Query re aircraft and AAA cielings

[el cid again]

This is a proposal to address two different issues:

1) Planes flying missions at very high altitudes and related house rules against them [the proposal meaning no need for house rules any more]

2) Planes being beat up by AAA at unrealistic altitudes (except the very rare guns that COULD do that)

Short form proposal:

A) Change the cieling field for aircraft to list the optimum operating altitude, OR OOA plus some fixed amount (e.g. 3000 feet).

B) Change the altitude field for AA guns and DP guns to the effective altitude of the gun.

Note: Right now DP guns (most or all) have NO altitude rating at all - the field says "0" - so proposal B will RESTRICT AAA in altitude but TURN ON guns that are not firing at all right now. Backup plan: IF giving DP guns an altitude rating STILL does not see them work in the AAA role, REDEFINE DP guns as AAA guns, which ARE in effect DP guns, since they shoot at surface as well as air targets.

Problems: SOME planes optimum operating altitude is sea level - mostly some kinds of flying boats. ALL planes optimum operating altitude is not a rigid line, and they are effective SOME distance above that altitude. Thus the possibility of using a fixed value like OOA + 3000. That way you could fly at some altitude above OOA, but not very far - not say to 35000 feet with a plane that is a dog at 15000 feet. Another issue is that you won't be able to tell a flying boat to do recon at 30,000 feet - which most could do. But this system would give planes with good altitude performance a real advantage, and it would not forbid them from flying over an arbitrary level (e.g. 25,000 feet) if they could do that.

[akdreemer]

ORIGINAL: el cid again

This is a proposal to address two different issues:

1) Planes flying missions at very high altitudes and related house rules against them [the proposal meaning no need for house rules any more]

2) Planes being beat up by AAA at unrealistic altitudes (except the very rare guns that COULD do that)

Short form proposal:

A) Change the cieling field for aircraft to list the optimum operating altitude, OR OOA plus some fixed amount (e.g. 3000 feet).

B) Change the altitude field for AA guns and DP guns to the effective altitude of the gun.

Note: Right now DP guns (most or all) have NO altitude rating at all - the field says "0" - so proposal B will RESTRICT AAA in altitude but TURN ON guns that are not firing at all right now. Backup plan: IF giving DP guns an altitude rating STILL does not see them work in the AAA role, REDEFINE DP guns as AAA guns, which ARE in effect DP guns, since they shoot at surface as well as air targets.

Problems: SOME planes optimum operating altitude is sea level - mostly some kinds of flying boats. ALL planes optimum operating altitude is not a rigid line, and they are effective SOME distance above that altitude. Thus the possibility of using a fixed value like OOA + 3000. That way you could fly at some altitude above OOA, but not very far - not say to 35000 feet with a plane that is a dog at 15000 feet. Another issue is that you won't be able to tell a flying boat to do recon at 30,000 feet - which most could do. But this system would give planes with good altitude performance a real advantage, and it would not forbid them from flying over an arbitrary level (e.g. 25,000 feet) if they could do that.

No problemn with A or B, preaching to the choir here...

[Andrew Brown]

ORIGINAL: AlaskanWarrior
No problemn with A or B, preaching to the choir here...

So, if we do implement A and/or B, then we will need the following:

For A] A list of all EFFECTIVE altitudes for all aircraft (I would prefer to use a value of effective altitude plus an additional value).

For B] A list of all EFFECTIVE altitudes for AA and DP guns.

Sounds like quite a bit of work, though.

Andrew

[witpqs]

I know the intention is to work around a limitation in the game engine... but I have reservations about this change.

Contrived example:

An AAA (or DP) gun could reach say 16,000 ft

An aircraft could reach 20,000 ft

This means the a/c in question could completely avoid the ground fire by flying high enough, even if its 'optimum' altitude were 10,000 ft. After the change this would no longer be the case.

Limiting things this way just doesn't make sense to me.

I do like giving a real advantage to a/c with good high altitude performance, and I do like avoiding a very annoying house rule.

I'm concerned that the a/c change would go too far. Fighters that were a dog at 25,000 ft now couldn't even try to intercept?

Could you give a few examples of a/c that would be modified?

