WW2 Heavy Bomber Concept

[Nexus1171]

I was thinking of a alternate history bomber design which would essentially perform the B-17's role but would include some physical characteristics of the XB-15, the Avro Lancaster, the B-17, and to a slight extent, the DeHavilland Mosquito.

Here's what I got so far

Engines

• Four R-1820's right from the outset rather than 4 x R-1690 which was less powerful ultimately
• Prototype stage to include a supercharger preferably; turbocharger by the pre-production/early production stage
• Nacelle arrangement similar to the B-17's

Wings

Either...

• Wing position similar to the B-17
• Wing design either the same as the B-17 or a design similar in plan-view to the XB-15 (same taper and aspect ratio) with the wing-area and physical thickness of the B-17

Cockpit & Nose-Cone

• Glass canopy arrangement similar to the Mosquito (except perhaps a bit larger) to permit superior visibility all around
• As an interesting note, from certain angles the XB-15 and the DeHavilland Mosquito's noses look alike
  

Fuselage

• Other than the nose and canopy leave that the same for the time being

Anybody interested?

[finsrin]

Does jog my mind about....
If there were a 1/72 XB-15.  Build one with six R-1820 engines from B-17 kits.
Voted for an XB-15 kit in FSM poll.

[Diamondback]

Hmmm... what would a quad-Merlin/Griffon-powered XB-15 redesigned with the B-17E/F/G "stinger" tail be like?

[GTX_Admin]

If one wants to play with small scales, you can get a XB-15 kit (along with some other bits) in 1/144 from Anigrand:

[Nexus1171]

The modifications I want to do would be very difficult with a model, but relatively easy with graphic art editing...

[jcf]

Only the original Model 299 prototype used the Hornet S1E-G (R-1690), which was a supercharged
engine, thus the 'S' in the model designator. The follow on Model 299B (YB-17, Y1B-17) used the
SGR-1820-39, again a supercharged engine.

Y1B-17A c/n 1897 serial 37-369 was originally ordered as a non-flying test aurframe, but the order
to convert it as a flying aircraft was issued May 12, 1937. It was primarily used as the
Model 299F(Y1B-17A) as a test-bed for development of the turbo-supercharger installation
with R-1820-51 engines.

The Model 294 (XB-15) wing planform would convey no aerodynamic benefit.

If you really want to 'Lanc o' Mossie-ize' a B-17 then use the high-wing layout of the Model 299J proposal;
skip the trike gear; add a long, shallow bomb-bay; give it a raised Mossie-ish canopy; and reconfigure
the tail for a rear gun/turret.






... anybody else see the Betty in the upper left profile sketch? 

[jcf]

Hmmm... what would a quad-Merlin/Griffon-powered XB-15 redesigned with the B-17E/F/G "stinger" tail be like?

Like a frowsy old dowager in sexy new stiletto heels. 

The Model 294 is very much the product of early-'30s concepts and aerodynamics,
so adding newer, more powerful engines really wouldn't do much.

[Nexus1171]

jcf

Only the original Model 299 prototype used the Hornet S1E-G (R-1690), which was a supercharged
engine, thus the 'S' in the model designator. The follow on Model 299B (YB-17, Y1B-17) used the
SGR-1820-39, again a supercharged engine.

So they were all supercharged?  Okay that eliminates one problem: The question is why did they use the R-1690 initially and not the R-1820?

Y1B-17A c/n 1897 serial 37-369 was originally ordered as a non-flying test aurframe, but the order
to convert it as a flying aircraft was issued May 12, 1937. It was primarily used as the
Model 299F(Y1B-17A) as a test-bed for development of the turbo-supercharger installation
with R-1820-51 engines.

That I did not know...

The Model 294 (XB-15) wing planform would convey no aerodynamic benefit.

Even if the cross section & wing-area was the same as the B-17 (T/C), but had the aspect ratio and taper ratio as the XB-15? (I just want to make sure we're on the same wavelength)

If you really want to 'Lanc o' Mossie-ize' a B-17 then use the high-wing layout of the Model 299J proposal;
skip the trike gear

Firstly: Didn't this design eventually get cancelled and later lead to the B-29?
Secondly: The Mossie has a Mid/Shoulder wing right?

reconfigure the tail for a rear gun/turret.

The Mossie has a Mid/Shoulder wing right?

Interesting how they went about designing the tail-gun, but frankly that tail looks like it would be quite an aerodynamic protrusion (the raised area).  After they faired it in, it looked pretty good.

Why did they choose the turret shape on the right versus the left (the left looks like it'd yield a better view)?

[Old Wombat]

Why did they choose the turret shape on the right versus the left (the left looks like it'd yield a better view)?

I would suggest that it was because those windows did not, in fact, provide a better view.

Although there is more window-space, the windows are well forward (astern?) of where the gunner sits & the sills of the windows being forward of that position restrict the vertical view, both up & down, of the gunner. By moving the windows back & sloping the tail fairing above the guns the gunner gets a much better field of vision. (Still not as good as that of the tail-turret of British bombers but the B-17, eventually, had the ventral ball turret to cover that gap in the tail-gunners field of view.)

