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Level Bomber Accuracy

Posted: Mon Aug 19, 2002 6:22 pm
by Rainerle
Hi,

before complaining about how I get bombed to pieces I wanted to know: How often did Level Bombers hit moving targets (i.e. ships) in RL. From which altitude and under what circumstances.
On the other hand, how accurate is the altitude stat in the battle report, or maybe those B25/26 A20 are dive-bombing and nobody tells me?
It's just that I want to know before going on a rant.

Respectfully
Rainerle

Posted: Thu Aug 22, 2002 1:15 am
by Odin
:) Hallo Nachbar!:D

I think high altitude-level bombing was clearly useless against moving targets, with common non-guided bombs. And those B25 so on were not dive-bombing capable and can only be succesfull only at low altitude attacks, best close to the surface.

In the game, version 1.0 i used my B17 for longe range anti-ship missions at 1000 feet, seems they never miss somewhat.

This is now corrected, so i use B25, B26 and so at 1000 feet and the Heavys only against airfields and such things..

Gute Nacht!



:D

Japanese BB hit at Guadalcanal

Posted: Thu Aug 22, 2002 6:42 am
by USSLockwood
I seem to recall there was a case where a Japanese BB was hit from a B-17 operating at high altitude during the Guadalcanal campaign. When the attack commenced, the Japanese TF commander dismissed the danger, since it was well known that
B-17's could not hit a ship while at atltude. One bomb struck the fantail can caused extensive damage, which later proved fatal as the ship was unable to escape from the vicinity.

Posted: Thu Aug 22, 2002 6:53 am
by Odin
But its luck....but its possible a heavy bomber could be sucessful against ships that are docked in port, of course.

Posted: Thu Aug 22, 2002 7:09 am
by Odin
The only case a major warship was sunk by level bombers was in the meditarian...

The italian fleet escaped after italian caese fire, to find a safe place to wait..

They were attacked by both allied and axis bombers.

And then, 14 or so Do217 attacked with 2,800 pound armour-piercing giuded bombs. A Battleship, i think it was the Roma, was hit, the first bomb went trough the complete ship and exploded under keel, the second broke it in two parts.

http://www.wpafb.af.mil/museum/annex/an41a.htm

But of course, in UV forget attacks in high altidute..

Re: Japanese BB hit at Guadalcanal

Posted: Thu Aug 22, 2002 7:34 am
by 1089
Originally posted by doktor
I seem to recall there was a case where a Japanese BB was hit from a B-17 operating at high altitude during the Guadalcanal campaign. When the attack commenced, the Japanese TF commander dismissed the danger, since it was well known that
B-17's could not hit a ship while at atltude. One bomb struck the fantail can caused extensive damage, which later proved fatal as the ship was unable to escape from the vicinity.

It was a destroyer, IIRC.

kp

Posted: Thu Aug 22, 2002 9:22 am
by Drongo
Posted by doktor
I seem to recall there was a case where a Japanese BB was hit from a B-17 operating at high altitude during the Guadalcanal campaign. When the attack commenced, the Japanese TF commander dismissed the danger, since it was well known that


Just for the anal retentives.....

During the Guadalcanal Campaign

19th Aug '42 - While bombarding US positions, IJN DD Hagikaze stuck by bomb from 3 high Alt B17's. She survived and after finally fixing her steering, sailed off (very embaressed).

25th Aug '42 - While stopped mid ocean to recover troops from a sinking transport, IJN DD Mutsuki was destroyed by 3 direct hits from bombs dropped by 8 high alt B17's (very, very embarressed). Another DD (Uzuki) was damaged by a near miss from the same stick of bombs. This is the incident that is most commonly accepted as the source of the comment "even B17's hit their targets once in a while" (or Japanese equivalent).

25th Oct '42 - IJN CL Yura, heavily damaged by earlier attacks by Marine dive bombers, was crippled by bombs from 6 high alt B17's. She had to be sunk by escorting DD's. The Yura had also been reportedly struck and lightly damaged by B17's of the same squadron exactly a month before (very popular).

There were other reported hits during the campaign but the above accounts were confirmed from both sides.

P.S. I do have a life, I just happened to have a book of the battle beside me when I saw the post:D .

