Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: SMIDSY on July 20, 2005, 02:57:48 AM
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i vaugly remember hearing something in a documentary about a "b17 gunship varient" that was armed with 20mms instead of fiddy cals. it didnt carry bombs i think and was placed randomly in the bomber stream to suprise the glorious sons of germany. is there any truth to this memory? if so, what were its specifications, exact armorment and in what #s were they used?
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AH HA!! found it! called the YB-40. it was indeed used to escort b17s. it didnt have 20mms. my gun count one a pic i found is 16x.50 cal MGs.
notice the aditional dorsal turret and twin waist guns.
(http://[URL=http://www.imageshack.us][IMG]http://img161.imageshack.us/img161/672/yb40fortress9ya.jpg)[/URL][/IMG]
here's a diagram
(http://[URL=http://www.imageshack.us][IMG]http://img161.imageshack.us/img161/184/xb408jz.jpg)[/URL][/IMG]
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Both it and its gunship B-24 cousin, the XB-41, were both duds. Once the regular B-17/B-24 had drop their bombs the gunships (YB-40s) were left behind. The regulars had to slow down and escort the gunship escorts.
The XB-41 never got out of the USofA.
XB-40: Conversion of B-17F-1-BO 41-24342
YB-40: Conversions of B-17F-10-VE 42-5732/5744, B-17F-30-VE 42-5871,
and B-17F-35-VEs 42-5920, 5921, 5923, 5924, 5925, and 5927.
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it did see service in europe. only info i could find was that of the 1st heavy bombardment wing. they were the 327th bomb squadron. according to the squadron records they shot down 5 german fighters. but they lost 2 yb-40s. they were a group from may 29, 1943 untill july 29, 1943.
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Originally posted by SMIDSY
they were a group from may 29, 1943 untill july 29, 1943.
thats about all i have heard.... 1 month of service, a total flop.
search it here on the BBS... it gets asked about every 6 months or so, i can recall distinctly 3-4 posts about it in this forum.
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Originally posted by MiloMorai
Both it and its gunship B-24 cousin, the XB-41, were both duds.
My kinda plane:D
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if you cant hit em... ADD MORE GUNS!
not suprised it was a flop, how would arming 10 (or whatever) amount of bombers in a group of hundreds of b17's make any difference what-so-ever?
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Sounds like an idiotic idea to me.
Kind of shows the Germans weren't the only "desperate" ones...
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I think the gunship libbies and buffs were a stop-gap measure while longer range escort fighters were being developed. Once the likes of the 'stang came into use in numbers, the idea was obsolete. Hence why lots of X's and Y's, but no plain-Jane 'B-40' and 'B-41', they were scrapped before full production.
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I can't help but think why they didn't add these extra guns to REGULAR B-17s, might have made a difference then even without the extra ammo load.
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admrose, the gunners on american bombers were far more successfull than pop culture would have us believe. in fact, a whole two thirds of all german and italian fighters were felled by the .50 cals of the american bomber fleet.
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source?
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some documentary i saw on...pbs a coupe years ago.
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Originally posted by AdmRose
I can't help but think why they didn't add these extra guns to REGULAR B-17s, might have made a difference then even without the extra ammo load.
As mentioned above, a B-40 with weapons and full ammunition weighs in about the same as a B-17 with full bombload. Even with a lighter ammo load, I would think a B-17 might not be able to support the weight of both the gunship's gunload AND bombs.
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Originally posted by SMIDSY
admrose, the gunners on american bombers were far more successfull than pop culture would have us believe. in fact, a whole two thirds of all german and italian fighters were felled by the .50 cals of the american bomber fleet.