If you want an example; think of trying to drive a bus or mini-van from the 1st passengers row, rather than the actual driver's position, & you will get the general idea.

:)

Guy

[Nexus1171]

Old Wombat

That I understand.  Did the technology exist to produce a powered ball turret in 1934-1935?

[Old Wombat]

Old Wombat

That I understand.  Did the technology exist to produce a powered ball turret in 1934-1935?

That I don't know for sure but in all probably yes, as I'm pretty sure the tech for the ball turret wasn't new. However, the concept was & was, I'd guess, more a case of coming up with the idea (as a result of combat experience) & designing it, rather than developing new technology.

:)

Guy

[RP1]

There were "dustbin" turrets - usually retractable on a few bombers of that era. I suspect that the cognitive leap required would be to realise that the gunner doesn't have to be sat upright.

RP1

[Nexus1171]

Uh, this is kind of embarrassing, I made a mistake.  I meant powered tail-turret...

[RP1]

So we just what-iffed a what-if?  :)

B-P Overstrand had a powered nose turret in 33/34:

http://en.wikipedia.org/wiki/Boulton_%26_Paul_Overstrand

Would push up size and weight of the A/C though, and make the fuselage a lot fatter, unless you came up with some crafty arrangement.

RP1

[Nexus1171]

RP1

1.) The BP Overstrand is an interesting example of an early powered turret aircraft.  I'm not sure if we had the same abilities in the US, but at least it was do-able

2.) As for the enlargement of the aircraft, I'm not so sure based on the following
- The B-17E was substantially larger than the Overstrand
- The gunner didn't sit in the rear turret; he sat in the tail; the turret was essentially part of the tail-cone

[RP1]

Hi,

I was thinking of the effects of adding powered turrets to an earlier aircraft, using more primitive technology with larger actuators etc. IIRC the Overstrand installation wasn't exactly compact, and this may reflect the state of the art at the time.

RP1

[elmayerle]

I'm thinking that you'd need larger actuators and plumbing because you wouldn't be operating at the higher hydraulic system pressures used later.  The development of increasingly higher-pressure hydraulic systems has been a driving force behind sturdier and more leak-proof fluid system connections.

[Nexus1171]

I'm curious to know if anybody is willing to help me with the basic design work.  I'm willing to work in stages (I've found this makes it easier)

[GTX_Admin]

Please define what you mean by "basic design work"?

[Nexus1171]

Greg,

I have a basic idea, but I can't draw very well so I'm looking for somebody to produce the basic shape.  Since I'm not paying people and to avoid misunderstandings (happened before), I prefer to work in stages such as
- Please modify X, then see how it comes out
- Please modify Y, then see how it comes out
- Please modify Z, then see how it comes out

If I can make that work and I can generate any interest, I can get into more details later. 
If I could actually draw well, I would just draw it out myself (I actually used to enjoy drawing -- it's frustrating as hell these days. 

[GTX_Admin]

Why not start with a sketch of your own (either on paper by hand or electronically using even a basic drawing program such as MS Paint or equivalent or even through taking pits of drawings of/from existing designs) and using those as a starting point.  We certainly won't criticise someone's skill or lack thereof.

This way, you do the work your self (which gives you the satisfaction of creating it), have a better idea of what you are thinking of  and get to practise.  The more you do the better one gets.  Others may then either offer input/advice or even help you with the drawing.

[Nexus1171]

GTX_Admin

I can draw on the existing image for some things, I'm not sure how good it'll look but it might help out with ideas.

[finsrin]

Remember those megafortress drawings that are on BTS somewhere?     Inspiring 

[Nexus1171]

This is the mod...


It's crap I know, but at least it gives an idea of what kind of canopy/cockpit shape I want.  I only drew a line over where the nose is simply to illustrate that for the basic shape I'm just interested in the shape of the glazed nose-cone not the small turret.

[taiidantomcat]

Interesting  :)

[GTX_Admin]

That works - good start.

[Cliffy B]

Gives the Fort a nice British flair, neat 

[Nexus1171]

GTX Admin

I'm glad you think so...


Cliffy B

The idea was inspired by the Lancaster to start with...

[cptmike2012]

Gives the Fort a nice British flair, neat 

Isn't the base aircraft a Douglas XB-19?

Regards,

CPT Mike

[ysi_maniac]

Gives the Fort a nice British flair, neat 

I think you can get it by scaloraming a Mosquito nose. Just one idea.

[Nexus1171]

ysi maniac

Do you mean like scaling a Mosquito up to the B-17's size? and then adding the guns and so forth?

[Nexus1171]

1.) The XB-15's profile if rotated nose up around 2-3 degrees does vaguely look like the Mosquito NF variants if you blend the nose turret with the nose: You'd have to thin the top fuselage a bit however.
2.) I've tried doing a scale-o-rama with the XB-15 and DH Mosquito but it's very difficult as the engines of the Mossie partially occlude the nose -- cutting out the engines and wings is easier said than done.