Fire Lane. Has there been a change?

[TimNiesen]

A Vietnam veteran came to Don1's office for back cracking a few days ago. They discussed this issue. He pointed out that most LMG were in the ground at about eight inches. In contrast a tripod MMG/HMG was at most 12 inches off the ground. Except if you are firing down a highway there are normally substantial variations in height over any long length of open ground. Three hexes is 120 yards. The VIetnam veteran thought that the house rule restriction of 3/5/7 for fire lanes for LMG/MMG/HMG was generous. Tim

 

[Actionjick]

A Vietnam veteran came to Don1's office for back cracking a few days ago. They discussed this issue. He pointed out that most LMG were in the ground at about eight inches. In contrast a tripod MMG/HMG was at most 12 inches off the ground. Except if you are firing down a highway there are normally substantial variations in height over any long length of open ground. Three hexes is 120 yards. The VIetnam veteran thought that the house rule restriction of 3/5/7 for fire lanes for LMG/MMG/HMG was generous. Tim

Really need some input from our infantry friends.

 

[ColinJ]

The drop of 5 feet seemed a bit much so I checked the calcs. Something seems off, but I could be wrong. Since the initial velocity downwards is 0, you only need to use d = 0.5at^2. If I botched the calc., let me know
d = 0.5 * 9.81 * (320/820) * (320/820) = 0.75m ~ 2.5'

Note that round will drop the same amount in a set amount of time. In 0.5 seconds, all rounds fired horizontally will drop 1.22m or 4'. In a set time, the distance travelled horizontally will change with muzzle velocity, but not the amount the round drops in the vertical.

 

[bendizoid]

Let’s say a crouching man has 4’ of target. It takes about .7 seconds for a bullet to drop 4’. (1/2 32 ft/sec^2*(.7^2)~4’. If the bullets travels 820 meters/sec * .7 seconds= 574 meters divided by 40 meters/hex = 14.3 hexes.


Apparently the firelane rules are fine as written.

 

[fzmann]

Really need some input from our infantry friends.

I wasn't an 0302 (USMC infantry officer), but rather an 0802 (party with arty!), but my M60 mg manual taught us (every Marine officer trained as an infantry platoon leader at the Basic School):
Effective range: 1100 meters
Maximum extent of grazing (the cone of the fire will hit an average height standing man) fire: 700 meters

Note that grazing fire was taught as the most desirable for FPL's (final protective line). FPL, I interpret as the USMC-taught equivalent of a fire line. However, the manual instructs to accept an FPL line that could be significantly shorter than 700 meters, and not consider that distance undesirable. The reason for this is the terrain will unlikely not allow for the 700 meter range.

In ASL terms, 700 meters is roughly 18 hexes. An American HMG has a 12 hex max normal range, but a .50 cal has a 16 hex normal max range. So I think an ASL fire lane being restricted to the MG max range is a game mechanic, and not an unreasonable one.

 

[Actionjick]

I wasn't an 0302 (USMC infantry officer), but rather an 0802 (party with arty!), but my M60 mg manual taught us (every Marine officer trained as an infantry platoon leader at the Basic School):
Effective range: 1100 meters
Maximum extent of grazing (the cone of the fire will hit an average height standing man) fire: 700 meters

Note that grazing fire was taught as the most desirable for FPL's (final protective line). FPL, I interpret as the USMC-taught equivalent of a fire line. However, the manual instructs to accept an FPL line that could be significantly shorter than 700 meters, and not consider that distance undesirable. The reason for this is the terrain will unlikely not allow for the 700 meter range.

In ASL terms, 700 meters is roughly 18 hexes. An American HMG has a 12 hex max normal range, but a .50 cal has a 16 hex normal max range. So I think an ASL fire lane being restricted to the MG max range is a game mechanic, and not an unreasonable one.

Thanks!

 

[Philippe D.]

How often do you have the opportunity, in an ASL game, to lay down a Fire Lane that goes further than 8 hexes? In practice, I don't think it makes much of a difference.

 

[buser333]

How often do you have the opportunity, in an ASL game, to lay down a Fire Lane that goes further than 8 hexes? In practice, I don't think it makes much of a difference.

Many of my Fire Lanes go the full distance, and oftentimes I wish they could go further. Fire Lanes are one of your greatest friends as a defender (and even sometimes as the attacker), especially through soft hindrances.

 

[fzmann]

How often do you have the opportunity, in an ASL game, to lay down a Fire Lane that goes further than 8 hexes? In practice, I don't think it makes much of a difference.

Totally dependent on the terrain and the circumstances. A lot of the BFP boards (e.g. OtO, BFPDW4a & b), offer opportunities for max range FL's.

 

[fzmann]

Many of my Fire Lanes go the full distance, and oftentimes I wish they could go further. Fire Lanes are one of your greatest friends as a defender (and even sometimes as the attacker), especially through soft hindrances.