Some quotes from 'Flying Guns – World War 2: Development of Aircraft Guns, Ammunition and Installations 1933-45' - details on my website :cool:
"On combat operations, the American bombers in the ETO expended 26.3 million rounds of .50" ammunition in 1943, and 36.2 million in 1944; the wartime total was 72.3 million rounds. (In October 1943, the ammunition consumption reached a peak of 632,773 rounds per operational day.) That corresponds to nearly 12,000 rounds for every enemy aircraft claimed shot down by the bombers. Because, as we have seen above, these claims were often far higher than the actual German losses, a more realistic average would probably exceed 40,000 rounds for every destroyed German fighter. "
and:
"In comparison, the American fighters expended 26.6 million .50" rounds and 262,189 20 mm rounds, and claimed the destruction of 5222 enemy aircraft in the air and 4250 on the ground. That corresponds to 2810 rounds per enemy aircraft claimed as destroyed. Because the fighter claims were usually much closer to reality, a very rough but reasonable estimate would be that a fighter was ten times more efficient as a gunnery platform than a bomber."
and:
"Some commanders were quite sceptical about the effectiveness of this form of defensive armament. In April 1943 Colonel Claude E. Putnam, commander of the 306th BG, gave as his opinion that four gunners needed to fire simultaneously at an enemy fighter to have a 50% probability to bring it down. Worse, he estimated that to only one in ten of the gunners who theoretically had a firing opportunity actually opened fire. His colleague of the 308th BG, T.R. Milton, shared his doubts, and feared that the defensive guns were often more a hazard than a protection, because the danger of “friendly fire” in a dense formation was high."
Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion forum (http://forums.delphiforums.com/autogun/messages/)
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Originally posted by Tails
As mentioned above, a B-40 with weapons and full ammunition weighs in about the same as a B-17 with full bombload. Even with a lighter ammo load, I would think a B-17 might not be able to support the weight of both the gunship's gunload AND bombs.
We're talking 16 guns, a fully loaded B-17G carried 12 - 4 more .50s plus ammo for them isn't going to break the bank.
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adm, you are underestimating the exess load added by ammunition.
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AdmRose, add the weight of chin turret and ammo because the gunship was a conversion of the standard B-17F then in service, which was not the B-17G.
The gunships also carried more ammo than the standard positions on the regular B-17s.
The ammunition load was over 11,000 rounds making the YB-40 well over 10,000 pounds (4,500 kg) heavier then that of a fully loaded B-17F.
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gunships as escorts was dropped because the weight of the extra guns and ammo left them as stragglers once the other ships dropped their bombs....in other words they ended up being the ones needing extra protection.
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Just adding more guns probably might not have made much difference. The B-17 was designed at a time well before the air corps had experience with operating bombers in the presence of modern enemy fighters, and at the time when armament standards were still being developed (and enforced on the manufacturers, not without difficulty).
As a result, the B-17's armament was a rather mixed affair, even on the redesigned E series and later models. The Sperry dorsal was a good turret, and the Sperry-Briggs ball turret was perhaps the best ventral turret in existence. The tail gun installation was primitive but effective. The waist and radio room gun installations were primitive and ineffective; their gunners faced a nearly impossible task aiming their guns manually at targets that passed fleetingly through their field of view. And the weak nose gun armament, and lack of armour there, was a major vulnerability of the B-17E and F.
That some redesign of stations and redistribution of guns could reduced weight and crew while actually improving the defense, was proven by the "Project Bovingdon" B-17, but this would have involved major redesign and an interruption of production.
Meanwhile, varying unofficial modifications were made to some aircraft: Including some that had 20-mm cannon as nose guns or tail guns. The nose gun was a one-off as far as I know, because the recoil damaged the nose structure and because the gunner found it difficult to handle; the tail cannon were more common and usually placed at the rear of the formation to deter enemy fighters with rockets or long-range guns.
The claims made by bombers' gunners for the destruction of enemy fighters were probably around a factor 10 too high, for numerous tactical, technical and psychological reasons. Many people knew this at the time and very few people believe these numbers now; but at the time they had propaganda value.
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Hi Emmanuel,
>the "Project Bovingdon" B-17, but this would have involved major redesign and an interruption of production.
That sounds interesting - what were the special features of the Bovingdon B-17?
>Including some that had 20-mm cannon as nose guns or tail guns.