[el cid again]

An AAA (or DP) gun could reach say 16,000 ft

An aircraft could reach 20,000 ft

This means the a/c in question could completely avoid the ground fire by flying high enough, even if its 'optimum' altitude were 10,000 ft. After the change this would no longer be the case.

Limiting things this way just doesn't make sense to me.

Let us consider a real world, historical example for which we have hard evidence:

The first raid on Clark AAF came in at 25,000 feet. The heavy AA guns had a cieling of 2,000 to 4,000 feet BELOW this. The AA guns fired, and the bursts (for maximum time of flight) were clearly well below the bombers. This was exactly what the attackers had in mind, and they had drilled for this attack for so long that, in spite of the fairly high altitude and lack of Norden bomb sights, they achieved the most accurate air bombardment of the war.

I am not sure why you might have a problem with bombers coming in over the AAA ceiling? It WAS an option, most of the time. Only the advent of very heavy AAA (150 and 203 mm) caused B-29s to be issued orders to avoid Singaport and certain targets in Japan. The game also increases first day of war Japanese bombing success - effectively duplicating the situation really existing on that day (and never again).

We also have a more complex option: we could rate certain planes (the best case might be recon planes) for service cieling - and others for optimum operating altitude. That way the recon planes could go in very high and be almost interception free except if the enemy fielded high altitude fighters - an accurate model.

[el cid again]

I'm concerned that the a/c change would go too far. Fighters that were a dog at 25,000 ft now couldn't even try to intercept?

A fighter that is a dog at 25,000 feet really could not intercept a recon flight (or anything else) at 30,000 feet. I see no problem with that at all.

[el cid again]

This data is for Japanese aircraft. EVERYTHING is metric: speed in kmh,
altitude in km. Presumably we would add about 1 km to optimum altitude because performance is pretty good at that level.

Designation MxSLSpd MxOASpd CrOASpd OptAlt Cieling
A5M4 369 435 296 4.6 9.80
A5M4-K 367 433 296 4.5 9.50
A5M5 402 475 296 4.4 9.35
A6M2 453 533 333 4.7 10.00
A6M2-N 370 435 296 4.7 10.00
A6M3m22 464 542 370 5.3 11.30
A6M5m52 485 565 370 5.5 11.74
A6M6c 475 557 323 5.0 10.70
A6M7 473 555 370 5.0 10.60
A6M8 490 572 370 5.3 11.20
A7M1 488 574 380 4.7 10.10
B4Y1 231 278 252 2.8 6.00
B5N2 318 378 259 3.9 8.26
B6N2 407 482 333 4.2 9.04
B7A2 485 567 392 5.3 11.25
B7A3 505 587 402 5.6 12.00
C6N1 519 609 389 4.9 10.47
C6N1-S 519 609 389 4.9 10.47
D1A2 258 309 222 3.3 6.98
D3A2 367 430 296 4.9 10.50
D4Y2 495 580 426 5.0 10.70
DC-2 266 322 270 2.5 5.40
DC-3 294 346 263 4.8 10.20
E4N3 192 232 148 2.7 5.74
E7K2 231 276 185 3.3 7.06
E7K2e 230 275 185 3.3 7.00
E8N2 251 300 185 3.4 7.27
E13A1 317 376 222 4.1 8.73
E14Y1 203 246 167 2.6 5.43
E15K1 398 469 296 4.6 9.83
E16A1 373 439 333 4.7 10.00
F1M2 313 370 204 4.4 9.44
F1M2-K 309 365 204 4.4 9.35
G3M2 315 373 278 4.2 9.13
G3M2-L 315 373 278 4.2 9.10
G4M1 363 427 315 4.7 10.00
G4M2e 343 406 296 3.8 8.11
G4M2m22 369 437 315 4.2 8.95
G8N1 505 593 370 8.2 10.20
H6K2 278 332 222 3.6 7.60
H6K2-L 278 333 240 3.3 7.00
H8K2 394 467 296 4.2 8.85
H8K2-L 353 420 296 3.8 8.13
J1N1 429 507 333 4.4 9.40
J1N1-C 451 530 278 4.8 10.30
J7W1 645 750 422 9.6 12.00
Ki-15II 432 510 320 4.5 9.58
Ki-21IIa 414 487 380 4.7 10.00
Ki-27 405 470 350 5.8 12.25
Ki-32 357 423 300 3.9 8.92
Ki-33 402 475 296 4.4 9.35
Ki-34 301 360 310 3.3 7.00
Ki-36 293 348 236 3.8 8.15
Ki-43Ib 424 494 320 5.5 11.70
Ki-43IIb 465 530 440 9.0 11.20
Ki-45a 467 547 360 5.0 10.73
Ki-45b 462 542 360 5.0 10.60
Ki-45c 459 540 360 4.7 10.00
Ki-46I 461 540 360 5.1 10.83
Ki-46II 516 604 400 8.6 10.72
Ki-46III 537 630 415 8.4 10.50
Ki-48I 407 480 350 3.5 9.50
Ki-48IIa 432 508 360 5.6 10.15
Ki-55 294 349 235 3.9 8.20
Ki-56 336 400 333 3.8 8.00
Ki-57I 359 430 320 3.3 7.00
Ki-57II 395 470 350 3.8 8.00
Ki-59 287 350 300 1.9 4.00
Ki-61Ia 512 596 400 5.5 11.80
Ki-61IIa 522 610 420 8.8 11.00
Ki-84Ia 538 631 445 4.9 10.50
Ki-100I 496 580 400 5.2 11.00
Ki-102a 498 585 440 4.8 10.20
Ku-8 184 224 150 4.6 4.60
L1N1 301 360 310 3.3 7.00
L2D2 301 354 259 4.7 10.00
M6A1 403 474 296 4.7 9.90
N1K1a 417 489 370 5.0 10.56
N1K1-Ja 503 583 370 5.9 12.50
N1K2-Ja 507 594 370 5.1 10.76
P1Y1a 462 546 370 4.4 9.40
Q1W1 265 322 241 2.1 4.49
Designation MxSLSpd MxOASpd CrOASpd OptAlt Cieling

