WW2 mortars and artillery. Most important thing to "get right" in the CM2 series?

[SelfLoadingRifle]

Good point. I do know from experience that a shell-scrape is a different kettle of fish from a properly prepared and cammed up fire-trench, but then again, I am from a different era. More reading and research is required.

"Wait-Out."

SLR

[Michael Emrys]

A quick point; check out the many photos of Allied foxholes in Normandy. In all examples I have seen, there has been no attempt at all to use cam and concealment. The result of course, is that they stick out like the proverbial beer mat on a billiard table.

That's been on my mind as well. With hasty entrenchments, the soldiers usually just dump the spoil around the hole, and it does become quite visible at a distance. Undisciplined troops will be similarly careless even digging more elaborate trench systems. But every text I have seen on the subject has strongly advised scattering the spoil away from the hole or covering it with sod or other native vegetation. All this requires work, and weary soldiers might well skip this step unless their NCOs and officers stay on top of them.

Michael

[ArgusEye]

The US army performed some suppression research itself. One of those experiments involved a comparative look at suppression due to different types of artillery against men in kneeling foxholes:

[winkelried]

Did some testing with the following setup:

U.S. off-map light mortars (60mm) at each target with area 50m diameter, 3 tubes, medium fire, medium duration

Germans one Fusilier squad each, split into two teams 20m away from each other - 10 simulations.

1. in the open standing - losses between 80-100%
   
2. in the open hiding - losses between 80-100%
   
3. foxholes standing losses 10%-30% causalties when round exploding within 5-10 m outside the foxhole and soldier is observing else only direct hits / hiding losses only with direct hits. close hits <10m have no effect
   
4. trench standing 10%-20% as in foxholes / hiding basically the same as foxholes.
   
5. wooden bunker - occasionally one casualty but gets nervous etc pretty quickly with direct hits
   
6. concrete bunker - no causalties, no effect observed.
   

So i really can't see the issue with the 60mm mortar being an uber-weapon. Loss rate for troops in the open are no surprise to me when looking at the fire density you get. For troops in foxhole/trench direct hits are deadly - which isn't a surprise either, but when the troops are hiding, they are well protected.

[winkelried]

The US army performed some suppression research itself. One of those experiments involved a comparative look at suppression due to different types of artillery against men in kneeling foxholes:

Cool - which report is this?

[winkelried]

Ran another test - same setup as above, but linear target in variable distance from the target (squad). 0-48 m in 8 m steps, troops in the open.

0, to 24 m yield high losses due to dispersion of the fire.

32 to 48 smaller losses due to occasional long shots.

Casualties due to impacts within ca 14m and less.

another test with different terrain cover (no trees) yielded no significant difference between the terrain types.

[ArgusEye]

Cool - which report is this?

Combat Developments Experimentation Command '75-'78 suppression quantification report, citing results fromt the suppression experimentation data analysis report of April '76. AD:B10579L

Note that the machine gun numbers are for six-round bursts, as opposed to the artillery numbers referring to a single blast. Suppression was measured by seeing if a soldier could be distracted enough to lose track of a target he was supposed to follow in the distance.

Following these numbers, the same can be said for the 60mm what was already said for the 50mm. Not that great as a field piece, nice if you can drop one down an enemy foxhole.

[LongLeftFlank]

winkelried - thanks for testing. Time permitting, I may try to replicate your tests using 81mm instead of 60mm. Those are the bad boys that inflict most of the devastating results I've been seeing on dug-in troops.

[winkelried]

winkelried - thanks for testing. Time permitting, I may try to replicate your tests using 81mm instead of 60mm. Those are the bad boys that inflict most of the devastating results I've been seeing on dug-in troops.

which is pretty logical. The 81mm mortar delivers quite a bang. I did a quick test btw - not many samples. But it seems, that hiding troops in trenches and foxholes helps a lot against 81mm too. direct hits are devastating - this is pretty obvious, but even close hits won't harm troops hiding in trenches and foxholes too much.

[Jammersix]

I should think it is rather well-accepted. Is there any particular aspect you wish to hear about?

The main issue you raised I'm interested in is light mortars having "very little effect" against a dug in infantryman.

If you wish a citation, you could do worse than "A THEORETICAL DETERMINATION OF THE BEST HEIGHT OF BURST FOR V.T. FUZED MORTAR BOMBS" from the Byfleet Army Operational Research establishment.

Okay, I'll take a look at it, thank you.

[Jammersix]

If you wish a citation, you could do worse than "A THEORETICAL DETERMINATION OF THE BEST HEIGHT OF BURST FOR V.T. FUZED MORTAR BOMBS" from the Byfleet Army Operational Research establishment.

