Visceral Impact Studios | 12 Dec 2015 7:45 a.m. PST |
Several threads popped up recently about modeling armor penetration in recreational tabletop wargames (note, that's recreational tabletop wargames…the opposite end of the spectrum in computational time and resources from, say, a DoD computer simulation). Many comments have focused on very, very simple calculation of armor thickness divided by a given value to derive an in-game value. Or whether or not a given warhead type (e.g. LAW heat) can penetrate a given tank (e.g. T-72A). Missing from all of these discussions are crucial topics such as armor slope, material composition, and, most importantly, how tanks are actually built and what constitutes a "kill" in a tactical context for tabletop gaming purposes! Let's start with that last item first. Most gamers and many game designers focus on stuff like "Sherman 75mm shell vs side of Tiger I tank: can it penetrate?" That's the wrong question if building a model that functions in an entertaining fashion for tabletop gaming. First off, looking only at "penetration" is bonkers. Tanks can be rendered tactically combat ineffective by non-penetrating hits. These can range from heavy rounds that cause casualty inducing spalling on the tank's interior surfaces to weapons and mobility kills that cause the tank crew to bail out. What everyone seems to forget is that an AFV is only as effective as the gooey meat-bags inside it. Mess with the meat bags and the armor doesn't matter. Even the best modern MRAPs can "survive" a huge IED blast directly under the vehicle. But the guys inside, while surviving, will be completely combat ineffective with broken bones, concussions, and even internal bleeding and organ/soft tissue damage. And in WWII, American 57mm anti-tank gun crews targeted German tank tracks to immobilize the tank and then call in air and arty on top. Knowing what was coming their way, the tank crews bailed out. In addition to the meat bags being vulnerable even in the absence of a penetration, the tank itself has many bits that simply can't be armored and whose destruction can render an AFV combat ineffective. Even messing with the internal combustion engine's ability to access clean air can disable an AFV! And the vents needed to allow an AFV to breathe are vulnerable as are it's tracks, weapons, etc. So what matters most is NOT guns vs armor PENETRATION but: WEAPON VS VEHICLE COMBAT EFFECTIVENESS. And here we'r talking about many shades of gray from temporary disablement to total combat ineffectiveness with combat effectiveness linked to, but not totally dependent on, an AFV's physical state. That means, for recreational tabletop wargame purposes, a system should conveniently represent anything from an AFV being rendered temporarily combat ineffective to totally combat ineffective due to a critical hit to catastrophic physical destruction. You'll notice that the last two have the same tactical result (AFV is combat ineffective) but different physical result (with the former the AFV can look essentially intact while the latter is a flaming wreck). That also means when analyzing a game system one must be very careful comparing only isolated penetration data points of multiple, inconsistent test parameters. |
Mobius | 12 Dec 2015 7:57 a.m. PST |
Well you are right that there is more to killing and AFV than penetration of its armor. But there is a problem in ruling an AFV as 'killed' when it is no longer combat effective. That is when there is a unit morale system in the game. There are cases where the unit commanders tank is damaged and no longer able to move or fire but the commander still directs his subordinate tanks. So the tank isn't killed when it comes to unit cohesiveness. |
Wolfhag | 12 Dec 2015 8:46 a.m. PST |
I'm trying out an app called Armor Inspector: link This seems to do a pretty good job of determining compound armor values and gives crew and systems locations behind the armor that can damaged/destroyed. You can adjust the image to fit any target angle or aspect. It's little bit of a hassle using an electronic device but better than accessing various charts and doing calculations. It also eliminates a lot of die rolling. Damage is determined by a die roll modified by the weight of the shell (not all shell sizes have the same weight). APCR rounds are lighter and will cause less damage. APHE rounds have a better chance of starting a fire or causing an explosion but are only effective if full penetration occurs. HEAT rounds have a damage modifier of +1 for every 10mm of over penetration and cannot cause spall damage on partial penetrations. I also have a nomograph to show how successful penetration is against armor to cause damage. The more over penetration the greater the damage. Partial penetrations can cause spall damage to crew and components inside tank. Depending on the size of a bursting charge and armor HE shells can cause damage components or daze the crew adding additional time for them to fire. I have not done any morale rules yet. Wolfhag |
tbeard1999 | 12 Dec 2015 9:22 a.m. PST |
I generally agree with the points made. In addition, when assigning armor and penetration values, a logarithmic equation works better than a linear "X mm of armor equals 1 point". The reason is that penetration calculations for weapons yield results thought to be accurate, plus or minus X%. For higher penetration weapons, this range can easily exceed the linear divisor. In FFT1 and 2, we used a linear scale. In FFT3, we went with a logarithmic scale, which produced more reasonable results. It also allowed us to have relatively low values (0 to about 16), yet make meaningful distinctions at the low end. A linear scale that makes meaningful armor distinctions between, say, an M2A2 Bradley and a BTR-60 will need something like 1 point of armor per 10mm of protection. But that means that the armor value of an M1A2HA will something like 80(!). A well designed logarithmic scale can do the job a lot better. |
Rod I Robertson | 12 Dec 2015 9:36 a.m. PST |
