B-17 Tokyo Tanks

[Hoggardhigh]

Hi all,
Regarding production of the B-17 series, it is my knowledge that additional outer wing fuel tanks, known as " Tokyo Tanks," were fitted at the factories beginning with later B-17F production.
I have one question: could ALL B-17E thru G models accomodate these tanks?

Thanks

 

[Kai Stemm]

I believe so as the "Tokyo Tanks" were just a nickname for self sealing fuel tanks and they were on board b-17s b-24s and b-29s

 

[Greg Boeser]

The wing tanks were factory installed and were standard in the late F and G models. Probably not retrofitted in earlier production a/c.
E models could be fitted with one or two 410 gallon ferry tanks in the bomb bay, but each took up 1/2 of the bomb bay. Early versions were unprotected, but later ones were self-sealing.

 

[Kai Stemm]

E models could be fitted with one or two 410 gallon ferry tanks in the bomb bay, but each took up 1/2 of the bomb bay.

Tokyo tanks were the term for inside the wing self sealing tanks and I goofed and dident realize the types asked if a "ship" is at war keep it fighting till it goes down

 

[Denniss]

Tokyo tanks = engineers found a way to convert unused space in wings to fuel tanks.
Probably paired with minimizing effect on production to not cause a loss (even if it's just temporary).

 

[Shortround6]

Getting back to the original question, a few paragraphs from the B-17F & G manual may be instructive.

1. MAXIMUM LOAD
(a) B-17F airplanes, with modified landing gear
and added cord-wise wing tiptanks, can be flown up to
and including a gross weight of 64,500 pounds with
the following restrictions.

(b) At 64,500 pounds the extra wing tip tanks
must be full to obtain the effect of a relieving load on
the wings in flight. Care must be exercised in taxying
avoiding rough ground. Take-offs, above a gross weight
of 56,000 pounds may only be made on smooth fields
or prepared runways. All pivot turns on one wheel,
while taxying, will be avoided.

(c) All B-17 type aircraft, equipped with the extra
wing tip cord-wise tanks, must be operated in accordance
with (b) preceding, whenever the wing tip tanks are more
than half full. Maximum permissible indicated airspeed of
B-17F airplanes, with extra wing tip tanks full, must be
limited to 230 mph, when loaded to 64,500lbs. Maximum
maneuver permissible at 64,500lbs; positive 2.056; negative 1.22;
landing gear, 2.1.

Now I take that as without the modified landing gear fitting the wingtip tanks to a B-17E in the field is pretty much going to be a waste of time as the overloaded airplane stands a good chance of breaking/collapsing the landing gear in less than perfect conditions.
There were 512 B-17Es built compared to 3405 B-17Fs (not all of which got the tip tanks/beefed up landing gear) and 4035 B-17Gs. Number of "E"s in service when surplus Toyko tanks became available in repair centers over and above replacements for active B-17Fs and Gs would be pretty small.