Contenders for the MX-948 Competition (leading to the XB-55)

[devi]

I know, that to thirteen firms have dispatched request for competition.
1) Boeing Model 474--------------XB-55
2) Convair Model ?
3) Martin Model 247 or Model 247-1
4) ? Model ?
5) ? Model ?
6) ? Model ?
7) ? Model ?
8) ? Model ?
9) ? Model ?
10) ? Model ?
11) ? Model ?
12) ? Model ?
13) ? Model ?

What can you add?

 

[lark]

Devi,

What is the source about " thirdteen firms... " in a competition
for the XB-55 ?

Thanks.

 

[devi]

Hi lark.
I read in magazine Aviation Week,1948.
I shall look exact date.

 

[devi]

Hi lark.

Source: Aviation Week,1948, Vol.49, N.3 (Unfortunately page I do not know)

If you will find, write who participated at competition.

 

[lark]

Thanks Devi,

The search is on...

 

[hesham]

Hi Devi,

may be Convair model-1,and anther thing, Boeing also participate by model-484.

source: B-58 Hustler book.

 

[devi]

Hi hesham.

Convair Model 1-------aka Convair Model 109/XB-46.
Boeing Model 484----other bomber competition.

 

[Skybolt]

Devi, not much from Aviation Week on July 19, 1948, as you can see. But, an interesting snippet of information in a later news, from November 15, 1948: for of the original competitors were jet-powered...

 

[ChuckAnderson]

Hi Devi!

I just thought that I'd post this information, should anyone wish to use it as a reference in researching XB-55 information.

It's a three-view line drawing of the Boeing Model 474 (XB-55), and its from Boeing Aircraft Since 1916, by Peter M. Bowers.

Chuck

 

[Justo Miranda]

From "Airplane Five Views" by Bernhard Klein ,B.C.F.K. Publications 1974 (via Chuck Davis)
and "Finescale Modeler January 1998

 

[Stargazer]

Boeing's Model 484 was proposed in the B-58 competition:

 

[Skybolt]

Model 484 was an early design. The final B-58sque Boeing submission (B-59) carried the Model 701 designation. One of the few projects included in the new "Convair Deltas" book by Specialty Press are precisely some iterations of that.

 

[Triton]

Model of Boeing Model 474.

Source: Source: Boyne, Walter. Boeing B-52 - A Documentary History Jane's Publishing Company Limited 1981 p. 49.

 

[Triton]

Artist's concept of Boeing Model 479.

The Model 474 matured into the Model 479, powered by six J-40 engines. This became the competition winning XB-55, the intended successor of the B-47. With the simultaneous development of the B-52, the XB-55 was shelved.

Source: Source: Boyne, Walter. Boeing B-52 - A Documentary History Jane's Publishing Company Limited 1981 p. 49.

 

[overscan (PaulMM)]

http://www.ebay.com/itm/WESTINGHOUSE-XJ40s-POWER-PLANT-ARRANGEMENT-/290736818269?pt=LH_DefaultDomain_0&hash=item43b143c85d#ht_500wt_1413

 

[Stargazer]

This one has "L-173-15" written at the bottom of each page... Could it be related to the Lockheed L-173 proposal (MX-948 submission) which lost out to Boeing's XB-55?

 

[overscan (PaulMM)]

Yes. Thats why I titled the post " engine arrangement on Lockheed L-173-15" ???

 

[Stargazer]

Yes. Thats why I titled the post " engine arrangement on Lockheed L-173-15" ???

Oops. I had not even looked at the complete title! I figured this one from the plans!!! :-[

 

[Stargazer]

A very interesting derivative of the XB-48 prototype was studied by Martin under the designation "Model 247-1."

This is the USAF design report about it:

http://www.ebay.com/itm/U-S-AIR-FORCES-MODEL-247-1-MEDIUM-BOMBER-DATED-1949-/290775848142?pt=LH_DefaultDomain_0&hash=item43b39754ce

 

[Stargazer]

More pics:

 

[circle-5]

Factory proposal display model of the Douglas Model 1126 medium bomber. This aircraft was the Douglas entry for Project MX-948 "General Research on Bomber Aircraft" in 1948.

Note overall configuration similarities to Boeing's model 450-1-1 (bottom right) which was a precursor to the XB-47.

Upper and lower retractable, remotely-operated twin-gun turrets are located just aft of the flight deck.

 

[circle-5]

More...

 

[hesham]

Great find Circle-5,


thank you,and there is also a flying boat variant from it.

 

[circle-5]

I would love to see that...

 

[hesham]

I would love to see that...

Just Info from Mr. Tony Butler.

 

[lark]

In his 2e book about American Secret Projects , Mr Buttler
just said that a flying boat variant was - considered..

 

[Pioneer]

Nice find Circle 5!It's a nice design. Can anyone please enlighten me as to what the winning design (if any) came out of Project MX-948 ??

Regards
Pioneer

 

[circle-5]

Nice find Circle 5!It's a nice design. Can anyone please enlighten me as to what the winning design (if any) came out of Project MX-948 ?? Regards Pioneer

I believe it was the Boeing Model 479 (derived from the turboprop 474) -- USAF designation XB-55. This competition was intended to produce a successor to the Boeing B-47, but was cancelled in favor of what became the B-52.

