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Heavy Bomber defensive weapons

Discussion in 'Air War in Western Europe 1939 - 1945' started by GunSlinger86, May 14, 2021.

  1. RichTO90

    RichTO90 Well-Known Member

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    Um, no, 37, not 31, unless you think the missing and badly damaged Luftwaffe aircraft were victims of ASB? So 7.78 claimed per loss...and there were also 20-odd Luftwaffe fighters damaged less than 60%, all of which could likely have been claimed. So closer to 5.1 claims per "hit". Meanwhile, the Luftwaffe overclaiming was "only" two-to-one...or maybe 2.87-to-one. Of course, if you count the 17 B-17 surveyed and the 121 damaged but repairable, you get a near perfect record for the Luftwaffe. Except that for the purposes of the air war, the real telltale was the 882 Luftwaffe sorties required to do that damage.
     
  2. Thumpalumpacus

    Thumpalumpacus Active Member

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    "Um", none of that minutiae addresses my actual point. When you feel like doing that, let me know.
     
  3. Kai-Petri

    Kai-Petri Kenraali

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    The Germans invented the Shcräge Musik for night bombers. Quite deadly for the bombers. Flying below the bomber and shooting with 20-30 mm mg's at the Wings fuel. Often the ammo was explosive.
     
  4. RichTO90

    RichTO90 Well-Known Member

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    No, I did address your point, but if the minutia confuses you, here is the thing...the overclaiming, by both sides, was irrelevant and focusing on it misses the most important thing, which was the number of sorties the Germans had to fly to shoot down a single bomber. It required 14.7 sorties to shoot down a single bomber and nearly 4.5 sorties to do any damage at all. The number of claims made by air gunners was essentially irrelevant to the winning of the air campaign.
     
  5. Thumpalumpacus

    Thumpalumpacus Active Member

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    My point wasn't about actual kills at all, so the relevance outside of the disproportionate claims themselves is vanishingly small. Thanks anyway, I appreciate the time you've taken.
     
  6. RichTO90

    RichTO90 Well-Known Member

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    What was your point then? That air forces - hell, all forces - overclaim?
     
    Last edited: May 19, 2021
  7. Thumpalumpacus

    Thumpalumpacus Active Member

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    I've already repeated it once. Scroll up.
     
  8. RichTO90

    RichTO90 Well-Known Member

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    Sure, "My point was that massive overclaiming by American gunners (288 claimed vs 31 actual to use your figure) was present there, and that multiple gunners shooting at the same targets likely played a role." But what is the significance of that? How does it actually relate to the air war? American gunners massively overclaimed? Okay, so did German, and British, and Soviet pilots and gunners. The Luftwaffe routinely reduced initial claims by two thirds before publishing them, which may indicate that the Luftwaffe claims on 14 October were as massively inflated as the American. More revealing is the effort the Luftwaffe required to do what it did, which was simply unsustainable in the long run. When the Eighth Air Force quadrupled its sorties in 1944, the Germans were unable to match it.
     
  9. Brutal Truth

    Brutal Truth Active Member

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    I think that Thumpalumpacus point was that's easier for gunners in a massive formation of heavy bombers to claim over-kills than for fighter pilots.

    What about 20 mm guns in bomber turrets? The Americans had one in the tail turret of the B-29, but later it was often removed and replaced with a .50. In general I think that 20 mm guns of the WW2 era were generally too heavy and bulky to make good bomber defensive weapons. Swapping two '50 for one 20 mm wouldn't do, the increased range and power would not compensate for the reduced volume of fire. I wonder if the Americans could have developed a heavier MG, for instance a .60 version of the Ma Deuce. That may have helped, but it would have been a considerably heavier weapons. Increasing the caliber by 20% and scaling up the weapon in proportion would result in a 70-75 % increase in weight.
     
  10. Kai-Petri

    Kai-Petri Kenraali

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    Well, at least German plane numbers were progressively going down as well as opposing the forces when it comes to attacking Allied bombers....

    The Defeat of the German Air Force

    [​IMG]

    And German pilot training time

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    German fighter effectiveness vs Allied bombers

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    Loss rates from documents

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    Fire powers compared. The B-17 seems to stay the same through the war.

