Real World AA Effectiveness

[Midshipman_Hornblower]

Considering the number of threads about AA and CVs in game, I thought folks here might be interested in this.  Today I found a declassified report by the US Navy summarizing USN AA effectiveness during WW 2.  The following table is from that report, with some rounding just to ease reading:

Gun (ammo)	Rounds Fired	Kills	Rounds/Kill
	(x 1000)
5" (AA Common)	224	342	654
5"  (VT)	118	347	340
3"/50	30	88	338
40 mm	1,272	743	1,713
1.1"	86	45	1,932
20 mm	3,265	618	5,287
50 cal	730	66	11,143
30 cal	113	4	28,127

The above summarizes all anti-air actions by US Navy ships, plus US merchant ships with armed guard detachments, in all theaters, for the entire war from Pearl Harbor to Tokyo Bay.  Basically, its a roll-up of all after-action reports by all navy ships and armed guard detachments.  Plane kills includes both Japanese and German aircraft.  A couple caveats are in order concerning the data.

First off, there's the definition of "kills".  In this report, it includes aircraft that were hit by AA fire, and were observed to go down within sight of the firing ship.  Planes that might have been damaged, then crashed on their way back to base (or on landing) weren't counted.  Thus, the report suggests that the actual number of planes destroyed by AA guns was probably somewhat larger than what's shown in the table.

Second, the report notes that data for the 3"/50 are suspect.  These guns were mostly installed on smaller patrol craft and auxillaries, and the record-keeping and reporting of these vessels was often deficient.

Likewise, data for the 30 cal machine guns should be used with a bit of caution, because of the small sample size.  Note that all navy ships together reported only 4 plane kills by these weapons in the entire war.

Minor point:  though not included in the table, the report notes 2 planes were shot down by 6"/47 guns, though these guns had neither AA-capable directors nor AA rounds available (both were developed after the war).

Final minor point:  the 5" category includes both 5"/25 and 5"/38 guns; the 3"/50 category does NOT include the obsolete 3"/23 mounted on some ships early in the war (which recorded no plane kills).

And, what about the effectiveness of those attacking planes?  Well, here's an interesting statistic from the report:  During the entire war, 7,600 enemy planes came within range of navy (and armed guard detachment) AA guns.  Of those, 715, or 9%, scored hits or damaging near-misses.  The breakdown of those attacks hits on one of my personal annoyances concerning the WoWS implementation of CVs:  in not 1 single case did the enemy planes attack with rockets.

 

[Torenico]

Could you provide a link to that specific document?

[Karstodes]

7 minutes ago, Midshipman_Hornblower said:

Considering the number of threads about AA and CVs in game, I thought folks here might be interested in this.  Today I found a declassified report by the US Navy summarizing USN AA effectiveness during WW 2.  The following table is from that report, with some rounding just to ease reading:

Gun (ammo)	Rounds Fired	Kills	Rounds/Kill
	(x 1000)
5" (AA Common)	224	342	654
5"  (VT)	118	347	340
3"/50	30	88	338
40 mm	1,272	743	1,713
1.1"	86	45	1,932
20 mm	3,265	618	5,287
50 cal	730	66	11,143
30 cal	113	4	28,127

The above summarizes all anti-air actions by US Navy ships, plus US merchant ships with armed guard detachments, in all theaters, for the entire war from Pearl Harbor to Tokyo Bay.  Basically, its a roll-up of all after-action reports by all navy ships and armed guard detachments.  Plane kills includes both Japanese and German aircraft.  A couple caveats are in order concerning the data.

First off, there's the definition of "kills".  In this report, it includes aircraft that were hit by AA fire, and were observed to go down within sight of the firing ship.  Planes that might have been damaged, then crashed on their way back to base (or on landing) weren't counted.  Thus, the report suggests that the actual number of planes destroyed by AA guns was probably somewhat larger than what's shown in the table.

Second, the report notes that data for the 3"/50 are suspect.  These guns were mostly installed on smaller patrol craft and auxillaries, and the record-keeping and reporting of these vessels was often deficient.