The Luftwaffe preferred 20 mm cannon as nose defense because they were able to inflict telling damage in the short firing time available during a head-on attack. They weight penalty wasn't that bad as the cannon received only small loads anyway.
The longer range of cannon compared to MG also played a role, just as in the USAAF considerations.
>The claims made by bombers' gunners for the destruction of enemy fighters were probably around a factor 10 too high, for numerous tactical, technical and psychological reasons.
When I saw this thread, I tried to find a table I saved a while ago, with a summary "enemy aircraft destroyed by the USAAF by month". Unfortunately, I couldn't find it anymore.
What was striking about the table was that from one certain month to the next, there was a decline of Luftwaffe fighters killed by bomber guns by a factor of (by memory) ten. I'm pretty sure that marked the point when more restrictive confirmation rules were introduced, making the kill statistics much more accurate than before.
Regards,
Henning (HoHun)
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Originally posted by HoHun
That sounds interesting - what were the special features of the Bovingdon B-17?
Installation of Consolidated nose and tail turrets, with the bombardier's position moved to a lower nose fairing and the radio operator moved to the nose to operate also the nose turret. (The aircraft had been built as a B-17E.)
Replacement of the Sperry dorsal turret by the lighter Martin turret.
Changes to the ball turret to make it roomier, more comfortable, and more reliable; the changes also allowed the gunner to wear a parachute inside the turret.
Deletion of the waist guns and radio room guns, and introduction of an open, powered mount for twin .50 guns on the dorsal spine instead.
Improved oxygen system with a larger supply (5 hours for the turret gunners instead of 2) and twin lines to every position to provide redundancy in case of combat damage.
The aircraft was 1000 lb lighter than a B-17F and had a better c.g. position, 28% of the mean aerodynamic chord instead of 31%. This, plus folding bomb bay doors, improved performance.
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"if you cant hit em... ADD MORE GUNS!"
I think that is the only way to increase hit probability.
Does anybody have the training material for bomber gunners where the dispersion for different gun mounts are pictured? See that and the powered turrets are making sense over the hand held guns...
-C+
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Testing done by the USAAF found that the bullet pattern during ground testing had the following results for 12 rounds to 600yds:
For the B-17:
ball turret > dia. 15' - 8.3mils
upper turret > dia. 21' - 11.7mils
chin turret > dia. 23' - 12.6 mils
waist(closed) dia. 26' - 14.3mils
side nose > dia. 34' - 18.7mils
tail turret > dia 45' - 25mils
For the B-24:
ball turret > dia. 15' - 8.3mils
upper turret > dia. 20' - 11.2mils
nose turret > dia. 23' - 12.9mils (Emerson)
nose turret > dia. 35' - 19.3mils (Motor Prod.)
waist(closed) dia. 23' - 12.9mils
waist(open) dia. 63' - 35.6mils
tail turret > dia 35' - 19.3mils
taken from: "Gunner" ISBN 1-55046-332-2
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I WANT BOMBERS!
I WANT BOMBERS WITH FRICKEN LAZERBEAMS ON THEIR HEADS.
(http://www.israellycool.com/dr%20evil%20pinky.jpg)
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lol! Funny Furball, funny... Just don't go making any mini-you's... We couldn't take multiples of you :)
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Any pictures of the Project Bovingdon b17?
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For whatever reason, no bomber in World War II was really capable of defending itself. Hand held and turretted aerial guns just don't have the accuracy required.
The U.S. started off with the right concept in the 1930s. It was making bombers that flew faster than any contemporary fighter. But this changed as bulky and heavy turrets were added to bombers, along with the near useless waste guns.
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At a time when no true long-range escort fighters were available, this wasn't really a bad idea. The problems wrought by the extra weight didn't become evident until after they were deployed.
In any event, the only extra firepower the B-17 needed was in the nose to ward off head-on passes by German fighters. This was, of course, remedied by the addition of a chin turret to the B-17G.
The arguments for extra firepower became moot with the arrival of the P-51 Mustang.
