Query re aircraft and AAA cielings

[el cid again]

different nations had different concepts of aaa, and divided it accordingly...

Yep. Japan had heavy and light. I was taught by USN - so I use Heavy, Medium and Light. But then I got to reading the Master Gunner of the British Army - Ian Hoag. I added Super Heavy.

[Splinterhead]

ORIGINAL: 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.

Why didn't they use their super AA to defend their cities?

[Kereguelen]

ORIGINAL: 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.

The Imperial Palace was nearly completely destroyed during war. I don't think that this just happened accidentally (the palace grounds were simply too large for such kinds of accidents) . Thus it seems that Hirohito was far from being "off-limits".

[Kereguelen]

ORIGINAL: Splinterhead

Why didn't they use their super AA to defend their cities?

Because the Japanese economy was unable to provide enough AA guns (actually unable to provide sufficient guns of all types).

[tabpub]

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.

I don't think that is correct; the 40 had a contact detonator which armed when it fired:
AMMUNITION--DATA

Number of rounds per clip 4
Number of clips per box 4
Number of rounds per box 16
Weight of projectile, complete 1.96 lbs
Weight of round (brass case) 4.75 lbs.
Weight of clip (assembled) 20 lbs.
Weight of box, loaded, 16 rounds 115 lbs.
Dimensions of box 12” x 12” x 22”
Tracer burnout 9 seconds
Condition of ammunition as received Clipped, ready for use
Fuse Bore safe (armed by rotation). Impact detonated self-destruction (operated on tracer burnout)

Fusing would only be present for 3in and higher guns.

[witpqs]

ORIGINAL: 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.

I have no doubt that they were ordered to avoid the weapon. As for avoiding bombing the Emperor, even in the Doolittle raid the Imperial Palace was off limits. I can easily see wartime publicity being somewhat different than plans. Plans change. If things had gone radically differently maybe he would have been tried.

The terms of the surrender (in spite of wartime determination it was not unconditional) included the Emperor remaining in place. I'm sure that wasn't MacArthur's decision but maybe he contributed to the decision making process.

Plenty of B-29's were lost overall. If they wanted to kill the Emperor - while there are never guarantees - a massive raid on the Imperial Palace would have been a good place to start, in spite of special AAA.

All irrelevant to WITP, but still interesting.

[witpqs]

ORIGINAL: Kereguelen

The Imperial Palace was nearly completely destroyed during war. I don't think that this just happened accidentally (the palace grounds were simply too large for such kinds of accidents) . Thus it seems that Hirohito was far from being "off-limits".

This is news to me. Still, it is very possible for a large B-29 raid nearby to miss with significant amounts of ordnance and hit the Palace Grounds. But maybe you're right. I know the palace was off0limits in the Doolittle raid, however that was very early on.

Anybody know for sure the war-time policy?

[akdreemer]

ORIGINAL: 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.

excuse me, but who is quibbling.. one base defended by 8" guns that could fire AA.. we need to model that but mentioning and modeling, historical availibility of AAA is quibbling.. even if you do know it does not mean that everyone else does... and I was attempting to correct your statement about the 40mm "But from the beginning the Allies have it in numbers." I never stated that the design was not available, but that it took till summer of 42 before the US ARMY had a prduction protoype. Then we had to produce it.

[akdreemer]

ORIGINAL: tabpub

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.

I don't think that is correct; the 40 had a contact detonator which armed when it fired:
AMMUNITION--DATA

Number of rounds per clip 4
Number of clips per box 4
Number of rounds per box 16
Weight of projectile, complete 1.96 lbs
Weight of round (brass case) 4.75 lbs.
Weight of clip (assembled) 20 lbs.
Weight of box, loaded, 16 rounds 115 lbs.
Dimensions of box 12” x 12” x 22”
Tracer burnout 9 seconds
Condition of ammunition as received Clipped, ready for use
Fuse Bore safe (armed by rotation). Impact detonated self-destruction (operated on tracer burnout)

Fusing would only be present for 3in and higher guns.

fusing for the 40mm is the selfdestruct limiting its max range to 4500-5000yards, assuming it did not hit something first (contact).

[akdreemer]

ORIGINAL: 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.

gee, what happened to the British and Commonwealth? The war is more than USA and Japan. The British considered up to 40mm as light. they attempted to develope a "medium" based on the 6lbr. their heavy was the 3.7"nad larger.

[el cid again]

Why didn't they use their super AA to defend their cities?

Das ist eine gute frage.

