AA artillery

[Korpen]

Korpen,

We have no real differentiations in 'effects of ammunition feed' in our abstract system.
Also, caliber limitations are somewhat realistic, in that if you look most nations did not exceed 25mm for AA weapons for some time... generally near WWII! Also, 3" AA artillery was generally viewed as sufficient until somewhere in the late 20's or mid 30's- depending on the Navy in quest1ion.

But that is not true! Most of the really early AA guns were 37mm and 40mm guns, and the UK used modified a large number of 102mm guns on HA mounts for AA during ww1. Germany modified both 88s and 105mm guns for use as AA guns. Your comment is however true when it comes to what field armies used, but unlike the navy weight was a major concern for them.   
But I might be unclear, the point I am trying to make is that there is no advantage of using a 13cm AA gun over an 88mm or 6cm AA gun if you do not have the improvements in FC, ammunition and target detection that makes use of the larger range and payload.

[Carthaginian]

We have no real differentiations in 'effects of ammunition feed' in our abstract system.
Also, caliber limitations are somewhat realistic, in that if you look most nations did not exceed 25mm for AA weapons for some time... generally near WWII! Also, 3" AA artillery was generally viewed as sufficient until somewhere in the late 20's or mid 30's- depending on the Navy in quest1ion.

But that is not true! Most of the really early AA guns were 37mm and 40mm guns, and the UK used modified a large number of 102mm guns on HA mounts for AA during ww1. Germany modified both 88s and 105mm guns for use as AA guns. Your comment is however true when it comes to what field armies used, but unlike the navy weight was a major concern for them.   
But I might be unclear, the point I am trying to make is that there is no advantage of using a 13cm AA gun over an 88mm or 6cm AA gun if you do not have the improvements in FC, ammunition and target detection that makes use of the larger range and payload.

Yes, many of the first 'AA guns' were 1.5" or so- and were wildly unsuccessful because they were slow to train and impossible to keep loaded at cyclic speed that could actually hit an aircraft. Perhaps I should have said 'effective' AA guns... because if you notice, by the 20's most navies had left the 37-40mm range behind and were working with 20-25mm weapons (in mounts as large as quads). AA guns that large didn't appear again until WWII experience (and tech) made them necessary and successful.

[Korpen]

[Yes, many of the first 'AA guns' were 1.5" or so- and were wildly unsuccessful because they were slow to train and impossible to keep loaded at cyclic speed that could actually hit an aircraft. Perhaps I should have said 'effective' AA guns... because if you notice, by the 20's most navies had left the 37-40mm range behind and were working with 20-25mm weapons (in mounts as large as quads). AA guns that large didn't appear again until WWII experience (and tech) made them necessary and successful.

Do I even have to mention the Brittish 40mm Pom-Poms? ;)
They did service for most of ww2 after all.
Would not say that ww2 experience was needed for AA guns around 40mm, the 40mm M/36 Gun was fielded from 1936 after all, and it was argubly the best gun of the class during the war. But while it was a good gun, it the was the later FC systems and mountings that made the gun great.

[Carthaginian]

Well, the famous/infamous Bofors 40mm was only in service form the mid-30's onward. It was arguably the most successful AA weapon of all time when coupled with excellent fire control... but it was a mid-30's development all the same, and only became widely deployed (and mounted in pairs and quartets) when the 25mm weapons proved ineffective.

The British 2-pounder Mk II (the WWI era one) suffered from a manifold number of defects- the fabric belts stretched, tore and fed poorly, and the mechanism was too light and suffered from feeding problems even new belts did not completely remedy. The successful 2-pounder MkVIII (which you are referring to) as with the Bofors model, was a 1930's development... though the 2-pounder was becoming dated by WWII, while the Bofors gun was just hitting it's stride..

[Korpen]

The British 2-pounder Mk II (the WWI era one) suffered from a manifold number of defects- the fabric belts stretched, tore and fed poorly, and the mechanism was too light and suffered from feeding problems even new belts did not completely remedy. The successful 2-pounder MkVIII (which you are referring to) as with the Bofors model, was a 1930's development... though the 2-pounder was becoming dated by WWII, while the Bofors gun was just hitting it's stride..

All true (the the later 2-pder used the same ammo as the Mark II) bbut I feel it do strengthen my argument that gun calibre is not the best thing to focus on, it just lead to debates on a subject that I think is basically irrelevant for the performance of a system. As someone said "only way to hurt someone with a gun is the run it over his foot".

I do not think we should force trough on my suggestion; as it is far from perfect, and both You and Guinness (prefer Kilkenny) have hade excellent points. But I really think we should keep the underlying point I was trying to make in that AA tech should focus on the things that are more or less unique to air defence weapon systems and makes them makes them weapon systems. 

[Kaiser Kirk]

A caliber limit should be in place as well, if for no other reason than to ensure that we don't wind up with a fused 40mm autocannon that could shred a WWI era aircraft. I propose the following amendment:

But my dream is that radar developed for maritime firecontrol would be mated to land based artillery for fuses, and *then* turned into rapid fire prox fused AA guns during the biplane era!

Wouldn't that put an interesting spin on the development of aircraft for warfare?

[Carthaginian]

But my dream is that radar developed for maritime firecontrol would be mated to land based artillery for fuses, and *then* turned into rapid fire prox fused AA guns during the biplane era!

Wouldn't that put an interesting spin on the development of aircraft for warfare?

LOL... yes, the spin of a crashing biplane that counts itself lucky it was not vaporized. ;)

[Guinness]

It doesn't seem like anyone participating in this discussion is all that far apart. I think we all want an approach based on the total package of technology required to shoot down aircraft, and I think we don't want that tech to progress too far out of sync with aircraft tech. At least that's my impression.

