75mm, eventhough there is no RL reason for the densities to be different from each other. This has shown that caliber has no effect on pattern. IMO the density is what counts, not the pattern as such. Could you conduct the test with 150/155mm and 75mm respectively ? However, having neither a TRP nor an LOS greatly increases the size of the pattern. What about the caliber ? For rockets, none of this matters--you always get the same pattern. They are 150 - ~300mm caliber. Would it be an idea to test and compare them against the 14" naval arty (which is of comparable to the larger rockest) ? NOTE: this is just how CM handles this stuff. I'm not saying this is realistic Good. Rockets are fired from short tubes or rails, neither of which imposes anywhere near the consistency of trajectory that a gun tube does. Depends what is included in the "anywhere near" in consistency. I am sure some of the inherent inaccuracy was downplayed by deliberate "aiming off". Also, rocket motors don't burn as reliably as shell propellant. But any deviation or quality flaws in the shell propellant will affect the shell flight more dramatically than a they affect rockets. Statistically speaking. So it's physically impossible to shoot rockets as accurately as tube arty. Not really. What you need is consistent quality and constant/predictable variables. The rest is just vector physics, statistics, trigonometry and geometry. And lets not forget the fact that you can blanket a more wide area in seconds with a batter of rockets than you can with a batter of field guns. If you get the benefit or surprise you can do more damage with the rockets than a regular arty barrage. [ 11-26-2001: Message edited by: tero ]</p>

A weapons dispersion is determined by test firing. Yes. Finnish artillery test fired every piece to get individual data on each and every gun. As I recall British Coastal Artillerists were the first folks to start employing something along the lines of firing tables. Can you say when ? Surely you are familiar with firing tables. I am aware of their existence. I had thought artillerists that rely on “Kentucky-Windage” died away sometime during WWI. Not exactly. Even today when you are firing over open sights you may not have time or resources to do proper mathematical calculations. If it is laid out like US ARMY Artillery FM’s there should be a decent write-up on dispersion and exterior ballistics. I dug it up and it is all there. One passage states (my translation): "If propable deviation values are known you can in practise calculate hit propability with sufficient accuracy instead of using normal distribution (firing ?) tables. The use of normal distribution density function is more accurate however. The relative difference between standard deviation and propable deviation is r = 0,675 s. To calculate the desired hit propability of at least one shot you can calculate the number of required shots with the formula N = K / hit propability where N is the number of required shots " K is 1.0 for 63%, 2.3 for 90%, 3.0 for 95% and 4.6 for 99% hit propability is A / 2-SL1Sp where A is the area of the target, SL1 mean deflection deviation and Sp is mean range deviation. The formula is based on normal dispertion and is valid only if the center of impact is at the target and the dimensions of the target are small compared to the mean deviations." The formula gives the number of shots reguired to hit a 15m by 75 m vessel at 10 km's when the center of impact is at the bow of the vessel and the propable deviations are 1,5v annd 0,5% as 11 shots. The number of arial rockets required to hit a gun with a 4m vulnerable radius is 126 if the dive angle is 30º, firing distance is 1000 meters and the gun is clearly visible to the pilot. For a 63% hit propability you need 55 rockets. 50% of the rounds fall within the two X’s immediately adjacent to the “O” And none will fall on the O at all ? I don’t recall providing my reckoning on numbers of rounds that will hit the MPI. You did not. Why ? Your point on bringing this direct fire anecdote up eludes me. It is not a direct fire anecdote. The arithmetics is OK but armies did/do include all these deviations into their firing solutions by default. 100% zone for what specific weapon, firing what specific charge, and at what specific range? Any arty piece, any charge, any range. Sounds like your talking about a standard sheaf for a mortar platoon? No, a standard sheaf for any arty battery, or batteries. I'm talking about systematic error inherent in the fire from one gun. If the error is systematic how difficult is it to take it into account when calculating firing solutions ? I am talking about inherent systematic error of one gun firing at a specific range, using a specific charge. Again, if the error is systematic and all specs are known how difficult is it to take it into account when calculating firing solutions ? The "aiming" method is very important. It decides if the 50% zones are overlapping or not as it were.

Originally posted by Berlichtingen: Not really. Rocket is a rocket. What I was getting at ws that even with the Cobra's ability to directly aim the rockets, they flew all over the place. change that to less streamlined rockets and fire them indirectly and they are going to scatter even more AFAIK FFAR's are fin stabilized. They are also meant to be fired at LOS ranges. What is their max range ? Also, is there a diffrence in the MV of the FFAR and the Nebelwerfer rocket ?

