The Titanium Bunker

[Michael Emrys]

Or something like that.

Michael

[John Kettler]

womble,

Very good! Hadn't encountered either of those, but are you familiar with this one?

http://www.answers.com/topic/impervium

Apparently, the Germans had some extraordinarily tough material of that name for some of their exotic projects. Google "impervium, nazis" for that. Full marks for coming up with a word I'd never seen or heard before. "Surds." Well played!

Finally, I'd be remiss if I failed to observe that Impervium could also be a substance or drug which protects the users from sexual predators.

Regards,

John Kettler

[womble]

womble,

Very good! Hadn't encountered either of those, but are you familiar with this one?

http://www.answers.com/topic/impervium

Apparently, the Germans had some extraordinarily tough material of that name for some of their exotic projects.

Anyone who's played a few CMBN scenarios is familiar with that one. For some reason the Germans only used it on their "hedgehog" antitank obstacles. Perhaps it was simply too dense for tank armour, and reacted badly to the alkaline environment of reinforced concrete.

[Kanonier Reichmann]

That passage compliments of "Victory was Beyond Their Grasp: with the 272nd Volksgrenadier Division from the Hurtgen Forest to the Heart of the Reich."

If only those foolish Americans would have known that just one or two AP rounds from any of those four tanks could have taken care of bunker 24 in a few seconds. They could have left the engineers with their demo charges behind and a lot of lives could have been saved since they wouldn't have been hit by that artillery fire. It should also be noted that the tanks were not subjected to any AT fire and had the freedom to drive around at will.

Here is an example of that bunker type that I found after a quick search

http://en.tracesofwar.com/article/7877/Westwall---Regelbau-SK-Bunker-Aachen-Forest.htm

The example you gave in the link was a furphy to say the least. It refers to a bunker built in the late 1930's for the German Westwall defences of their border region and hardly represents the typical concrete bunker encountered by Allied troops in Italy or the western front prior to winter in 1944. The Westwall bunker had 2 metre thick reinforced concrete walls which, I would suggest, is not your typical concrete bunker depicted in the CMx2 games to date. Perhaps when the Bulge game is released a special type of almost inmpervious bunker would be appropriate then, but only then.

Regards

KR

[Battlefront.com]

We've made changes to improve the chances of getting something inside the firing slit. Still testing the changes, but looks like we've swung in the other direction. Note that the problem discovered is really quite specific. It involves fairly close in fire from a pretty beefy cannon type weapon. Other than this instance we think the behavior is pretty good. Which is probably why this issue hasn't come up every time anybody has played against a bunker since we released CMBN v1.0.

Steve

[ASL Veteran]

The example you gave in the link was a furphy to say the least. It refers to a bunker built in the late 1930's for the German Westwall defences of their border region and hardly represents the typical concrete bunker encountered by Allied troops in Italy or the western front prior to winter in 1944. The Westwall bunker had 2 metre thick reinforced concrete walls which, I would suggest, is not your typical concrete bunker depicted in the CMx2 games to date. Perhaps when the Bulge game is released a special type of almost inmpervious bunker would be appropriate then, but only then.

Regards

KR

The fact is that we don't know what a CM bunker represents because it seems to be some sort of 'generic' bunker. I've also read that 2 meters thick for German concrete bunkers was standard. Certainly you aren't suggesting that the bunkers on the beaches at the French coastline weren't up to the standards of the West Wall (which was neglected for years btw). I've also read that Japanese log bunkers with coral reinforcing were almost impervious to anything beyond point blank range. They seemed to be capable of surviving massive bombardments from US battleship guns just fine. I imagine if they were using Palm Trees for their logs that would contribute to the bunker's resistance since the properties of Palm tree logs is much more springy than other types of logs. I believe that South Carolina being called "The Palmetto State" is a reference to a revolutionary war fort that was impervious to cannon balls from British warships because of the properties of the Palm Tree logs they were using.

If you have any reference material that you would like to share about non West Wall bunkers then I'd be interested in reading it. Opinions and assumptions without something substantive behind it aren't very helpful to moving the discussion forward.

[Steiner14]

I find it interesting, that everybody is caring about a single bunker and how it reacts but no one seems to look at the more important fact, that this bunker can easily be spotted from the first second: because the terrain is deformed around it.