 

[Pioneer]

Thank's for the verification Circle 5!

Regards
Pioneer

 

[circle-5]

A couple more photos of the proposal model and a scan of the factory 3-view drawing, courtesy of Jared Zichek. Note changed position of horizontal stabilizer.

Oval air intakes must have been in vogue at the time, as on the Convair XB-46.

 

[Stargazer]

Oval air intakes must have been in vogue at the time, as on the Convair XB-46.

And the Bell Venus.

 

[Mark Nankivil]

Beautiful model, great photos. Thanks for sharing!

Enjoy the Day! Mark

 

[nugo]

The competition involved 13 companies:
1) Boeing Model 474
2) Convair Model ?
3) Curtiss-Wright Model P-541
4) Douglas (Santa Monica Division) Model 1126
5) Fairchild Model 11? or 12?
6) Lockheed Model L-173
7) Martin Model 243
8) North American RD-1461
9) Northrop Model 31
10) Republic Model AP-42
11) ?
12) ?
13) ?
My opinion is that the competition can participate following companies or organizations:
Hughes
Central Aircraft Corp.(Burnelli)
Grumman Design 85 (Classified Bomber Study)---?
or ...
Will be interesting to your feedback.

 

[hesham]

Hi Nugo,


I suspect in Hughes,and may be Burnelli envolved,and there's nothing about Convair
in the book; Convair Advanced Designs.

 

[Stargazer]

The competition involved 13 companies:
1) Boeing Model 474
2) Convair Model ?
3) Curtiss-Wright Model P-541
4) Douglas (Santa Monica Division) Model 1126
5) Fairchild Model 11? or 12?
6) Lockheed Model L-173
7) Martin Model 243
8) North American RD-1461
9) Northrop Model 31
10) Republic Model AP-42
11) ?
12) ?
13) ?
My opinion is that the competition can participate following companies or organizations:
Hughes
Central Aircraft Corp.(Burnelli)
Grumman Design 85 (Classified Bomber Study)---?
or ...
Will be interesting to your feedback.

nugo, I have nothing against people making hypotheses or toting new designations from out of the blue. But when you assert something like "the competition involved 13 companies" you need to back it up. Do you have a document saying this? Then share it. Also, it seems a little strange that the Martin Model 243 and the Curtiss P-541, which never appeared before on this forum (or anywhere else to my knowledge) until yesterday, both coincidentally appear in your list today! You did exactly the same three days ago when I introduced the Martin Model 244 trainer, and suddenly you had a list that contained it!
So if it's hypotheses, please say it clearly and we can build up from there. If not, give your sources. And if you already had all that information before, why wait until now to share it?

 

[nugo]

Hi Stargazer2006!
I compared the data between these projects:
XB-55 (Data from Air Force Museum Fact Sheet)
General characteristics
Crew: 10
Length: 118 ft 11 in (36.25 m)
Wingspan: 135 ft 0 in (41.15 m)
Height: 33 ft 8 in (10.26 m)
Gross weight: 153,000 lb (69,400 kg)
Max takeoff weight: 168,000 lb (76,204 kg)
Powerplant: 4 × Allison T40A-2 coupled turboprop engines, 5,600 hp (4,200 kW) each

Performance
Maximum speed: 426 kn (490 mph; 789 km/h)
Cruise speed: 391 kn (450 mph; 724 km/h)
Range: 4,350 nmi (5,006 mi; 8,056 km)
Service ceiling: 42,000 ft (13,000 m)

Armament
Guns: 10× 20 mm (.79 in) cannons
Bombs: 24,000 lb (10,900 kg) bombs
Model 243: (as can be seen)
Crew:10
Gross weight was 158,000 lb (With one 25,000 lb. bomb and 7240 gals)
four Allison XT-40 engine
...G.L.M. Specification No.459 dated January 15,1948.
These data are similar...
Is it enough?
It is enough.
СW P-541---as has already been said about the document, medium bomber proposal to the MX-948 tender.
"the competition involved 13 companies"---Some info here http://www.secretprojects.co.uk/forum/index.php/topic,571.msg6675.html#msg6675 (from Aviation Week on July 19, 1948 and from Aviation Week on November 15, 1948).
Topic: XB-55 Competition A.K.A. MX-948 competition...


And Hi hesham!
Convair MX-948--source from American Secret Projects: Bombers, Attack and Anti-Submarine Aircraft 1945 to 1974: page 17
Four P&W PT-2C or -2D, with straight wings airplane(shows a picture).

 

[Stargazer]

Since both topics dealt with MX-948, they've been merged.

 

[hesham]

Oh yes Nugo,


I will have a look for it.

 

[circle-5]

Another MX-948 topic covers the Douglas 1126 proposal.


[Admin - joined topics]

 

[hesham]

Hi,


and here is the Lockheed L-173;


http://aviationarchives.blogspot.com/2014/02/off-drawing-boardlockheed-l-173.html