The unbearable lightness of heavy artillery

[Bulletpoint]

Visiting "Le Ham" on the "Road to Montebourg", I noticed the following problems with the 240mm howitzer artillery, making it seem a bit weak:

Shells will not blow away bocage, leaving the hedge hanging across the crater.

Shells will not blow away trenches, leaving them hanging across the crater.

Shells will be blocked by hitting tree branches, destroying the tree but not producing a crater. Impact on troops under the tree unclear. While mortar bombs did indeed sometimes detonate in the branches, I don't think a 300-pound shell would.

Shells will disable a wooden bunker with a direct hit, the bunker will not even start to burn however. There should only be a crater left.

Trees disappear readily in the shelled action square, but trees a bit farther from the impact are very unlikely to even lose their leaves.

A 2-story brick house took a direct hit but registered no damage - did not even get scratches on the walls.

[agusto]

Shells will be blocked by hitting tree branches, destroying the tree but not producing a crater. Impact on troops under the tree unclear.

In my experience tree-bursts are especially deadly due to the increased amount of shrapnell flying through the air.

[$Pec5]

I agree with Augusto. Tree Burst are ridiculously deadly. Would a 300lb shell explode in a tree? No idea.

Should trenches, bunkers, and bocage be eliminated from the blast of one of those shells? Seems to me like they should

The brick house thing is puzzling as well.

[YankeeDog]

Yeah... most of those are weird. As I commented in the other thread, I don't think BFC spent a heck of a lot of time working on the simulation of very large HE as it should really be quite rare at the CM level.

But a couple are probably not really an isse:

-- A large artillery shell could definitely detonate in a tree *if* the fuse was set to "quick". Technically, the fusing system on a 240mm shell is no different than the fuse on smaller shells. When set on "quick", the fuse is quite sensitive and will detonate the shell nearly instantly on contact with just about anything. And even with a large shell, treebursts would probably not cause a significant crater IRL -- a 240mm shell would turn the tree into toothpicks, and probably adjacent trees as well, but the shell has to bury itself in the ground to cause significant cratering. Earth absorbs explosive force very well. As already noted, treebursts can be desirable because they generate a very deadly shell fragment dispersion; much more deadly than the fragment pattern for a shell that detonates at ground level.

-- It's definitely not a given that a wood bunker would burn if hit by a large HE shell. It seems to be a common misconception that large HE explosions usually cause fires when they hit things like wood structures. They do not. In fact, in many cases large HE explosions are less likely to cause fires because the large explosion creates a temporary vacuum, literally blowing all of the oxygen away from the detonation point. If the bunker contained a significant amount of an inflammable material, it would be more likely to burn. But green wood logs and earth are not especially flammable.

Valid point, though, that regardless of whether a fire was started, a direct hit from such a large shell would probably turn the bunker into just a hole in the ground with some rubble around it; it's a bit silly that even when a very large shell or aerial bomb hits a bunker, the KO'd bunker still presents visually as a bunker. This is generally true of the game's damage model. For example, it doesn't matter if a tank's entire internal ammo stowage blows up, in the game it still presents visually in the game as an intact tank, when in fact large internal explosions can blow large parts of the tank (such as the turret) completely off of the chassis.

[Baneman]

Well, given that the damage model is unlikely to change in the near future, perhaps a quicker fix would be to eliminate structures ( like bocage ) where a crater exists - no roots, no bocage.

[Bulletpoint]

I agree that tree-bursts should be more devastating to infantry, but it didn't seem in this case that any nearby infantry took notice of it.

Well, I just presented this as feedback for the game developers to improve upon for their coming games. With so much detail modeled, it seems a bit jarring when things don't behave "believably"

[mjkerner]

-- It's definitely not a given that a wood bunker would burn if hit by a large HE shell. It seems to be a common misconception that large HE explosions usually cause fires when they hit things like wood structures. They do not. In fact, in many cases large HE explosions are less likely to cause fires because the large explosion creates a temporary vacuum, literally blowing all of the oxygen away from the detonation point.

Got that right! Now, if you could just get that message to Hollywierd!

[Bulletpoint]

Got that right! Now, if you could just get that message to Hollywierd!

I really hate the "gasoline barrel" film explosions

[womble]

It's a bit surprising that fortifications like bunkers and such aren't reduced to craters by "adequate" impacts, since the pits of foxhole fortifications often are overwritten by the crater object when hit direct with 105 and up. Likewise, since Bocage can be destroyed by DF HE or demo charges (which don't even leave a crater) it does seem like it should be possible to make "big" arty clear the stuff away when it makes a large enough crater.