That FOW with fortifications does not work. :mad:

[agusto]

I find it interesting, that everybody is caring about a single bunker and how it reacts but no one seems to look at the more important fact, that this bunker can easily be spotted from the first second: because the terrain is deformed around it.

That FOW with fortifications does not work. :mad:

Yes, that is an issue.

[c3k]

Yes, that is an issue.

And it is a known issue.

[pnzrldr]

FWIW - from a tanker. I've been in a Sherman, though never fired the gun, I've seen sights and the stadia reticle. I've fired M1IPs and M1A1s using the GAS (stadia reticle, ala 1944). At 100m or less I would say that the chance of burst on target gunnery resulting in a hit (round entering bunker through slit) by the third shot exceeds 90%. Based on my experience with 105mm and 120mm, I would expect a 75mm cannon to be roughly equivalent to shooting a .30-06 with a scope - it is after all a rifle with a good optical scope bolted to it. The big difference is you can nearly always see where the 75mm round hits, and adjust that hit onto your desired target for second and following shots. How many rounds would you need to hit a pie plate at 100m with your favorite rifle? This assumes the tank gunner and TC have 30 seconds or so to concentrate on his three shots and sense each round. If you cannot hit a pie plate at 100m you will have no hope whatsoever of hitting a tank at 1200m. Parralex might make you miss the first shot, but not the 2nd and 3rd. By 20 you would have put 15+ into the bunker.

As to behind armor effects, the bunker would be unlivable with AP entering from the strike on the rear wall kicking spall and dust. Concrete dust lingers - dark - cannot see out. Decent chance of killing or wounding occupants (leaving aside the real likelihood of hitting someone in the chest with the round itself) Any HE detonation, whether on the rear wall or embedded deep in it, would incapacitate everyone inside. You simply cannot overstate the magnifying effect of enclosure/compression on HE. They might not be dead, but they would be out of the fight with near certainty. A single hand grenade that gets through the slit and isn't kicked into a grenade sump would do just about as well.

However, I have had a 25lb plastique IED go off three feet from my right foot - with just armored HMMWV between me and it - and I wasn't more than rattled and made viable combat decisions within 3 seconds. Armor (or concrete) directly between you and BANG is GOOD! So I presume hits on the outer glacis, even from decent sized HE, would have limited effect.

Lastly, I'm curious about the direct fire model in CMFI. I'm a newb to CM, and haven't thus far seen direct fire weapons doing BOT gunnery. First round miss, adjust, second round bracket or hit. Does the game model this? Most common form of direct fire gunnery training in WWII, and a underdeveloped skill in our Army's current gunnery training (because we now have sexy sweet ballistic computers). Anyone got a link to a thread on this?

[pnzrldr]

FWIW - from a tanker. I've been in a Sherman, though never fired the gun, I've seen sights and the stadia reticle. I've fired M1IPs and M1A1s using the GAS (stadia reticle, ala 1944). At 100m or less I would say that the chance of burst on target gunnery resulting in a hit (round entering bunker through slit) by the third shot exceeds 90%. Based on my experience with 105mm and 120mm, I would describe a 75mm cannon as roughly equivalent to shooting a .30-06 with a scope - it is after all a rifle with a good optical scope bolted to it. The big difference is you can nearly always see where the 75mm round hits, and adjust that hit onto your desired target for second and following shots. How many rounds would you need to hit a pie plate at 100m with your favorite rifle? This assumes the tank gunner and TC have 30 seconds or so to concentrate on his three shots and sense each round. If you cannot hit a pie plate at 100m with an tank cannon, you will have no hope whatsoever of hitting a tank at 1200m. Parralex might make you miss the first shot (because you are so close and boresighted your gun at 800-1200m), but not the 2nd and 3rd. By 20 you would have put 15+ into the bunker with certainty.

As to behind armor effects, the bunker would be unlivable with AP entering from the strike on the rear wall kicking spall and dust. Concrete dust lingers - dark - cannot see out. Decent chance of killing or wounding occupants (leaving aside the real likelihood of hitting someone in the chest with the round itself) Any HE detonation, whether on the rear wall or embedded deep in it, would incapacitate everyone inside. You simply cannot overstate the magnifying effect of enclosure/compression on HE. They might not be dead, but they would be out of the fight with near certainty. A single hand grenade that gets through the slit and isn't kicked into a grenade sump would do just about as well.

