Why are rooftops more vulnerable to small arms?

[Pvt. Ryan]

I had a situation last night where the remaining member of a Syrian ATGM crew was lying on a rooftop of a small one story building. There was an entire US squad inside the building and an entire US squad on the roof of the building. The two US squads blazed away for two full turns expending all ammo before the lone Syrian ( ) finally died.

[Dirtweasle]

Holy cow. Where's that Lone Syrian guy that used to come around here!

Seriously though, that's messed up.

[LongLeftFlank]

Originally posted by YankeeDog:

I don't know about in Syria, but in many buildings here in the US, the low parapet wall that often surrounds the roof of a building is *not* necessarily as strong or as thick as the structural wall below it.

For example, the building in which I live, which is a 5-story tenement, the exterior walls are double-course masonry brick, with plaster and wood backing. But the roof parapet is just single-course masonry brick with a lead cap.

Given what's been posted here recently about shatter gap etc. with small arms rounds (& esp. 5.56), I'm not sure exactly what a single course brick wall like what's on my building roof would stop, but I think it's pretty obvious it would stop considerably less (or get shot to bits much faster) than the double course wall that starts below the roof level.

Of course, buildings vary alot. A friend of mine lives a more modern high-rise. His a apartment has a balcony with a low poured concrete wall around it -- more than enough to stop most small arms fire.

So maybe what we really need is some more building type options, to represent different strengths of construction. I find it hard to believe all buildings in Syria are of identical construction.

Regards,

YD

Yes, I've posted on this several times. There's a major distinction between the cover offered by

(a) "traditional" structures in which the (thicker) walls are the major load bearing elements and

( more modern (cheaper) structures in which an interior skeleton of steel and poured cement is surrounded by relatively thin cinderblock or "curtain" walls with big windows, designed to keep the weather out and not much else. This applies to the roof parapets as well, which exist mainly to shield any rooftop HVAC equipment from the elements.

In cities like Damascus and in WWII Europe you'd also see older ("prewar") apartment buildings from the pre air-con era which were based on structural steel but retained thicker walls and smaller windows. These buildings would have interior courtyards and stairwells (so you'd be vulnerable moving between floors).

There's also © cinderblock houses, sheds and shacks, which offer great concealment but weak cover.

In (a) the thick load-bearing walls of masonry or mud brick provide good solid cover, akin to a stone or cement "wall". You can fire out windows from a kneeling position and mousehole if you have time. On the other hand, if the walls are blown out part of the ceiling/roof may come down on you too depending on how good the rafters are.

In (, since the walls are flimsy, your best cover is to lie prone on the cement floor/balcony (if you're higher than the shooter) in spite of loss of visibility or get behind the pillars. Even if the walls are blown away (which even bullets can do over time), the structural skeleton will likely retain its integrity and still offer cover (though far less concealment). This building type wouldn't appear at all in WWII but should form the majority of modern multistory (>2) structures. They just don't build 'em like they used to.

FWIW. Civil engineering grogs chime in...

[ March 13, 2008, 03:18 PM: Message edited by: LongLeftFlank ]

[Battlefront.com]

Dirtweasele,

The game engine mechanics / maths do not consider the angles.

Yes and no. Yes angle is always considered in terms of determining the path of the weapon's trajectory and what it intersects with. It's easier to hit something on a lower roof from a higher roof than vice versa, for example. The no part is..

But, if I understand you, since the paraphet wall is only 1/3 or 1/2 the height of a normal wall that is what is considered not the multiple planes of material and not that they are at angles, do I have that correct?

Correct. There is no incredibly complex materials simulation of buildings like this. It would be a bad use of CPU cycles when abstraction (aka "luck") does very well at covering the possibilities. The reason is that with the exception of very marginal shots and extreme angles there really shouldn't be much variation in real life.

BTW, we've had a detailed discussion about building materials in the ME and Syria in particular. The conclusion is that the run of the mill buildings are most likely built to lower engineering standards than what ballistics tests are conducted against. The most common material appears to be hollow concrete block walls one block thick. Brick, reinforced concrete, and other more robust materials are likely found only in high end buildings. We can't simulate every possible combo of building materials so we've simply gone with what is most common.