    [​IMG]

    German gun relative destruction potential ( single shot )

    [​IMG]

    Trends of size of opposing forces towards the end of war

    [​IMG]
     
  11. Kai-Petri

    Kai-Petri Kenraali

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    Air warfare of World War II - Wikipedia

    The Germans began losing one thousand planes a month on the western front (and another 400 on the eastern front). Realizing that the best way to defeat the Luftwaffe was not to stick close to the bombers but to aggressively seek out the enemy, by March 1944 Doolittle had ordered the Mustangs to "go hunting for Jerries. Flush them out in the air and beat them up on the ground on the way home.",[113] as Mustangs were now ordered to fly in massive "fighter sweeps" well ahead of the American combat box heavy bomber formations, as a determined form of air supremacy effort, clearing the skies well ahead of the bombers of any presence of the Luftwaffe's Jagdflieger fighter pilots. By early 1944, with the Zerstörergeschwader-flown heavy Bf 110G and Me 410A Hornisse twin-engined fighters being decimated by the Mustangs whenever they appeared, direct attack against the bombers was carried out instead by the Luftwaffe's so-named Gefechtsverband formations with heavily armed Fw 190As being escorted by Bf 109Gs as high-altitude escorts for the autocannon-armed 190As when flying against the USAAF's combat box formations. However, Doolittle's new air supremacy strategy fatally disabled virtually any and all of the Luftwaffe's defensive efforts throughout 1944. On one occasion German air controllers identified a large force of approaching B-17s, and sent all the Luftwaffe's 750 fighters to attack. The bogeys were all Mustangs flying well ahead of the American bombers' combat boxes, which shot down 98 interceptors while losing 11. The actual B-17s were well behind the Mustangs, and completed their mission without a loss. In February, 1944, the Luftwaffe lost 33% of its frontline fighters and 18% of its pilots; the next month it lost 56% of its fighters and 22% of the pilots. April was just as bad, 43% and 20%, and May was worst of all, at 50% and 25%. German factories continued to produce many new planes, and inexperienced new pilots did report for duty; but their life expectancy was down to a few combat sorties. Increasingly the Luftwaffe went into hiding; with losses down to 1% per mission, the bombers now got through.[114]

    By April 1944, Luftwaffe tactical air power had vanished, and Eisenhower decided he could go ahead with the invasion of Normandy. He guaranteed the invaders that "if you see fighting aircraft over you, they will be ours.

    -------------

    Could you say the bomber guns were used less and less during missions as the fighters did the "dirty work" and took care of the interceptor planes?
     
  12. Thumpalumpacus

    Thumpalumpacus Active Member

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    The fact that any other forces also overclaimed has no bearing on the idea that bomber gunners in particular may have been overclaiming because multiple gunners were shooting at the same target. That's why your replies do not address my point. Thanks for trying.
     
  13. Thumpalumpacus

    Thumpalumpacus Active Member

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    Exactly, and positing one possible factor.

    If I remember rightly, the .60 mount weighed almost as much as a 20mm, with a shell almost as large (80% diameter) as a 20mm shell but lacking the explosive charge.
     
    Last edited: May 19, 2021
  14. Brutal Truth

    Brutal Truth Active Member

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    I'm not aware the USA ever developed a .60 (15.2 mm) MG in WW2. Maybe there were proposals or designs, but I don't know about them. It was just my idea.
     
  15. Thumpalumpacus

    Thumpalumpacus Active Member

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    You can read more here: Springfield Armory Museum - Collection Record
     
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  16. RichTO90

    RichTO90 Well-Known Member

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    That may be the assumed point, but is it correct? The Luftwaffe day fighters claimed 171 aircraft, probably after the RLM reduced them as they did automatically. So it is probable the original count was more like 523. In 882 sorties that is 0.59 claims per sortie. The Eighth Air Force gunners claimed 288 enemy aircraft in 229 sorties, so 0.8 claims per sortie, little different than what the Germans claimed.