[el cid again]

Japan has few high altitude aircraft. Note, however, the Ki-46 is rated very high, and the G8 bomber is also rated high. So is that "miracle plane" J7.

[witpqs]

ORIGINAL: el cid again

An AAA (or DP) gun could reach say 16,000 ft

An aircraft could reach 20,000 ft

This means the a/c in question could completely avoid the ground fire by flying high enough, even if its 'optimum' altitude were 10,000 ft. After the change this would no longer be the case.

Limiting things this way just doesn't make sense to me.

Let us consider a real world, historical example for which we have hard evidence:

The first raid on Clark AAF came in at 25,000 feet. The heavy AA guns had a cieling of 2,000 to 4,000 feet BELOW this. The AA guns fired, and the bursts (for maximum time of flight) were clearly well below the bombers. This was exactly what the attackers had in mind, and they had drilled for this attack for so long that, in spite of the fairly high altitude and lack of Norden bomb sights, they achieved the most accurate air bombardment of the war.

I am not sure why you might have a problem with bombers coming in over the AAA ceiling? It WAS an option, most of the time. Only the advent of very heavy AAA (150 and 203 mm) caused B-29s to be issued orders to avoid Singaport and certain targets in Japan. The game also increases first day of war Japanese bombing success - effectively duplicating the situation really existing on that day (and never again).

We also have a more complex option: we could rate certain planes (the best case might be recon planes) for service cieling - and others for optimum operating altitude. That way the recon planes could go in very high and be almost interception free except if the enemy fielded high altitude fighters - an accurate model.

You've got it backwards. I do want bombers able to fly in over the AAA ceiling (if such was really the case). I am worried that the changes you propose will prevent that because aircrafts' maximum altitude might be set too low. That's why I asked for an example.

The key cause for concern in your initial message is using 'optimum operating altitude' for aircraft. Well, what if the B-25C had an 'optimum' altitude of 12,000 ft but was still 80% effective at 20,000 ft? Setting 12,000 ft as its maximum altitude would make it much more vulnerable to flak than IRL. [NOTE: This is a made up example to illustrate my concern. I do not have 'optimum altitude' data for the B-25C.]

Do you see what I am asking about?

[witpqs]

ORIGINAL: el cid again

I'm concerned that the a/c change would go too far. Fighters that were a dog at 25,000 ft now couldn't even try to intercept?