When we move to Europe we'll definitely have to increase things to include (at least) two types since European urban buildings are generally a lot tougher than rural farmhouses, but not necessarily so. An old Norman stone house is certainly night and day different than one made from wood and plaster.

Lastly, Charles has not only made some building penetration tweaks for some rounds but he has also decreased one of the variables for rooftops that should increase protection a bit more for the occupants.

Steve

[Battlefront.com]

To answer John's question about why rooftops are used at all... well, why are the crests of hills used? Why are woods used even when the enemy has VT fuzes and the ability to use them? Why do soldiers crouch around the corner of a building leaving themselves exposed to fire from all the other angles? Etc.

The answer is always the same... because the tactical situation at that very second offers an overall better opportunity for using the terrain in that way than in some other way. Change a variable or two and what was once a great place may suck, or what once sucked may become great. Monte Cassino comes to mind when talking about a bad place made great

Rooftops in an urban area are extremely powerful when they are orientated correctly. But like a hill or other prominent feature, it ceases to be such a great place to be if the enemy has the ability to direct fire at it without an equal or greater ability to respond.

There is a video many of us saw last year that showed an Insurgent attack on (supposedly) a US FOB. It appeared to be a key building that had been reinforced with sandbags and all kinds of stuff. The insurgents attacked it from several angles at once and it was obvious that despite the reinforcement the occupants within it were definitely worse off than the insurgents in the streets. Eventually something VERY big hit it and the whole thing appeared to explode.

Lesson here is what I've already said... a roof (or more generally a building) is an advantage only as long as the enemy is at a disadvantage. Once the advantage is lost the roof/building can become an extremely unpleasant liability. Especially if a tank or a JDAM comes into the picture!

Steve

[LongLeftFlank]

Originally posted by Battlefront.com:

Correct. There is no incredibly complex materials simulation of buildings like this. It would be a bad use of CPU cycles when abstraction (aka "luck") does very well at covering the possibilities. The reason is that with the exception of very marginal shots and extreme angles there really shouldn't be much variation in real life.

BTW, we've had a detailed discussion about building materials in the ME and Syria in particular. The conclusion is that the run of the mill buildings are most likely built to lower engineering standards than what ballistics tests are conducted against. The most common material appears to be hollow concrete block walls one block thick. Brick, reinforced concrete, and other more robust materials are likely found only in high end buildings. We can't simulate every possible combo of building materials so we've simply gone with what is most common.

When we move to Europe we'll definitely have to increase things to include (at least) two types since European urban buildings are generally a lot tougher than rural farmhouses, but not necessarily so. An old Norman stone house is certainly night and day different than one made from wood and plaster.

Lastly, Charles has not only made some building penetration tweaks for some rounds but he has also decreased one of the variables for rooftops that should increase protection a bit more for the occupants.

Steve [/QB]

I understand your game design decision, but continue to disagree with it and feel strongly that realistic urban battlescapes is a key element that will make the Marines module a grittier, more infantry-centered and more intense gaming experience than CMSF.

Selecting and "strongpointing" sturdy buildings is a staple of asymetrical MOUT from Stalingrad and Ortona to the present day. This isn't a trivial matter. If any building can be alternately a miniature fortress and a piece of Swiss Cheese, then almost no historical tactics can be reasonably replicated.

And sure, fine, the US can always call in a JDAM (a la our earlier debate on the 'futility' of Syrian fortification in general), but that continues to be a red herring to me. I mean, we already know the Syrians are massively outgunned and in nearly all battles are not fighting to "win", but rather to bloody the enemy before being overwhelmed.

Terrain is the "third side" in any wargame or war, and how units interact with it is as decisive as their use of firepower. And in MOUT, the terrain is largely buildings and walls.

Without at least a minimal differentiation between "heavy" and "light" buildings, a lot of the richness already in the game becomes, er, window dressing and it's basically Pac Man with guns.

Wacawacawacawaca

[Battlefront.com]

LLF,

I understand your game design decision, but continue to disagree with it and feel strongly that realistic urban battlescapes is a key element that will make the Marines module a grittier, more infantry-centered and more intense gaming experience than CMSF.