VIS: I am reminded of a story from Iraq of a British Tank which was ambushed by insurgents. The Tank was a Challenger II IIRC and suffered a mobility kill compounded by being bogged as well. The crew did not abandon the vehicle but stayed buttoned up and fought for hours in situ. The vehicle was hit by 17 different infantry anti-tank weapons of various sizes and while suffering lots of superficial damage, was not rendered inoperative. The tank crew defended themselves as best they could but as video systems failed they became progressively more and more blind and could not stop all the attacks against them. Finally the tank was rescued, it's track repaired and it was towed out of whatever it had bogged down in. The crew drove her back to their base and enjoyed a well earned rest. What this story shows is that an accurate small scale simulation must treat the AFV and the crew as two separate components which are linked together unless both are completely destroyed in the first instance of combat. While this approach may be satisfactory for smaller scale skirmish and tactical level games it will tend to bog down games at higher levels so more abstraction is needed and penetration values become less important. The best solution to my mind is to have AFV combat create several possible outcomes for damage and morale. These might be: No effect- the attack was ineffective. Suppression – Degrades the AFV's performance for a short time. Impairment – Degrades the AFV's performance for a longer period of time. Neutralization – The vehicle or crew is completely unable to continue operation for a period of time. Kill – the vehicle and/or crew have been so damaged that they are out of service for the rest of the game. Catastrophic Kill – the vehicle and crew has been destroyed in such a way as to harm other friendly forces (and possibly enemy forces in close proximity), either physically or by hurting their morale. Suppression, impairment and neutralization should trigger morale checks and if failed the AFV should be required to withdraw from combat unless and until it can be rallied. So the scale of the game system in part determines the relative value of the penetration numbers and armour configuration. The lower the scale of combat, the more relevant and technical such data becomes and the more detailed the combat effects can be. At larger levels of combat more abstraction and streamlining is needed to allow speed and playability to be maintained. This is of course nothing new to ground wargames. It would likely apply to naval games too but I am not qualified to make that judgement. For air combat I don't know. That would require more focus on energy, maneuver, and target acquisition and less on armour and penetration. Cheers and good gaming. Rod Robertson. |
tbeard1999 | 12 Dec 2015 9:47 a.m. PST |
Also, note that modern MBTs can have very different armor thicknesses even across the frontal arc. Soviet MBTs, especially, have a wide variance in protection. For instance, the T-80B has the equivalent of 370-470 mm of rolled homogenous armor across the front of its turret. It has 230mm on its lower front hull and 430mm on its upper front glacial. The values for the T-72A are 270-390mm across the front of the turret and 190mm for lower hull and 400mm for upper hull. A 105mm M111 APFSDS round will penetrate 315-385mm RHA at 1600m (as I recall). So…it will bounce off the T-80B most of the time if it hits the turret front or the front glacis. But it will penetrate some areas of the turret front and all of the front lower hull. It will usually penetrate the T-72A in a front turret hit but will not penetrate the front hull. Unless, of course, the metallurgy of the tank is substandard and the round hits just right so that penetration is maximized. My guess is that the Soviets determined which areas were statistically more likely to be hit, then armored those areas more. Anyhow, if you are going to establish a single "front armor rating" (as we do in FFT), then the combat system needs to build in a wide range of possibilities. Oh and simply averaging armor values is not an ideal solution. You need to weight the protection areas, which requires judgment. And the result may be unsatisfactory, so "reality testing" is critical. For instance, assume a simplistic hypothetical -- a Tank A with 100-300mm of armor. A hit has a 50% chance of hitting the 300mm armor and a 50% chance of hitting the 100mm armor. Tank B's 100mm main gun will penetrate 230mm of armor. If you average Tank A's armor rating (200mm) and apply a simple "if penetration equals armor, target is penetrated" combat system, you'll get poor results. The 100mm gun will penetrate Tank A's armor every time in the game. But in the real world, the 100mm gun will only penetrate 50% of the time, So a more sophisticated combat system is needed. |
Skarper | 12 Dec 2015 10:42 a.m. PST |
This is an interesting problem. I was impressed by the Panzer-war files because they gave 10 locations on each facing and covered issues like the shot trap under the mantlet on the Panther. You also need to allow significant damage from a non-penetrating hit that could kill/wound or just terrify the crew. There has been a move towards simplification in wargame rules. I'm not saying the old complex rules were good, but some complexity in the right place can greatly enhance our 'recreational' games. With spreadsheets, smart phones and so on we can well handle a bit more maths. It no longer has to be on the fingers of one hand. |
donlowry | 12 Dec 2015 10:55 a.m. PST |
