Any internal structure to fast jet external fuel tanks?

Sep 14, 2009 14 Replies

The subject header says it clear enough...



I'm going to be building the 1/72 scale (God's OWN scale!) IMC battle damaged F-105 and one of the parts that has damage is the fuel tank. It shows internal ribbing with a plastic backing. I was originally going to just use the motor tool to scrape away the plastic, but I got to wondering if the internal structure exists at all...



Any former Thud techs got the straight dope?



Thanks all!


-andyh


1) God's OWN scale is WAY larger than 1/72...

2) Yes - external tanks have internal structure. It's a monocoque pressurized vessel built just like any of the rest of the airplane, with supporting longerons, ribs, formers, etc.

Some older ones may have had bladders - newer ones (that I'm familiar with) don't; but still have metal supporting structure underneath the composite.

God works in any scale He wishes. He simply likes 72nd best.

i do not. it's lilliputian and i like big. 1/48 for huge bomber and 1/32 for the rest. build bigger! now go and sin no more.

Might they also have had internal baffles to prevent gas sloshing back and forth?

...I think He likes 1:1 best...anything else is just an imitation.

I'd call that semi-monocoque. That is a term I've seen very frequently when talking about aircraft structure. Full monocoque truly gets its strength from skin only. Atlas missile was full monocoque, Thor, Titan semi. I don't know of any aircraft that was truly monocoque. Even single engine plywood Lockheeds, and the Mesquito had formers. Wimpy maybe came close, but even then I think there was some structure inside. One big problem with full monocoque is attaching anything to structure (like wings, cockpit, engine. If it has formers or bulkheads, stringers, any longerons, it is semi-monocoque

Even the use of corregated metal only stiffened skin in one direction, so those planes had internal structure (Ford Trimotor, Junkers, etc.

I was always told to beware false prophets. Especially if they hump for scales sponsored by the NFB ;)

how about false profit from cheap kits?

:

If I could make good money from Starfix kits, I'd overload ebays servers selling em. They go for a buck around here.

i wonder if there are any good kit makers in isreal? i'm sure they have boutique resin guys, but what about injection stuff? i'd love a native merkava to build.

I don't know about the 450 gallon wing tanks the Thud carried, but the 370s the F-4 carried didn't have any such structure inside as you say. They had formed metal cones for the nose and tail, a rolled sheetmetal cylinder for the center section with a screwed together seam on the lower left side, had a bulkhead at the front and rear of the cylinder for baffles, and the plumbing inside. There were no longerons, ribs or any other such struuctures. Scott Wilson

...I would call those bulkheads "internal structure". And I would have thought there would have been at least four logitudenal "runners" to hold those bulkheads at length. And a strongback of some sort for the BRU/swaybraces and service fittings.

Interesting...I may have to look into Phantom drop tanks...

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required