A fighter that is a dog at 25,000 feet really could not intercept a recon flight (or anything else) at 30,000 feet. I see no problem with that at all.

That's not what I mean.

I mean: Fighters that were a dog at 25,000 ft now couldn't even try to intercept enemy aircraft that are at 25,000 (because its maximum altitude would be set to its optimum operating altitude - just for example say 15,000 ft)?

In other words:
- Fighter A (IRL) has optimum altitude 15,000 ft, maximum altitude 25,000 ft.
- Change is made in database to set Fighter A maximum altitude to 15,000 ft.
- Fighter A can no longer even try to intercept anything over 15,000 ft, when in real life its ceiling was 25,000 ft?

This is what I am concerned about. Is this a valid concern or are there no meaningful such situations that will occur in the game?

[Andrew Brown]

ORIGINAL: el cid again

This data is for Japanese aircraft. EVERYTHING is metric: speed in kmh,
altitude in km. Presumably we would add about 1 km to optimum altitude because performance is pretty good at that level.

Those altitudes are a great deal lower than the maximum altitudes. My view is that reductions as large as these would restrict things too much, as "witpqs" mentions. There may be cases where maximum altitides should be reduced, for example the comments made about the B-17, but I think that such reductions should be as small as is reasonable, and be done where it can definitely be shown that an aircraft could not operate at a particular altitude.

What about the reductions in AA ceilings of they were reduced to "effective" altitudes? What kind of reductions would that change result in?

[el cid again]

Those altitudes are a great deal lower than the maximum altitudes. My view is that reductions as large as these would restrict things too much, as "witpqs" mentions. There may be cases where maximum altitides should be reduced, for example the comments made about the B-17, but I think that such reductions should be as small as is reasonable, and be done where it can definitely be shown that an aircraft could not operate at a particular altitude.

What about the reductions in AA ceilings of they were reduced to "effective" altitudes? What kind of reductions would that change result in?

I regard these questions (and witpqs questions) as very intellegent and germane. So I propose to examine them in some detail below. But never forget that, no matter what, we must compromise in some way. We have only one altitude rating for each plane and each AA weapon. There must be cases where something is not quite in sync with reality: I was addressing the complaint that most planes cannot really operate at their service cielings in most military operations. At the same time, I was addressing the complaint that AAA cielings are in many cases overstated. Lowering both seems a logical theoretical solution. But, as always, the devil is in the details.

First, I don't like the idea above that we limit ourselves to specific data about aircraft, or they get full service cieling. There are real problems with this:

1) We have more than a few developmental aircraft about which we do not have exhaustive performance data.
2) We have more than a few relatively esoteric aircraft about which we do not have the kind of information we do about more famous types.

It is probably safer to model with some set of rules based on the hardest data we can get. By that I mean take some number we can know (e.g. cieling) and use a proportion of that (for the aircraft type and engine type - meaning is the engine turbosupercharged, etc.) This also vastly reduces the research burdon in the direction of something that might be achieved in a reasonable time frame. We could read every word written in every language about every plane on our list and probably only add a few % to the data we already have. For a simple model we have sufficient data for a reasonable result IMHO.

IF I were to propose a general rule it would be the opposite: Since the vast majority of planes lack high altitude performance, then rate it as a dog at altitude UNLESS you have specific information to the contrary. On our list Japan has less than 10% high altitude planes, for example. Not a lot. The Allies do better - but not a lot better. And in both cases, most of the high altitude planes come later. [Which makes the few around in 1942 very valuable. The Ki-46 is a high altitude plane virtually immune to interception - and this would make that show up.]

[el cid again]

That's not what I mean.

I mean: Fighters that were a dog at 25,000 ft now couldn't even try to intercept enemy aircraft that are at 25,000 (because its maximum altitude would be set to its optimum operating altitude - just for example say 15,000 ft)?

In other words:
- Fighter A (IRL) has optimum altitude 15,000 ft, maximum altitude 25,000 ft.
- Change is made in database to set Fighter A maximum altitude to 15,000 ft.
- Fighter A can no longer even try to intercept anything over 15,000 ft, when in real life its ceiling was 25,000 ft?

This is what I am concerned about. Is this a valid concern or are there no meaningful such situations that will occur in the game?