However, I have had a 25lb plastique IED go off three feet from my right foot - with just armored HMMWV between me and it - and I wasn't more than rattled and made viable combat decisions within 3 seconds. Armor (or concrete) directly between you and BANG is GOOD! So I presume hits on the outer glacis, even from decent sized HE, would have limited effect. If the concrete is less than 2 feet or so, you might get penetration with AP - folks with hard pen data on the historical rounds would know more. If it doesn't penetrate, net effect is near zero ("yark, that was close!") but if it does penetrate, it is worse than a rear wall hit, as spall will be much more significant and you may get the actual AP round to fragment as it comes through.

Bottom line - whether a bug or a modeling glitch, the circumstance described in the beginning is extraordinarily unrealistic and detracts from gameplay realism. I just played the Casa Nostra scenario though, and thought the bunker model was fairly good overall. Hit one from behind on the door with a bazooka and caused partial fatalities on crew. Hit one from direct rear with a demo charge and KIA everybody. MGs from front penetrated about every 3rd burst or so and caused decent suppression. Will hope for a patch that helps with cannon vs. bunker model. Also concur with the post regarding visually acquiring bunkers. Worth noting that not every engineer deserves the title and some bunkers stick out like sore thumbs. However, some like the VC or Japanese on Guadalcanal you don't see until you literally trip over them. Would expect the game model to cover the gamut.

Lastly, I'm curious about the direct fire model in CMFI. I'm a newb to CM, and haven't thus far seen direct fire weapons doing "burst on target" (BOT) gunnery. First round miss, adjust, second round bracket or hit. Does the game model this? Most common form of direct fire gunnery training in WWII, and a underdeveloped skill in our Army's current gunnery training (because we now have sexy sweet ballistic computers that make us lazy - until they break). Anyone got a link to a thread on this?

[Kanonier Reichmann]

The fact is that we don't know what a CM bunker represents because it seems to be some sort of 'generic' bunker. I've also read that 2 meters thick for German concrete bunkers was standard. Certainly you aren't suggesting that the bunkers on the beaches at the French coastline weren't up to the standards of the West Wall (which was neglected for years btw). I've also read that Japanese log bunkers with coral reinforcing were almost impervious to anything beyond point blank range. They seemed to be capable of surviving massive bombardments from US battleship guns just fine. I imagine if they were using Palm Trees for their logs that would contribute to the bunker's resistance since the properties of Palm tree logs is much more springy than other types of logs. I believe that South Carolina being called "The Palmetto State" is a reference to a revolutionary war fort that was impervious to cannon balls from British warships because of the properties of the Palm Tree logs they were using.

If you have any reference material that you would like to share about non West Wall bunkers then I'd be interested in reading it. Opinions and assumptions without something substantive behind it aren't very helpful to moving the discussion forward.

If you have a reference to said reading material specifically dealing with the standard of 2 metre thick steel mesh reinforced concrete walls for Axis machinegun only bunkers I'd be interested in reading about it.

Regards

KR

[Wicky]

Platoon tactics in attacking a pillbox- Infantry Training Part VIII 1944

[Battlefront.com]

FWIW - from a tanker. I've been in a Sherman, though never fired the gun, I've seen sights and the stadia reticle. I've fired M1IPs and M1A1s using the GAS (stadia reticle, ala 1944). At 100m or less I would say that the chance of burst on target gunnery resulting in a hit (round entering bunker through slit) by the third shot exceeds 90%.

Yup, we agree. We've made adjustments to the forthcoming v2.01 (Normandy) patch to address the issue. The targeting logic for hitting the slot worked just fine at far to medium distances, but up close it simply wasn't aiming for the firing slit. Obviously if you put your reticle on the wrong spot you will have a 90% chance of hitting the wrong spot

As soon as we get v2.01 out the door we will get working on v1.02 for Italy.

As to behind armor effects, the bunker would be unlivable with AP entering from the strike on the rear wall kicking spall and dust.

Definitely there was a problem with crews being unrattled proportional to the incoming fire. That should also be adjusted with the next patch.

