Hey Dan,
Actually, I'm not really that knowledgable about the Atom-Bombers. (Well, I am now...
) I just did a bit of research after I saw your post 'cuz that's what I like to do! Before this I had almost nada info in my head on the subject, but now it's turned into a small quest! This is really interesting stuff, I must say...
Anyhoo, yeah the 509th B-29's were highly modified and the only armament retained were the tail guns. The fuselage turrets as well as the sighting domes were removed and capped. Here's a photo of Straight Flush and a relative closeup of the port dome cap:
(I'm sure you know this already, but you may be able to click on these photos to get a larger image. The auto-resize on this forum doesn't always work... Anyhoo, this first one is a rather nice shot!)
Alotta stuff was removed from these B-29's to lighten them up as there was a buncha atom-bomb related equipment on board some, if not all, of the aircraft; not to mention the bombs themselves. (When not carried, I believe they used ballast in place of the bombs for training purposes.)
There was also a general desire to make them lighter and a bit faster because of the nature of their mission and the relative unkowns involved.
I guess there were probably alotta factors involved in the removal of much of the standard internal equipment, but these are the ones that seem to be repeated most often wherever I look.
The engines were different as well, as were the props. They were cuffed Curtiss Electrics, if I'm not mistaken. I'll have to dig that info up. I think it may be on that website somewhere...
One more word about markings, I came across a bit of info that I found to be interesting:
Even though the spurious tail markings were adopted to mask the true identities of the aircraft, the 509th's ships apparently could be discerned, at a distance, from B-29's of the actual units that used these markings because the markings applied to the 509th ships were not applied as precisely as those of the other units' ships. I guess there were differences in shape & size of the geometric symbols and of the letters used. This would make sense, the other units would undoubtedly have some sort of template systems in use because of the large number of aircraft to be marked, but the 509th likely wouldn't bother with such templates for these temporary markings. Some may find this to be boring, but I LOVE it!!!
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