OK - I see your concern. Well - IF you have ANY change of intercepting 10,000 feet above your optimum operating altitude - that is a game fiction. You don't, you know you don't, you would not try, and you would not be allowed to try if you wanted to. Intercept is HARD - it is very heavy on fuel consumption and it is very hard on an engine to du a sustained wide open throttle run. So - yes - my proposal would indeed not allow you to do that - but - that is not a problem IF you are interested in an accurate model of air combat.

Now there is a special case - a case where air combat might involve aircraft above OOA. This is the case where you are on CAP or escort duty way above the OOA. In that case you DIVE on your opponent (gaining speed as you do so) and, typically, you make one pass, and win, lose or draw you run (taking advantage of your faster than normal airspeed to get away). This was something Americans did, eventually, to help compete vs planes they coult not outmaneuver. The problem with it is that, once in an air combat furball, you get to climb right back above OOA, where, under terms of combat, you would not dare to go, or if you did, you might suffer awful consequences for. Since our air combat model is having trouble for LARGE enagements which, by definition, involve more than one pass, I think it is better to have the planes altitude restricted, and to rationalize that by saying "this represents the altitude of the actual combat and not necessairily the initial altitude."

Look at this issue in a different light: a high altitude plane has a very similar ceiling to regular planes - sometimes actually lower. [Look up the service cieling of a Claude - or Nate - to see what I mean]. Now, IF you DO NOT rate planes for OOA, THEN the "high altitude" planes have NO advantage at altitude over their opponents. By saying regular planes cannot get up there, we give some real value to the high altitude planes. Further, we also give some value to heavy AAA. IF we adopt effective AA cielings, many planes with FULL service ceilings can just fly too high. But IF we adopt BOTH effective AA cielings and optimum altitude, then REGULAR planes are subject to heavy AAA - but high altitude planes have a choice - which is crudely accurate.

For every compromise, you must give and take something. It is a question of what you prefer. I prefer to give an advantage to high altitude planes, and to let AAA perform its historic function: you have real trade off decisions - IF you go in over the AAA you are less accurate.
And AAA is a killer - it causes more kills than fighters do.

[el cid again]

You've got it backwards. I do want bombers able to fly in over the AAA ceiling (if such was really the case). I am worried that the changes you propose will prevent that because aircrafts' maximum altitude might be set too low. That's why I asked for an example.

The key cause for concern in your initial message is using 'optimum operating altitude' for aircraft. Well, what if the B-25C had an 'optimum' altitude of 12,000 ft but was still 80% effective at 20,000 ft? Setting 12,000 ft as its maximum altitude would make it much more vulnerable to flak than IRL. [NOTE: This is a made up example to illustrate my concern. I do not have 'optimum altitude' data for the B-25C.]

Do you see what I am asking about?

OK. Let us consider a slightly more complex model. [Reality is more complicated still, but this is a closer approximation, for the sake of understanding. In my databases there is a Sea Level Maximum Speed and an Optimum Operating Altitude Maximum Speed. They also have a Speed Correction Factor. You ADD this factor (speed) to your maximum speed every 200 meters you climb UNTIL you reach OOA. THEN you SUBTRACT this factor from your maximum speed for every 500 meters you climb. Similarly there is a Rate Of Climb Correction Factor. It is based on the average time to climb to OOA - so it does not apply below OOA. But ABOVE OOA you subtract this factor from your rate of climb for every 200 meters you climb - until you reach service cieling - at which point you subtract 1 meter per minute from the ROC for every 200 meters until ROC reaches zero - which is your absolute ceiling.

The point is that above OOA you have a double penalty - speed drops off and ROC drops off - and the latter is a more severe issue than the former. As your ROC approaches zero, the danger of stalls in certain flight attitudes increases dramatically. Which is why the idea of a service ceiling - you cannot safely operate above this even in a NON-combat situation. In combat, you are unwise to operate even near it - unless for some technical reason it is an exceptional situation (as in you might live if you do and not if you don't). Our simple model has NO effects we know of degrading performance at altitude - and it is much more correct to allow NO ops up there than to allow unlimited ops.

