How accurate *is* CMBS?

[Michael Emrys]

Or as I have posted more than once, "It was a big war and just about anything you can imagine likely happened at one time or another. Doesn't mean that it happened more than once though."

Michael

[kipanderson]

Hi,

On ‎23‎/‎01‎/‎2018 at 9:22 PM, Vergeltungswaffe said:

To me the immersion is in taking it very slow. Giving your troops time to spot potential targets and then dealing with them in the sneakiest possible way.  Keeping casualties to an absolute minimum (in pbem or vs the AI) is satisfying imho.

Agreed ! 

In all versions of CM. 

All the best,

Kip.

[Michael Emrys]

On January 23, 2018 at 1:22 PM, Vergeltungswaffe said:

To me the immersion is in taking it very slow. Giving your troops time to spot potential targets and then dealing with them in the sneakiest possible way.  Keeping casualties to an absolute minimum (in pbem or vs the AI) is satisfying imho.

I'd go along with this too.

Michael

[IMHO]

On 2/7/2018 at 3:25 AM, Battlefront.com said:

Step two is to prove there's something to be concerned about.  Step three is to try and quantify what, if any, problem there is.  Step four is to try and isolate what factors may or may not have an influence on the outcome.  Step five is to propose a remedy.

CMBS setup

12 T-90As vs 12 spotters and 12 Paladins, firing Excaliburs. Three runs in three columns. Damage indicates only tracks damage as even direct hits are able to damage no module but tracks (though one can destroy the vehicle outright).

• destroyed 1 2 1
• immobilized 5 1 2
• red circle 1 0 1
• yellow circle 0 2 3
• yellow square 2 1 1
• no damage 3 6 4

Penetrations / Direct hits 1/3 2/3 1/3

Reality check source

Who Says Dumb Artillery Cannot Kill Armor by Maj. (Ret.) George A. Durham, Field Artillery Journal, Nov-Dec 2002, results of the four year US Army study for 155 HEs

Effect of a direct hit:

• Real-life: "A direct hit with an HE round with a PD fuze consistently destroyed the various target vehicle" - I assume they mean 100% destruction
• CM - 4/9 ~44% destruction

Effect of a near miss:

• Real-life: "155-mm rounds that impact within 30 meters cause considerable damage". I'd say from the context and photos by considerable they mean enough damage to take the tank out of battle though it may be available for further out-of-battle repairs. Out-of-battle repairs would be out of the CM context so they equal to total kills.

• CM:

  • The damage model provides for track damage only - no damage to gun, targeting etc. whatsoever. I didn't test with other vehicles but it may be CM engine models the damage only for penetrations. I.e. the engine first calculates whether the projectile is able to penetrate and IF it penetrated CM calculates the damage it may cause inside. It may be true for all the armour present in the game or it may be limited to ERA-equipped vehicles and/or tanks/heavy armour. Moreover I saw cases when a projectile hits ERA (text label) then it "goes though the tank", creates the crated and disabled the tracks.

  • Track-damage - approximate meters, except for 2-3 cases all craters were at the sides of the vehicle

    • 1-2m - immobilized

    • 3-4m - red circle / yellow circle / yellow square

    • 5-6m+ - no damage whatsoever

@Battlefront.com, does it qualify for a steps 2-3-4? To propose a remedy one has to know how the engine works inside. Or it will be wild dreaming.

[IMHO]

By the way, instant ATGM launch acquisition works for Javelin teams as well. But what's the real life story behind it? Javelin's regular CLU does not have a laser rangefinder to set off LWRs, Javelin launch is undetectable by Doppler radars at all reasonable launch ranges... So what's the magic that allows CMBS tanks to know they're fired upon when real life tanks do not know?

