1944: Flak Alone Blasts the Allies out of the Sky

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SpicyJuan
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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#151

Post by SpicyJuan » 24 Oct 2015, 00:46

stg 44 wrote:AFAIK the non-Kamikazee aircraft were not low altitude attacks.
Then at what altitude? Also, no matter what it is, it's a completely different ball game when you have at most 1 or 2 squadrons to fire at, as compared to hundreds that are flying very closely together.

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#152

Post by stg 44 » 24 Oct 2015, 01:40

Right, it s a lot easier to hit bomber boxes at high altitudes than fast moving lower altitude aircraft. Now the RAF at night were more spread out and harder to hit, there proxy fuses might well help.


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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#153

Post by T. A. Gardner » 24 Oct 2015, 04:03

stg 44 wrote:Right, it s a lot easier to hit bomber boxes at high altitudes than fast moving lower altitude aircraft. Now the RAF at night were more spread out and harder to hit, there proxy fuses might well help.
Actually, you have it backwards. Altitude = protection from gunfire. The major reason for this is the slant range of the gun decreases as altitude increases. So, at lower altitudes you have more firing time. Speed is not protection like altitude is. While it helps a little it doesn't make up for the increase in firing time the target is engaged.

An extra minute or two of firing time per barrel equals 10 to 20 rounds a minute thrown at the target(s). The battery predictors of the 1940's are more than capable of tracking and giving accurate predictions on bombers up 400 mph or more. This equates to 60 to 120 rounds per battery more fired at a target and commensurately increases the probability of a hit or kill substantially.
The Sterling bomber was disliked by its crews because loaded it had a very limited maximum altitude. Being the low planes in the bomber stream they were the easiest and most hit targets as a result.

Now, these predictors have problems with maneuvering targets and it won't be until the mid 50's that a predictor can really handle those.

Now, if the bombers go to about 30,000 feet + you start looking at horribly large guns like the postwar British Green Mace:

Image

Now you have a gun weighing 20 + tons that is water cooled, incredibly complex, and firing very expensive ammunition. All that makes the SAM an attractive alternative.

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#154

Post by thaddeus_c » 24 Oct 2015, 15:28

stg 44 wrote:
T. A. Gardner wrote:
Paul Lakowski wrote:cant see SAM solving the high altitude bomber, but give a short range wire guided AAM to any descent 'two seater' fighter and the kill rate should sky rocket.
I've suggested this elsewhere: The Luftwaffe adopts an AAM based on the V-1.
Won't work. V-1 was not designed or able to function on the vertical plane. This was as close as you'd get to the V-1: https://en.wikipedia.org/wiki/Henschel_Hs_117

The V-2 based missile instead of the V-2 would have been doable:
https://en.wikipedia.org/wiki/Wasserfall
why wouldn't the air launched V-1 (variant) work? am aware of pulse jet having a service ceiling but they were working on small disposable jet version.

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#155

Post by stg 44 » 24 Oct 2015, 16:13

The pulse jet used was not designed for that sort of vertical work for one, while the entire design of the fuselage of the missile was for horizontal stability, not vertical.

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#156

Post by JAG13 » 25 Oct 2015, 17:07

thaddeus_c wrote:
stg 44 wrote:
T. A. Gardner wrote:
Paul Lakowski wrote:cant see SAM solving the high altitude bomber, but give a short range wire guided AAM to any descent 'two seater' fighter and the kill rate should sky rocket.
I've suggested this elsewhere: The Luftwaffe adopts an AAM based on the V-1.
Won't work. V-1 was not designed or able to function on the vertical plane. This was as close as you'd get to the V-1: https://en.wikipedia.org/wiki/Henschel_Hs_117

The V-2 based missile instead of the V-2 would have been doable:
https://en.wikipedia.org/wiki/Wasserfall
why wouldn't the air launched V-1 (variant) work? am aware of pulse jet having a service ceiling but they were working on small disposable jet version.
Better use the Hs-293, after all the Germans did consider using them in that role, was fully developed, capable, and with a wire guided version available if jamming ever warranted it. It would put 300Kg of explosives in the middle of a B-17 vic, the only difficulty (beyond surviving the escorts, but if used in 1943 not that much of an issue) would be, again, how to detonate at the right time...