    Of course, it gets further complicated when you know the actual Eighth AF claims were 186 enemy aircraft destroyed, 27 probables, and 89 damaged, while another 23 were claimed by USAAF and RAF fighters (16 destroyed, 1 probable, and 6 damaged).

    Problematically though, that whole comparison is apples to oranges. The actual comparison is German fighter claims of 121 destroyed and 51 probable -171 total, versus USAAF/RAF claims of 202 destroyed and 28 probable - 230 total. Actual losses were 37 German fighters lost or written off versus 67 American bombers lost or written off (Eighth Air Force actually reported 60 lost and 7 written off, but others say 13 were written off. Then there are the Allied fighter losses, which do not appear with the German claims, since the Luftwaffe study only counted bombers.

    In other words, making any assumptions about air losses and who did what to whom are a huge kettle of dead fish. Unless you like differential equations.
     
  17. Thumpalumpacus

    Thumpalumpacus Active Member

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    The topic, though, is "heavy bomber defensive weapons". Introducing a comparison to LW fighter overclaiming is indeed apples-to-oranges.
     
  18. RichTO90

    RichTO90 Well-Known Member

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    If the topic is "heavy bomber defensive weapons" why did you bring up aerial gunner over claiming? One digression leads to the other; as my Granny used to say, if the sauce is good for the goose it is good for the gander.
     
  19. Kai-Petri

    Kai-Petri Kenraali

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    The WWII Fighter Gun Debate: Defensive Armament

    British

    The Lancaster had Frazer-Nash turrets, initially in the same arrangement as on the early models of the Halifax. The Lancaster happened to have much better aerodynamics than the Halifax, and the great majority of Lancasters retained their nose, dorsal and tail turrets. The ventral turret was deleted, and on many aircraft it was replaced by a fairing for the H2S radar.

    Four Browning .303 machineguns were installed in the tail turret of a Lancaster. The gunner also had the best view towards the rear, where any attacker was likely to appear, and he controlled the defense. On his signal the pilot would start the evasive "corkscrew" manuever.

    Another concern was the continuing use of the .303 machineguns as bomber armament, although .50 guns were occasionally installed. After the first years of the war most fighters had armour plating and windscreens that rendered the .303 ineffective. But it was not that easy to redesign the gun turrets for heavier weapons, and to make things worse no British .50 was available. American Browning .50s were apparently not in sufficient supply to re-arm Bomber Command's aircraft entirely. And the 20mm Hispano was a slim, but long and heavy weapon, not ideal for installation in a gun turret.
    But the de Havilland Mosquito was a bomber as well as a nightfighter. Calculations showed that the unarmed Mosquito, relying on speed and altitude to evade German fighters, was a more efficient way to deliver bombs to the target than the four-engined "heavies". Not carrying armament resulted in enormous savings in weight and drag, reduced the crew to two, and reduced the cost of the aircraft. This resulted in the creation of the Light Night Strike Force. Evidently, a bomber that relied purely on high performance was vulnerable to technical developments; but the Mosquito was a brilliant design, and remained extremely difficult to intercept throughout the war. Only at its very end the Germans managed to put a small number of jet-engined nightfighters in service.

    8th AF

    The answer to the fighter treat, it was believed, was to have more and heavier guns per bomber, attacks by fleets of 300 or more bombers, and close-packed formations that were carefully arranged to give each gunner the best possible field of fire. The "combat boxes" would be able to bring more firepower to bear on the enemy fighters than any bomber formation had ever done before.

    Only small men would fit in the ball turret of a B-17. Although uncomfortable, this was a much more effective defense than remote-controlled weapons with periscopic gunsights, and it caused less drag than a "dustbin" turret.

    The Boeing B-17 Flying Fortress and Consolidated B-24 Liberator certainly were heavily armed. In the first versions, the armament of the "Flying Fortress" had consisted of only five manually operated machineguns, an arrangement that invoked sharp criticism from the British, who considered the aircraft "practically indefensible against any modern fighter."