While your points are valid, you can't make the process too complicated for the players -- so it either needs to be imbedded within the rules, or abstracted in some way. In my home-baked rules, I assume that any penetration puts the tank out of commission. In most tactical games, the crew is of little use without their vehicle, so I usually ignore them. (In a campaign game, of course, I'd keep track of them.) In the case of non-penetrating hits, I roll for the crew's morale (assuming the hit had some chance to penetrate in the first place). If they fail the check, they bail out. Once out, they won't reenter the vehicle if: a. it's burning, 2. it's still being fired upon, or 3. they are being fired upon. If none of these things are happening, they will reenter the vehicle if they can pass morale (which went down when they bailed out). I rate both armor and guns by centimeters, not millimeters, and if the gun's penetration just barely over-matches the armor (on the aspect of the tank that was hit), it's a 50% chance of a kill. |
nickinsomerset | 12 Dec 2015 12:14 p.m. PST |
"but as video systems failed" No video systems in the CII, but the optics were all shot out. One of ours on Telic 1, Tally Ho! |
Rod I Robertson | 12 Dec 2015 12:22 p.m. PST |
Nickinsommerset: I stand corrected. I read the story a few years ago and was weak on the details. Thanks. Cheers and good gaming. Rod Robertson. |
Lion in the Stars | 12 Dec 2015 1:01 p.m. PST |
A counter-argument for you, VIS, is the tendency of troopers shooting at tanks until they were burning to make sure they weren't playing dead. I honestly don't mind the Flames of War 3 damage states: OK, "bailed" (ie, not presently combat effective but might be effective soon), and brewed up. If you bail a bailed vehicle, it's dead. Mobility kills are part of the bailed result, as a bailed tank can neither move not shoot. It's possible that 'bailed' results are not common enough in the Flames engine, outright kills are probably twice as common as bails. Mobility-only effects only happen in terrain. If you want more detail, say for a skirmish game, you will slow the game down some as you figure out what happened to the tank. |
wrgmr1 | 12 Dec 2015 1:09 p.m. PST |
Great posts in this discussion. Rapid Fire being a platoon/company based armour/infantry rule set, uses a cumulative damage scale for armour. Your unit can receive light damage which causes no adverse effects. Heavy damage which creates a turn out of action. Two light damage equals a heavy. Two heavy damage, unit destroyed. Seems to work pretty well in our games. |
Visceral Impact Studios | 12 Dec 2015 3:39 p.m. PST |
Hey Lion! I wasn't arguing for more detail, not at all! I'm just noting that in developing single armor facings for just 2 to 4 facings it's not as simple as dividing X armor thickness by Y factor. Ty did a great job of describing the process in detail. Our tank "armor" value setup for our upcoming rules is along the lines of FFT and FoW: front, side, and deck. Vehicle stands also have a Hit Point value. For vehicle stand status we just track two things too: Friction Points (which can be rallied off and represent minor wounds, confusion, fear, light damage, etc.) and Damage Points (which are permanent and when DP = HP the stand is eliminated). Friction points limit movement, modify combat ability, etc. and replace the usual wargame status markers of bailed/disordereeld/demoralized/etc. We've even replaced the term "armor" with "protection". So protection values with HP can represent a spectrum of vehicle damage resistance. Most importantly, the crew's Teamwork and Bravery values represent its ability to deal with the chaos of combat. For Rush of Battle, the meat sacks in the tank are as important as the steel! :-) |
spontoon | 12 Dec 2015 4:29 p.m. PST |
I once read a book ( Shield of Zion, I believe) about the IDF tank forces. Israeli tankers being the most experienced and successful at the time; their opinion seemed to count most about what weapons were most worrying to them. The gist of the chapter on being hit was that they didn't like being hit by anything! Even AK fire would do damage that could impair their functioning; such as destroying antennae; lights; out side personal kit; jam hatches and other moving parts; etc. Remember, the first Tiger captured in WWII in N. Africa was abandoned by the crew after the turret was jammed by a 6pdr. AP round jamming the turret! |
skippy0001 | 12 Dec 2015 11:32 p.m. PST |
Tractics still reflects what is said. I remember concussing a tank crew with a 150/L12 Brummbar gun, critical hit of a Porsche Elefant's driver hatch with a 120mm mortar round, losing Tiger Tank commanders to partisan squads with LMG's, enduring whiz-bang panzerfaust fire against my T-34's. Someone should update Tractics. |
Visceral Impact Studios | 13 Dec 2015 6:06 a.m. PST |
I've seen some of those discussions too. And for many years gaming was indeed dominated attempts at hyper-detailed games using detailed hit location charts mapping the entire surface of the tank. But this discussion is NOT peimarily about Ditto's reference to rivet counting as that design approach came to be known in gaming circles. It's really about the challenging process described so well by Ty Beard of FFT. How do you translate the reults of that rivet counting process into an elegant recreational wargame model resulting just a single armor/protection value for each broad facing? The topic was sparked by several threads on FoW TY's values for front/side/rear armor. Folks were discussing the approach of "100mm of armor / factor 20 = Armor 5"…which would not explain results such as the values for a Tiger I and Panther in FoW which factor in slope. Nor would it explain how in other rules aome weapons are allowed to damage vehicles when faulty guns vs armor test data "proves" that auch a weapon could never penetrate a given vehicle's armor. Which is another part of the discussion: when using a single value for a given arc what is the cut off point for lesser weapons being able to damage a vehicle in that arc? |
Visceral Impact Studios | 13 Dec 2015 6:18 a.m. PST |
