MG classes of fire

[Bil Hardenberger]

I did a search on MG fire and was happy to discover that Grazing fire will be represented in CM.

However, what about Plunging fire? (with respect to the ground)

How about Fixed fire and Traversing fire? (with respect to the target)

These are all very important aspects of the MG battle. If they are in, great. If not, why?

[Dar]

Is there something more scientific to this than just tracking every slug? I was excited to learn that every bullet coming down the barrel will be tracked so that you can set up a decent crossfire, but what additional tracking is needed for fixed, traversing and plunging?

Thanks,

Dar Steckelberg

[Guest Big Time Software]

Uh, not familiar with the term "plunging fire", so can't help you with that one yet. Traversing fire is abstracted because the squads are abstracted. However, a MG will jump targets more frequently the closer they get to the MG. This reduces the potential of causing harm, but increases the number of heads that can be kept down.

Steve

[Guest L Tankersley]

<BLOCKQUOTE>quote:</font><HR>Uh, not familiar with the term "plunging fire", so can't help you with that one yet. Traversing fire is abstracted because the squads are abstracted.<HR></BLOCKQUOTE>

I believe that "plunging fire" is more or less what it sounds like - firing down on targets from above. I haven't heard it used wrt MG fire, but for example during the Civil War guns in forts in cliffs on the banks of the Mississippi would use plunging fire against boats on the river below.

I'm taking this opportunity to ask about the abstraction of squads as targets because I saw it brought up in one or two other threads. I presume that a squad has an assigned position value, along with associated data such as posture, activity, etc. that determines whether it can be seen/fired on as well as its vulnerability to that fire. My question is, what is the impact (if any) of casualties on the vulnerability of the squad?

For example, say a 12-man squad is running across an open field under fire. You don't track every small-arms round individually, so you've got some equations incorporating a random factor to work out how many casualties are taken. Assuming the same conditions, does a smaller (say, 8-man) squad have the same probability of suffering casualties?

I can think of arguments on both sides of the issue - you could say that with fewer men there's a smaller target and less likelihood of getting hit, but on the other hand, fewer men means fewer targets which implies more fire directed at each individual man. Obviously, there's a limit as the unit size approaches zero (when you've only got one man, you can't take more than one casualty). I don't have any agenda here as to how you handle this; I'm interested because of my background in modeling and simulation, and wondering how you've handled this question.

L. Tankersley

[Sefchick]

Plunging Fire is indirect fire over a hill say. It causes whats called a "Beaten Area" by the bullets. Its a way to interdict an area to the enemy in the same way as artillery. It was used alot during WW1 and it is in the Machine Gun Manuals of the US Army (Atleast it was when I got out in 93.).

I really haven't heard about its use in WW2.

I have heard about fire lanes and FPLs(Final Protective Line). Fire Lanes are used to keep an enemy from crossing say a road by shooting a machine gun down the road. Some call this Grazing Fire. FPLs are when the Machine Gun fires across the Squad,Platoon,Co. front when its about to be overrun. Any enemy whould be hit by Machine Gun fire if they cross that line.

Hope this helps...

Joe

[Bil Hardenberger]

Steve,

Here is a quote from FM 23-65 (Browning MG .50 HB, M2) Now I grant you that this is a current manual, but the basics of MG use haven't changed all that much since WW1:

<BLOCKQUOTE>quote:</font><HR>Classes of Fire with Respect to the Ground.

(1) Plunging fire. Fire in which the angle of fall of the rounds (with reference to the slope of the ground) is such that the danger space is confined to the beaten zone, and the length of the beaten zone is materially shortened. Plunging fire is obtained when firing from high ground to low ground, when firing from low ground to high ground, and when firing at long ranges.

(2) Grazing fire. Grazing fire is fire in which the center of the cone of fire does not rise more than one meter above the ground. When firing over level or uniformly sloping terrain, the maximum extent of grazing fire obtainable is about 700 meters

<HR></BLOCKQUOTE>

Sefchick is exactly right. Although I have heard of it's use in WW2. I cannot remember from where right now though... of course, if it was used in WW1 why wouldn't it have been used in WW2? If nothing else, it was definately available.

[Guest Big Time Software]

L. Tankersley, funny, I JUST answered this question in some other thread. Upshot is that the unit's headcount does affect chance of being hit, as well as its action (running in open ground is different than crawling).

Thaks for all the info on Plunging Fire. It was what I thought it was, but for some reason the term wasn't logged into the 'ol bean of mine

I'm not sure it is simulated, but I do know that height/slope does give larger weapons advantages for similar reasons. I'll ask if it could be extended to MGs. Charles is the one who knows all the details about the physics. Me? I just like to play with the results

Steve

[Guest L Tankersley]

[From the DEAD BODIES thread...]

<BLOCKQUOTE>quote:</font><HR>Dar, the chance of getting a hit on a squad is lowered in proportion to its headcount.<HR></BLOCKQUOTE>

Hmmm, on secon thought I may have been mistaken about having an agenda, just a tad.

