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Still disliking Artillery


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The amendment is friendly. I based the comment on the scale of one map in Fall. If the full position is more like 2 miles on a side, fine. (Some of that is just empty space to the outliers of Huguette, however).

There was also a satellite position miles away to the south, where the 155s lived, but it wasn't the object of the main Viet Minh attacks, and I thus wouldn't count it as part of the position.

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As for no one really disagreeing, bully, and that was the reason I paused before continuing to see whether that was accepted. (Some might resisting drawing any conclusions about tactical matters from that larger scale, operational-period history, but if we don't have to have that argument, so much the better).

Next question - what is the typical lethality per shell seen in games of CMBN today? Start with the figure for 105mm artillery firing indirect. Then let's get a figure for 81mm on map fire. Targets in field fortifications as one data point to collect, targets in typical terrain cover without the benefit of field works as additional data points. We want to know the ratio of shells fired to men directly made casualties. Is it 25 to 1, 10 to 1, 5 to 1? Let's get a handle on the scale of the issue and whether it is present for the indirect FOs or only for on-map mortar fire.

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Ubique

Rudyard Kipling

There is a word you often see, pronounce it as you may –

“You bike,” “you bykwee,” “ubbikwee” – alludin’ to R. A.

It serves ‘Orse, Field, an’ Garrison as motto for a crest;

An’ when you’ve found out all it means I’ll tell you ‘alf the rest.

Ubique means the long-range Krupp be’ind the long-range ‘ill –

Ubique means you’ll pick it up an’, while you do, stand still.

Ubique means you’ve caught the flash an’ timed it by the sound.

Ubique means five gunners’ ‘ash before you’ve loosed a round.

Ubique means Blue Fuse, an’ make the ‘ole to sink the trail.

Ubique means stand up an’ take the Mauser’s ‘alf-mile ‘ail.

Ubique means the crazy team not God nor man can ‘old.

Ubique means that ‘orse’s scream which turns your innards cold!

Ubique means “Bank, ‘Olborn, Bank – a penny all the way” –

The soothin’, jingle-bump-an’-clank from day to peaceful day.

Ubique means “They’ve caught De Wet, an’ now we shan’t be long.”

Ubique means “I much regret, the beggar’s goin’ strong!”

Ubique means the tearin’ drift where, breach-block jammed with mud,

The khaki muzzles duck an’ lift across the khaki flood.

Ubique means the dancing plain that changes rocks to Boers.

Ubique means mirage again an’ shellin’ all outdoors.

Ubique means “Entrain at once for Grootdefeatfontein.”

Ubique means “Of-load your guns” – at midnight in the rain!

Ubique means “More mounted men. Return all guns to store.”

Ubique means the R.A.M.R. Infantillery Corps.

Ubique means that warnin’ grunt the perished linesman knows,

When o’er ‘is strung an’ sufferin’ front the shrapnel sprays ‘is foes;

An’ as their firin’ dies away the ‘usky whisper runs

From lips that ‘aven’t drunk all day: “The Guns! Thank Gawd, the Guns!”

Extreme, depressed, point-blank or short, end-first or any’ow,

From Colesberg Kop to Quagga’s Poort – from Ninety-Nine till now –

By what I’ve ‘eard the others tell an’ I in spots ‘ave seen,

There’s nothin’ this side ‘Eaven or ‘Ell Ubique doesn’t mean!

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My experience gained from CMX1 was that the smaller the map the more potent a threat artillery was. Playing on larger maps neutrailised its effects as the opponent was pickier, had to be pickier, on using it.

I felt very annoyed/sickened that when first playing CMBN on its launched all thos bloody stupid scenarios with fleeing infantry bouncing off invisible walls around the battlefield and running back into the barrage. Stupidest bloody thing I have ever seen in a claimed realistic game.

Salts derived War Office reports has plenty on artillery effectiveness and various cover divisors. It almost seems we inherited a CMSF artillery mod.

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JasonC:

Next question - what is the typical lethality per shell seen in games of CMBN today? Start with the figure for 105mm artillery firing indirect. Then let's get a figure for 81mm on map fire. Targets in field fortifications as one data point to collect, targets in typical terrain cover without the benefit of field works as additional data points. We want to know the ratio of shells fired to men directly made casualties. Is it 25 to 1, 10 to 1, 5 to 1? Let's get a handle on the scale of the issue and whether it is present for the indirect FOs or only for on-map mortar fire.