Likewise, data for the 30 cal machine guns should be used with a bit of caution, because of the small sample size.  Note that all navy ships together reported only 4 plane kills by these weapons in the entire war.

Minor point:  though not included in the table, the report notes 2 planes were shot down by 6"/47 guns, though these guns had neither AA-capable directors nor AA rounds available (both were developed after the war).

Final minor point:  the 5" category includes both 5"/25 and 5"/38 guns; the 3"/50 category does NOT include the obsolete 3"/23 mounted on some ships early in the war (which recorded no plane kills).

And, what about the effectiveness of those attacking planes?  Well, here's an interesting statistic from the report:  During the entire war, 7,600 enemy planes came within range of navy (and armed guard detachment) AA guns.  Of those, 715, or 9%, scored hits or damaging near-misses.  The breakdown of those attacks hits on one of my personal annoyances concerning the WoWS implementation of CVs:  in not 1 single case did the enemy planes attack with rockets.

 

Wonder the number of round that the Type 96 25mm Gun needed to shot down an US plane.

[Kesh_Lives]

7 minutes ago, Midshipman_Hornblower said:

And, what about the effectiveness of those attacking planes?  Well, here's an interesting statistic from the report:  During the entire war, 7,600 enemy planes came within range of navy (and armed guard detachment) AA guns.  Of those, 715, or 9%, scored hits or damaging near-misses.  The breakdown of those attacks hits on one of my personal annoyances concerning the WoWS implementation of CVs:  in not 1 single case did the enemy planes attack with rockets.

On the attack side, you need to look at the USN side and the FAA as well, for rocket use in attacks.  Not to mention USAF/RAF use of rockets.  

Also, I wonder what the percentage of hits is for the USN and FAA, too, vs the IJN.  Of course, the attacking aircraft in this case are not just carrier planes.  Lots of land-based stuff attacked US naval forces.  Lots of 5th AF attacked IJN ships, too.  

The IJN AA wasn't anywhere near this good, because they didn't have the VT shells on the heavy end, and the 25mms weren't nearly as good as the 40mm Bofors.

 

 

[xHeavy]

The Japanese Rockets are limited to their Bakas which were carried by two engine bombers to a few miles of USN Ships and then released. The manned rocket with the human as the guiding system would take on the biggest in view.

The Germans actually sunk the Roma on her way to surrender in the Med with a new guided air to surface missile. A then new spinner with a pretty decent warhead.

Thats one of the reasons why I have trouble when Wows talk about dual purpose AA guns like the 5 incher and fail to allow for that use in game. It does not matter anyway, its a game and they do what they do.

The biggest AA situation in all of WW2 has to be at Remagan Bridge for two weeks after it was taken. A entire AA Corps Army was located there working very hard to defend bridge against EVERYTHING in the german inventory including large ballistic v missiles attacking the span. It finally failed I think 10 days on.

One minor thought, The Lincoln Memorial has ww2 damage from AA weapon fired in the vicinity by accident. You will find the damage along the top roofline to this day.

[Karstodes]

2 minutes ago, xHeavy said:

Thats one of the reasons why I have trouble when Wows talk about dual purpose AA guns like the 5 incher and fail to allow for that use in game. It does not matter anyway, its a game and they do what they do.

You do have those guns in your AA load out, they just do not force the player to pick between shooting ships and shooting plane. 
 

And in some case they did not gave it: the Tribal are a prime example. 

[BrushWolf]

24 minutes ago, Midshipman_Hornblower said:

Considering the number of threads about AA and CVs in game, I thought folks here might be interested in this.  Today I found a declassified report by the US Navy summarizing USN AA effectiveness during WW 2.  The following table is from that report, with some rounding just to ease reading:

Gun (ammo)	Rounds Fired	Kills	Rounds/Kill
	(x 1000)
5" (AA Common)	224	342	654
5"  (VT)	118	347	340
3"/50	30	88	338
40 mm	1,272	743	1,713
1.1"	86	45	1,932
20 mm	3,265	618	5,287
50 cal	730	66	11,143
30 cal	113	4	28,127

The above summarizes all anti-air actions by US Navy ships, plus US merchant ships with armed guard detachments, in all theaters, for the entire war from Pearl Harbor to Tokyo Bay.  Basically, its a roll-up of all after-action reports by all navy ships and armed guard detachments.  Plane kills includes both Japanese and German aircraft.  A couple caveats are in order concerning the data.