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Originally posted by AquaShrimp
The U.S. started off with the right concept in the 1930s. It was making bombers that flew faster than any contemporary fighter. But this changed as bulky and heavy turrets were added to bombers, along with the near useless waste guns.
Aqua i think your logic here is flawed, but I dont know where to start.
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Which part is flawed? U.S. bombers in the 1930s flew faster and higher than any current fighters.
Turrets and hand-held guns were added to bombers in the early 40s, reducing their speed and making them increasingly vulnerable.
A report done on bomber defenses after World War II cited that bomber speed, and not defensive armament, was the main factor in the safety of bomber formations.
Even Tony Williams said that it took 50,000 rounds fired from bomber guns to down a single fighter.
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What was the name of the B-17 that was armed with 19 .50 caliber machine guns? It was profiled in that Dogfights show, just can't recall the name or which theater it was in. It was at the time it was attacked by enemy planes the most heavily armed B-17 in the US inventory. It was an epic battle too, think the B-17 crew accounted for quite a few kills.
ack-ack
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Bombers designed in the '30s were faster than fighters designed in the '20s and early 30's and they were as fast as fighters designed late in the 30's. In that particular time more time was spent developing bombers specifically to be faster than the fighters. Problem with that is 1. the bombers didnt carry a large load 1,000 to 2,000 lbs of bombs, 2. As soon as the bombers got faster, fighter development picked back up and soon the fighters were faster than the bombers. As soon as they figured out that the bombers needed to carry larger loads they realized that they would not be able to outrun the fighters so they had to arm them, and then add armor to protect the crews. Yes adding armaments to the bombers slowed them down, but by the 40's any bomber carrying a significant load of bombs was not going to be able to outrun a fighter anyway and they needed the guns to defend themselves. There were exceptions like the Mosquito but it only carried 2,000 lbs and then later 4,000lbs. It wasnt so much the guns themselves but the defensive formations were the bombers flew close together to provide support to each other and provide a deterient to fighters. You dont have to shoot down a fighter, just tear it up, hole its radiator, damage the wings, wound the pilot bad enough and they'll go away
It would be interesting to know how fast a B-17 would be with only 4 crewmembers, no guns and ammo and the extra oxygen, etc and only 8,000lbs of bombs
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lol. Deja vu... (<--- remembers asking for this a year ago...)
I still want it! Come on! While it was definately unsuccesful in real life, I know people who fly the B-17, dump all its bombs on takeoff and fly into FT (TT nowadays) and just use it as a gunship. The speed issue and lack of bombs that made it utterly useless in real life wont effect it here, as people dont really understand the art of bombing anyway... And, ive already got a skin in mind! Tampa Tornado! I can post a pic here. I know it didnt fight in that skin, but it WAS based at molesworth... Anyway, YES! to the YB-40
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Originally posted by Serenity
lol. Deja vu... (<--- remembers asking for this a year ago...)
If you look at the original post, you'll note that this was actually asked nearly 2 years ago. :)
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I have seen some writing on the YB-40. It was noted that it would fall behind on return trips from bombrun as it was heavier than an empty 17 so would get attacked as it fell out of formation being slower.
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Originally posted by Grant Pratt
I have seen some writing on the YB-40. It was noted that it would fall behind on return trips from bombrun as it was heavier than an empty 17 so would get attacked as it fell out of formation being slower.
Yes, but since when do we fly with more than one person in AH?!? Dont you know??? Cooperation is a cardinal sin!!!:furious
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I read about this plane on this link http://www.daveswarbirds.com/usplanes/american.htm
(Scroll down the navigation bar on the left side of screen to 'Bombers,' at the bottom of the section should be the YB-40)
I hear about it but problems were inevitably encountered. The problem about having so many .50 cal's on board even without bombs made the YB-40's heavy and slow, so once when the 'Regular' bombers had dropped their payload, the YB-40's would fall behind. Plus, having a plane with a production value of only twenty planes is way too small to be used in Aces High.