Accuracy

Posted: Thu Aug 22, 2002 11:09 am
by Rainerle
How,

thanks for the replies but ...
why is it, that on every occasion (PM not socked in/targets available) the AI Level Bombers (A-20/B-25/26/Hudson - 20-40 A/C) at 6000 ft always hit several of my (moving and hopefully evasing) ships (even the nimble destroyers/APD on fast transport) ?? Has anybody noticed similiar snipe bombs vs. sitting duck behavior ?

respectfully (but frustrated) from Münster
Rainerle

Posted: Thu Aug 22, 2002 11:35 am
by strollen
Drongo gave you information about B17 attacking from high altitude (which I assume is in the 10-15,000 range.)

I provided information in the B17 thread about B17 attacking in the low-medium altitude (3-6,000) during the Battle of Bismark Sea, in which they were fairly effective (5% bomb hits). One commonly quoted number is that B17 hit with about 1% of their bombs for all attacks.

So do the math 40 B25/B26 will drop 240 500 lb bombs.
Worse case if only 1% hit that is still 2 hits per run. A 2-3% hit rate (or 97-98% miss rate if you prefer) yields 5-8 hits. Since 500 lb would cause moderate to severe damage to a destroyer or APD it will often cause them to lose power, steering etc. (1 500 lb = ~12 5" shells) A damaged ship will have a harder time evading bombs and pilots would generally aim for damaged ships.

So don't kid yourself if you are being attacked by 20-40 Medium bombers without CAP you are going to have ships damaged and often sunk. From my reading of 5th Air Force accounts this pretty much happened in real life.

Accuracy

Posted: Thu Aug 22, 2002 5:40 pm
by Rainerle
Hi and thanks for your replies,

this is exactly why I started this thread, to know how often this happened in RL.
cause if I do the math the other way I get the result that the bomb takes approx. 20 seconds to reach a ship from 6000 ft. in which time a DD (34kn) will travel 350 meters, a AP (9kn) will travel 92 meters an dif both turn as hard as they can they will be quite off the place the bomb load comes down.
I remember stories on PQ-17 where lots of german LB never hit the target but the accumulation of near misses caused the machine to malfunction (i.e. steam tubes ripped off) and the hull to leak (again due to pressure).
So maybe we need more near misses with additional damage and less hits.

Respectfully
Rainerle

Bomb Accuracy and evasion

Posted: Thu Aug 22, 2002 10:06 pm
by dtx
A DD trying to evade bombs from a high level bomber might be as likely to move into the path of the bombs and as evade them.

Bomb accuracy is measured via Circular Error Probability (CEP) and for WWII level bombers, accuracy was very very poor. The CEP is the distance from the target type that at least half of the bombs would be expected to strike. For fixed targets, I believe the CEP for B-17 was at least 1 Km (my memory is weak regarding the actual number). I can't imagine how large the CEP would be for moving targets. Hence, the chance that a B-17 hits a moving target like a DD would be very small. However, as noted, if you drop enough bombs, you eventually may hit the target. My gut feel is that UV models this well.

[I vaguely remember that a Jap DD at Midway managed to avoid getting hit 30+ times(?) by SBDs. An unusual event - but war is often a series of chance events]

(In UV, I have noticed once a ship takes a single hit, it seems to be easy to hit by the remaining bombers - I assume this is a result of being partially disabled plus the fact that bombers may be attracted to the burning vessel).

For a very detailed CEP discussion: http://www.mercat.com/QUEST/Accuracy.htm

Recent results

Posted: Mon Aug 26, 2002 5:20 pm
by Rainerle
Hi,

so dtx you say that even vs. fixed targets they "miss by a mile !!!";)

ok level bombing results of the last 4-5 days:

42 LB 9 Hits --> 4,6667 a/c per hit
11 LB 2 Hits --> 5,5 a/c per hit
89 LB 19 Hits --> 4,68 a/c per hit
12 LB 3 Hits --> 4 a/c per hit.

So approx. every 5th Levelbomber scores a hit from 6000 ft.
a rate my divebombers do not achieve.

Respectfully
Rainerle

Too high accuracy !!!

Posted: Wed Oct 09, 2002 4:08 pm
by Rainerle
Hi folks,

I hereby repeat my question:

When in history did Level Bombers hit a moving target ???

Rainerle

Ok

Posted: Wed Oct 09, 2002 4:41 pm
by Luskan
Ready, this is straight from The second world war (bloody big book) by Pf John Keegan, in the Pacific section (about 300 big pages with small type) in the war for the islands (one of three 50 page chapters that deal with the area and period covered by UV).

