Japanese shipborne flak

[castor troy]

ORIGINAL: PaxMondo

ORIGINAL: obvert

I would say Pax that there were some other factors. As with many other facets of the IJ 'war plan' often the best solution was not followed extensively or efficiently. It wasn't just numbers, although that is true. It was also models that were emphasized, tactics and procedure, logistics and many other factors that kept AA from being a top notch tool for the IJ, on land or on ship.

As I mentioned, if you stack a bunch of units you get a decent effect in game, but then you've hung a few other bases out to dry completely. So it is scale, but on ship it's really the complete lack of a 40mm or other medium AA gun that kept them much farther back.

Erik,

100% agree, there were other factors and no medium AA is a huge hole. Still, for me, it all about the economy ... even if they had had the Bofors designed and tooled up, they couldn't have built enough of them and gotten them installed soon enough to have mattered without some other big things not getting done. I mean they would had to have NOT built some DD's or a few hundred planes or .... and each one of those "ors" was in huge demand.

I think it's more a question of how many Bofors or whatever AA gun they could have built instead of all the 25mm they actually have built. It's not like in the game, when you can "build" AA guns using armament pts
instead of building ships. In real life, they just couldn't swap building some destroyers, freighters or subs into building aircraft or AA guns. Industry isn't industry. And then they couldn't even rebuild the Bofors
in their dedicated industry so they just kept building the 25mm which they saw as sufficient.

[JeffroK]

IRL, dont forget that the success rates by Allied AA is swayed towards the 20mm & 40mm due to having to fight off Kamikaze attacks which penetrated closer. Conversly, the IJN Light AA didnt get a similar chance so their heavier AA had more chances.

[Yaab]

Thread resurrection.

Guys, do you ever see capitals ship (DD/CL/CA/BB/CV) use they smallest AA ammo (1.1 inch, 20mm, 0.303 MG, 40mm) at all? I only see used ammo in heavy DP category, while the smallest AA ammo remains untouched after every AA action and stands at 36 (36), which is full ammo compliment on the ship info screen.

[adarbrauner]

Ok recently someone well informed agan explained that the AA fire is divided in 3 phases: first approach, bombing run, and then the "escape";
first approach is at the altitude set for the attacking air unit; so if TBs for example come in at 14k alt., then only the higher caliber AA guns shall fire;

than the bombing run itself, if executed at a low altitude as in the case of TBs or diving bombers or low alt bombing, shall be met by all the guns small calibers included;

then the egressing/ escape track;

that should explain why at times only the higher calibers expend ammunitions;

I hope i rember well the content of that post;

to me, it comes as understood that only the attacked ship shall expend ammunition in the "bombing run" track; maybe there's a hard check also for some other ships in the TF to contribute in this phase;
While all the caliber-abled ships in the TF shall fire in the first phase;
possible the "after strike" phase is fired by the attacked ship only as well?

correct me please if uncorrect;

[adarbrauner]

Ok sorry, LoBaron had already written it before, so why your question Yaab?

[GetAssista]

ORIGINAL: Yaab
Thread resurrection.

Guys, do you ever see capitals ship (DD/CL/CA/BB/CV) use they smallest AA ammo (1.1 inch, 20mm, 0.303 MG, 40mm) at all? I only see used ammo in heavy DP category, while the smallest AA ammo remains untouched after every AA action and stands at 36 (36), which is full ammo compliment on the ship info screen.

Sure they do fire, when they can reach the target that is. I even did the test recently showing that small calibers of non-attacked ships in the TF contribute in the attack run phase

[PetrOs]

Actually, in the real history, US Navy decided to move away from 20mm and 40mm to 3" automatic AA by 45. The problem was that 20mm was found to lack range and stopping power to stop a kamikaze, and 40mm also. While most 40mm hits would have prevented the plane to return to base, the damaged plane was often still controllable and needed more hits. 40mm was also too small for proximity fuse action. 3" automatic gun with proximity fuse was found to be the best compromise, having the high range, high ROF and the effect to kill-stop any incoming plane.

Also, in reality, the difference was HUGE between proximity-fuse and no proximity-fuse in the same gun.

Official US Navy statistics said for WW2 RPB rate (rounds per bird, per http://www.ibiblio.org/hyperwar/USN/rep ... index.html)
5" Common - 654
5" VT Proximity - 340
3"/50 - 338
40mm - 1713
1.1" - 1932
20mm - 5287
50cal - 11143
30cal - 28127

The RPB rate per weapon actually got worse during the war except in 45, where it was better, but it was mainly due to the huge expansion of the navy and thus the inrush of not experienced gunners. Sometimes it was extreme - in 1942 the 5" commons had the RPB of 252, while in 1944 of 1157, efficiency down by 4.5 times....