Here's a good extreme example to guide the discussion: 1. What is the smallest caliber weapon that can consistently and reliably destroy a track on a modernm MBT? 2. If using one armor value per src ahould balues be set ao that weapon can damage a MBT from the side arc? 3. Or is there a different, better criteria for question 1? For Rush of Battle we chose small but still aignificant weak points common to all AFVs as the ceiling for side/rear protection values. That means even decent autocannon rounds have a small (1/6) chance of doing a little damage (2 DP out of 8 to 10 HP) to the best MBT from the side. In mosst cases that means firing an IFV section's autocannons (1 stand = 2 or 3 vehicles) at a section of MBTs is simply telling the MBTs to "aim here". OTOh, to spntoon's point, MBTs can't totally ignore 30mm ACs chewing into them from the side/rear. That doesn't mean a WWII era 20mm AA gun can destory an Abrams! But it does mean that a T-80 can't slough off high qualoty 25mm rounds steadily beating on its vulnerable points evne though the system uses just one protection value for side armor. |
Visceral Impact Studios | 13 Dec 2015 7:48 a.m. PST |
Aaahhhh…got it. Totally misunderstood, sorry about that!!! My comment was really focused on the TY discussion too. Doh!!! Re: the Abrams issue and tracks, any idea on the smallest caliber round capable of reliably "tracking" a vehicle? 12.7mm? 20mm? larger? Your example of the Abrams goes to the heart of this thread. But I've also seen references to parts of the Abrams being vulnerable to 25-30mm rounds from the side and rear. Small areas to be sure but still large enough that under sustained fire something important might get hit. In other words, enough that Abrams can't ignore a BMP-2 sans ATGM to its flank. |
Mobius | 13 Dec 2015 8:18 a.m. PST |
1. What is the smallest caliber weapon that can consistently and reliably destroy a track on a modernm MBT?2. If using one armor value per src ahould balues be set ao that weapon can damage a MBT from the side arc? 3. Or is there a different, better criteria for question 1? For Rush of Battle we chose small but still aignificant weak points common to all AFVs as the ceiling for side/rear protection values.
Why are you messing with the side armor value in trying to reflect track weakness? Just have a track armor rating. It's not that hard. You do this then hulldown matters. Your "smallest caliber weapon" is not going to "reliably destroy a track on a modern MBT" that is hulldown. So your game is not compromised by a side armor value that considers only hull up value. |
Visceral Impact Studios | 13 Dec 2015 10:22 a.m. PST |
Why are you messing with the side armor value in trying to reflect track weakness? Just have a track armor rating. It's not that hard. You do this then hulldown matters. Your "smallest caliber weapon" is not going to "reliably destroy a track on a modern MBT" that is hulldown. So your game is not compromised by a side armor value that considers only hull up value. I'm not…it was just an extreme example of the challenges faced when boiling down armor values to a single value for an entire arc. Using only the STRONGEST part of a given facing doesn't make sense. So, as Ty discusses so well, how does one factor together the weakest portions with the strongest portion to derive a single value for the arc? What you're proposing isn't the topic of the thread! It results in multiple values for the arc. :-) |
Mobius | 13 Dec 2015 11:07 a.m. PST |
What you're proposing isn't the topic of the thread! It results in multiple values for the arc. I don't see anything in the thread title or the first post saying that a vehicle's facing must be boiled down to one number. That's just tying your hands. It's like saying one number must represent a guns penetration. One value per facing is just 1973 WRG armor rules. Let me quote something from the first post:
most importantly, how tanks are actually built and what constitutes a "kill" in a tactical context for tabletop gaming purposes! And in WWII, American 57mm anti-tank gun crews targeted German tank tracks to immobilize the tank and then call in air and arty on top There you go. Tracks. Tanks are built with tracks. If you can't hit it (when hulldown), you can't kill it. WRG wasn't good at handling hulldown either. Hopefully things have advanced in 40 years. |
thomalley | 13 Dec 2015 11:10 a.m. PST |
Hopefully things have advanced in 40 years Considering the number of "new" rules that have, one die per x figures and 6s kill, 5 or 6 saving throw, not sure they've advanced too much. |
Wolfhag | 13 Dec 2015 11:22 a.m. PST |
How can you realistically assign a single value to a tanks armor protection taking into account its horizontal and vertical slope/angle? Most WWII tanks had a gap between the turret and hull top that was only 10-15mm wide taking up only 2%-3% of the total target area. How can you model that small area? Some of the info you are looking for should be here: link I did an analysis of the front aspect of a Panther A model that showed about 12%-14% of the hits would bounce off because of angles over 70 degrees like the roof, turret side (front frontal aspect), mantlet and the cupola. However, using the T/D ratio rules if the round were large enough it would cause damage. Randomized hit location tables are not accurate because a round does not hit a tank "randomly". The round hits somewhere around the aim point and the more accurate and closer means you may hit exactly where you aim. To have an accurate hit location table you need to be able to select an aim point like in a video game. However, at long distances (3+ seconds time of flight) it can be truly random anywhere on the target but not at less than one second time of flight. Big difference. For me that seems a big limitation of a hit location chart. I'm just stating this because you can't really model penetration unless you model an almost exact hit location if you are going to take into account the nuances of armor configuration and compound angles, especially for unexpected ricochets which do happen. So I think it comes down to some type of mechanic for aiming to influence hit location that can determine armor protection. I think that's a fairly historic model of tank gunnery. Personally I don't see any way you can have a simple and abstract rule that would incorporate all of the items above. For me using abstractions like hit points and friction does not model the hardware and physics of protection and damage or give the right "feel". However, you can use any type of system that can somewhat model reality to a degree that a large % of players would buy into it. It just depends which abstraction you accept and you won't please everyone. Wolfhag |