First off, there's the definition of "kills".  In this report, it includes aircraft that were hit by AA fire, and were observed to go down within sight of the firing ship.  Planes that might have been damaged, then crashed on their way back to base (or on landing) weren't counted.  Thus, the report suggests that the actual number of planes destroyed by AA guns was probably somewhat larger than what's shown in the table.

Second, the report notes that data for the 3"/50 are suspect.  These guns were mostly installed on smaller patrol craft and auxillaries, and the record-keeping and reporting of these vessels was often deficient.

Likewise, data for the 30 cal machine guns should be used with a bit of caution, because of the small sample size.  Note that all navy ships together reported only 4 plane kills by these weapons in the entire war.

Minor point:  though not included in the table, the report notes 2 planes were shot down by 6"/47 guns, though these guns had neither AA-capable directors nor AA rounds available (both were developed after the war).

Final minor point:  the 5" category includes both 5"/25 and 5"/38 guns; the 3"/50 category does NOT include the obsolete 3"/23 mounted on some ships early in the war (which recorded no plane kills).

And, what about the effectiveness of those attacking planes?  Well, here's an interesting statistic from the report:  During the entire war, 7,600 enemy planes came within range of navy (and armed guard detachment) AA guns.  Of those, 715, or 9%, scored hits or damaging near-misses.  The breakdown of those attacks hits on one of my personal annoyances concerning the WoWS implementation of CVs:  in not 1 single case did the enemy planes attack with rockets.

 

What is missing is the information on how many bombers were shot down by planes when they were attacking. The US did use rockets against ships, the IJN and KMS getting them is about balance.

15 minutes ago, Karstodes said:

Wonder the number of round that the Type 96 25mm Gun needed to shot down an US plane.

I would think it would be similar to the US 1.1" Chicago Piano. Neither were very good AA weapons.

[Midshipman_Hornblower]

6 minutes ago, BrushWolf said:

What is missing is the information on how many bombers were shot down by planes when they were attacking. The US did use rockets against ships, the IJN and KMS getting them is about balance.

Correct.  The report only covers AA gunnery, and only by the USN.  Aircraft shot down by friendly fighter planes are not included.  Likewise, the report does not include friendly aircraft shot down by mistake, although that did occur on several occasions (the Sicily invasion being a particularly notable case).

[Burnsy]

10 minutes ago, Midshipman_Hornblower said:

Correct.  The report only covers AA gunnery, and only by the USN.  Aircraft shot down by friendly fighter planes are not included.  Likewise, the report does not include friendly aircraft shot down by mistake, although that did occur on several occasions (the Sicily invasion being a particularly notable case).

Is there some reason that you aren't including a link to the source of your information for these metrics?

[Midshipman_Hornblower]

28 minutes ago, xHeavy said:

The Japanese Rockets are limited to their Bakas

The breakdown did include a "miscellaneous" type attack category, which included a few cases where navy ships anchored in the Thames fired on German V-1's, and COULD also have included Japanese Bakas.  Then again, those may have been included in the "suicide" category.

[Midshipman_Hornblower]

4 minutes ago, Burnsy said:

Is there some reason that you aren't including a link to the source of your information for these metrics?

For some reason I don't understand, when I tried to copy the link from my browser, it didn't work.  So, since you asked, here it is, hand-typed:

www.ibiblio.org/hyperwar/NHC/newPDFs/USN/action%20reports/USN.AA.Antiaircraft.Action.Summary.1945-10.pdf

[Midshipman_Hornblower]

1 hour ago, Torenico said:

Could you provide a link to that specific document?

See above.

[Burnsy]

13 minutes ago, Midshipman_Hornblower said:

For some reason I don't understand, when I tried to copy the link from my browser, it didn't work.  So, since you asked, here it is, hand-typed:

www.ibiblio.org/hyperwar/NHC/newPDFs/USN/action%20reports/USN.AA.Antiaircraft.Action.Summary.1945-10.pdf

Thanks, I am trying to figure out how to fix the link so it works.