And when we have that info then it can be cross-referenced to what the War Department thought. Incidentally from other places ;;

Broadly, if guns fire with their barrels parallel, then their fall of shot will reflect the layout of the guns on the battery position. As already described straight line gun positions were the norm for much of the first half of the 20th century and lasted until the late 1950's when the two troop (8 gun) battery was replaced by 6 guns. This introduced battery centre instead of the pivot gun as the basis for the battery’s firing data and with it the inverted double chevron layout for the guns. This gave depth and a more circular pattern to a battery’s fall of shot when guns fired parallel at the same range. Of course the terrain often dictated something else, for example a gun line along the edge of a wood.

Made me wonder if too much modern practice had tinged the artillery model.

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Again the question: can someone name a scenario that can be tested?

For example: a company of grenadiers in foxholes spread in an area 100x100m against 100 shells of 105mm artillery - what is the expected number of killed/wounded?

We can discuss here all day about what we feel is over-/under-/wrongly modelled. If we want BFC to change something we need real world data and test the game against it. I'm no grog but I will do the testing. I also have the feeling that artillery is a bit too effective here.

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poesel71 - no, don't stuff a full company into a 100x100 meter square, that is way too dense a target to be representative. More like one platoon in that much area. Not using all of it, clumped here and there within it, to be sure, but every unit in the platoon contained within a box of that size.

Then put a single 105mm FO fire mission directly on the densest clump within the platoon - to target just as a human would in CMBN. (A big part of any overperformance likely stems from that perfect target selection, and the true aim point nearly always being right on the intended aim point).

Case one, the platoon are in foxholes. Case two, they are behind hedgerows or in light buildings or a mix of such things, but tactical cover such as they would be using in a firefight against enemy infantry, not meant to be specialized against artillery fire. And with a spade having been involved in creating said cover.

Then, case three, same target as in one including the foxholes, but the shooters are 2 81mm mortars firing direct. Case four, same target as it two, but the shooter are against 2 81mm mortars firing direct.

Report firing time, rounds expended, and men directly made casualties. Ending morale states of the platoon would also be useful, as portion of the survivors in red morale states, for example. (They should be regulars and led, but with no bonuses, lest that skew the base result too much).

Ideally each trial should be repeated 10 times, reporting the mean result for men hit and red morale, and a standard deviation, high and low result across the 10 trials for each of the four cases, would be useful additions.

So now we have a complete spec and just need the tests actually run...

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jason - ok, let's be a bit more specific

Platoon: US rifle troop has three troops with 12 men plus 3 men HQ - 39 total. Split or unsplit?

Deployment:

Foxholes: line or double-line or W? What would be typical?

Urban: do you have a map in mind? If not I would take one of the small vilages.

Fire mission:

On second thought 100x100m is a bad idea since we have circular target areas. So it will be an area target with 110m diameter.

How many shells of 105 and 81? With or without TRP?

Finally: most important question:

What is the expected outcome of this? What happened in real life to these 39 men in foxholes/buildings? Because at the end of this test we will have some new data point but without some (more or less) agreed outcome to compare it to its useless.

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jason - ok, let's be a bit more specific

Platoon: US rifle troop has three troops with 12 men plus 3 men HQ - 39 total. Split or unsplit?

If you're going to be having them in cover like foxholes and buildings, you pretty much have to split them or design the cover to accommodate entire squads without any "dangling".

Fire mission:

On second thought 100x100m is a bad idea since we have circular target areas. So it will be an area target with 110m diameter.

How many shells of 105 and 81? With or without TRP?

I think it would be useful to have a mission of 81mms firing indirect, either off or on-map, or possibly both, to compare things to. Not sure what comparing off-map 105s with on-map 81s tells us. I've been doing some scatter pattern tests with 81mm mortars, to compare the dispersion at different experience levels; so far the better troops keep the "box" a bit narrower than the conscripts, but their ranging is hardly different at all. The experience level shows mostly in speed of finding the range, and RoF. But the pattern isn't anywhere near wide enough to just set up an area fire mission on a 100m frontage and expect the scatter to cover it with two mortars; you'd need at least 3 (which is handy, cos that's how many an American Armoured Infantry Support Company has :) ).

Finally: most important question:

What is the expected outcome of this? What happened in real life to these 39 men in foxholes/buildings? Because at the end of this test we will have some new data point but without some (more or less) agreed outcome to compare it to its useless.

At least it provides some comparison between different modes of artillery.

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LongLeftFlank,

Haven't seen that Dien Bien Phu map since I read HELL IN A VERY SMALL PLACE while in high school. Dad got me into reading Bernard Fall, and I've never regretted it. How the Viet Minh got their guns into position to shell Dien Bien Phu is quite a story in itself.

JasonC,

I think your question regarding lethality per shell is spot on and a very good start.

dieseltaylor,

What you say makes perfect sense, since the artillery footprint becomes an ever greater fraction of the total map, greatly increasing the likelihood of being hit and simultaneously constraining both deployment and maneuver options. I think the only rational solution is to scale down the artillery in such situations. Otherwise, artillery becomes entirely too dominant.