I'll think about how to make sure the same tech progression is clear without references to specific calibers. Off the top of my head, the best way to do that seems to be specifying capabilities, which is essentially what we have now that we seem interested in revising, so it's going to take a few more iterations, I think.

If anyone has a suggested revision of my proposed tech tree, or another one to use instead, please feel free to post it and we can keep working on it.

[Kaiser Kirk]

It doesn't seem like anyone participating in this discussion is all that far apart. I think we all want an approach based on the total package of technology required to shoot down aircraft, and I think we don't want that tech to progress too far out of sync with aircraft tech. At least that's my impression.

Actually I wasn't entirely joking. I'd be perfectly happy if it could develop out of synch with aircraft :) I think Billy Mitchell's show case would look rather different against a BB armed with QF prox fused secondaries- which would also work very well for MTB deterrence work or shore bombardment or soft killing combatents <15km away.

However..

I would guess others might want them linked, and if so, the total package approach is probably correct.

[Jefgte]

Your proposal technos progress by 5 years is a good choice & the AA mounts are looking good.

You could take a fresh Guinness.


Jef  :D

[Carthaginian]

I think Billy Mitchell's show case would look rather different against a BB armed with QF prox fused secondaries...

Hell, if Alabama and Ostfriesland could have shot back at all, Billy Mitchel would have died a nobody. ;)

Basically, having the tech progress too fast would do away with the aircraft carrier as a viable weapon of war and would ensure the continued dominance of naval gunfire.

[Tanthalas]

I think Billy Mitchell's show case would look rather different against a BB armed with QF prox fused secondaries...

Hell, if Alabama and Ostfriesland could have shot back at all, Billy Mitchel would have died a nobody. ;)

Basically, having the tech progress too fast would do away with the aircraft carrier as a viable weapon of war and would ensure the continued dominance of naval gunfire.

I think thats what they want...

[Guinness]

Here's a revision with calibers removed, with the exception of the minimum size of gun that can fire a proximity fused shell. I don't think it suffers to much...

1914: Machine guns caliber, aimed by eye. Barrage balloons for air defense.
1919: Autocannon aimed by eye. Improvised barrage anti-aircraft weapons firing timed exploding munitions, effective to altitudes of 10,000 (4700m) feet.
1924: Purpose built barrage AA guns with elevations up to 45 degrees. Effective to altitudes of 20,000 feet (9400m).
1929: Dual purpose guns. Dedicated barrage AA weapons with elevations up to 85 degrees. AA plotting tables.
1934: Dedicated and Dual purpose elevations up to 90 degrees for barrage AA weapons. Early lead computing gunsights for automatic AA fire. Early radar guidance for barrage AA weapons. Automated fuse setters and barrage AA director fire.
1939: Mature lead computing gunsights. Improved radar guidance for both automatic AA weapons and barrage AA weapons. Proximity fuses for guns larger than 75mm.

Or a different approach. Trying to link AA tech directly to the level of aircraft they can defeat (again years are fudgible later. Concentrate on the steps for now please):

Baseline: None. Rifles and machine guns fired wildly at the sky. Effective against 1906 historical year aircraft.
1910 Machine guns, improvised barrage AA weapons, and barrage balloons. Effective against historical 1910 aircraft level
1915  Improved barrage and machine gun AA. First weapons designed for the task appear. Effective against historical 1914 aircraft
1920: Further improvements in gun and mounting design. Effective against historical 1916 aircraft
1925: Higher elevation barrage AA guns. Multiple machine-canon AA mountings common. Effective against historical 1918 aircrafts
1930: Dual purpose guns and AA plotting tables and early directors. Effective against historical 1922 aircraft
1935: Early lead computing gunsights. Early radar guidance for barrage AA possible. Automated fuse setters. Effective against historical 1928 aircraft
1940: Mature lead computing gunsights. Improved radar guidance for automatic and barrage AA weapons. Proximity fuzes for guns larger than 75mm. Effective against historical 1935 aircraft

Thoughts?

[Carthaginian]

I personally like the latter... it honestly makes sense and shows a good 'action, reaction' scenario, and allows aircraft to be useful, as long as you keep researching.

[P3D]

Caliber restrictions are silly. The main reason to use larger calibers is to reach level bombers flying high. What level bombers?

What should be expected for the era?
Machine guns with tracers are pretty common. So that should be about the first level. Include here field guns on ad-hoc platform mainly against balloon.
Barrage balloons I'd call of very limited usefulness.

There have been large caliber (3") AA guns with 85* elevation during WWI, I don't see any particular reason why to limit elevation in such an artificial way. Now, 3" AA guns were IRL effective until 1940 or so.

Linking what type of A/C a given tech could defeat is a bad idea. Put enough rounds around the volume occupied by the plane and there will be hits. Until late 1930s (and the appearance of armor on planes) 7-13mm MGs worked just as fine. And those calibers will be mostly aimed by eye and tracers.

We need about three AA tech in the Nverse period. One (equivalent, say, to the current first tech) to include everything aimed by eye.

1912: Machine guns up to 30-40mm aimed by tracers, ad-hoc timesetting for exploding large-caliber (~3" and larger) shells
With slow aircraft speeds this should be adequate for a while. Then, as A/C speed increases, the need emerges for
1920 : Primitive AA directors, automated fuse setting, high-ROF large-caliber guns
Then a later tech for DP guns and better (whatever that means) AA directors in, say, 1928.

Honestly, I don't really see the emergence of the proximity fuse until ~ 1940. But, well, as it would make BBs protected from planes without guided bombs, why not?