Mobius | 13 Dec 2015 11:35 a.m. PST |
Here is a [Pdf] sample of a rule set that assigns a single value for armor facing and has a hulldown rule. link |
Mobius | 13 Dec 2015 11:51 a.m. PST |
To have an accurate hit location table you need to be able to select an aim point like in a video game. Now, I'm going to have to take the other side of this point. I don't particularly like the ultra accurate model either. That is because the player has more information than an actual tank gunner did/does about the armor of his target. Plus, I once played in a game where you could choose the exact location on the target (Men in Armor) you could hit if close. First thing you do is take out the gun, with a gun barrel hit. Then the tracks so the target can't run away. Easy – peasy. |
Rod I Robertson | 13 Dec 2015 1:53 p.m. PST |
Perhaps we are looking at this from the wrong perspective. Might not a statistical study of the hits which killed or disabled tanks be a better starting point than comparing hypothetical armour resistance and round penetration. Don't militaries and manufacturers collect and study such data? While I would expect it to be classified for modern vehicles is such data in the public domain for the Cold War? It might be worth while reverse engineering armour values rather than trying to come up with them by a derivative process. Cheers and good gaming. Rod Robertson. |
Wolfhag | 13 Dec 2015 4:14 p.m. PST |
Mobius, wow Men in Armor, that's an old one. I've played it too and don't disagree with you. However, (IIRC maybe I'm wrong) Men in Armor used a modified hit location method for a die roll where the player could modify/tailor it AFTER the shot so the player had control of where it would land. I'm talking about an optional aim point (with some restrictions that would default to a center mass aim point based on range, magnification, etc) that the rounds lands in a distance and direction the player CANNOT influence after the results of the shot. Somewhat like a video game? In order to really do that you need to determine the MPI and vector of the shot from the aim point and not use "To Hit + DRM" type mechanics unless someone knows another way, I'd be interested in hearing it. How is it done in Combat Mission? I also agree about the player having too much knowledge. However, it was common knowledge where the opponent had weak spots and where the fuel and ammo storage was and I'm pretty sure these were targeted when/if they could. That includes the bottom of the Panther D and A model mantlet bottom. Regarding compound angles. I've used them in games and for the vast majority of the time they don't really effect whether the round would penetrate or not but when it does it makes things pretty interesting because a shot everyone expected to KO the target does not letting him get off another shot. I think that's because most battles are at no more than a 20% horizontal angle where the effect is small. I'm not sure how you'd bring into play brittle armor like late German WWII. Rod: The problem I see with a statistical analysis of an after battle examination is not knowing the time line of when the hits took place and the range of the shot. It was not unusual for tankers to put rounds into KO'd tanks when they first came upon them. Also they are going to have a hard time (but but impossible) determining the range the shot was taken. I'm pretty sure there are some good studies but I think they would only be representative of that specific battle. An analysis of battles in the hedgerows of Western Europe would have different findings than the battles in the northern plains. Also firing at defenders in hull down locations would skew the finding to be mostly turret hits. Wolfhag |
Mobius | 13 Dec 2015 9:11 p.m. PST |
@Wolfhag
How is it done in Combat Mission? That game too runs in problems when they get something like a gun mantlet (King Tiger) value wrong and shots go to center mass and a good many hits go there. Run your numbers and see the probablities of shots going to the gun barrel at various ranges. Also, when firing at moving targets your spread should get real large. |
Mobius | 14 Dec 2015 4:07 a.m. PST |
Men in Armor had some flaws from the mechanics that weren't apparent because of the great amount of detail supplied. It placed the target shape into a 10x10 box grid. With the tank target shape in boxes. But with a lot of empty boxes above and outside the shape. In that game you do move the location of impact on the vehicle after the firing if it was a miss. But it had to be moved toward center of target (the number of boxes depending on range) until it was a hit on the target. This with the tank silhouette not being the center of the target grid led to things like the most common location hit is upper side turrets. (Not bad if you are a small target like a Stuart tank with angled side turret boxes rated as 999mm+ of armor). If both target and firer were stationary and under something like 250m the firer didn't need to roll location. He got to pick which box he wanted to hit. The back story of Men in Armor is that the author John Reynolds was mentor to Brian Stokes. Stokes later went on to make his own set of rules, Tank Charts. |
lincolnlog | 14 Dec 2015 6:20 a.m. PST |