Regards,

John Kettler

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poesel:

The War Office documents that J D salt extracted data from would prove useful in setting up the tests as you may be able to get an approximation for your test design and what you are actually comparing. It is not perfect and I would hope that someone can direct you to US WW2 tests.

There is a link somewhere on this or the Brixia thread I believe or someone may have it to hand.

For kick-offs one test for the 3" mortar said a point target was a 0.06 chance of a hit per shell .... therefore 70% destruction chance for 20 shells.

Another WO document is on 81 targets in an area 150 x 100 yards and using 25pdrs, sa 105mm and a 75mm.

http://mr-home.staff.shef.ac.uk/hobbies/ww2eff2.pdf

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Just for giggles

1 US plt, all in foxholes and HIDDEN with a 115m area target over the plt.

vs 1x 105mm btty (Wespe) - offmap

The 105's fired themselves empty over some 8-9 minutes - 96 shells

Plt HQ 2x killed

1st Sqd 2x killed, 1x yellow wound

2nd sqd, 1x yellow wound

3rd sqd, 1x yellow wound

all units cautious at the end of the barrage.

Interestingly the last 2 shells to fall each caused a casualty, and so until that point the plt had only suffered 2 deaths. A

The end of games states showed

35 men ok

2 men killed

2 men wounded

P

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Very interesting would be in the open. This below suggests a hit rate differential and I suspect a 105mm is more lethal.

"Neutralising effect, in NW Europe, on an enemy in open positions, was achieved with a bombardment intensity of 0.02–0.08 lb/sq yd/hr. in 25-pdr equivalents.

Lethal effect: A density of 0.1 lb/sq yd causes 2% casualties on targets in slit trenches, about 20% on targets in the open."

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Just for giggles

1 US plt, all in foxholes and HIDDEN with a 115m area target over the plt.

vs 1x 105mm btty (Wespe) - offmap

The 105's fired themselves empty over some 8-9 minutes - 96 shells

Plt HQ 2x killed

1st Sqd 2x killed, 1x yellow wound

2nd sqd, 1x yellow wound

3rd sqd, 1x yellow wound

all units cautious at the end of the barrage.

Interestingly the last 2 shells to fall each caused a casualty, and so until that point the plt had only suffered 2 deaths. A

The end of games states showed

35 men ok

2 men killed

2 men wounded

P

This is what I would like to see, because I believe it to be realistic. 105 bttry with a minimum 115 area target? Sounds goood. Experience should affect how correctly the barrage actually corresponded to the aim point, but not the dispersion--because the dispersion was largely on purpose.

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One of the concepts yet to be discussed is the MPI (Mean Point of Impact). This is the region in which most of the projectiles fired at a given charge and elevation will fall. The best of all possible worlds for someone conducting a shoot is for the planned aimpoint, the DMPI (Desired Mean Point of Impact) to coincide, but real shoots don't work that way. The combination of all the degradation factors, what's called the error budget, tends to move the MPI away from the DMPI. To use a more common example from rifle or pistol shooting, there's where you aim and where the bullets hit.

Let's say we remove many of the error sources from the equation by taking a rifle and clamping it firmly atop a bench rest. Further, we'll use only ammunition of the same type and the same Lot Number. Let's further specify that the air is still, the temperature constant and lighting consistent throughout the firing of 100 rounds. Even with these strong measures in place, the grouping will tend not to hit the center of the target. It may be, for example, high and left. The DMPI is the center of the bulleye; the MPI is the center of the primary group of shots. Zeroing is designed to adjust the MPI, as much as possible, onto the DMPI.

The link, taken from Army FM 6-20 Artillery, describes, quite thoroughly, the concept of the MPI and shows it follows definite statistical laws.