[IMHO]

Description:

A bit different setup to speed up testing - 100 experiments in five batches of 20 each:

• All tubes and spotters are Elite
• Fire mission is preplanned to the points where tanks are
• Mission effect is set to General, I assume it denotes something like Variable-Time vs. Point-Detonation, HE vs. HEFRAG

Results:

• Direct hits 3 4 10 6 7
• Module damage 1 0 4 0 1
• Knock-outs 1 2 6 4 3

Analysis:

• Unlike previous tests I had module damage here - weapons, smoke launchers, targeting etc.
• If direct hit does not result in the module damage then it resulted in severe tracks damage though ALWAYS a step or two short of total immobilization. I didn't count tracks as modules in the table so these cases are reflected in direct hits less module damage and knock-outs.
• Comparing to the 100% of severe damage from the direct hits as given in the Field Artillery article I gave above we'll have different results depending on what we count as severe damage in CMBS context:
  • If we equal knock-outs AND module damage AND severe tracks damage to "severe damage" then 100% of direct hits resulted in severe damage
  • If we count knock-outs AND module damage as severe damage then 22/30=73% of direct hits resulted in severe damage
  • If we use only knock-outs then we have only 53% of direct hits
• Since I used different experience level and point fire command instead of direct aiming the ratio of shots to direct hits is not comparable to the first data set.
• Near miss NEVER results in module damage - only tracks damage. I didn't do all distance measurements between tanks and points of impact in near misses but a rule of thumb is:
  • Light tracks damage starts at ~8m from the tank
  • Total immobilization requires 1-2-3 meters
  • In-between those two we have varying degrees of track damage

IMHO:

• All non-airburst direct hits from 155mm HE should result in total knock-outs - whether PD or delayed. Arguments:
  • All direct 155mm HE hits are named as lethal for tanks in "Who Says Dumb Artillery Cannot Kill Armor" by Maj. (Ret.) George A. Durham, Field Artillery Journal, Nov-Dec 2002
  • Even at 10 feet airburst for each M107 there are three fragment penetrations for 2" RHA plate. Source: Report on protection from fragments from HE ammunition by Aberdeen Proving Grounds of 1961. At point detonation there should tens of them with much higher energies. I figure even Abrams top of the nose should have multiple perforations save turret or engine compartment
  • Assorted Russian language sources:
    • Krasnopol 152/155mm HE testing. Krasnopol is a Russian equivalent of Excalibur
    • WWII tests of ML-20 152mm howitzer
• Near misses within 10/20/30m should result in total immobilization AND considerable module damage BUT NO crew casualties. Arguments:
  • Field Artillery Journal gives 30m as "considerable damage" distance
  • Russian 152mm HE damage tables give 20m as an equivalent distance
  • Judging from "Report on protection..." give 6-10m as the distance with enough fragments to penetrate 25-30mm RHA; tracks and wheels are not RHA but side/back tank armour is thicker

Edited February 10, 2018 by IMHO

[Kinophile]

Nice work! 

Can you upload/link to your testing scenario file? 

[IMHO]

31 minutes ago, kinophile said:

Nice work! 

Can you upload/link to your testing scenario file? 

Thanks! Here you go!

ztst_155HEvsT90.btt

ztst_155HEvsT90 0.bts

Edited February 10, 2018 by IMHO

[HerrTom]

2 hours ago, IMHO said:

• Near misses within 10/20/30m should result in total immobilization AND considerable module damage BUT NO crew casualties. Arguments:
  • Field Artillery Journal gives 30m as "considerable damage" distance
  • Russian 152mm HE damage tables give 20m as an equivalent distance
  • Judging from "Report on protection..." give 6-10m as the distance with enough fragments to penetrate 25-30mm RHA; tracks and wheels are not RHA but side/back tank armour is thicker

I'd contend that this point needs some slight change in wording - Near misses within 10/20/30m should sometimes result in total immobilization and/or considerable module damage.

From my investigations before the amount of damage and what gets hit will be highly variable - especially as you get further and further away.

Good work though, I love the data!