[Burnsy]

http://www.ibiblio.org/hyperwar/NHC/

That much of it works but I can't figure out where you jumped from there.

[Burnsy]

https://www.ibiblio.org/hyperwar/NHC/NewPDFs/USN/Action reports/USN.AA.Antiaircraft.Action.Summary.1945-10.pdf

@Midshipman_Hornblower  I got it working I think.  Is the above link correct?

Here is the root:

https://www.ibiblio.org/hyperwar/NHC/NewPDFs/USN/Action reports/

[b101uk]

given its from Oct 1945 and in most cases aircraft kills have been revised down since, I would take it with a pinch of salt, given there is ample opportunity for multiple ships to claim the same kill.

[xHeavy]

1 hour ago, Karstodes said:

You do have those guns in your AA load out, they just do not force the player to pick between shooting ships and shooting plane. 
 

And in some case they did not gave it: the Tribal are a prime example. 

I can accept your position.

I am accustomed to fluid war and the necessary flow between surface action and air action is not too much of a problem for me.

I usually get in a DD Jumped by a CV and everyone in range on red fires on me. Since no one is yet in range for surface action, airdefense can be carried out nicely in combination of smoke and rudder input that varies.

[warheart1992]

What I find interesting is how VT (Variable time) or proximity fuzes almost halved the amount of AA rounds needed to shoot a plane down.

[Asym_KS]

2 hours ago, warheart1992 said:

What I find interesting is how VT (Variable time) or proximity fuzes almost halved the amount of AA rounds needed to shoot a plane down.

The saying "if it flies...it dies..." is so true because of Proximity warheads.   Pretty darn effective and getting smarter every year.

[warheart1992]

19 minutes ago, Asym_KS said:

The saying "if it flies...it dies..." is so true because of Proximity warheads.   Pretty darn effective and getting smarter every year.

It's pretty darn insane what's happening with the evolution of munitions technology ,especially with AFVs since WWII. Still, surface ships are no slouch either.

[Midshipman_Hornblower]

7 hours ago, Burnsy said:

https://www.ibiblio.org/hyperwar/NHC/NewPDFs/USN/Action reports/USN.AA.Antiaircraft.Action.Summary.1945-10.pdf

@Midshipman_Hornblower  I got it working I think.  Is the above link correct?

Here is the root:

https://www.ibiblio.org/hyperwar/NHC/NewPDFs/USN/Action reports/

Yes, that's it.  I'm not the world's most adept when it comes to computers, so thanks for the fix.

[Diddy_Kongs_Quest]

uh thats a significant amount of kill for AA guns....dang.

[Kartaugh]

9 hours ago, Karstodes said:

Wonder the number of round that the Type 96 25mm Gun needed to shot down an US plane.

Five quadrillion.

[Kaigun_Chusa]

9 hours ago, Karstodes said:

Wonder the number of round that the Type 96 25mm Gun needed to shot down an US plane.

6.02214076 × 10²³

[Nevermore135]

10 hours ago, Karstodes said:

And in some case they did not gave it: the Tribal are a prime example. 

In the case of the Tribal class, while technically dual-purpose, the 120mm guns were limited to 40 degrees of elevation, which severely limited their ability to defend themselves from certain types of aircraft (especially dive bombers) when under direct attack themselves. They were, however, more effective at engaging low, level-flying aircraft (like torpedo bombers) and contributing to mass AA fire over other ships. Their ability to function as AA weapons was very limited. For comparison, the 127mm dual-purpose guns deployed by the IJN on the later Fubukis and some subsequent destroyers (Yugumo, Shimakaze) had maximum elevation angles between 55 and 75 degrees, and these ships have dual-purpose weapons in game.

My guess is that considering the limitations of the game mechanics (i.e. guns engage all aircraft within range with equal efficiency, etc), WG needed to make a cutoff somewhere when it came to marginal cases like this. It’s a limitation of the “all or nothing” nature of the AA mechanics.