HOWEVER - clearly a plane is effective above the OOA in a sense meaningful for our air combat model. The devil is in the details really may boil down to this question: WHAT is the amount to add to OOA to be realistic in this model? While I was thinking of something like 1000 meters (it is a nice number and almost seven of my 500 foot performance incriments for speed and 16 of my ROC incriments) - maybe it should be more than that? But a MULTIPLE of 1 km is so much I worry that it becomes meaningless for really low altitude planes - say seaplanes of many kinds. So I have two ideas to throw out for consideration - both with some advantages and disavantages:

1) Make the addition 2 km - twice the 1 km that may not be quite enough but not so much it makes a really low altitude plane seem pretty high.

2) Split the difference - halfway between service ceiling and OOA.

Both are simple rules that can be applied in all cases without a lot of research.

[el cid again]

What about the reductions in AA ceilings of they were reduced to "effective" altitudes? What kind of reductions would that change result in?

This is a very good question. It really divides into four categories:

Light AAA - machine guns up through about 30 mm
Medium AAA - about 35 mm to about 65 mm
Heavy AAA - about 75 mm to about 130 mm
Very Heavy AAA - about 150 mm to about 203 mm

Now there are a number of ways to approach rating the "effective" altitude for AAA in these categories - and I am not working from hard data here having made a specific choice about what criteria is best. This is a top of the head ball park discussion, and for specific guns the answer may be different (and can be different because the game lets us define a ceiling for each separate gun). For example, if fusing sets a limit of 22,000 feet, it does not matter if you can shoot higher in theory or not - you cannot get a burst above that altitude - period - so IF the gun is effective at that altitude it is its effective altitude. Similarly, a 40mm had a fuse setting limit - I forget what exactly - but that will control - forget the ballistics or fire control - you can't shoot with effect more than the ammo allows.

OK - by category. And think of effective AA as half a sphere - where altitude = range. [Don't ask me to explain why many references give "effective altitudes" on the order of 150% of "effective range" - I only am a Navy anti-air warfare specialist. I have no clue what they are thinking of?]

Light AAA is very short range - and effective value vs aircraft is probably in the range of 1 km. Lighter mgs really don't get that far, and heavier guns may get 1.5 or 2 km - but beyond that your chances are not good. The very best late war guns MIGHT reach 3 km.

Heavy AAA is rather longer in range - and effective values vs aircraft are generally in the range of 6 km or more.

Medium AAA is in between - as you might expect. It is also a category pretty much dominated by the Allies. The Japanese have SOME OLD 40mm - but with poor effect ratings (true). They also copied the Bofors - but failed to produce it in numbers - and I do not know if the game has it or not in its late war form. But from the beginning the Allies have it in numbers. These guns should have effective ranges in the range of 3-5 km (lower for pre war guns, higher for the Bofors).

Very Heavy AAA is a very special case. Almost unknown, its development was too late in the US to see wartime service. [But see the post war Worcester class cruisers]. Japan barely got guns of this sort into service - two kinds of 6 inch and one kind of eight inch. These weapons are effective at the operating altitude of a B-29 - 10 km.

Now there is a special case - what might be called very strange AAA?
Dutch cruisers, and most Japanese large ships, had main guns (and in the case of Japan ammunition) intended for AAA use. The rate of fire and rate of traverse/elevation is too slow, but against a constant bearing closing range target (the most dangerous kind), they might hit you. This we COULD simulate by giving these guns very awful altitude ratings. It was actually this that led to two of the Japanese very heavy AAA projects - the Navy 6 and 8 inch were put in single turrets with special gear to make elevation and traverse effective. The IJA, on the other hand, tried a whole new design, and while it shoots fast enough, it barely seems to elevate and train enough. Still - the operational site of this weapon (the Imperial Palace) was posted as off limits - either as a precaution or because it was effective.

[witpqs]

el cid again,

This is exactly the kind of information & discussion that I was seeking. [8D]

You've sold me on the approach. BTW, I have no veto or even vote here, just a voice.

As you say, the devil is in the details - exactly what settings to use for which AAA guns and aircraft.

Of course, the game model is a bit of a black box to us. There might be unintended consequences. Maybe we could get Mike Wood to read this thread and comment?

BTW, I as far as I know the Emperor and Imperial Palace were off limits to bombing for political reasons. It was feared that if the USA killed him it would greatly diminish the chances of Japan surrendering. Even as things stood factions in the IJ Army nearly pulled off a coup to stop the surrender.