2 hours ago, IMHO said:

• Krasnopol 152/155mm HE testing. Krasnopol is a Russian equivalent of Excalibur
• WWII tests of ML-20 152mm howitzer

Do you have a link to these sources?  I'd love to take a look

 

 

[IMHO]

49 minutes ago, HerrTom said:

I'd contend that this point needs some slight change in wording - Near misses within 10/20/30m should sometimes result in total immobilization and/or considerable module damage.

You may well be right.There's some hard data in "Report on protection..." - they have the number of penetrations for M107 at 20 and 50 feet against different armour thickness. So it gives the number of fragments with different energy levels. Can be extra/interpolated.

49 minutes ago, HerrTom said:

Do you have a link to these sources?  I'd love to take a look

1. I've gone through good WWII-era ML-20 data but it was quite a time ago. They specifically tested HE and HEFRAGs against German armour. I don't remember where I took the reports. Most interesting were PzV and PzVI tests.
2. For Krasnopol/Excalibur there're some show-off vids against tank targets.

Overall it's also proved by Haiduk's Lostarmor pics. And here are the pics from the Field Artillery Journal.

Edited February 10, 2018 by IMHO

[c3k]

I don't think this game does an adequate job simulating non-kinetic effects behind armor. Meaning, it doesn't show when the tank gets its bell rung.

A massive HE hit ("massive" meaning a 6" shell or thereabouts) would have a huge effect on the various modules inside a tank. By "module" I mean computers, sights, hydraulic fittings, crew members, fuel lines, etc. Tanks are designed to resist a lot of flying metal and other effects. At a certain point, that resistance is overcome.

Solid-state circuitry, in hardened containers, on isolation mounts, go a long way towards adding to the resistance to shock. But, a big hit? Yeah.

The problem is twofold: first, show quantitative effects from real-world examples...which are provable and sourced; second, show how the game deviates from this.

It seems like some progress is being made towards the first. (The Ft. Sill tests and HerrTom's work). The second is also getting some gradual progress.

[IMHO]

@c3k, except the papers I've referred to I know of Danish Army Artillery School and Defence Research Service experiments. When I said

22 hours ago, IMHO said:

BUT NO crew casualties

I was referring to their results. They put M107 and BAE L15 155mm HE at 1-1.5m from a decommissioned Centurion hull and used accelerometers and barometers to measure the effects in multiple tests. The hull was not penetrated and the "crew" survived albeit with a temporary suppression. Everything on the outside was ripped off - read the damage to the modules was extensive. Though 1.0-1.5 is QUITE A NEAR miss so I didn't put the research as a source initially. There's an article about the experiments but it's quite scant unfortunately - http://www.patriotfiles.com/archive/danskpanser/Artikler/Destruerede_kampvogne_for_skud_igen.htm

2 hours ago, c3k said:

The second is also getting some gradual progress.

It would be interesting to hear from @Battlefront.com. I'm sure development pipeline is kept to its fullest as it always happens so it would be good to know Steve's thoughts.

PS And thoughts about BFC choice between "realism" and fun as well. I'll do some testing with instant detection of ATGM launchers but if they go the way I believe they will than this together with considerably higher damager from artillery barrages will take away a certain "dynamism" from the game. I believe the cost of rushing in armour will increase considerably and the game may end up looking the way real Syria, Yemeni wars are. Not like Rumsfeld doctrine and more like Israel deciding to back down from Lebanon due to high costs.

Edited February 11, 2018 by IMHO

[c3k]

47 minutes ago, IMHO said:

@c3k, except the papers I've referred to I know of Danish Army Artillery School and Defence Research Service experiments. When I said

I was referring to their results. They put M107 and BAE L15 155mm HE at 1-1.5m from a decommissioned Centurion hull and used accelerometers and barometers to measure the effects in multiple tests. The hull was not penetrated and the "crew" survived albeit with a temporary suppression. Everything on the outside was ripped off - read the damage to the modules was extensive. Though 1.0-1.5 is QUITE A NEAR miss so I didn't put the research as a source initially. There's an article about the experiments but it's quite scant unfortunately - http://www.patriotfiles.com/archive/danskpanser/Artikler/Destruerede_kampvogne_for_skud_igen.htm

It would be interesting to hear from @Battlefront.com. I'm sure development pipeline is kept to its fullest as it always happens so it would be good to know Steve's thoughts.