One of the issues with Cold War gaming, is we tend to apply modern statistics and technology. Similar to applying Cold War tech to WWII. Just looking at the T72, the T72U was theoretically a relatively an easy tank to kill. By 1990 this was one tough bast*rd. The addition of composite armor, plus Kontakt 5 ERV had rendered NATO AT rounds nearly obsolete. But in 1985 when the Kontakt 1 was just coming into service, our tanks could still hold their own. Remember Kontakt 5 was not really deployed until the Cold War was all but over. Look at ATGMs which have been discussed in detail on other threads. With the advent of composite type and reactive armors, ATGMs were improved with top attack and tandem warheads. Also, there has been no mention of HESH. High Explosive Squash Head was a mainstay of British ARVs and even the M60A2 had a HESH round. HESH didn't so much kill the vehicle as it killed the crew. The idea is it caused the inside of the armor to break free and kill the crew and if lucky hit ammunition or fuel and killed the vehicle as well. But as VIS mentioned you don't have to kill the vehicle to render it ineffective. The problem is each type round has a different effect on each armor type. HESH is totally ineffective against Chobham, Composite, spaced or ERV armors. HEAT is less effective against Chobham. It is slightly less effective against spaced and Composite. Composite and Reactive are slightly more effective than Chobham. As armor improved ammo improved. So we're now back to how much detail do we want in a set of rules. Back in the 80's I wanted all the detail I could get, and spent entire Saturdays 10-12 hours playing a single game. I'm old, don't have time for this, can't find others with time for this. Also games need to be tailored for the standard 4 hour Con game slot. My solution was, a round penetrates or it doesn't. If the round doesn't penetrate, the vehicle takes a non-penetrating hit roll. A roll of 1 is a mobility kill this roll is ignored if the vehicle is hull down. A result of 11+ (on a D10 modifiers apply) a top hit is scored. Looking at statistical data versus HEAT, Composite Armor provides approximately 25% more protection. Composite + Kontakt 1 supplies approximately 50% more protection. Chobham supplies about 50% more protection. I simply adjust the penetration of the round. I also have an optional rule for random penetration, this accounts for hits that are not solid, glancing etc. Random penetration applies to artillery as well as AT fire. Understand that I'm not playing a 15 or 20mm skirmish game, but a 3mm tactical game. Games from battalion to regimental level. When discussing armor penetration and what kills a tank, there needs to be a heavy dose of both abstraction (like donlowry I'm not going to count casualties in a tank crew, no use), and good logical best guess. |
Visceral Impact Studios | 14 Dec 2015 4:52 p.m. PST |
But in 1985 when the Kontakt 1 was just coming into service, our tanks could still hold their own. Remember Kontakt 5 was not really deployed until the Cold War was all but over. Ok, I'll bite. Based on what? How many Challengers and Abrams have engaged the T-72U in combat? What was the source for the data? |
Weasel | 14 Dec 2015 8:34 p.m. PST |
Accounting for every possible factor, facing, location and angle is great. Now make it playable :-) |
lincolnlog | 15 Dec 2015 5:15 a.m. PST |
Multiple sources list the T72U Ural as the initial 1973 production model, with about 15-16" of frontal armor. This vehicle had a coincidental range finder. Laser Ranger Finder and Composite armor to the from only were a feature of the T72A which came available in 1979. The T72M (export version has been engaged in combat and would be superior to the T72 Ural. By the way, I didn't mean to Kontakt 1 was first deployed in 85, but was first added to the T72 in 85 and designated the T72B. link en.wikipedia.org/wiki/T-72 link GlobalSecurity.org has quite a bit of information on the T72, unfortunately it's spread across about 20 articles. By the way many sources indicate Ural as the tanks name, when in actuality it was the base model designation. I also have Jane's at home and that source seems to agree with these. |
lincolnlog | 15 Dec 2015 5:37 a.m. PST |
As discussed in the ATGMs topic, there is a lot of abstraction and conjecture at work in any war game, even simulations. Yes it's best guess in most cases. My point of the long post is, that modeling cold war armor and penetration is probably the most complicated period in history, because of the technical arms race. It can drive you nuts trying to stat out the same vehicles 5 model variants. The T64 and T80 are the same, base models improved over time. |
Visceral Impact Studios | 15 Dec 2015 8:38 a.m. PST |
lincolnlog, those are secondary sources! :-) I guess what I'm asking is, what's the primary source? Testing on a captured vehicle? How'd they get it? Who did the test? What were the test parameters in terms of ammo, propellant, range, angle, vehicle condition, etc.? Totally agree on the complexities of trying to model Cold War and modern guns vs armor. My point is that nearly all of the underlying information is purely anecdotal ("My buddy in Iraq saw an RPG-7 bounce off a Bradley"…which begs the question which model of the RPG-7, which Bradley, and how did he know?) or it's of very questionable provence. I don't think that one should just throw up his hands and declare that it doesn't matter. But I would also take with a shaker of salt any information or model presented as definitive;y accurate. It just doesn't exist in the public domain. On that note I would commend the work of Ty Beard and his partner on FFT. It took them years to crunch their numbers and based on his comments on the topic they clearly gave this a lot of thought. |
lincolnlog | 15 Dec 2015 10:34 a.m. PST |
VIS – The only information available is data from Israel, Soviet Afghan War, and the two Gulf Wars. It's always going to be a guess on capabilities. For the most part the Israeli's were using NATO or re-manufactured NATO equipment and ordnance. But, its a poor comparison because they were primarily shooting at T55's and T62's, and some T72's more recently. But these are not T72As, Bs or BVs, they are Ms (the export version) which is what our forces were killing in droves at extreme ranges in Iraq. What does that tell us for the Cold War? Nothing! Because it's out of context. The M1A1 or A2 is a Gen 3 MBT shooting at early Gen 2 MBTs, with tank rounds that are several generations past what we would have been using in 1983-85. All we have are reference materials with the best guess from those materials. There is a lot of data available, yes they are secondary sources. But, none of this should be classified any longer. This is all obsolete tech. They also perform ballistic studies on ordnance when it's developed. So the question is how much armor a new round can penetrate, but rather how good is the armor. War games are based on history and mathematics, history is obtained from secondary sources. It's the best that can be hoped for. |