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#157

Post by Paul Lakowski » 25 Oct 2015, 21:13

Yep that's what I was getting at.

The historical production of 40,000 major rockets & 16,000 guided missiles were divided over ~ 36 different programs secrete from each other.
So on average 1500 per program which sounds OK. When you remove the four main programs [Hs-293 ; X-1 ; V1 & V2], you are left with ~ 300 missiles per program for the rest, not enough for testing & development to say nothing of training and war usage. That's an average of > 11,000 missiles for each of the main programs.

If we extrapolate based on a military C-IN-C in charge ; we could see 36 program getting 100 guided missiles per program to develop through the early war period . Then if we narrow this down to 6 program to test/train mid war, we consume another <500 missiles each, leaving ~ 50,000 rocket/missiles [~ 40% guided].

What to do with this asset?

We have about 20,000 guidance units to use on 50,000 rockets [rest autogyro] over 2-4 programs or 10-30,000 per program. The roles are SAM ASM SSM & SRBM. Testing development & training would show that the autogyro are in accurate at range , while the guidance units are sensitive and could be easily jammed & countered , so over all accuracy will not be great and the target will have to justify the expenditure of missiles.... in other words they would have to be of strategic importance. Alternatively all targets should be short range but of crucial operational importance.

What we know from history is that the ASM show 50% hit chance in training against stationary targets while in battle against moving ships it was 17%. With enemy maneuvering and firing back these figures fell to 10% and with heavy jamming a year later hit chances fell to 3-4%.

Going on V1-V2 results we get 5.7% of range or 5.7km radius @ 100km, which means 50% of warheads should land within 6km radius [102km2]and all warheads should land within 15km radius [~600km2]. A 500LB warhead has destruction area of km2 vs infantry ; 2/3 km vs vehicles/structure and 1/3km vs AFV. So to destroy every single infantry within the 15km radius @ 100km range should require < 600 rockets each with 500lb warhead. these strikes will also destroy 2/3 of all structure/vehicle & 1/3 of all AFV.

At 50km range the figures should be 3Km CEP .All warheads should land within 7km radius covering 149km2 . So it should take 150 rockets to destroy all infantry and 2/3 of all vehicle /structures plus 1/3 of all AFV.

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#158

Post by lufty1 » 25 May 2016, 18:06

Here is what this thread has been missing - NARA report FMS D031 by FLAK General Walther von Anthelm about the experiments and discussions on contact fused flak shells in 1944-45. Can be downloaded from http://www.sturmpanzer.net

He describes the raid in "around mid-"april 1945 on airfields around munich which he witnessed from a flak battery "attack was by 180-200 aircraft in 6/10 cover; 17 were shot down ..." etc describes how some came down.

Use against night bomber streams were 2x improved in a/c downed; daytime 3x

I can't attach the pdf - will try to make a smaller file

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#159

Post by stg 44 » 25 May 2016, 19:02

lufty1 wrote:Here is what this thread has been missing - NARA report FMS D031 by FLAK General Walther von Anthelm about the experiments and discussions on contact fused flak shells in 1944-45. Can be downloaded from http://www.sturmpanzer.net

He describes the raid in "around mid-"april 1945 on airfields around munich which he witnessed from a flak battery "attack was by 180-200 aircraft in 6/10 cover; 17 were shot down ..." etc describes how some came down.

Use against night bomber streams were 2x improved in a/c downed; daytime 3x

I can't attach the pdf - will try to make a smaller file
Did it say what the shells were though? I've seen some argument that they might have been proximity fuses

Edit: read the report, it would appear that where just standard contact fuses. Its surprising that such a simple change got results like that.