I'm thinking about this statement, and about how Fionn's pitiful remnants of SS PG squads have been doing heroic duty, and I wonder. If your statement is taken at face value, it sounds like a squad that has only 2 of 8 original members active is only 1/4 as likely to take casualties from a given weight of fire. That sounds a bit off to me.

Now, I recognize that most units that suffer that many losses will probably be brittle and relatively unlikely to press forward, preferring to hug the ground or head for the rear, but in the cases where they don't it seems like they have an unrealistic resistance to incoming fire. I can see this being the case when subjected to Area Fire, but it seems to me that the effectiveness of aimed direct fire on such a unit shouldn't drop off so rapidly.

This might be something for you to think about/look into, anyway.

Oh, and since I've more or less abandoned all pretense of lurking, you can call me Lee.

Leland J. Tankersley

[Rob Deans]

Just a note on plunging fire. As far as MGs are concerned, plunging fire is less effective than fire delivered parallel to the ground. To use this example (bear with me)....

Take a 2 foot long piece of cardboard and glue 10 dowels, about two inches in height, so that they form a line accross the card. "The Section" (squad). Now look along the row of "men" at ground level so that they all appear to be lined up. Imagine firing a machine gun at the first man. If your bullets miss the first they have a good chance of hitting the next and if they miss him then the next and so on and so on. This is the power of the beaten zone and the effectiveness of grazing fire. One burst could hit multiple targets. Now take "The Section" and look at it from a high angle. Imagine shooting a machine gun at the first man. If the bullets miss they go into the ground. Remember, in this example, you are looking from the point of view of rounds that are plunging whether they are that way because of the higher elevation of the firer or because of the extreme range at which they were fired. This is why plunging fire is less effective than the same weight of grazing fire.

Thanks,

Rob Deans

[Fionn]

Lee,

1. Welcome from the lurker's closet .

2. Trust me, just because they are 1/4 size doesn't mean they are invulnerable.. Those 2 man units haven't faced any really serious enemy fire yet since they took the wall line.

IIRC they faced a bazooka, some long-range MG fire (500 metres or so) and in the south a few well-suppressed MGs.

When they attack the town they suffer more (as you will see soon). (And yes I've sent another turn in ...)

------------------

___________

Fionn Kelly

Manager of Historical Research,

The Gamers Net - Gaming for Gamers

[Guest Big Time Software]

<BLOCKQUOTE>quote:</font><HR>For example, say a 12-man squad is running across an open field under fire. You don't track every small-arms round individually, so you've got some equations incorporating a random factor to work out how many casualties are taken. Assuming the same conditions, does a smaller (say, 8-man) squad have the same probability of suffering casualties?

I can think of arguments on both sides of the issue - you could say that with fewer men there's a smaller target and less likelihood of getting hit, but on the other hand, fewer men means fewer targets which implies more fire directed at each individual man.<HR></BLOCKQUOTE>

At longer ranges, where fire is not aimed, the probability of casualties approaches (though not quite) proportionality to the number of men in the target unit. More men occupying more space means more probability that a bullet will hit something. But at closer range, when fire is more aimed, the casualties are much less correlated with the number of men. Medium range is a mix between these two cases.

<BLOCKQUOTE>quote:</font><HR>of course, if it was used in WW1 why wouldn't it have been used in WW2? If nothing else, it was definately available<HR></BLOCKQUOTE>

Positions were far more static in World War I which would allow for the kind of sighting and rangefinding necessary for effective plunging MG fire techniques, especially to areas outside of LOS (basically, indirect fire). I'm not saying it never happened in WW II, but I would bet it happened a lot more in WW I. In WW II low-level indirect fire like this would have been handled more often (and more effectively, I think) by company mortars. So plunging, indirect MG fire is unlikely to be included in CM (though I've taken note of it for possible future inclusion).

Charles

[Bil Hardenberger]

I just have this to say about Steve and Charles, fantastic.

You two are very candid and you go out of your way to answer these questions, some of which must make your eyes roll... if you keep this level of support up then I predict CM is going to be huge.

I, for one, appreciate the effort.

[Guest L Tankersley]

Sounds good!

[Simon Fox]

"In WW II low-level indirect fire like this would have been handled more often (and more effectively, I think) by company mortars. So plunging, indirect MG fire is unlikely to be included in CM (though I've taken note of it for possiblefuture inclusion)."

As you say Steve this may not be so relevant for the scope of CM1 but you should certainly think of it for CM3 as early war British and Commonwealth forces had organic machine gun battalions. In histories of these units you can often read descriptions of indirect "shoots" as preliminary "bombardments" to assaults (along with arty and mortars) also in defence there are descriptions of possible enemy assembly/concentration areas out of LOS being registered for interdiction by indirect fire. If you want any more info I can dig it out.