Originally posted by Jeff Duquette: I dunno. Could be. I have some old US Naval Range and Ballistic Tables laying about here somewhere. From the late 30’s. As I recall they include firing tables for calibers up to 14” guns. Seems to me like the fall patters in CM are directly connected to the caliber. The bigger the caliber the wider the dispersion pattern. This could be…like I say I have not played with CM’s rocket artillery much. I am typically on the receiving end of it I usually pick a 81mm mortar over them. I am speaking purely in generalities and attempting to explain that WWII conventional artillery typically delivers a much tighter pattern of rounds than WWII rocket artillery. Yes. But both were after all area fire weapons for the most part and you could blanket a target are more effectively more rapidly with a rocket barrage than a conventional arty barrage. Generally speaking. I am less interested in the implications to specific wargames. Like I said above; "As to whether rockets are being accurately portrayed in any wargame, IMHO I think a wargame should reflect a tendency toward much larger dispersion zones for rocket barrages relative to more conventional artillery barrages". But should the rocket arty get handicapped because of them ? Even than I suspect I would want to hear what the designers intentions were or how they went about developing random dispersion patterns for artillery fire. One thing I seem to remember about them was something about preventing gamey use of arty as the main force. This really should not be an exercise in mumbo-jumbo. There can be no debate if the nomenclature is not explained and equalized. You should know that.

Originally posted by Jeff Duquette: Tero: I suspect the nomenclature is perhaps different in the Finish Army. Not really. I served in the coastal arty so the nomenclature is known to me. I just want to know the actual mean average and mean deviation, statistically speaking. How did you come up with the 50% zone ? Also, does the calculations apply to a single tube or a whole battery ? It basically defines a weapons shot pattern based purely on systematic error. Disregarding such quantifiable, non-athmospherical aspects as barrel wear. To the best of my knowlegde most, if not all (well, at least the Finnish army did/does), armies kept a log book on arty pieces so they could monitor barrel wear and alter firing solutions to match it and get better accuracy. Of the 50 rounds fired 25 will in theory fall on one side of the mean range line (short\under) and 25 will fall on the other side of the mean range line (long\over). Same deal with deflection error. Twenty-five rounds will fall to the right of the mean deflection line, and 25 will fall on the left of the mean deflection line. How many of them impact at the actual, absolute, target point ? By your reconing only 4 rounds come even close. 46 impact anywhere within the 50% zone BUT the target point proper. And the rest (50) outside it. Does not sound viable. I have seen a 4 gun battery hit a target the size of a rowing boat at 2000 meters with the fourth salvo. Field artillery works a bit differently, I know, but the idea is (as I understand it) to get the 100% zone as tight as possible. IIRC the Finnish arty used a square of 100x50 meters as the basis for its 100% zone at the battery level. The apex of the mean deflection line and the mean range line is the MPI: Mean Point of Impact....loosely speaking the MPI can sort of be thought of as the centroid of the target area you are trying to suppress or destroy. The actual shot pattern would trend toward an elongated elliptical shape. However a rectangular area is easier to quantify and I suppose close enough for HE work. It’s all based upon a normal distribution so I suppose if you were so inclined you could figure out the 2% zone if you really wanted to. What is the firing pattern you are assuming: all guns pointing at the target point, guns pointing at the target point by the section or guns pointing at the target zone by the battery ?

Originally posted by Jeff Duquette: WWII rockets had fairly large dispersal patterns relative to conventional artillery. In contrast the blast effect radius is wider. Incidentaly: is there any correlation in CM between the 14" naval arty shell fall pattern and the rocket fall pattern ? Here are the probable error numbers from a TFT for the 28cm Rocket Projector (Schwere Wurfgerat 40): Range = 600m…Deflection Probable Error = 10m…Range Probable Error = 80m...... What is the propability percentage of occurrances on these errors ? 50 % ? Or 100 % ? Being "propable" would mean that not all rounds fired go wildly off target. What is the firing sequence turnaround time for a mount ? 1 rocket per second ? Is there any correlation between a single rocket and a salvo, ie is the target point drifting due to mount deviation caused by recoil ? The normal artillery target rectangle base is 100meters for the whole battery. I do think the rocket arty in CM gets short changed (along with the rest of the trade). The fall pattern density is too weak and even the zones you describe do not seem to apply. You say the 50% zone is 120m x 60m. As things stand it would seem that 85% of the rockets fall outside this zone.

Von Heinrich sent this post to me: Hi I am really sorry, but I can't participate in the Nordic championships anymore. Today I got a new assignment at work that involves a great deal of travel. I won't be able to send files more that once a week, and I don't think that that is enough. It sucks, but that's life? Good luck and good hunting, Henrik This would mean our section is missing one body. [ 11-22-2001: Message edited by: tero ]</p>