It also then opens up the option of having a smaller shell with greater propellant, as they were getting one shot kills with 5cm guns on twin engine fighters against bombers. Taking the existing 5cm shell (or a 55mm one as they experimented with that caliber for a mid-range weapon) and putting a bunch of propellant behind it, like the FLAK 41 tried to do with the 88mm shell, and going for those direct hits would be a viable option, as it would be a much lighter shell than even the standard 88mm gone, so less taxing on the crew firing it rapidly, while saving material and allowing for even more rapid firing, so as to fill the target space with even more shells and likely increasing the kill count. The guns could be smaller and lighter even that then regular 88mm gun and much less expensive than complex than the huge 128mm FLAK guns, plus use a lot less propellant than that while getting extremely high velocities and altitudes with these smaller shells, assuming you could fit both the timed and contact fuse in a 5cm shell.

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#160

Post by T. A. Gardner » 26 May 2016, 06:21

Shooting down aircraft with heavy AA guns at long range is different from using light AA guns against low flying aircraft. The heavy guns require a fire control system using optical rangefinders or radar along with a fire control computer to accurately place the fire. The object isn't so much to hit the target, but rather get close for the burst to damage it.
As altitude and speed of the target increase, the probability of a kill by any particular battery of heavy guns, regardless of what they're firing, does down. The gun's range with some particular round is fixed. The flight time is fixed. The rate of fire is largely fixed too by the time it takes to cycle through the loading sequence.
Using smaller, sub-caliber shells was proposed. The British did exactly that post war with the Green Mace system. They even water cooled the gun barrel and added automatic loading to increase the ROF. Still, the gun simply couldn't keep up with aircraft development.
The 8.8 cm Flak 18 / 36 the Germans used as their main heavy AA gun has literally just a few minutes of firing time against a particular aircraft at most when it is flying at 25,000 feet. At 30,000 you need the 12.8 cm to have more than a minute or so of firing time. This is against B-24 or B-17. Against RAF bombers flying at 20,000 feet or so they do a bit better.

So, it becomes simple math. Let's say the ROF is 20 rpm. 6 x 20 is 120 rounds. Three minutes of firing time at any particular bomber = 360 rounds. If the Pk = 1 is 600 rounds it's about a 50 - 50 probability that any one bomber will be brought down. If the guns are firing at a particular box instead the Pk drops substantially.
If you double the effectiveness of the rounds the Pk = 1 and it's likely a single battery firing at a single aircraft for three solid minutes will shoot that one bomber down.
Now, if 20 fly through the zone of fire in those 3 minutes and 1 is brought down, the flak isn't all that effective.

AA guns, be they US, German, British, or anyone else's, versus high flying fast (300 mph +) bombers simply can't do the job. They can't fire enough shells in a short enough time to bring the bombers down in sufficient numbers to stop the raid. They can't even start to make a dent.

If instead you have a SAM that can bring a bomber down just 50% of the time and your firing time due to the huge increase in range is now 10 minutes you can shoot down 3 to 6 with one battery of 6 missiles (assuming a less than 10 minute reload time). But because the range is vastly increased more batteries can fire. They have more time to engage. Thus, they become far more effective than guns and that's why heavy AA guns have disappeared from use.

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#161

Post by Paul Lakowski » 27 May 2016, 06:06

Guidance systems of the 1940s were very poor in actual battles ....so 50% hitting in training vs large stationary target is reasonable. If that large target was moving the hit rate might be cut in half, while something like a slow moving bomber might be half again. So in training you might be looking at 12%, but real combat might cut this in half again to only a few %.

Don't worry hit chances with flak was a lot worse, with 10,000 major flak in the west- killing only 3500 bombers in the whole of 1944. The reported figures to bring down a bomber was 16,000 shells for the 88mm flak....so that's a kill rate of % 0.00625. The hit rates must have much higher with at least 10,000 US bombers being damaged....that sounds like about 8000 shells per hit.

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#162

Post by lufty1 » 30 May 2016, 12:11

A bit more on my earlier post.

Gen Von Axthelm is his name according to Edward westermann's book.(Flak)

The article FMS D031 is worth a read (at sturmpanzer.net)

Looking again at that book (p190 and p280-1 for refs), it mentions the date as being 9th april 1945. It states that 13 bombers were brought down (von Axthelm said 17)

The references in the book are KriegTagesBuch des Chefs des Luftwaffefuhrungsstabes T321/reel 10/frames 4746959, 4747010, 4747050, 4747052, (Nara war diary entries late mach/april 1945); Golucke book Schweinfurt p 156; Control commission for German notes on flak p50 IWM

Anyone have access to Nara microfilm?