Well, we agree that realistic urban battlescapes are key. The difference is we think we've got it already Sure, it isn't perfect... but nothing ever is. As far as I know nobody even comes close to the level of realism we have put into CM:SF thus far. The game, as is, is certainly far, far, far away from having MOUT "window dressing", so I can't really take your final comment seriously.

I too would like to see the ability for the scenario designer to designate a specific building "fortified" and have it exhibit stronger defensive qualities. The development problems with this, unfortunately, prevent it from being included at this point. Since it is RARE for a building in the middle of a dynamic battle to be found and manned in a fortified state the absence of it isn't really that important. For a counter-insurgency sim it would probably be far more important, but that's not what CM:SF is.

Steve

[Rocky Balboa]

Originally posted by Battlefront.com:

I too would like to see the ability for the scenario designer to designate a specific building "fortified" and have it exhibit stronger defensive qualities. The development problems with this, unfortunately, prevent it from being included at this point. Since it is RARE for a building in the middle of a dynamic battle to be found and manned in a fortified state the absence of it isn't really that important. For a counter-insurgency sim it would probably be far more important, but that's not what CM:SF is.

Steve

Sounds like an idea for another module ...... CM:SF Special Ops ????

[Dirtweasle]

Originally posted by Battlefront.com:

...

BTW, we've had a detailed discussion about building materials in the ME and Syria in particular. The conclusion is that the run of the mill buildings are most likely built to lower engineering standards than what ballistics tests are conducted against. The most common material appears to be hollow concrete block walls one block thick. Brick, reinforced concrete, and other more robust materials are likely found only in high end buildings. We can't simulate every possible combo of building materials so we've simply gone with what is most common...

[...]

...Lastly, Charles has not only made some building penetration tweaks for some rounds but he has also decreased one of the variables for rooftops that should increase protection a bit more for the occupants.

Steve

So I'm playing a scenario, (al Uhbula (sp?)) a custom scenario from over at the CM MODS website), and I'm playing as the Americans. The enemy is up on the second floor balcony and shoots at an advancing squad. My squad is roughed up a bit, and goes to ground, crawls across the street into a building. Elapsed time ~20, maybe 25 - 30 seconds. I have an M1A1 Tank in support, so I area target the place where the enemy shots came from. The tank depletes all the HEAT rounds, at least 4 or 5 for sure might 've bewn more. Yet the building is by all appearance unscathed.

How come?

My expectation was the 120mm HEAT rounds would knock the heck out of that wall. Drive holes through it and rearrange the contents behind it. I'm not expecting a catastrophic explosion from the HEAT round, but a little something a few nice holes at the least.

Not sure what happened to the enemy in the bldg by the way after my tank rounds were so ineffective I gave up the sceanrio for the night.

[Clavicula_Nox]

Originally posted by Rocky Balboa:

</font><blockquote>quote:</font><hr />Originally posted by Battlefront.com:

I too would like to see the ability for the scenario designer to designate a specific building "fortified" and have it exhibit stronger defensive qualities. The development problems with this, unfortunately, prevent it from being included at this point. Since it is RARE for a building in the middle of a dynamic battle to be found and manned in a fortified state the absence of it isn't really that important. For a counter-insurgency sim it would probably be far more important, but that's not what CM:SF is.

Steve

Sounds like an idea for another module ...... CM:SF Special Ops ???? </font>

[MikeyD]

I believe the life expectancy on balconies was tweaked slightly this or last build (I can't recall which) to make it a bit less suicidal. But I do agree, I've scampered my men into cover only have a "D'oh!" moment when i realised they've all run to the unseen balcony on the far side of the building! When making tactical considerations I have to consider whether the building i'm entering has balconies or not. Balconies change the whole dynamics of the fight.

[Dirtweasle]

You know, that's true and maybe I should 've mentioned that in my posts about pathfinding. The little buggers just have to get out on the balcony.

[YankeeDog]

Ya, I've said it before, but I'll restate here to try to get some momentum on this:

Balconies are basically suicide; they're a really bad place to be in a firefight.

I have no particular problem with balconies being modeled this way -- I've seen buildings with balconies that are very open and exposed, with nothing more than steel railing or perhaps a very thin masonry wall. Some balconies I've seen do have concrete walls that would offer much more protection.

But if CMSF can only model one type of balcony, the "open and exposed" type is fine with me.