Also very much depended on the evasion patterns. Just as an example -
In early war USN Avengers rolled from side to side agressively, making what they assumed violent turns to avoid the AA. Losses to AA were still high. Once, during excercise, one of the VT group commanders who was ill and not flying stood behind a 20mm gunner and noticed that the gunner easily followed the manover - violent rolls made nearly no changes on the aircraft course or height. He had an idea, and asked the pilots in the next attack to use elevator only, flying an extreme wave pattern in vertical plane. No 20mm gunner could follow such aircraft, as the plane's angular movement through gunsights was much more rapid. This was evaluated a few more times, and then applied on combat runs, losses per attack were MUCH less. That guy was however nearly lynched by rear gunners - they were affected by extreme G-forces going from negative to positive, and in the first test run ALL gunners left their lunch in the cockpit...




IJN lacked the effective gun between the good 100 and 127mm guns, and also a good VT fuse. 25mm were too short range, and 25 round magazines meant frequent stops for changing... They tried to replicate the british army model 40mm AA Bofors but not very successfully, and they discontinued the Pom Pom usage which was however too low velocity anyways. An effective automatic weapon of 37-65mm caliber would have increased their AA enormously.

[Yaab]

ORIGINAL: adarbrauner

Ok sorry, LoBaron had already written it before, so why your question Yaab?

I just wonder if small AA guns fire at all or only start firing if heavy DP ammo is totally depleted. I get attacked by dive/topredo bombers, but only heavy DP ammo has its stock used in AA combat.

[Zorch]

ORIGINAL: PetrOs

Actually, in the real history, US Navy decided to move away from 20mm and 40mm to 3" automatic AA by 45. The problem was that 20mm was found to lack range and stopping power to stop a kamikaze, and 40mm also. While most 40mm hits would have prevented the plane to return to base, the damaged plane was often still controllable and needed more hits. 40mm was also too small for proximity fuse action. 3" automatic gun with proximity fuse was found to be the best compromise, having the high range, high ROF and the effect to kill-stop any incoming plane.

Also, in reality, the difference was HUGE between proximity-fuse and no proximity-fuse in the same gun.

Official US Navy statistics said for WW2 RPB rate (rounds per bird, per http://www.ibiblio.org/hyperwar/USN/rep ... index.html)
5" Common - 654
5" VT Proximity - 340
3"/50 - 338
40mm - 1713
1.1" - 1932
20mm - 5287
50cal - 11143
30cal - 28127

The RPB rate per weapon actually got worse during the war except in 45, where it was better, but it was mainly due to the huge expansion of the navy and thus the inrush of not experienced gunners. Sometimes it was extreme - in 1942 the 5" commons had the RPB of 252, while in 1944 of 1157, efficiency down by 4.5 times....

Also very much depended on the evasion patterns. Just as an example -
In early war USN Avengers rolled from side to side agressively, making what they assumed violent turns to avoid the AA. Losses to AA were still high. Once, during excercise, one of the VT group commanders who was ill and not flying stood behind a 20mm gunner and noticed that the gunner easily followed the manover - violent rolls made nearly no changes on the aircraft course or height. He had an idea, and asked the pilots in the next attack to use elevator only, flying an extreme wave pattern in vertical plane. No 20mm gunner could follow such aircraft, as the plane's angular movement through gunsights was much more rapid. This was evaluated a few more times, and then applied on combat runs, losses per attack were MUCH less. That guy was however nearly lynched by rear gunners - they were affected by extreme G-forces going from negative to positive, and in the first test run ALL gunners left their lunch in the cockpit...

IJN lacked the effective gun between the good 100 and 127mm guns, and also a good VT fuse. 25mm were too short range, and 25 round magazines meant frequent stops for changing... They tried to replicate the british army model 40mm AA Bofors but not very successfully, and they discontinued the Pom Pom usage which was however too low velocity anyways. An effective automatic weapon of 37-65mm caliber would have increased their AA enormously.

Don't overlook the role of the gun director for larger guns. The US Mark 37 Director was vital in making the 5/38 an effective AA weapon. See https://en.wikipedia.org/wiki/Ship_gun_ ... MK_37_GFCS

[PetrOs]

Yes, the gun directors were of course also a thing VERY helpful here, and later also mated to very good radars by the time.

[Yaab]

Finally!

Small AA ammo used off Rangoon against AI's Nells.

[adarbrauner]

ORIGINAL: Yaab


Finally!

Small AA ammo used off Rangoon against AI's Nells.

N
what altitude.

Was that the ship attacked?