"In August 1942 MacArthur had been given a new air commander, General George Kenney, who had wrought a revolution in the USAAF's anti-ship tactics. Previously, though army pilots had reported numerous successes against the Japanese navy, after action analysis had revealed that they had hit very little (if anything) at all.

Kenney transformed their methods. Recognising that the USAAF's chosen method of precision bombing from high altitiude lay at the root of the failure, he trained his medium range bomber pilots to attack at low level with guns and fragmentation bombs. When the 51st Division left Rabaul for Lae on 2 March 1943 it was first intercepted by a large fomation of Flying Fortresses employing the old high altitude level bombing technique, which hit only one ship (a small oiler which sank). The next day however, a similar sized formation of medium bombers (B-25s, A-20s, Australian Beaufighters) found it again, skimmed in at sea level, escaped the attention of the Zeros patrolling at high altitude to deal with the expected fortresess and sank all the transports, and four of the eight destroyer escorts.

the battle of the Bismarck Sea was a significant victory etc. et al ad finitum ad nausea.

Does this answer your question in a more general way?

Posted: Wed Oct 09, 2002 5:59 pm
by siRkid
The answer has to take into consideration, how often the Allies use LBs to attack ships at high altitude. Then compare the number of hits to the number of sorties.

But....

Posted: Thu Oct 10, 2002 11:08 am
by SwampYankee68
In an operational game, shouldn't the choice of altitude be left to the squadron commander, especially in light of the fact that you can't specify naval targets?

This is one of my biggest frustrations with this game (admittedly I am a more casual player than you all appear to be).

The theater commander being responsible for setting the altitude of an outgoing strike just doesn't sit right with me in light of the scope of this game (not to mention WitP).

I'd be happy to see a toggle to have the AI set altitudes given the type of target and maybe some other criteria.

Maybe in V1.50?

Re: But....

Posted: Thu Oct 10, 2002 8:33 pm
by NorthStar
Originally posted by Swamp_Yankee
In an operational game, shouldn't the choice of altitude be left to the squadron commander, especially in light of the fact that you can't specify naval targets?

This is one of my biggest frustrations with this game (admittedly I am a more casual player than you all appear to be).

The theater commander being responsible for setting the altitude of an outgoing strike just doesn't sit right with me in light of the scope of this game (not to mention WitP).

I'd be happy to see a toggle to have the AI set altitudes given the type of target and maybe some other criteria.

Maybe in V1.50?
I don't necessarily accept this. Because the altitude setting controls the balance of vulnerability vs. effectiveness, this is definitely withing the Theater Commander's realm. I don't want some cowboy squadron leader to take my last group of B-17s in over Rabaul at 6000 ft!

Where I think the problem lies is that instead of actual altitude (is there really THAT MUCH difference between 7000 and 8000 feet?), each squadron should have ALTITUDE BAND settings. That is, they should attack at Very Low (Skip Bombing), Low, Medium, High, and Very High (Above fighter) altitudes. This would allow control of the risks to your aircraft (which you should have) without all the hand ringing about the exact perferct attack altitude. Let the AI commander, withing the given band, decide on the precise attack altitude.

As usual, just my $0.02

Posted: Thu Oct 10, 2002 11:57 pm
by Bax
The only case a major warship was sunk by level bombers was in the meditarian...
I'm sure the crew of the Tirpitz might beg to differ! :D

Re: Re: But....

Posted: Fri Oct 11, 2002 12:08 am
by XPav
Originally posted by NorthStar

Where I think the problem lies is that instead of actual altitude (is there really THAT MUCH difference between 7000 and 8000 feet?), each squadron should have ALTITUDE BAND settings. That is, they should attack at Very Low (Skip Bombing), Low, Medium, High, and Very High (Above fighter) altitudes. This would allow control of the risks to your aircraft (which you should have) without all the hand ringing about the exact perferct attack altitude. Let the AI commander, withing the given band, decide on the precise attack altitude.
As usual, just my $0.02
100% agree. Non-supercharged aircraft suffer their penalties at High and Very High alts.

not really

Posted: Fri Oct 11, 2002 7:41 am
by Luskan
Originally posted by Bax


I'm sure the crew of the Tirpitz might beg to differ! :D
I think the point was that the Italian warships were moving when they got hit (and later they were hit and sunk at their moorings).

The Tirpitz wasn't moving - hadn't moved from Tromso in a long time (and was never going to either after 617 did their thing).