However, I have had a 25lb plastique IED go off three feet from my right foot - with just armored HMMWV between me and it - and I wasn't more than rattled and made viable combat decisions within 3 seconds. Armor (or concrete) directly between you and BANG is GOOD! So I presume hits on the outer glacis, even from decent sized HE, would have limited effect.

Agreed. Also agree you came a wee bit too close to not being here to type. Glad to still have you with us.

Lastly, I'm curious about the direct fire model in CMFI. I'm a newb to CM, and haven't thus far seen direct fire weapons doing BOT gunnery. First round miss, adjust, second round bracket or hit. Does the game model this? Most common form of direct fire gunnery training in WWII, and a underdeveloped skill in our Army's current gunnery training (because we now have sexy sweet ballistic computers). Anyone got a link to a thread on this?

Yup, all of that and more is modeled. By "and more" I mean the interesting complications which come into play when a target is moving. For the most part all gunnery stuff in CM is a "literal" simulation. When things don't work as expected it's usually because a refinement is needed.

For example, when you're 1000m out from a bunker, aiming is less precise by definition. When you're 15m away aiming is extremely precise. If you're aiming at some crunchies... at that range aiming won't likely influence the outcome much because lethality is about the same for most circumstances. But if you absolutely have to get the round in a tiny slot to have an effect, aiming becomes critically important because a miss won't have the desired effect. Which is why the close up aiming logic has been changed.

Note that this problem has probably been around since 2006 (Shock Force Beta). Obviously it's not a common problem since it took about 6 years to hear about it

Steve

[ASL Veteran]

If you have a reference to said reading material specifically dealing with the standard of 2 metre thick steel mesh reinforced concrete walls for Axis machinegun only bunkers I'd be interested in reading about it.

Regards

KR

The west wall bunker in my first description was a machine gun only bunker. It doesn't matter what's firing from the bunker. It only matters how much effort went into making it. Field works concrete bunkers probably won't be 2 meters thick, but even so you shouldn't assume that any tank can destroy a bunker easily from beyond point blank range. Don't forget that concrete bunkers also have a means of shutting the firing ports when they aren't being used. I'm not sure what your expectation is though - do you expect any tank to blast a field works bunker into rubble from 1000 meters with one shot of AP? What would be the point of spending all the time and resources into building a bunker like that in the first place?

[rocketman]

After running into concrete bunker behaviour that seemed odd I did a test with MG bunkers between 40-500 m from M4 Shermans, either on level ground as the bunker or on a gentle slope. I have only run the test once, but some observations so far (and shouldn't be considered full conclusions just yet):

• Shermans only fire HE (not AP)
• Almost all hits are low of the embrasure, making penetrating shots very rare, even from 40 m
• Even when HE get penetrating shots, it doesn't kill the enire crew or even none of them. Wouldn't a blast like that in a confined space kill everyone instantly?
• Crew behaviour appears like this: one man is standing, manning the MG, the rest kneel below the embrasure. The only kills I saw was direct hits on the guy manning the MG - no matter how many hits they take, they never cower, no matter their state
• Since the main gun fires single shots, and those rarely penetrate, "Target Light" is actually much more effective as the bullits have a much greater chance of penetrating and hitting the standing guy, who is replaced by the next, and by the next and so on until the crew is gone. Even at a long distance "Target Light" is prefered
• The only way to knock out the bunker from the front is a direct HE hit on the MG itself, which causes the crew to abandon

[MOS:96B2P]

 

After running into concrete bunker behaviour that seemed odd I did a test with MG bunkers between 40-500 m from M4 Shermans, either on level ground as the bunker or on a gentle slope. I have only run the test once, but some observations so far (and shouldn't be considered full conclusions just yet):

• Shermans only fire HE (not AP)
• Almost all hits are low of the embrasure, making penetrating shots very rare, even from 40 m
• Even when HE get penetrating shots, it doesn't kill the enire crew or even none of them. Wouldn't a blast like that in a confined space kill everyone instantly?
• Crew behaviour appears like this: one man is standing, manning the MG, the rest kneel below the embrasure. The only kills I saw was direct hits on the guy manning the MG - no matter how many hits they take, they never cower, no matter their state
• Since the main gun fires single shots, and those rarely penetrate, "Target Light" is actually much more effective as the bullits have a much greater chance of penetrating and hitting the standing guy, who is replaced by the next, and by the next and so on until the crew is gone. Even at a long distance "Target Light" is prefered
• The only way to knock out the bunker from the front is a direct HE hit on the MG itself, which causes the crew to abandon

 

 

rocketman, 

 

This is interesting stuff.  Most of my bunker busting TACSOP is centered around using demo teams.  It probably would not have occurred to me to use a tank's Target light instead of Target.   If you come to some final conclusions on this or just some more useful observations please let us know.