Von Axthelm (nara D031) referred to 17 shot down of which several over the Schleissliem(?) air base

YES! - The 8th air force historical site 8thafhs.org chronology for 9th april 1945 does refer to an attack on Neuburg oil depot and airfield and Schleissheim airfield by 289 B-17s. It states

"1. 333 B-17s are sent to hit a munitons plant at Wolfratshausen (76) and Oberpfaffenhofen (107) and Furstenfeldbruck (139) Airfields; 2 B-17s are damaged beyond repair and 12 damaged; 1 airman is WIA. Escorting are 137 of 146 P-51s; they claim 4-0-10 aircraft on the ground.

2. 289 B-17s are sent to attack an oil depot (89) and airfield (66) at Neuburg and Schleissheim Airfield (128); 3 B-17s are lost and 42 damaged; 2 airmen are KIA, 5 WIA and 56 MIA. The escort is 193 of 203 P-51s; they claim 1-0-3 aircraft in the air and 70-0-37 on the ground; 3 P-51s are lost (pilots MIA).

3. 228 B-17s are dispatched to hit Riem Airfield at Munich (212); 10 others hit the secondary, the marshalling yard at Ingolstadt; 3 B-17sa re lost. 149 of 151 P-51s escort; they claim 6-0-4 aircraft on the ground; 1 P-51 is lost (pilot MIA).

4. 402 B-24s are sent to hit airfields at Lechfeld (109), Memmingen (96), Leipheim (88) and Landsberg (62) and Landsberg E landing ground (33); 1 B-24 is lost, 1 damaged beyond repair and 7 damaged; 2 airmen are KIA, 1 WIA and 9 MIA. 193 of 205 P-51s escort claiming 4-0-5 aircraft on the ground."

If we look at item 2, 3 B-17s were lost and 42 damaged, but 56 crew were MIA which does not tally with 3 B-17 lost. However the losses at first glance do not tally with the german claims (von Axthelm witnessed the raid and flak and describes how some bombers came down). Maybe US 15 af was active in the same locations

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#163

Post by T. A. Gardner » 31 May 2016, 23:28

I'd guess that the bulk of the 56 MIA were from damaged aircraft. Either they bailed out prematurely, or were somehow blown clear of the aircraft, or something like that.

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#164

Post by stg 44 » 04 Nov 2016, 19:19

Not sure if this has been posted here already, but I came across the line "if introduced in 1944 it might had changed the course of the war" in regard to flak radar, so it seems to fit in this thread. Had such a system been ready in time for early 1944 perhaps the bomb offensive could have been shut down.
https://books.google.com/books?id=KrWJD ... em&f=false
Image

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Re: 1944: Flak Alone Blasts the Allies out of the Sky

#165

Post by T. A. Gardner » 04 Nov 2016, 20:19

This, was hands down, the most effective land based AA fire control system of WW 2:

Image

It goes several steps beyond Egerland in integration of fire control to the battery.

Unlike the German system that still transmits data to the guns and the gun crew acting on it, the SCR 584 system was integrated into the gun aiming system itself. The 90mm M2 / M3 gun had power on the mount. There was a small gasoline engine and generator mounted on the gun. The guns in the battery were tied into the SCR 584 radar and M9 gun director system that automatically aimed the guns, accounted for parallax errors in position between the guns and the director, and using the powered fuze setter and rammer would allow for an almost 20% increase in ROF. All the crew on the mount did was load shells and monitor the gun's operation. With VT fuzing, the performance was far, far better than any other heavy AA gun at the time.
The system could also integrate searchlights in use into it, slaving these to the fire control and radar system as well.
It was effective enough that in late 1944, the US Army reduced 90mm gun batteries from 6 to 4 tubes with no loss of effectiveness. It was also mobile. The British followed this lead with GL Mk IV, and post war everybody adopted similar systems for their heavy AA guns.

Making the US adoption of such a system easier, was they already had a similar one in service with the USN and the 5"/38 gun. It was simply a matter of transferring extant technology to the land system.

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