PS And thoughts about BFC choice between "realism" and fun as well. I'll do some testing with instant detection of ATGM launchers but if they go the way I believe they will than this together with considerably higher damager from artillery barrages will take away a certain "dynamism" from the game. I believe the cost of rushing in armour will increase considerably and the game may end up looking the way real Syria, Yemeni wars are. Not like Rumsfeld doctrine and more like Israel deciding to back down from Lebanon due to high costs.

My Danish is quite poor. Other than "Hans Christian Andersen", it is non-existent. I'm therefore limited to looking at the pictures of the Centurion and wondering about the cool vowels.

The pictures start with the tank missing its track. That prevents drawing any conclusions about track damage. I note the shell on the ground: is that where it was detonated?

The roadwheels and return rollers appear functional, post-detonation.

The only apparent damage is some sheet-metal panniers and storage bins being torn off...hardly "Everything on the outside was ripped off". Again, I'm just going by the two pictures.

Smoke Grenade launchers seem fine. The armored housings for sights seem fine. Barrel and fume extractor (which is thin metal) seem fine.

Without understanding the article, I cannot tell what it says about internal subsystem damage.

 

[IMHO]

@c3k, https://translate.google.com/ 

[IMHO]

Quick test of BMP-2 vs. Bradley M2

Test setup: 10 IFVs firing on 10 three storey buildings placed at ~390m. IFVs are veteran, normal motivation, no leadership bonus. IFVs fire for ten and fifteen seconds at the second storey each having 3 three-man breach teams hiding. Teams get immediately suppressed and stay put. IFVs don't have enough time to break the walls they are shooting on.

Conclusions - all IMO:

• CMBS RoF being lower than the technical RoF IRL is normal as this represents the effect of bursts. But 2A42 is 2.0/2.4 times slower than M242 by this parameter. IMO M242 RoF accurately represents actual RoF or even exceeds it whereas 2A42 looks unnaturally retarded. Higher barrel sway of 2A42 should not produce such a chilling effect at mere 390m to require such a degradation of RoF.
• A universal measure of lethality for HEFRAGs is Kg of ammo shot at the enemy per minute. Here every Kg of ammo delivered by 2A42 is only 78% as lethal as M242. To me that's hard to explain as both rounds are not a rocket science and were created at about the same time and technological level.
• At technical RoF 2A42 should be 2.6 time more lethal than M242 by Kg/min due to higher caliber and comparable RoF whereas it's represented in game as having similar or lower lethality. So for BMP-2 in short distance HEFRAG application instead of soft skinned vehicle with a immensely more powerful armament - something totally matching traditional Soviet doctrine - we have still a soft-skinned vehicle with inferior armament.

Please comment...

26.22%

Edited April 4, 2018 by IMHO

[kraze]

TBH after the 200+ : 0 outcome of that battle of US vs. russian troops in Syria this February I have to say CMBS is probably not accurate enough

[IMHO]

Which one? US decimating tribal/PMC raid party? Does "0 outcome" mean no US casualties?

Edited April 4, 2018 by IMHO

[c3k]

Weapon stability affects lethality/accuracy as well as ROF.  Ammo count affects ROF.

The 2A42 whips around quite a lot. The BMP sights are...not able to compensate. The M242 is far more stable, as is the sighting system. The ammo count available to each is very different: US philosophy is to provide enough ammo for multiple engagements. (Look at reloads for ships, tanks, IFVs, arty, etc. Abrams routinely carries 12,000 rounds of machinegun ammo.) Soviet/Russian philosophy seems to be enough ammo for one engagement. 

Just some random thoughts...

[Sgt.Squarehead]

Edited April 4, 2018 by Sgt.Squarehead

[IMHO]

2 hours ago, c3k said:

The 2A42 whips around quite a lot

2A42? Not 2A72?