HidaSeku | 15 Dec 2015 10:49 a.m. PST |
One thing that always interest me are the larger caliber artillery/SPG (155mm and above) firing HE rounds vs the heavily armoured tanks. Looking at penetration, most HE won't penetrate the armor of the tank. However, it stands to reason that even a modern MBT taking a 155mm HE round to the front will not just brush it off. I've heard that a near miss can even flip a tank and even just being close can throw a track. My favorite is reading about the SU-152 shooting and ripping the turrets off of Tiger tanks So, I've always been very leery of using any penetration charts, even if the angle is calculated in and whatnot simply because of the effect of HE. It can be simple to say that a certain caliber and above will destroy the tank regardless, but what about the effects of smaller caliber HE? The main reason not to consider it is the possibility that in the middle of a wargame something ridiculous will happen. If there's a 0.00001% chance of a rifle grenade taking out a Tiger from the front, then using Murphy's law there's a 100% chance it will happen and ruin a perfectly good game. I'm not sure if there is a good solution to this, and some level of abstraction is definitely needed. I'm curious to hear others' ideas on this. |
Weasel | 15 Dec 2015 11:40 a.m. PST |
"Golden shot" mechanics are always problematic, because by assigning them a chance, we almost certainly overstate the chances. "20 on 1D20"? that sounds low but it's a 5% chance. It'll happen. What's the real life chance of an RPG7 going through an Abrams? Exceptionally low, but there's been a few "Golden BB" hits taken. If you pelt enough tanks with enough RPG, sooner or later, something will happen juuuuuuust right (or wrong, from the crews perspective). Should we factor that into the rules though ? |
Wolfhag | 15 Dec 2015 11:49 a.m. PST |
HidaSeku Dumb rounds and artillery: link Weasel: Check out the Tank Inspector and Armor Inspector app on YouTube. It does give a full rotatable 3D image of a tank with computed compound armor values on each plate/face with system and crew locations. Turret is rotatable too. I'm sure it will offend some miniature purists. The most I can do is 5 aspects plus top aspect with shaded areas for behind armor systems and a pre-figured armor strength for each aspect. I can post a system I've been using that has delivered results like a Sherman taking out a Tiger's gun sight by hitting the gun sight opening and rounds hitting the tank commander that is unbuttoned. It models a rounds impact on a scaled image/picture of the target so any location or weak spot has a chance to get hit without additional charts or die rolls. By using a scaled image of the target you can pretty much realistically model all of the strengths and weaknesses without needing abstractions or additional die rolls, charts and steps. It's a completely different way to approach the hit / location mechanic we are used to. Wolfhag |
Weasel | 15 Dec 2015 11:50 a.m. PST |
Wolfhag – Kind of like those old Rogue Trader "targeting templates" ? where you'd aim at a vehicle silhouette and roll for deviation? |
Wolfhag | 15 Dec 2015 11:59 a.m. PST |
Weasel, I'm not familiar with it but it sounds like the same principle. Wolfhag |
Mobius | 15 Dec 2015 12:28 p.m. PST |
By using a scaled image of the target you can pretty much realistically model all of the strengths and weaknesses without needing abstractions or additional die rolls, charts and steps. It depends on what one means additional die rolls. You do realize that the penetrations of guns given is based on probability. For the US this is the V50 criteria. Where there is a 50% chance that at least 50% of a shells mass will pass through armor. It is common practice to generate probabilities with die rolls. See WWII criterias here: panzer-war.com/page33.html |
Wolfhag | 15 Dec 2015 1:40 p.m. PST |
Mobius, That statement was talking about modeling for hit location and armor thickness, not penetration and damage. Yes, I'm familiar with the WWII Ballistics work on page 81 and much of your excellent works. I used their % penetration chart as a basis to create a nomogram to show damage levels based on partial and full penetrations. I did one with and one without die rolls and am leaning towards the one without die rolls. It reflects the need for over penetration to cause full damage. I like the chart they have but having to break down the % of penetration takes too long, no one likes the math. Right now my nomogram reflects less than 80% penetration no damage. 80-100% penetration creates spall damage against crew and internal components. 100-110% is a partial penetration with no APHE effects and over 110% is full penetration causing full damage and APHE effects. I admit it's somewhat subjective but no one can really calculate exactly what will occur during AP penetration against armor. I'm trying to find a balance and keep it somewhat simple. At conventions I've played needing 120% penetration to KO a tank and players seemed OK with that and the explanation. Since the target image has crew locations, drive train, fuel and ammo areas shaded we can tell immediately without a die roll if something vital is hit and damaged but I do have a variable damage table to roll dice on. If there is no visual feedback like a fire or explosion the player needs to continue to fire at the same target. You can use your co-ax mg on crews bailing out if close enough. The chart does reward players to fire at tanks where full penetration may not occur and have a chance to cause damage to internal components or kill crew and render the vehicle a mission kill without a full penetration. This causes players to start withdrawing their beloved Tiger tanks earlier than they would have expected as it increases their vulnerability range by a few hundred meters. While the chart is an additional step much of the time it's not necessary as the penetration vs armor values can readily show a clear over penetration or the chance of a partial so it is not used for every hit during a game, especially at close ranges. I have not gotten any complaints about it. I don't think I'm contributing anything to Visceral's question so I'll put my response to your other questions on a link outside this discussion. I appreciate the questions and feedback. Wolfhag |