Can I assume your comment about FL's sometimes aiding the attacker refers to the machine gun not able to attack elsewhere? This is true, and an example of the many choices we're forced to make during an ASL game

 

[buser333]

Can I assume your comment about FL's sometimes aiding the attacker refers to the machine gun not able to attack elsewhere? This is true, and an example of the many choices we're forced to make during an ASL game

No. I mean using them as a weapon to aid in the attack by helping to make defensive repositioning difficult.

 

[Stewart]

Found it...A.2 Mentions 2/5/7 range./

 

[bendizoid]

Let’s say a crouching man has 4’ of target. It takes about .7 seconds for a bullet to drop 4’. (1/2 32 ft/sec^2*(.7^2)~4’. If the bullets travels 820 meters/sec * .7 seconds= 574 meters divided by 40 meters/hex = 14.3 hexes.


Apparently the firelane rules are fine as written.

My math is wrong, in .7 seconds a bullet drops ~ 8’, not four feet, it takes .5 seconds for a bullet to drop 4’ and it travels 10.25 hexes. This is my final answer. Thank god I got it in time before somebody else destroyed my theory with better math.

 

[Actionjick]

My math is wrong, in .7 seconds a bullet drops ~ 8’, not four feet, it takes .5 seconds for a bullet to drop 4’ and it travels 10.25 hexes. This is my final answer. Thank god I got it in time before somebody else destroyed my theory with better math.

Well at least you had the sack to try the math. I looked at it and decided to hit the sack instead! Siesta.

 

[Jwil2020]

Well, I think the muzzle velocity of an MG42 was 820m/sec. I'll leave it up so someone else to calculate, how far a bullet would drop vertically after travelling two hexes, i.e. 80m or in 1/10 of a second. And I will not begin to think about how far it could travel if the MG would not be fired exactly horizontally...

That said you may lay a FL shorter than is maximum allowed distance. If you want, you can limit the length of the FL of a German LMG to less than 8 hexes.

von Marwitz

FWIW all bullets travel in a parabolic shape. A modern 30-06 hunting rifle cartridge (.30 caliber) is considered a high-powered rifle with a very flat trajectory. That said, most north American hunters will usually zero their 30-06 to hit the bull's eye (point blank) at 200 yards. This means that the bullet will hit about 2 inches above the bull's eye at about 100 yards, and will hit about 71 inches (almost 6 feet) below the bull's eye at 500 yards (457m). Therefore, the shooter would have to hold almost 6 feet high to hit the bull at that extreme range (and assuming NO wind to factor in).

This is only a representative example. Bullet trajectories will differ slightly depending on powder load, bullet weight, barrel length, etc. The key point is that bullets begin dropping as soon as they leave the muzzle, and they drop very quickly.

It is reality of bullet trajectories that have always made me a little suspicious of the science (realism) behind the FL rule. But that's just me....

 

[klasmalmstrom]

Personally I've never seen a Fire Lane just a constant (more-or-less) firing of the machine gun at a fixed angle/direction/etc.

I've more seen it as representing a machine gun crew that is concentrated on firing along a specific avenue/"area", constantly lowering/raising the barrel as needed depending on where in the "area" the targets are, etc.

 

[Jazz]

It is reality of bullet trajectories that have always made me a little suspicious of the science (realism) behind the FL rule. But that's just me....

There's your problem....expecting reality from a game with cardboard playing pieces.

I'll sit down now....

 

[Actionjick]

Personally I've never seen a Fire Lane just a constant (more-or-less) firing of the machine gun at a fixed angle/direction/etc.

I've more seen it as representing a machine gun crew that is concentrated on firing along a specific avenue/"area", constantly lowering/raising the barrel as needed depending on where in the "area" the targets are, etc.

It seems as if that's what it would entail.

 

[Jwil2020]

It seems as if that's what it would entail.

Actually, I don't expect reality from any game. I happen to be solo playing Bulge 65 right now, and having a blast. Talk about a departure from reality! My only point with the FL rule is that it is quite realistic if targets are crossing the FL sequentially- giving the MG crew time to adjust the aim point as each target appears. But not so much if the targets are crossing the FL simultaneously at vastly different ranges.

But hey, the rule is the rule. It's been on the books for 36 years, and is an important part of the game mechanics. I recognize the design intent was to give MGs more impact on the battlefield, which the rule accomplishes quite nicely. My philosophy is to try to apply the rules as written as best as I understand them, and enjoy the great experience ASL provides me.

Game on, my friends!

 

[klasmalmstrom]

I can see the (at least) morale effect of having a machine gun firing in one's direction - even when only a fraction of the bullets may reach one's exact "area". Just noticing bullets rip into the ground 20-30 meters close to you could be enough to have an effect.