At first glance, after one rough reading (that is, without following up on any of the studies cited in the paper mentioned) it appears that this paper does not address any mortar bomb strike against a soldier in a foxhole at any height lower than one foot.

[LongLeftFlank]

which is pretty logical. The 81mm mortar delivers quite a bang. I did a quick test btw - not many samples. But it seems, that hiding troops in trenches and foxholes helps a lot against 81mm too. direct hits are devastating - this is pretty obvious, but even close hits won't harm troops hiding in trenches and foxholes too much.

But aye, there's the rub! Hiding isn't enough....

First of all, the AI does not cause its units to Hide (hunker down) in response to incoming fire, which in 1 player mode basically lets you blast them out of their holes using 81mm without needing direct hits. In WeGo mode, you must wait until the next Orders phase to Hide your units -- in the meantime they have to suck it up.

In addition, even if you do Hide your units from incoming, the TacAI will frequently self- cancel that order when enemy units are in the vicinity. In that case, your guys resume sitting upright in their holes in "fighting position", soaking up the shrapnel (unless they're Cowering).

That's why I suggested that a tweak that causes entrenched infantry to fight prone by default as opposed to "taking the knee" might largely address the problem without mucking about with the existing mortar ROF, accuracy or ballistics models, which seem well-thought out. I'd settle for them to Cower a lot more while being shelled, even if it meant they were shooting far less.

Again, the bottom line is that 81mm -- however much of a "buzz kill" it proved to be in forcing infantry attacks to go to ground -- should not exterminate dug-in infantry in concealment terrain with the rapidity and thoroughness it does in the game. If mortars truly had this kind of "Argus eye" (), frontline combat in both World Wars would have been very, very different.

[GreenAsJade]

Great research, recommendations.

Hope BFC pick it up...

[winkelried]

So to put it short the artillery seems to be modeled quite correctly its on the receiving end where we need improvement

• the TacAI needs some tweaking that the pixeltruppen keep their heads and butts down under artillery fire. They should put their heads up only between volleys and get into cover at incomings and not just after the impact.
  
• covered foxholes against treebursts etc would be nice.
  
• shelters without firing slit would be nice as would be basements.
  

[ArgusEye]

At first glance, after one rough reading (that is, without following up on any of the studies cited in the paper mentioned) it appears that this paper does not address any mortar bomb strike against a soldier in a foxhole at any height lower than one foot.

True.

But it adresses the angle of incidence of the shrapnel, and that is the main reason that foxholes work quite well against ground bursts.

Read up on the lessons learned documents from Vietnam. American patrols frequently come under attack from 60mm mortars, but very few casualties result. And this is not due to lack of precision, given the distances sometimes quoted.

[undead reindeer cavalry]

This is pretty amusing.

A half meter is about 20 inches.

Your statement means that someone one yard away is at more than 150% of effective range.

I suspect you misplaced at least one decimal point.

This type of statement is easy to make on the internet. So is the mistake.

It would be considerably harder to make five meters (more than TEN TIMES your claimed effective range) from an exploding light mortar round.

haha yes there's an error with my number. the official lethal area for 60mm grenade with impact fuze is still today 1 square feet against troops in open positions. i am sorry for enlarging the area to that with radius of 0.5 meters.

[undead reindeer cavalry]

But aye, there's the rub! Hiding isn't enough....

First of all, the AI does not cause its units to Hide (hunker down) in response to incoming fire, which in 1 player mode basically lets you blast them out of their holes using 81mm without needing direct hits. In WeGo mode, you must wait until the next Orders phase to Hide your units -- in the meantime they have to suck it up.

In addition, even if you do Hide your units from incoming, the TacAI will frequently self- cancel that order when enemy units are in the vicinity. In that case, your guys resume sitting upright in their holes in "fighting position", soaking up the shrapnel (unless they're Cowering).

That's why I suggested that a tweak that causes entrenched infantry to fight prone by default as opposed to "taking the knee" might largely address the problem without mucking about with the existing mortar ROF, accuracy or ballistics models, which seem well-thought out. I'd settle for them to Cower a lot more while being shelled, even if it meant they were shooting far less.

Again, the bottom line is that 81mm -- however much of a "buzz kill" it proved to be in forcing infantry attacks to go to ground -- should not exterminate dug-in infantry in concealment terrain with the rapidity and thoroughness it does in the game. If mortars truly had this kind of "Argus eye" (), frontline combat in both World Wars would have been very, very different.

yes, something like that. the 60mm round has 20-35 meter suppressive radius (i mean in reality, not in the game). combined with the 1 square foot killzone this makes 60mm round a suppressive weapon against enemy in foxholes.

btw 81mm has 5 square feet lethality area so we are still talking pretty much about direct hits against foxholes.