Visceral Impact Studios | 15 Dec 2015 1:50 p.m. PST |
Wolfhag, you are contributing, at least indirectly. The issues that you're covering or sort of the underlying issues that others (FoW, FFT, and RoB) deal with when boiling down a facing to one protection value. For example, TY uses just 1 frontal arc value against all ammor. FFT shades things a little finer with different ammo and armor types modding the single armor value a bit. Our upcoming Rush of Battle rules fit in between with vehicle Hit Points and weapon Damage Points shading the relationship between hunter and hunted. It's all good and very interesting! :-) |
Wolfhag | 18 Dec 2015 8:58 a.m. PST |
Visceral, I put together a few examples of the gunnery, armor penetration and hit location routines I've been working on. It appears to be a different approach to what you are working on. I trying to develop a physical model of a target for the player to aim at and determine a hit location. I don't always use die rolls and modifiers the way most other games do so I'm not sure if this will be much help to you. The activation routine I use is a time and motion/task system that is determined by task, vehicle performance and crew training. There are some decisions by the player that can effect when they activate but there is not much randomness about it. However, there is a 5%-10% chance each time a gun fires that a SNAFU can occur that will interfere with the crews ability to perform. This is all a WIP but different versions has proven playable and enjoyable by players at numerous conventions. I haven't been able to have very many people familiar with what I'm doing give me any feedback on how right or wrong it is so any feedback appreciated. Here is the link: link Thanks, Wolfhag |
Mobius | 18 Dec 2015 12:08 p.m. PST |
Can you hit a Panther at 80 yards in this location with a 75mm?
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Wolfhag | 18 Dec 2015 2:08 p.m. PST |
Mobius, Is there anything special about that picture or something I should know about it? Is it specific to all 75mm guns? I'd expect any 75mm gun that can depress low enough at 80 yards could hit it. On page 5 I have the rear 45 degree target aspect for the Tiger II, the Panther would pretty much look the same. That location could be hit but it all depends on the aim point and dispersion. Under ideal conditions dispersion would be pretty small and most likely he'd hit right where he aimed. I'm not using trunnion cant and parallax as part of the error budget which could effect the aim point at 80 yards. If the question was could a 75mm miss the entire tank at 80 meters the answer is yes it could. In a situation where the gunner used minimal aim time (snap shot) after slewing the turret onto the target the MPI column modifier is a 2D6 so at 80 meters the MPI could go to the 1300 meters, enough for a miss. The 2D6 is subjective and not based on any formula but does give the result I'm looking for – a miss if you don't take your time. The targeting limitations are that there is not a horizontal target image aspect to cover all 360 degrees. That's one of the reasons I like that Armor Inspector app because it can do a full 3D rendition of any vertical or horizontal aspect and give the armor thickness. Some Russian guy developed it. I hope that answers your question. Wolfhag |
Mobius | 18 Dec 2015 6:30 p.m. PST |
The dispersion of a 75mm at 1000yds is .375yds but the vehicle was moving so the ability to get the aim at center target was greatly reduced. The British had a term for a variable error called shoot-in error that for the 20pdr a .516 sd at 1000yds. Which is the error in finding the center mass. So the dispersion is error from the point of aim and shoot-in is the error in putting the center aim at the center mass. And this is a stationary target. |
Lion in the Stars | 18 Dec 2015 7:45 p.m. PST |
The dispersion of a 75mm at 1000yds is .375yds Wow, that's quite good! To put that into rifle terms, that's a 1.35 minute-of-angle dispersion, on par with WW2-era sniper rifles. ===== VIS, I think something you have been tapdancing around is how long it takes to resolve any given shot on a vehicle. This ends up being the controlling factor on how many vehicles people will want to have on the table. Team Yankee and Flames of War are intended to have lots of vehicles (30+ per side!), so you need to have a quick-to-resolve shooting system. Classic Battletech, on the opposite end, has a complex shooting/armor system which makes it trying to have more than about 4 vehicles per player. So, how many vehicles per side do you want in your game? |
Mobius | 19 Dec 2015 9:49 a.m. PST |
Wow, that's quite good! To put that into rifle terms, that's a 1.35 minute-of-angle dispersion, on par with WW2-era sniper rifles. It may seem even better than that as that is a 50% zone average of a number of tests. Some were quite good, some were bad. It might be a problem with ammo. Also, that is the 50% zone which is 1.349 x std. deviation. It also represents the deviation from center of a cluster of hits. Not that the center was on the target center. The center may be off to the side of the target. There were other problems with the gun as a loose sight to gun linkage caused an almost equal error. |