However, if this is the case, the TacAI shouldn't be so gung-ho to send entire squads out onto a balcony, where they line up like napoleonic musketeers and get slaughtered by the first burst of automatic weapons fire that comes their way. While such behavior might make sense for conscript squads, I've seen even Veteran US squads do this, usually with disasterous consequences.

End result right now is that you have to avoid buildings with balconies like the plague, because your little pixel soldiers will head out onto the balconies and get slaughtered whether you like it or not. Only exception is that I will sometimes send a small team into a balcony building as an OP. But in this case, I'm hoping that the team will not be spotted, and I'm not planning on fighting from the building.

I need to play with 1.08 a bit more to be sure, but what I've seen so far suggests that even with the slightly improved balcony/roof cover of 1.08, the above still holds true. Soldiers on balconies might not die quite as quickly, but they still die. when exposed to anything worse than long-range, harassing fire.

My SWAG is that what's causing the issue is the TacAI trying to get as many guns as possible in the squad into a good firing position. In general, this is an important part of what the Infantry TacAI needs to do. But the "get the guns on the line" demon in the TacAI needs to be balanced with cover, bunching, and preservation demons.

Consider how the TacAI treats better forms of linear cover like low walls and trenches: If squad facing is perpendicular to the linear cover, the squad shakes out along the linear cover, getting most of the soldiers in the squad (a) protected behind the linear cover, and ( able to fire over linear cover. While there has been the occasional hiccough, the squad TacAI has worked very well for me in this kind of situation most of the time.

But the TacAI seems to try to do roughly the same thing on on balconies as it does for low walls and trenches. And balconies are nowhere near as good cover as a low wall or trench. Worse, the balcony is generally much shorter end-to-end than a low wall or a trench, meaning the squad gets highly concentrated, standing almost shoulder to shoulder on the balcony.

So IMHO, specifically WRT balconies, the TacAI needs to give exposure, bunching, and preservation higher piority, at the cost of firepower. This means at most a single steam on any given balcony, with the rest of the squad further inside the building, better protected (but with less LOS/LOF). I do recognize this would reduce available firepower, but lining up an entire squad on a balcony is just too dangerous to be useful 99% of the time.

And arguably, once the lead starts flying, even the lookouts on the balcony should probably pull back -- if they're not already casualties!

Rooftops can present some of these issues, but in my experience not a bad because the TacAI doesn't bunch soldiers up so much on rooftops.

At any rate, temporary workaround for now if you simply must occupy a balcony building, at least when you're playing US, is to always split teams so you can spread out to different floors and/or use face commands to spread out to different walls. Not ideal, but better than having the entire squad lined up on one balcony like they're watching a parade go by.

In summary, balcony =/= trench or low wall. Balconies are inferior cover, and the TacAI needs to take this into account.

Loving the continued improvements, BFC; keep it up!

Cheers,

YD

[Childress]

Originally posted by YankeeDog:

From what I've read, when fighting from inside buildings, trained infantry stays as far away from the windows as possible.

That is, you fight from deep inside the room, and fire out through the windows from there.

Not currently, possible. CMSF restricts the deployment of the squad to the outer peripheries of rooms. No intermediate positions for ambushing or extra concealment as in CM1x; they're always nose to window- or balcony. Maybe something to revisit in the future.

[YankeeDog]

Defintely something to revisit, then. It's not so bad right now in "regular" buildings w/o balconies, but when there's a balcony, sending the entire squad to the periphery is creating an unrealistically high level of exposure.

Cheers,

YD

[SgtMuhammed]

Originally posted by Dirtweasle:

So I'm playing a scenario, (al Uhbula (sp?)) a custom scenario from over at the CM MODS website), and I'm playing as the Americans. The enemy is up on the second floor balcony and shoots at an advancing squad. My squad is roughed up a bit, and goes to ground, crawls across the street into a building. Elapsed time ~20, maybe 25 - 30 seconds. I have an M1A1 Tank in support, so I area target the place where the enemy shots came from. The tank depletes all the HEAT rounds, at least 4 or 5 for sure might 've bewn more. Yet the building is by all appearance unscathed.

How come?

My expectation was the 120mm HEAT rounds would knock the heck out of that wall. Drive holes through it and rearrange the contents behind it. I'm not expecting a catastrophic explosion from the HEAT round, but a little something a few nice holes at the least.

