Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!cbnews!cbnews!military From: jfb@ihlpm.att.com (Joseph F Baugher) Newsgroups: sci.military Subject: Re: Dirigibles & airships Summary: YB-40 escort "fighter" Message-ID: <1991Jun27.013548.27846@cbnews.cb.att.com> Date: 27 Jun 91 01:35:48 GMT References: <1991Jun25.022204.22999@cbnews.cb.att.com> Sender: military@cbnews.cb.att.com (william.a.thacker) Organization: AT&T Bell Laboratories - Indian Hill - Naperville, Illinois Lines: 70 Approved: military@att.att.com From: jfb@ihlpm.att.com (Joseph F Baugher) In article <1991Jun25.022204.22999@cbnews.cb.att.com>, mruxb!patter@bellcore.bellcore.com writes: > > > From: mruxb!patter@bellcore.bellcore.com > On the issue of sending B-17 gunships over Germany. Yes, it was tried. > The ship was called the B-17F. According to a book I have by Jablonski, > they did real well on the run *to* Germany, but as soon as the real > bombers unloaded, they ran for home. The gunships couldn't keep up and > they were no match for the defending fighters. The chin turret used on > the G models was first tried on the Fs. > Here are a few more details on the escort version of the B-17 bomber, which bore the designation YB-40. Hope someone finds this as interesting as I did! The bomber escort variant of the Flying Fortress was designated YB-40, where Y stood for "service test". It was produced in an attempt to provide better defenses for B-17 daylight bomber forces which were suffering appalling losses in their raids against German targets on the European continent. The first XB-40 prototype was produced by the Vega division of Lockheed. They converted a standard Boeing-built B-17F to escort configuration by adding a dorsal turret aft of the radio compartment carring a pair of 0.50-cal machine guns, a chin turret equipped with a pair of 0.50 cal machine guns, and twin gun mounts instead of the usual single gun mounts at each waist position. The bomb bays were replaced by storage areas which carried additional ammunition for the guna. Additional protective armor was also fitted. Twenty more Vega-built B-17Fs were converted to YB-40 configuration, plus four TB-40 trainers. A variety of different armament configurations was tried. Some YB-40s were fitted with four-gun nose and tail turrets. Some carried cannon of up to 40-mm in calibre, and a few carried up to as many as 30 guns of various calibres in multiple hand-held positions in the waist as well as in additional power turrets above and below the fuselage! Oddly enough, there don't seem to have been any photographs ever published of these 30-gun YB-40s (insofar as I am aware), although I have seen some drawings. The first operational YB-40 sortie took place in May 1943 against St. Nazaire. Eight othere missions were later flown. Very early on, it was found that the effect of the additional drag of the turrets, plus the extra weight of the guns, armor, and additional ammunition, was to reduce the speed of the YB-40 to a point where it could not maintain formation with the standard B-17s that it was supposed to protect, especially on the way home from the target after the B-17s had released their bombs. The YB-40 could protect itself fairly well, but not the bombers it was supposed to defend. Consequently, it was recognized that the YB-40 was an operational failure, and the surviving YB-40s were converted back to standard B-17F configuration or used as gunnery trainers back in the States. However, the YB-40 was to have one lasting impact. The chin turret originally introduced on the YB-40 was later adopted as standard for the B-17G series. For all of you serial-number freaks, here are the numbers for the YB-40s: XB-40: Conversion of B-17F-1-BO Ser. No. 41-24342 YB-40: Conversions of B-17F-10-VE Ser. Nos. 42-5732/5744 B-17F-30-VE Ser. No. 42-5871 B-17F-35-VE Ser. No. 42-5920, 5921, 5923, 5924, 5925, and 5927. References: United States Military Aircraft since 1909, Gordon Swanborough and Peter Bowers Famous Bombers of the Second World War, William Green Joe Baugher AT&T Bell Laboratories 200 Park Plaza Naperville, Illinois 60566-7050 (708) 713 4548 ihlpm!jfb jfb200@cbnewsd.att.com