Lets add it to the list:

Japan had pre war designs for standard escorts, but failed to mass produce them. Why?

Japan had the finest of 3 inch guns - something like our post war 3 inch 50 - but they had it EARLY - and failed to produce it in numbers. Why?

Japan a genuine political advantage in the anti-colonial sentiment in Asia - and (contrary to our assumptions and propaganda) Japan was NOT peopled or run by fanatics who had zero intention of empowering them. The Foreign Service was DOMINATED by such people, and TOJO himself was a big fan of their ideas - but Japan (with a few exceptions) failed to exploit this opening which would have made the autarky they sought a great deal more likely to come to pass. Why?

Japan was a pioneer in radar technology, and since WWII Japan demonstrated it had plenty of talent to teach and produce electronics of all kinds. But it FAILED to produce sufficient quality and quantity of radar during the war - often wasting years for the most marginal of improvements on captured or existing designs. Why?

Japan was not logistically oriented - in spite of the spectacular success of the Zaibatsu before and after the war. Why?

Japan had better intelligence than our other rivals in the great game. Japanese leaders were continually briefed about the status of the US Atom Bomb project, while the Germans were stunned we could make it work, in spite of limited success at the margins. The famous Russian intel on the same project pales beside the Japanese achievement of stealing samples of soil from reactor sites and stealing complete bomb plan sets.
Yet Japan failed to come to terms with what this would mean, if they didn't come to terms with us. Why?

The list is almost endless. There are specific answers to specific questions, not that we always know them all. But the general answer is that Japan was an extraordinarily divided society. Worse, it was an extraordinarily divided society with broken political institutions which had never really matured in the first place. "Government by assassination" may put a gang in power, but it does not give them strategic vision, nor political sales skills to sell that vision. What Tojo liked didn't matter when he was just a front man for a triumverate of generals who really ran things. By the time he got two of them out of the picture, his time was almost gone, and it was too late to change anything strategic - except maybe to kowtow and try to end it - something he was not up to doing. But Tojo was, in a sense you never read, an honorable man: utterly uncorrupt, a pioneer in aviation, someone the state could count on when very senior officers ran amok and needed to be reigned in, in more than one sense. He had very severe limits, particularly of what he understood, but he was not in it for profit, nor was he brutal, nor was he a lot of other things we usually assume or even hear. He was really just a fairly little man in a job utterly too big for him, with much less power than someone outside the system could appreciate, and he just walked away in the end. He went home to his family, and that is where we found him when the war ended. Doing nothing at all. With modest assets and habits. Japan was a nation dominated by a radical Army cabal that even ultra nationalists like Tsuji bemoan - one of the principle generals felt the critical decision was that to invade China - and he quit and said so - years before we got into it. That decision was NOT a proper national policy - but a decision made by a few generals NOT even in power and more or less forced on the nation over time. Japan was too divided and too dangerous to do things in a really organized and rational way.

[el cid again]

The Imperial Palace was nearly completely destroyed during war. I don't think that this just happened accidentally (the palace grounds were simply too large for such kinds of accidents) . Thus it seems that Hirohito was far from being "off-limits".

Well put. The Army didn't get their super heavy battery up until much too late, and the decision to avoid it was not made in time to save much of the place. The emperor lived in a sort of bunker. It is almost impossible to believe if you go there now - or even 35 years ago when I went. This makes it more clear we were avoiding the gun, not saving the emperor.

[el cid again]

I don't think that is correct; the 40 had a contact detonator which armed when it fired:
AMMUNITION--DATA

I can see why you think so. It certainly SOUNDS like you are right.

As usual, reality is more complicated. Also, there may be different kinds of ammunition used at different times, so it may be more complicated than I know about? But, basically, the problem is this:

AAA is DANGEROUS to YOUR side IF you let it come down and blow up. Mostly it misses the enemy plane - so what happens after that? It comes back down - in YOUR country - and hits whatever is there. Most of the damage - virtually all- done to Honolulu on Dec 7 was from US AAA guns!
And THAT in spite of the fact it was almost all shrapnel - spent metal - not explosive rounds hitting things! You just don't design AAA shells to blow up your buildings - that is the ENEMY's job! SO what to do? Bofors thought the answer was to have a time fuse. That was a left over from WWI era AAA - you set the fuse for the range you set your fire control predictor - so many seconds - and that caused a large shell to burst. Well, the 40mm was to HIT the target and THEN explode - so contact fusing seemed the way to go to get the TARGET. But what if you missed the target? Bofors thought you use the time fuse to get rid of the shell BEFORE it could hit ANY ground target. Which is why the fuse was so short. They figured practical range and didn't even let you have a chance at longer ranges. I forget the number - but it is not that great - and someone posted it in this forum last month.