[PaxMondo]

ORIGINAL: PetrOs
IJN lacked the effective gun between the good 100 and 127mm guns, and also a good VT fuse. 25mm were too short range, and 25 round magazines meant frequent stops for changing... They tried to replicate the british army model 40mm AA Bofors but not very successfully, and they discontinued the Pom Pom usage which was however too low velocity anyways. An effective automatic weapon of 37-65mm caliber would have increased their AA enormously.

Agreed. As has been discussed here many times, even with a bigger gun than the 25mm, the IJ would have been stymied.
They were still missing two critical pieces:
1. Directors (as Zorch noted)
2. hydraulic turrets


They had the know how for both, the issue is that they didn't have enough those 'know how' bodies to produce enough of everything they needed.

Then, the killer, they had a core leadership/belief that they weren't needed. So what 'know how' they did have didn't get used efficiently.

[BBfanboy]

ORIGINAL: PaxMondo

ORIGINAL: PetrOs
IJN lacked the effective gun between the good 100 and 127mm guns, and also a good VT fuse. 25mm were too short range, and 25 round magazines meant frequent stops for changing... They tried to replicate the british army model 40mm AA Bofors but not very successfully, and they discontinued the Pom Pom usage which was however too low velocity anyways. An effective automatic weapon of 37-65mm caliber would have increased their AA enormously.

Agreed. As has been discussed here many times, even with a bigger gun than the 25mm, the IJ would have been stymied.
They were still missing two critical pieces:
1. Directors (as Zorch noted)
2. hydraulic turrets


They had the know how for both, the issue is that they didn't have enough those 'know how' bodies to produce enough of everything they needed.

Then, the killer, they had a core leadership/belief that they weren't needed. So what 'know how' they did have didn't get used efficiently.

Like ASW, flak is a defensive tool and the IJ leadership believed an honorable warrior had to be all about the offence. Defensive measure received only afterthoughts. That is why they opted for two-gun turrets on their BBs and cruisers (better for offence because fewer guns can be knocked out by a single enemy hit, leaving more to shoot back), whereas the USN went the other way to triple gun turrets which saved weight for AA guns.

[Yaab]

ORIGINAL: adarbrauner

ORIGINAL: Yaab


Finally!

Small AA ammo used off Rangoon against AI's Nells.

N
what altitude.

Was that the ship attacked?

The Nells come at 5000-6000 feet and drop bombs from that altitude.

[Yaab]

Thread resurrection.

Just checked if the manual speaks about flak and its disruptive effect on bomber targeting. Used CTRL+F and keywords "disrupt/disruption" in connection to flak and searched the entire manual. The search returned no hits. The in-game/Tracker database for flak/DP guns also speaks in terms of their accuracy and effect, and does not hint at their disruption capability.

Basically, when you think about flak in terms of damaged/destroyed aircraft then the flak might seem ineffective. In my previous tests in this thread, the attacking Allied dive-bombers suffered no losses in their attacks. However, they also achieved no hits on my ships, when my ships were defending themselves with DP guns in number roughly corresponding to the number of attacking aircraft.

[Alfred]

Read michaelm75au comments in this thread
 
http://www.matrixgames.com/forums/tm.asp?m=2222977&mpage=1&key=disrupt&#2223425
 
for confirmation that flak does disrupt enemy bombers.
 
Alfred

[Yaab]

Thanks! I surmised from combat animations that such disruption effect may occur, but I was wondering if I missed this information in the manual.

[Yaab]

THREAD RESURRECTION.

Jap ships use 25mm Type 96 AA guns (device 1682).

However, the land base version of this gun, 25mm Type 96 AA guns (device 726) upgrades to 25mm Type 96 AA gun (2) (device 727). So the single mount upgrades to a double mount. The double mount has better stats. Its Effect jumps from 22 to 35, and the Accuracy jumps from 47 to 57.

Now, since 25mm mounts on ships have mostly two guns (and later three guns), do shipborne 25mm guns fire at their single gun Effect/Accuracy? It seems to me with each additional gun in a mount, gun's Effect/Accuracy should go up. Yet, in Tracker/Editor there is only one sungle-gun device (id 1682) for ships, and there is no hint of any change stat-wise. The naval version of the 25mm gun has the same stats as a single-gun land-based mount.

Actually, upped Effect/Accuracy should apply to all multi-gun flak mounts on all ships, shouldn't it?

[Sardaukar]

http://www.navweaps.com/Weapons/WNJAP_25mm-60_mg.php

Probably the reason is this:

The magazines for the Type 96 held only 15 rounds, so frequent stoppages for change outs were required.

Why the land-based is better is beyond me.