Not sure what happened to the enemy in the bldg by the way after my tank rounds were so ineffective I gave up the sceanrio for the night.

Because there are no damage decals or the * system from CMx1. The only visual of damage to the building is when the wall goes away or when the building crashes to the ground. Damage decals are being looked in to for vehicles and buildings but aren't a top priority right now.

The enemy inside though are feeling the HEAT believe me. I have started using much more supressive fire lately since I quit using vehicle smoke. 3 or 4 rounds from a 120 or 105 usually means my infantry has no one to fight when they enter the building.

[hoolaman]

Originally posted by YankeeDog:

Defintely something to revisit, then. It's not so bad right now in "regular" buildings w/o balconies, but when there's a balcony, sending the entire squad to the periphery is creating an unrealistically high level of exposure.

Cheers,

YD

I should point out that the balcony and rooftop protection was increased in 1.08, and infantry behaviour also tweaked to the effect that suppression makes them duck and therefore not die.

So I find it much improved. YMMV of course.

[Childress]

Originally posted by YankeeDog:

It's not so bad right now in "regular" buildings w/o balconies, but when there's a balcony, sending the entire squad to the periphery is creating an unrealistically high level of exposure.

Agreed. Addressing a minor, unglamorous limitation like this would go a long way towards decreasing the 'flavor' deficit in regards to infantry ops.

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[SgtMuhammed]

Snipers don't go out on balconies. They stay back where you can't see them and shoot at you through very small openings.

[Combatintman]

Originally posted by Adam1:

Personally, I believe balconies should add to the protection of a building, with the men staying off them. Only snipers should ever be out there...when the enemy is far.

Yes and no - of course balconies add to protection (not much mind - 7.62 GPMG will go through balconies and walls of most buildings) but there is a reason sometimes why people venture out onto them. Difficult to see/engage an enemy at street level if you're in a building with the balcony in the way.

Snipers are more likely to be on rooftops with small loopholes knocked out of the wall. There are plenty of pictures of both Iraq and Afghanistan showing this.

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[YankeeDog]

Originally posted by Hoolaman:

I should point out that the balcony and rooftop protection was increased in 1.08, and infantry behaviour also tweaked to the effect that suppression makes them duck and therefore not die.

So I find it much improved. YMMV of course.

Yes, as I noted above, I have seen some improvement in 1.08, and I'm looking forward to experiencing more of the improvements I play more under this version. Had a nice hour of game-time tonight involving some MOUT situations, in fact, but balconies didn't really come into play.

Anyway, as I tried to point out above, I don't think the "cover level" of balconies, and soldiers' ability to use it, is the root of the problem. The most important issue seems to be the way a squad will bunch up onto a balcony. It's great as long as there's little or no incoming fire -- everyone in the squad can bring their weapons to bear.

But with the soldiers so badly bunched up, very bad things can happen. . . twice already since 1.07 came out I've seen an entire squad standing on a balcony taken out by a single RPG. Granted, both of these incidents were in 1.07. But the soldiers appear to be exhibiting the same bunching behavior in 1.08. I'll have to see what happens the next time I catch an RPG sailing towards a balcony, but I'm not optimistic; with the squad that bunched up, any HE should be quite deadly.

And I do understand that if a squad wants to direct fire onto a street-level target from an upper floor with a balcony, they're going to have to go out on the balcony; the balcony floor blocks LOS otherwise. But I would still be really surprised if it's advisible for all 9 men of a Stryker squad troop out onto the same balcony and queue up like a chorus line.

At some point, some kind of dispersion routine has to kick in. As I noted, the player can do this manually by ordering split squads, but I view this as rather tedious micromanagement. I should be able to order a squad into a certain floor of a building, give them a face order, and have them take up *reasonable* (not necessarily perfect) fighting positions on said floor. I do not view all nine men lined up shoulder to should on the same balcony as a reasonable fighting position.

As dire complaints seem to be all too common around here, allow me to finish this by saying that, in general, I'm having a lot of fun with 1.08 (as I did with 1.07), and that this issue is certainly not "ruining the game" for me. I only bring it up to point out a specific aspect of the game I think could use some improvement.

Cheers,

YD