[akd]

Concrete bunkers in game are not proper fighting MG bunkers, but have a form more similar to coastal observation bunkers.  More typical fighting bunkers would not have wide open slits with occupants standing exposed behind them, so I am uncomfortable with the idea of their vulnerability matching their 3D model.

[rocketman]

Good point akd - makes sense.

 

I made some more tests, so this is a revision of above mentioned observations.

• Shermans do fire both HE or AP and tend to shoot either/or consecutively. Not sure if it is due to distance.
• HE seems pretty useless. Since penetrations are rare, crew casualties are low. And even though they get blasted repetedly they do not cower, which seems odd.
• Even if you park a Sherman some 20-30 m straight ahead of a bunker, they are no less accurate or get more penetrating shots. Indications rather to the opposite, they miss the bunker completely.
• When using Target, it fires both HE/AP/MG so it is possibly the better alternative after all. But not all of the time.
• AP shells can take out a bunker with one shot. Too bad we can't choose which ammo to use, as HE seems less effective.
• Hits tend to appear in clusters, which indicates that the gunners aren't especially good at adjusting their aim (see below)

Clusters - one good aim, one way too low.

 

Clusters - all too low.

 

Single AP-shot takes out bunker.

[akd]

 

Single AP-shot takes out bunker.

Long-standing bug. AFAIK, even MGs will penetrate this upper portion of the bunker. Doesn't kill occupants, but makes their morale drop. Larger shells make their morale drop so much they "bail out."

[John Kettler]

The beehive charges have nothing whatsoever to do with the Vietnam flechette munition of the same moniker. WW II US and British beehive charges were shaped charges used by combat engineers and so called because of that distinctive shape. Here is a pic of one. Tall legs are for ensuring proper standoff.

http://www.lexpev.nl/minesandcharges/europe/unitedkingdom/beehivecharge.html

 

That's a tremendous account of a Sherman vs a bunker. 

 

During the Battle of France, the Germans ran into a bunker which they pounded with 88 mm fire from across the River Meuse, whose width is of the order of 120 meters, at least at Marche. Spitting range for the 88. It took a prolonged DF bombardment to silence the thing, and there was scarcely a portion without a crater in it. Indeed, the bunker didn't look like a bunker anymore, so great were the surface deformities from the dozens of hits. Maybe someone can find the pic, which is a real attention getter.

 

Regards,

 

John Kettler

Edited July 12, 2015 by John Kettler

[c3k]

Good point akd - makes sense.

 

I made some more tests, so this is a revision of above mentioned observations.

• Shermans do fire both HE or AP and tend to shoot either/or consecutively. Not sure if it is due to distance.
• HE seems pretty useless. Since penetrations are rare, crew casualties are low. And even though they get blasted repetedly they do not cower, which seems odd.
• Even if you park a Sherman some 20-30 m straight ahead of a bunker, they are no less accurate or get more penetrating shots. Indications rather to the opposite, they miss the bunker completely.
• When using Target, it fires both HE/AP/MG so it is possibly the better alternative after all. But not all of the time.
• AP shells can take out a bunker with one shot. Too bad we can't choose which ammo to use, as HE seems less effective.
• Hits tend to appear in clusters, which indicates that the gunners aren't especially good at adjusting their aim (see below)

Clusters - one good aim, one way too low.

 

Clusters - all too low.

 

Single AP-shot takes out bunker.

 

 

Great job, love the pix.

 

The clusters: different tanks, or the same tank being given a new target command at the same bunker?

[rocketman]

It was a while since I did the test, but if I remember correctly each cluster is all hits from the same tank during one or several consecutive turns.

[Bulletpoint]

 

 

 

Clusters - all too low.

 

Just a guess, but it almost seems like the tank is aiming for the individual crewmembers inside?

[rocketman]

True. Looks excactly like that. I'm also thinking if the TacAI considers the target an MG rather than an object/structure, and therefore uses HE too much.