[undead reindeer cavalry]

• in the open standing - losses between 80-100%
  
• in the open hiding - losses between 80-100%
  

in theory being prone should reduce the effects considerably, as these rounds are all impact fuzed and the 60mm is highly sensitive to soft ground effects.

[Jammersix]

haha yes there's an error with my number. the official lethal area for 60mm grenade with impact fuze is still today 1 square feet against troops in open positions. i am sorry for enlarging the area to that with radius of 0.5 meters.

That's why people ask for citations.

[hoolaman]

Did some testing with the following setup:

U.S. off-map light mortars (60mm) at each target with area 50m diameter, 3 tubes, medium fire, medium duration

Germans one Fusilier squad each, split into two teams 20m away from each other - 10 simulations.

1. in the open standing - losses between 80-100%
   
2. in the open hiding - losses between 80-100%
   
3. foxholes standing losses 10%-30% causalties when round exploding within 5-10 m outside the foxhole and soldier is observing else only direct hits / hiding losses only with direct hits. close hits <10m have no effect
   
4. trench standing 10%-20% as in foxholes / hiding basically the same as foxholes.
   
5. wooden bunker - occasionally one casualty but gets nervous etc pretty quickly with direct hits
   
6. concrete bunker - no causalties, no effect observed.
   

So i really can't see the issue with the 60mm mortar being an uber-weapon. Loss rate for troops in the open are no surprise to me when looking at the fire density you get. For troops in foxhole/trench direct hits are deadly - which isn't a surprise either, but when the troops are hiding, they are well protected.

Thanks for doing this work winkelried. The 1.01 patch did attempt to address earlier problems with cover AND concealment in foxholes, I did quite a bit of testing to make sure it was so.

Of course I'm not saying its perfect now, the point about cowering more often is a good one, but I still think many people were so scared off from foxholes in the original release that their original impressions have stuck.

[sburke]

Thanks for doing this work winkelried. The 1.01 patch did attempt to address earlier problems with cover AND concealment in foxholes, I did quite a bit of testing to make sure it was so.

Of course I'm not saying its perfect now, the point about cowering more often is a good one, but I still think many people were so scared off from foxholes in the original release that their original impressions have stuck.

I am one of those. Between just not being sure how much protection I can expect and issues about getting LOF from a foxhole near hedgerows, I simply don't bother with them most of the time. That may change, but right now I am playing offense and will have to wait for my next defensive fight to try them again based on what folks seem to be finding.

+1 on the thank you to Winkelreid for all the testing.

[ArgusEye]

URC, I suspect you are confusing effective casualty radius and the density of fire rule-of-thumb to ensure neutralization of a position. Those are quite dissimilar things. It's not that puny.

By the way, my usual sources fail me in obtaining an issue from INFANTRY magazine, from 1990, more specifically an article in there: "The 60mm Mortar : how good is it?" by John M. Spiszer.

I also wonder if anyone has found a copy of D. Nathan and R. D. Webster, "A Fragmentation and Lethality Evaluation of the 60MM Mortar in the Fragmentation Material Program"?

[LongLeftFlank]

So it seems that after all this (intelligent and civil) discussion, all we really need here is a self-protective reflex to the infantry accompanied by the agonized howl INCOMING!!!!!!!!!

I'm sure Mord will be delighted to provide a suitable voice mod, for the Yanks at least!

Not sure what kind of bloody hack would be required to add this while doing the least violence to the engine.... Perhaps each indiect round has a silent(?) and invisible "pre-impact" that does no damage but triggers the appropriate "near miss" behaviour in nearby troops?

[winkelried]

So it seems that after all this (intelligent and civil) discussion, all we really need here is a self-protective reflex to the infantry accompanied by the agonized howl INCOMING!!!!!!!!!

I'm sure Mord will be delighted to provide a suitable voice mod, for the Yanks at least!

Not sure what kind of bloody hack would be required to add this while doing the least violence to the engine.... Perhaps each indiect round has a silent(?) and invisible "pre-impact" that does no damage but triggers the appropriate "near miss" behaviour in nearby troops?

+1 from me. I think the engine is almost there - you hear the screaming of the incoming rounds - at least for the big guns. then it's about how long the guys should hug the ground after a round has fallen until they raise their heads again.

[undead reindeer cavalry]

URC, I suspect you are confusing effective casualty radius and the density of fire rule-of-thumb to ensure neutralization of a position. Those are quite dissimilar things. It's not that puny.

i am aware of the difference between the two. the rules of thumb expect typical conditions in general sense (e.g. target troop concentrations).

the lethality area really is just that: 100% losses. it's not just neutralization.

the numbers do not make the 60mm or 81mm impact fuzed HE rounds puny at all. the 60mm has 140 square meter lethality area against standing men - everyone dies in two action spots as a result of a single 60mm round.