    But when the 8th AF began operations, the US heavy bomber had been redesigned, taking into account the combat reports from Europe. They had dorsal turrets and ventral "ball" turrets with two Browning .50 M2 machineguns. A tail gunner controlled two more .50s. Two windows in the waist of the aircraft each accomodated a single .50 gun. In the B-17 another single .50 was fired from the radio room. Of course all this armament was rather heavy, to a total of over 2580 kg (5700 lb),and that was more than the bombload on long-range missions. In principle this gave them excellent defensive firepower in the entire rear hemisphere.
    The front was a weak point, however. Although the prototype had had a nose turret, the frontal defense of the production B-17 was limited to a number of manually aimed machineguns, initially a single .30 machinegun; it was soon replaced by a .50, and one or two more .50s were installed in small "cheek" windows. The B-24 had similar armament. This was not enough, because the Germans soon understood that the B-17 was really vulnerable to frontal attack. Not only was the forward firepower limited, there was no armour to protect the crew from such attacks.

    The German pilot Anton Hackl commented:[One accurate half-second burst from head-on and a kill was guaranteed. Guaranteed! )

    At first units in the field improvised more powerful nose armament, but the B-17G and B-24H introduced powered nose turrets with two .50s

    These nose turrets were a fortunate spin-off of new experiments with the "air cruiser" concept: The YB-40, a heavily armed "escort fighter" version of the B-17, and the XB-41, a similar version of the B-24. Only one prototype of the XB-41 was completed, but twenty-one YB-40s were created. Combat experience showed that the YB-40s with all their additional armament, armour and ammunition were too slow to maintain formation with the B-17s, and that ended the experiment.

    Why did the heavy bombers fail? Apparently the leaders of the 8th AF simply underestimated the difficulty of the task the gunners faced. There were some skeptics, such as Col. Claude E. Putnam, the commander of the 306th BG, who estimated in 1943 that only 10% of the gunners who could theoretically have fired at an enemy aircraft really did so, and that at least four gunners needed to fire to have a 50% probability to shoot an enemy aircraft down. The commander of the 308th shared his doubts, wondering whether the guns were not more a hazard than a protection.

    The attacking fighters were small targets in an often confusing battle, and it was not at all evident that gunners would see them, identify them, estimate their distance and speed, aim correctly, and fire at the right time. This looked good on paper, but in practice it was an almost impossible task. During WWII, the hit probability for fixed, forward-firing guns was estimated to be only about 2% for an average pilot; and the operation of flexible guns is far more complex.

    Another factor was that the gunners were not trained well enough.[27] After the outbreak of war a large training program was created, but there was little experience in the field, little equipment, and it was very difficult to find and retain competent instructors. During the war some improvements were made, but as late as 1944 a War Department report admitted that some gunners simply didn't know how to operate their gun turrets! Operational units had priority for equipment, and gunnery training was sadly neglected: It was mid-1944 before enough aircraft were made available to gunnery schools and gun cameras became available for training purposes.

    The assumption that the concentrated fire of a "combat box" would fend off fighters also had a fundamental flaw: It ignored that the fighters would react by concentrating their attacks. Initially the Luftwaffe went after the lower groups, but later it often attacked the lead group, because they knew that it contained the lead bombardier. The formation did offer significant protection to the bombers; indeed any bomber that left the formation became an easy kill. But it was not enough.

    The exaggerated kill claims gave a false impression of the effectiveness of the defensive guns, and for this reason the 8th AF continued unescorted daylight attacks for far too long. The usual reason given for the excessively high claims is that any German aircraft shot down was claimed by multiple gunners, who had all fired in its direction. In addition, too often any puff of smoke from a German aircraft was interpreted as a sign of a fatal hit, while it often enough just indicated a rough handling of the throttle. The gunners had to do an impossible job in extremely dangerous conditions, and can hardly be blamed for compiling incorrect statistics.

    .
     
  20. Brutal Truth

    Brutal Truth Active Member

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    Here I thought that somebody would say that it's a silly idea, and it turns out they tried it in reality! :D Do you know if it was intended for fighters or for bombers too? Anyway, that was a converted German gun. I was thinking about up-scaling the .50 Browning AN/M2. In theory it should have resulted in a lighter weapon than the German model, but probably just up-scaling a model it's not as simple as it sounds.
     

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