[el cid again]

Plenty of B-29's were lost overall. If they wanted to kill the Emperor - while there are never guarantees - a massive raid on the Imperial Palace would have been a good place to start, in spite of special AAA.

All irrelevant to WITP, but still interesting.

I concur in detail. The emperor apparently never left the place - the opposite of Saddam Hussein. Until the fall of 1945 he was going to stay put - then move to a massive structure under construction in Western Central Japan. And his bunker was nothing like the ones the British broke in Europe. I think it was feasible to get him - if we were willing to pay the price. And THAT might have made the war UNENDABLE in any sane sense. It was a near thing as it was. See Japan's Longest Day.

All irrelevant.

[el cid again]

This is news to me. Still, it is very possible for a large B-29 raid nearby to miss with significant amounts of ordnance and hit the Palace Grounds. But maybe you're right. I know the palace was off0limits in the Doolittle raid, however that was very early on.

Anybody know for sure the war-time policy?

I collect stuff about wartime atomic policy - on BOTH sides (although few know there WAS a Japanese atomic policy at all). And it is anything but clear even when you get a document in original form. For example, the first extant Japanese atomic policy document (authorizing the SECOND Japanese "Manhattan Project" - the Navy one) clearly says the MAIN purpose is to create an "engine to power large ships or industrial facilities" - but a famous Japan scholar (John W. Dower) who is married to a Japanese insists it is a "cover story" and the real purpose was an atom bomb. [Now Dower is an apologist who always UNDERSTATES Japan's atomic research, so if HE says that is the purpose, I find it interesting.] But WHY put a "cover story" in a secret document the enemy and the public won't see? Why don't you have to tell the truth to yourself about why you are spending this money? Well, US policy re the fate of Axis nations and their leaders is HARDER to get your hands on than esoteric Axis atomic research. And when you DO get something, it is very different from what you read in the histories - see the letters of the Secretary of the Treasury for example (Henry Morgenthou or something like that).

[el cid again]

one base defended by 8" guns that could fire AA..

I was giving an example. It is not the only place. And the example I gave is also germane in another sense: until about two years ago we did not know about it. It was either not known we avoided Singapore due to the guns, or it was believed it was all an intel error - they were not there - they were never found. EXCEPT this - we just found them!! How many cases did we NOT find the guns? Japan was not occupied by US occupation government troops - it was run by Japanese administrators and police backed up by the US Army. VERY different from what we did in Europe. And for some years we were not too keen on what happened to the Japanese - starvation was acceptable and not even news. So people did whatever they could - and one thing they could do was sell scrap metal. LOTS of guns we NEVER WILL find! There is no proper accounting for the huge guns on Tsushima, for example. I don't think we know how many there were. But I know of one site in Japan where the eight inch single was noticed, because that site is mentioned in US Naval Weapons of World War Two. So the new one just found in Singapore is certainly not the only one.

Now the army 150 mm seems to have only had one site. But there was a NAVY 150/2/3 something as well - and it seems to have been fielded rather earlier and in more mountings (singles and triples at least). But no ordnance historian I know will hazard a guess how many - upwards of 130 were cast - and many mounted on ships but later removed to be replaced by eight inch - so they were certainly available. And that is a lot more than we ever made, even post war, in that class

Sid

[el cid again]

fusing for the 40mm is the selfdestruct limiting its max range to 4500-5000yards, assuming it did not hit something first (contact).

4500 rings a bell - I think they add 10% for safety - fuses are not uniform in quality. I think this is right. No matter the ballistic situation, you are not going to engage beyond that range.

[akdreemer]

ORIGINAL: Kereguelen

ORIGINAL: Splinterhead

Why didn't they use their super AA to defend their cities?

Because the Japanese economy was unable to provide enough AA guns (actually unable to provide sufficient guns of all types).

actually you are close to the truth. Reading Westerman on German Flak and the amount of resources that was put into the Flak. Things like one third the budget for AA guns and ammo.. indeed it is the ammo and replacement barrels that hit the pocket really hard...

[el cid again]

Board and private discussion and thought have caused me to modify the proposal:

For Aircraft, use Optimum Operating Altitude plus 2 km. This means that the entire high performance flight regime is allowed, but the non-high altitude planes are substantially restricted compared with now.