[Bulletpoint]

It's a bit surprising that fortifications like bunkers and such aren't reduced to craters by "adequate" impacts, since the pits of foxhole fortifications often are overwritten by the crater object when hit direct with 105 and up. Likewise, since Bocage can be destroyed by DF HE or demo charges (which don't even leave a crater) it does seem like it should be possible to make "big" arty clear the stuff away when it makes a large enough crater.

It seems like somebody just forgot to put a check mark in the right box, somewhere in the code..

[YankeeDog]

It's a bit surprising that fortifications like bunkers and such aren't reduced to craters by "adequate" impacts, since the pits of foxhole fortifications often are overwritten by the crater object when hit direct with 105 and up. Likewise, since Bocage can be destroyed by DF HE or demo charges (which don't even leave a crater) it does seem like it should be possible to make "big" arty clear the stuff away when it makes a large enough crater.

I suspect part of the issue is that for gameplay reasons, it would not be ideal for a unit to simply disappear when destroyed -- there should be some sort of visual clue to the player that he's successfully KO'd the bunker (assuming he has a unit who can see it). So ideally, the regular "intact" bunker 3D model should be replaced with a "bunker rubble" 3D model, er sumfink.

Seems to me this would be doable, and it wouldn't surprise me if it's on "the list" somewhere. Apparently, it just hasn't reached the top yet...

[agusto]

I agree that tree-bursts should be more devastating to infantry, but it didn't seem in this case that any nearby infantry took notice of it.

What? Well, then i think this might be a rare occurance of the damage model not working as intended. My experience with tree bursts is that they so deadly in CM that even small shells like the one of the short 75mm sherman main gun regularly cause casualties at distances like 50 meters from the point of impact if they hit a tree. I rember one time, when i was playing the Troina campaign, i was shelling german positions in a small wood with a sherman tank and when i took some friendly fire casualties due to the tree bursts my first thought was "There must a sniper somewhere! Those explosions are so far away, it cant be them...". Tree-bursts are already extremely deadly in CM.

[Bulletpoint]

I suspect part of the issue is that for gameplay reasons, it would not be ideal for a unit to simply disappear when destroyed --

I think that the crater where the bunker used to be would be a clue

[JasonC]

"Would a 300lb shell explode in a tree?"

The weight of the shell doesn't matter at all, it is just a question of the fuze.

With a "quick" fuze, yes even a heavy shell would detonate on striking a branch.

With a "delay" fuze, it wouldn't. The fuze would still ignite internally, but the shell actually detonates 1/100 of a second later - by which point the shell will have hit the ground and buried itself as deep at it is going to go, and stopped.

So it is up to the gunners, basically. If they want to move lots of earth to destroy things on the ground or dig people out of entrenchments, they use fuze delay and they get that. If they want high airbursts to shower fragments on infantry not expected to have overhead cover, they use fuze quick and they get that.

[Bulletpoint]

"Would a 300lb shell explode in a tree?"

The weight of the shell doesn't matter at all, it is just a question of the fuze.

I'm no military expert, but it seems to me that even a very sensitive fuze would need to register some kind of change of momentum of the shell. The volume of a tree canopy is mostly air, filled with twigs and foliage. Most shells falling through a tree would hardly even touch those twigs and leaves, and even if they did, I must admit I don't understand how anything inside the shell would be able to register that a few leaves were brushed aside. The heavier the shell, the higher the total kinetic energy, and the more matter would be needed in front of it to cause a given change of velocity.

Now, of course the shell could also strike a big branch or the trunk, in that case I agree that it would burst above ground. But this should happen a bit rarely, and it seems in this game, if the shell intersects with any point of the tree's crown, it will explode.

[YankeeDog]

I'm no military expert, but it seems to me that even a very sensitive fuze would need to register some kind of change of momentum of the shell. The volume of a tree canopy is mostly air, filled with twigs and foliage. Most shells falling through a tree would hardly even touch those twigs and leaves, and even if they did, I must admit I don't understand how anything inside the shell would be able to register that a few leaves were brushed aside. The heavier the shell, the higher the total kinetic energy, and the more matter would be needed in front of it to cause a given change of velocity.

Now, of course the shell could also strike a big branch or the trunk, in that case I agree that it would burst above ground. But this should happen a bit rarely, and it seems in this game, if the shell intersects with any point of the tree's crown, it will explode.

Momentum-actuated fuses were used in WWII, but were not the most common type of fuse used with HE artillery shells, particularly large ones. Most artillery shells used other mechanisms to sense when the nose of the shell contacted something. Momentum-triggered fuses were usually used on ordnance designed to detonate only when it hit something really hard and substantial -- Armor-piercing shells and torpedoes being two good examples (in torpedoes, the primary fuse was often magnetic and/or pressure-sensing. Ideal detonation for a torpedo is directly *under* the ship. But most torpedoes also had a backup contact fuse in case they ran too shallow and made direct contact with a ship's hull).