http://www.globalsecurity.org/military/library/policy/army/fm/6-40/Ch3.htm

What and FO/FOO does is make an initial call for fire, observe where the spotting round lands, then adjust to the DMPI before switching to (FFE) Fire For Effect. Because artillery is not precise in range (shown in diagrams at link), this is a bit haphazard and has real limits, which is why when a 100 meter bracket is obtained, only then is FFE ordered. Given proper orientation between the target and the axis of fire, the statistical spread will distribute fire in front of, on, and past the DMPI, ensuring reasonable coverage. At the same time, accuracy in terms of lateral positioning (deflection error) will keep the impacts vey close to their desired axis. Thus, decent range estimate, proper axis of fire, proper computations at FDC or weapon itself, right munition and density of fire = desired terminal effect. That's IF all those things are right. Many important factors are known (gun history, temperature, bore wear, repairs, if any, statistical performance of the ammunition and so on), but the single biggest problems are VE (Velocity Error) and the least controllable error of all MET (Meteorological Conditions). Every weapon is going to experience variations in velocity, and I read in a study conducted at the National Training Center by RAND that variation within a mortar section was as much as 4 meters/second. But the killer is the weather data, without which artillery and mortars have a big problem. Depending on wind direction, wind force, air temperature and density, weather can shift the MPI, sometimes, with disastrous results. Master Gunner Ian Hogg says that during the Korean War, in the high, cold windy mountains, false ranges well beyond the actual had to be used in order to simply get the rounds to the target. So, if MET data are available, they can be factored in. But who probably doesn't have it? Mortars firing in direct lay! And which weapon is more affected by MET conditions, field artillery or mortars? Mortars!

We've already established that there is velocity variation in mortar firing (NTC data were for the M107 4.2" mortar), but we haven't discussed the significant difference MET plays in mortar accuracy as opposed to field artillery. MET data, or the absence thereof, are highly significant for mortar effectiveness because of two factors, lower muzzle velocity for a given bore size, thus, more time to influence the projectile's trajectory, and higher max ordinate (top of trajectory), thus exposing the mortar projectile to more potential wind variations, variations unlikely to have been compensated for. Also, most mortar rounds have fins, introducing the potential for what's called weathercocking in which a finned projectile in flight tends to turn into the wind.

The above means that that fearsome fowl, the mortar firing in direct lay, is inherently less accurate than one firing with an FDC or similar in the loop. This is true because the mortar firing in direct lay is almost certainly missing the MET data and also likely lacks the VE data as well.

If BFC can figure out some way to depict the above, then this, particularly in conjunction with some better depiction of cover modeling (WO data a good start), troop behavior under fire and maybe modified saves for different cover types, should tame the direct lay mortar beast.

While we're on cover, please note that mortar effectiveness drops far more slowly than does field artillery as cover increases. This is the direct result of the mortar's higher trajectory, which allows targets to be hit which are otherwise somewhat masked by terrain. In the WO excerpts John Salt compiled, there is a table showing the results of field tests on this very subject. I believe they compared the 25-pounder to the 3-inch mortar. This seems to me to be a good check for BFC of what's under the hood in CMx2 vis a vis real world data.

Regards,

John Kettler

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While out walking moments ago, I had some more thoughts about fire support modeling.

Returning to the direct lay mortar problem, I feel I should note the direct lay mortar has a perfectly legitimate responsiveness advantage over the same weapon, at the same elevation and charge, which is fired in indirect lay.

Nor does the direct lay mortar gunner have to worry about orientation relative to the GTL (Gun Target Line) or axis of fire, being its origin, thus not having to consider offset angles. With the target under direct observation, there is less likelihood of inducing more MPI error while moving the MPI to the DMPI. Adding an FO/FOO to the mix, plus an FDC (Fire Direction Center) only increases the potential error budget.

Summing up, I believe a mortar firing in direct lay should be both more responsive and quicker in adjustment (very nearly the projectile TOF (Time Of Flight, as seen in several vids)) than the same mortar, with everything the same, in indirect lay, and under FO/FOO control or similar. I do NOT believe any mortar using a TRP should be able to displace during the game and still use the TRP. That's simply ridiculous because registration fires have to first be conducted to establish a TRP in the first place. Nor do I believe that targets being fired at by a mortar in direct lay should be subject to FFE unless on or close to a TRP, without the use of spotting rounds to adjust fire.

Regards,

John Kettler

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Just checking: I thought it _is_ the case that you can't use a TRP if you move? Or is that something we lost coming to CMx2?

I got curious and decided to run a quick test. Turns out that mortars cannot target a TRP outside of LOS for indirect fire without an FO like they could in CMx1 (IIRC). However, FOs can call indirect fire onto TRPs outside of LOS after they have moved, and use on-board mortars that have also moved.

I don't know about direct fire weapon accuracy near TRPs.

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Pete - a potentially useful but somewhat confusing report.

Were there 4 men killed and 3 men wounded, or 2 men killed and 2 men wounded?

We don't actually want the men on "hide", but normal heads up until the shells make them duck.

And next would be a test without foxholes, but using linear cover - hedgerows, next to buildings looking around a corner, next to a wall, a variety for the platoon's units, each a typical combat form of cover for a maneuvering force.

Also, as mentioned, we need a sample not one run-through, like 10 times with each set of conditions. Otherwise anecdote and variance like that you noted in your late shells, is all we are learning about - that it can happen sometimes, I mean. Which we already knew.

But thanks for running the test - getting there...

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