Boeing 707, 727 and 737 fuselage cross-sections.

[nonsense]

Originally Posted by DaveReidUK

Followed by the circular Caravelle, Trident and One-Eleven.

Doesn't the Caravelle share the cockpit structure with the Comet?

[washoutt]

Wasn't the Boeing Stratoliner (1938) not also circular in cross section? That would precede the Comet.

[oxenos]

I had long believed that Boeings had a machine that extruded an endless tube of fuselage, with different lengths being cut off for the various types.

[DHfan]

Originally Posted by nonsense

Doesn't the Caravelle share the cockpit structure with the Comet?

Sud-Aviation licenced the Comet cockpit design from de Havilland for the Caravelle.

[DHfan]

Originally Posted by washoutt

Wasn't the Boeing Stratoliner (1938) not also circular in cross section? That would precede the Comet.

Not a jetliner...

[HOVIS]

Originally Posted by DHfan

Sud-Aviation licenced the Comet cockpit design from de Havilland for the Caravelle.

They reciprocated with the engine stub wing design for the BAC 1-11. Or so I was told when I noticed the Sud Aviation data plate during an engine change.

[Alan Baker]

The 707 fuselage lower lobe was deeper than the forward fuselage lower lobe of the 727 (thus the double bubble effect was less noticeable on the 727). The rear fuselage of the 727 was deeper than the forward section (a feature perpetuated on the 757). The 737 used the 727's forward fuselage section throughout its length. The C-135 was not circular, it just didn't have a crease line, which reappeared when the 707 upper lobe was widened for 6 abreast seating.

[DuncanDoenitz]

Originally Posted by oxenos

I had long believed that Boeings had a machine that extruded an endless tube of fuselage, with different lengths being cut off for the various types.

Still available in larger branches of B&Q. (Please ask a colleague for assistance).

[Self loading bear]

Originally Posted by DuncanDoenitz

Still available in larger branches of B&Q. (Please ask a colleague for assistance).

When properly terminated with sausage end clips it can be inflated to widebody when still warm from the extruder.

[Mooncrest]

Originally Posted by Alan Baker

The 707 fuselage lower lobe was deeper than the forward fuselage lower lobe of the 727 (thus the double bubble effect was less noticeable on the 727). The rear fuselage of the 727 was deeper than the forward section (a feature perpetuated on the 757). The 737 used the 727's forward fuselage section throughout its length. The C-135 was not circular, it just didn't have a crease line, which reappeared when the 707 upper lobe was widened for 6 abreast seating.

Thankyou Alan. This makes everything much clearer.

[Mooncrest]

Thankyou everyone for your replies. I consider myself enlightened and educated.

Speaking of 707s, I've just been looking at pictures of the cockpit of John Travolta's old 707. It's remarkably tidy and neat for its vintage and I guess set the template for the 727, 737 and 747 cockpits, although bearing in mind there was never an FE station on the production 737s.

[DaveReidUK]

Originally Posted by Alan Baker

The 707 fuselage lower lobe was deeper than the forward fuselage lower lobe of the 727 (thus the double bubble effect was less noticeable on the 727). The rear fuselage of the 727 was deeper than the forward section (a feature perpetuated on the 757). The 737 used the 727's forward fuselage section throughout its length. The C-135 was not circular, it just didn't have a crease line, which reappeared when the 707 upper lobe was widened for 6 abreast seating.

Excellent summary. (note to self) change adjective applied to C-135 from "circular" to "egg-shaped"

This might be of interest - there are several versions on the Net, this one includes the DC-8 for comparison:

[ATNotts]

Originally Posted by oxenos

I had long believed that Boeings had a machine that extruded an endless tube of fuselage, with different lengths being cut off for the various types.

I remember reading or hearing similar, I think in the 1970s, but obviously an urban myth.

[Sue Vêtements]

Time for a new thread maybe? . . . "What cross section?"

and then there's Egg Shaped . . .



Building something like that has to be an interesting job though - better than a career IT at least


Sorry for the interruption. Back to the original thread

[dixi188]

How come the B707 and DC-8 arrived on the scene at almost the same time with almost the same dimensions?
Obviously sized to the available engines, but who was spying on whom?

[Jhieminga]

The way I remember from reading about the two designs is that the 707's fuselage shape was widened in response to the DC-8 going for six-abreast seating. At that point Boeing realised that they needed the same on the 707 and widened the upper part of the double bubble, but leaving them with two different fuselages for the C-135 and 707 families.

This image doesn't show the full fuselage shape for these types, but it is a nice comparison.

[tdracer]

Originally Posted by dixi188

How come the B707 and DC-8 arrived on the scene at almost the same time with almost the same dimensions?
Obviously sized to the available engines, but who was spying on whom?

My understanding was that Boeing originally planned to use the KC-135 fuselage cross-section for the 707, but potential customer airlines quickly pointed out that the DC-8 cross-section allowed more seating and hence was more desirable.
So it's far from a coincidence that the 707 and DC-8 fuselage cross-sections are so similar.

[treadigraph]

Of course, Pan Am hedged their bets a bit by also ordering some 20 DC-8s which they flew between 1961 and '68 before flogging them on to Delta, United and one or two other airlines...

Looking at the cross section of the KC-135, if drawn accurately the inner skin looks to be double bubbled and the outer skin smoothed over the crease? Is that right?
,

[dixi188]

There is no inner skin, I think it is the shape of the frames that are beefed up at the floor attachment.

[treadigraph]

Ah, gotcha, thanks!