B-29 fuel capacity

[Hoggardhigh]

Hi all,

Joe Baugher's website claims that later production B-29's had a maximum fuel load of 9438 gallons including bomb-bay tanks. However, all B-29 cutaways of the type's fuel system seem to suggest that ALL B-29 subtypes retained the 8168 max. fuel load of early aircraft. Does anyone know if that is true or not?

Thanks

 

[Shortround6]

It seems to be true.

See: Pilot manual B-29 -B-29A.pdf

Pages 8 & 9
late model B-29s had 3 fuel tanks in the center section of the wing holding 1350 gallons while B-29As had three tanks holding 1100 gallons. The drop-able tanks in the bomb bays were four 640 gallon tanks and the inner and outer wing tanks seem to be the same on all planes.
Early planes did NOT have the 3 tanks in the wing center section which seems to be in the sing section between the two bombbays.

 

[Hoggardhigh]

It seems to be true.

See: Pilot manual B-29 -B-29A.pdf

Pages 8 & 9
late model B-29s had 3 fuel tanks in the center section of the wing holding 1350 gallons while B-29As had three tanks holding 1100 gallons. The drop-able tanks in the bomb bays were four 640 gallon tanks and the inner and outer wing tanks seem to be the same on all planes.
Early planes did NOT have the 3 tanks in the wing center section which seems to be in the sing section between the two bombbays.

Why the smaller fuel load in the B-29A's?

 

[Shortround6]

The B-29A used a different form of wing center section construction. The B-29A was built by Boeing at the Navy-owned Renton plant. While the B-29s were built in other factories. On the B-29 the wing center section was split on the centerline and bolted together. This center section held the engine nacelles and the outer wings were attached to it. On the B-29A a very short one piece center section went through the fuselage and did not project past the sides of the fuselage. sections of wing holding the engines in pairs were attached to the center section and the outer wings attached at exactly the same points as the B-29.

Apparently (but I could be wrong) this change in construction left less room. I have no idea why this one factory used this form of construction unless it was to use some legacy tooling from the Boeing Sea Ranger flying boat which was to have been produced by this specially built factory.

The wing was about 2 feet shorter than a B=29 wing and they used a similar or perhaps identical airfoil.

Just a wild guess.

 

[Old Wizard]

 

[Hoggardhigh]

The B-29A used a different form of wing center section construction. The B-29A was built by Boeing at the Navy-owned Renton plant. While the B-29s were built in other factories. On the B-29 the wing center section was split on the centerline and bolted together. This center section held the engine nacelles and the outer wings were attached to it. On the B-29A a very short one piece center section went through the fuselage and did not project past the sides of the fuselage. sections of wing holding the engines in pairs were attached to the center section and the outer wings attached at exactly the same points as the B-29.

Apparently (but I could be wrong) this change in construction left less room. I have no idea why this one factory used this form of construction unless it was to use some legacy tooling from the Boeing Sea Ranger flying boat which was to have been produced by this specially built factory.

The wing was about 2 feet shorter than a B=29 wing and they used a similar or perhaps identical airfoil.

Just a wild guess.

Does anyone have a diagram showing the wing differences between the B-29 and B-29A?

 

[2banaviator]

May I suggest that you check the B-29 documentation posted at Avialogs. There are a number of manuals there, which you can read for free and download with a subscription. The annual subscription is nothing compared to the for-profit documentation websites, and you get to download pdf's to your heart's content. I've downloaded hundreds of files from their site.