2 hours ago, c3k said:

Weapon stability affects lethality/accuracy as well as ROF

1. We hit a vertical wall rather than a horizontal plane so we don't have the distance error magnification.
2. AFAIK for HE-I/HEFRAG the accuracy of M242 and 2A42 are comparable. It's APDS that makes M242 1.5-2.0 times as accurate. So for HEFRAG for a vertical wall we're talking about decimetres with lethality radius of 7m if I remember the latter correctly.

2 hours ago, c3k said:

The ammo count available to each is very different: US philosophy is to provide enough ammo for multiple engagements... Soviet/Russian philosophy seems to be enough ammo for one engagement. 

1. I don't know about the US philosophy but the Soviet one is exactly you've got as much ammo as you can and then you're on your own.
2. I really don't understand how it explains the 2A42 in-game parameters  

Edited April 4, 2018 by IMHO

[Rinaldi]

2 hours ago, Sgt.Squarehead said:

@kraze states a fact - a unit using Russian equipment and doctrines got their ass whooped worse than I did as a kid for giving my mom lip, and you call him a troll. I'm sensing a disturbing pattern of 'hear no evil' with you when it comes to uncomfortable truths.  The alleged reaction to the leak is also eyebrow raising if it was 'mere disinformation' from the West.

Normally I'd say this is all off-topic - except its not. In addition to a subtle race going on between the two sides technologically to upgrade current systems, there's a doctrinal race happening as we speak: look no further than the ARMOR article I posted a few days ago. Its all well and good to show how the material they use performs but its equally valid discussion to show how Russian and US aligned countries use these materials to fight. Someone explores this and gets dismissed out of hand, poor show.

Edited April 4, 2018 by Rinaldi

[IMHO]

@Rinaldi, I believe that case is kind of irrelevant. Here we have a fully controlled lab experiment where CMBS demonstrates behaviour that differs from the verifiable real life to the tune of over a hundred if not two hundred percent. Certainly a margin this wide can explain a general sentiment about CMBS that RUS forces are considered unplayable agains US

PS I didn't test by I believe UKR BMP-2 results could be even more... Remarkable...

Edited April 4, 2018 by IMHO

[A Canadian Cat]

15 minutes ago, Rinaldi said:

@kraze states a fact - a unit using Russian equipment and doctrines got their ass whooped worse than I did as a kid for giving my mom lip, and you call him a troll. I'm sensing a disturbing pattern of 'hear no evil' with you when it comes to uncomfortable truths.  The alleged reaction to the leak is also eyebrow raising if it was 'mere disinformation' from the West.

Yes, but the incident in question here was artillery and possibly air support vs a mechanized force with no AD. So, the relative capabilities of the IFV's guns was not a factor and therefore not relevant to this thread. Assuming of course we are talking here about the attack by Russian forces on a base where US advisors were stationed in Nothern Syria. Let me know if I have that wrong.

[Sgt.Squarehead]

37 minutes ago, Rinaldi said:

a fact - a unit using Russian equipment and doctrines got their ass whooped worse than I did as a kid for giving my mom lip, and you call him a troll. I'm sensing a disturbing pattern of 'hear no evil' with you when it comes to uncomfortable truths.

The facts surrounding the event are rather more complex than you imply.....Either you know that and you are taking the ****, or you don't know it and you should.  Suffice it to say that were the Russians to pull the same sort of dirty trick on the SDF, or other US backed forces, the world would never hear the end of it.

[sid_burn]

21 minutes ago, IMHO said:

@Rinaldi, I believe that case is kind of irrelevant. Here we have a fully controlled lab experiment where CMBS demonstrates behaviour that differs from the verifiable real life to the tune of over a hundred if not two hundred percent. Certainly a margin this wide can explain a general sentiment about CMBS that RUS forces are considered unplayable agains US

Anyone who truly believes Russian forces are considered unplayable against the US needs to take a long hard look at whether it’s the game or whether they are just not as good as they think they are.