[akdreemer]

ORIGINAL: el cid again

What about the reductions in AA ceilings of they were reduced to "effective" altitudes? What kind of reductions would that change result in?

This is a very good question. It really divides into four categories:

Light AAA - machine guns up through about 30 mm
Medium AAA - about 35 mm to about 65 mm
Heavy AAA - about 75 mm to about 130 mm
Very Heavy AAA - about 150 mm to about 203 mm

hmmm. different nations had different concepts of aaa, and divided it accordingly... Forget about very heavy. Yes there were guns heavier than 5.25" that were capable of firing at air targets-the British 8" gund mounted in the heavy cruisers comes to mind. However in all practical sense this is not even an issue because there was no way technology at the time could produce an effective super heavy.

Now there are a number of ways to approach rating the "effective" altitude for AAA in these categories - and I am not working from hard data here having made a specific choice about what criteria is best. This is a top of the head ball park discussion, and for specific guns the answer may be different (and can be different because the game lets us define a ceiling for each separate gun). For example, if fusing sets a limit of 22,000 feet, it does not matter if you can shoot higher in theory or not - you cannot get a burst above that altitude - period - so IF the gun is effective at that altitude it is its effective altitude. Similarly, a 40mm had a fuse setting limit - I forget what exactly - but that will control - forget the ballistics or fire control - you can't shoot with effect more than the ammo allows.

So far so good, and exactly what I have been saying....ad naseum

OK - by category. And think of effective AA as half a sphere - where altitude = range. [Don't ask me to explain why many references give "effective altitudes" on the order of 150% of "effective range" - I only am a Navy anti-air warfare specialist. I have no clue what they are thinking of?]

Light AAA is very short range - and effective value vs aircraft is probably in the range of 1 km. Lighter mgs really don't get that far, and heavier guns may get 1.5 or 2 km - but beyond that your chances are not good. The very best late war guns MIGHT reach 3 km.

Heavy AAA is rather longer in range - and effective values vs aircraft are generally in the range of 6 km or more.

Medium AAA is in between - as you might expect. It is also a category pretty much dominated by the Allies. The Japanese have SOME OLD 40mm - but with poor effect ratings (true). They also copied the Bofors - but failed to produce it in numbers - and I do not know if the game has it or not in its late war form. But from the beginning the Allies have it in numbers. These guns should have effective ranges in the range of 3-5 km (lower for pre war guns, higher for the Bofors).

Be careful here, maybe the British had the 40mm in some quantity, but the Royal navy did not use it in any significant numbers till late war. The the US Navy did not have any mounted in ships till mid 1942 at the earliest. The US Army, according to Vol 1 of the US Army Ordnance Department in WWII (Green Book), clearly states that the production prototype for the 40mm was finalized in the summer of 1942. Up to then the 37mm was also getting into full production, but it was determined that there was not enough production capacity to supply two guns. So it was not until summer of 43 that the 40mm was in full production and production of the 37mm was then terminated. It is also interesting to note that the US Army land forces used only .50's and 37/40mm, no interim calibers like 20mm.

Very Heavy AAA is a very special case. Almost unknown, its development was too late in the US to see wartime service. [But see the post war Worcester class cruisers]. Japan barely got guns of this sort into service - two kinds of 6 inch and one kind of eight inch. These weapons are effective at the operating altitude of a B-29 - 10 km.

Now there is a special case - what might be called very strange AAA?
Dutch cruisers, and most Japanese large ships, had main guns (and in the case of Japan ammunition) intended for AAA use. The rate of fire and rate of traverse/elevation is too slow, but against a constant bearing closing range target (the most dangerous kind), they might hit you. This we COULD simulate by giving these guns very awful altitude ratings. It was actually this that led to two of the Japanese very heavy AAA projects - the Navy 6 and 8 inch were put in single turrets with special gear to make elevation and traverse effective. The IJA, on the other hand, tried a whole new design, and while it shoots fast enough, it barely seems to elevate and train enough. Still - the operational site of this weapon (the Imperial Palace) was posted as off limits - either as a precaution or because it was effective.