The technology for fuses sensitive enough to trigger on contact with very light things like small twigs and leaves did exist in WWII, but was not common -- you usually only see this sort of very sensitive contact fuse used for special applications like AA shells, where was desirable to have the shell detonate if it brushed the very thin aluminum skin of an aircraft, but missed more substantial parts.

But most artillery shells could definitely be detonated by contact with a modest-sized branch, and certainly by a larger branch or tree trunk. I wouldn't expect a typical HE artillery shell fused on HE quick to make it very far into a tree canopy before detonating

[Bulletpoint]

Thanks for all replies, it's impressive how much military knowledge there is on this forum

[JasonC]

Bulletpoint - yes the shell needs to decelerate to initiate the fuze. But to give you an idea how sensitive they are, they require special internal "breakers" (effectively) to avoid being set off by hitting raindrops when fired in the rain. There are a series of those in the nose of the fuze, so a few successive impacts of small enough momentum won't set the round off. The same would prevent detonation just hitting a leaf or small twig. But any solid branch is going to change the shell momentum enough to set off a "quick" fuze. If occasionally it didn't, the round would still detonate after hitting the ground.

BTW, slight correction to my previous - the standard time delay for the "delay" fuze setting is 1/20 of a second, not 1/100.

[A Canadian Cat]

I vote for this thread as the winner of "Title of the year"

[DasMorbo]

I vote for this thread as the winner of "Title of the year"

+1 vote.

I am always astonished by how much brains is around the forum.

Direct contradiction to the often heard insult that only dumb/aggressive people are fascinated by military.

Best regards

Olf

[agusto]

+1 vote.

I am always astonished by how much brains is around the forum.

Direct contradiction to the often heard insult that only dumb/aggressive people are fascinated by military.

Best regards

Olf

That you have heard that insult so often has probably got something to do with you living in Germany. It is the Second World War and its prelude that still gives some people in Germany/Austria goose bumps when it comes to anything that is connected with the military. Some people think that beeing "fascinated" by the military (i put the "" there because i find that to be an unlucky phrasing) is equal to having militaristic and fascist views of how society should be organized. However IMO those are two different things that not necessarily have anything to do with each other.

[JonS]

The technology for fuses sensitive enough to trigger on contact with very light things like small twigs and leaves did exist in WWII, but was not common -- you usually only see this sort of very sensitive contact fuse used for special applications like AA shells, where was desirable to have the shell detonate if it brushed the very thin aluminum skin of an aircraft, but missed more substantial parts.

I'm not sure about that. Direct Action fuzes were already fairly common by the last 2-years of WWI, where they were used a lot to destroy wire entabglements - hitting the wire caused an airburst, which was a lot more effective at wire cutting than having the rounds burrow into the ground and heave everything upwards.

Nigel Evans indicates that Direct Action were a fairly standard fuze for British field arillery in WWII, not some special sauce reserved for particular applications.

[YankeeDog]

I'm not sure about that. Direct Action fuzes were already fairly common by the last 2-years of WWI, where they were used a lot to destroy wire entabglements - hitting the wire caused an airburst, which was a lot more effective at wire cutting than having the rounds burrow into the ground and heave everything upwards.

Nigel Evans indicates that Direct Action were a fairly standard fuze for British field arillery in WWII, not some special sauce reserved for particular applications.

Interesting. I seem to recall having read somewhere that AA fuses were especially sensitive, since large parts of even combat airplanes are fairly lightly built and therefore might not set off a "coarser" fuse on impact.

But perhaps very sensitive fuses were in wider use against ground targets than I have assumed. Certainly makes sense, given the general nastiness of airbursts. Even detonating just a meter or two above the ground as a result of hitting a bush or other minor vegetation on the way down would substantially increase a shell's lethality.

[JonS]

You might be thinking of VT/Prox, definitely a WWII development? They were reserved for aerial targets for quite a while, because of their extra effectiveness against a/c, their relative scarcity, and the fear of the fuze falling into enemy hands and being reproduced.

[YankeeDog]

You might be thinking of VT/Prox, definitely a WWII development? They were reserved for aerial targets for quite a while, because of their extra effectiveness against a/c, their relative scarcity, and the fear of the fuze falling into enemy hands and being reproduced.

No... something different. Vaguely recall reading something about a "super sensitive" fuse the Germans developed for AA use, so it definitely couldn't be VT, as the Germans never had VT.