[el cid again]

BTW, I as far as I know the Emperor and Imperial Palace were off limits to bombing for political reasons. It was feared that if the USA killed him it would greatly diminish the chances of Japan surrendering. Even as things stood factions in the IJ Army nearly pulled off a coup to stop the surrender.

I am not sure this is accurate information? It appears that the WARTIME policy was to try Hirohito as a war criminal, IF he survived, and killing him was something of a personal if not operational intention of many in the campaign. POST WAR this was changed, and I always was let to believe by MacArthur. [I long said it was just about his only decision I approved of.] But it turns out maybe he misled us here as well, and was actually ORDERED to go that way. Either way, it appears Hirohito was anything but off limits during the war - or for much of it. [The formal plan was to deindustrialize Japan, forcing starvation, to break up all eight Zaibatsu, to break up all government institutions, etc.] But there clearly WAS an order issued by the strategic air force to avoid the site of this IJA weapon - the range circle was drawn on the weapon not on the palace - it just happens that was the target it defended. Or so the artillery historians record.

[el cid again]

hmmm. different nations had different concepts of aaa, and divided it accordingly... Forget about very heavy. Yes there were guns heavier than 5.25" that were capable of firing at air targets-the British 8" gund mounted in the heavy cruisers comes to mind. However in all practical sense this is not even an issue because there was no way technology at the time could produce an effective super heavy.

This is almost correct. It IS correct for the USA - and we tried. For a good discussion of this see US Cruisers (USNI) and specifically CLAAs real and designed, culminating in the Worcester Class, as well as mention of application on other types of ships. We had a devil of a time getting the 5 inch 54 and 6 inch automatic to work - both effectively missed the war and were too expensive to cost justify (although both might have been killers in SURFACE battle - if there were one).

It is NOT correct in respect to Japan, and therefore for our game. It is a bit of an esoteric subject, but apparently at least three types were effective, and for tecnical reasons we can now understand. It turns out that Japan was rather better at theory than we were in physics - they often could work out on a blackboard what we had to measure to know. And they had some very "high tech" ideas in several fields not often discussed in classical histories. In this case, one of the ideas was the AAA simulator. Japan FORBADE the expendature of AA ammunition for practice - on economic grounds. But it was anything from saying you got no practice. They had BETTER practice than we did. We would shoot at a canvas sleeve towed at a constant speed by a tug aircraft - nothing at all like an attacking aircraft behaves - and we did that in broad daylight in good weather (cancelling the exercise if it was not). Japan - BEFORE WWII - had what you might call "planetarium" technology simulators - gigantic rooms of dome shape with projectors, with full directors that worked wired in, and with scale model planes and other flying things to confuse you. They simulated AAA in all lighting conditions. And they saw no reason to limit the simulators to existing AAA guns, so they build them to deal with threats up to 10 km - 32000 feet - which as it happened turned out to be B-29 altitude. They also authorized development of very heavy AAA, and a family of munitions which was constantly improved to feed it. Ultimately supported by radar, what might be called fire control computers, and mountings that permitted rapid elevation and traverse, they fielded systems regarded as too dangerous to challenge. The AAA war was an attrition battle, and we elected NOT to pay the price to attack certain targets - which in AAA school is taught as a victory for the defense. [Every target NOT engaged is a victory]. See, for example, Singapore, very much in range, but not engaged, defended by 8 inch AAA.
If we DO NOT model this, our model is not accurate.

[el cid again]

Be careful here, maybe the British had the 40mm in some quantity, but the Royal navy did not use it in any significant numbers till late war. The the US Navy did not have any mounted in ships till mid 1942 at the earliest. The US Army, according to Vol 1 of the US Army Ordnance Department in WWII (Green Book), clearly states that the production prototype for the 40mm was finalized in the summer of 1942. Up to then the 37mm was also getting into full production, but it was determined that there was not enough production capacity to supply two guns. So it was not until summer of 43 that the 40mm was in full production and production of the 37mm was then terminated. It is also interesting to note that the US Army land forces used only .50's and 37/40mm, no interim calibers like 20mm.

This is quibbling. I know all this. I am trying to do a SIMPLIFIED discussion, and the design was AVAILABLE when the Pacific Campaign begain. It took a while to convert - and presumably our ship data shows when a ship had what - mostly. If not - we fix it.