Douglas XB-19 "Hemisphere Defender"

[lark]

Gentlemen,

Is there anyone of you who haves ever seen illustrations of the
6-engined initial design for the XB-19 ?

(3-view or artists impression)

Thanks in advance..

 

[rousseau]

The XB-19 in my imagenation is not a 6 engine bomber only 4.

 

[devi]

Hi lark.

Thanks for a source( Republic Rainbow development ).

At me is 3-view dravings and in two or three days I shall show.

Whether has looked source Aviation Week, 1948, Vol.49, N.3?(source of XB-55 competition)

If has looked, please show us.

 

[lark]

I have at least two sources mentioning a six engined
initial design for the Douglas XB-19.

One in Air Classics and one in Wings/Airpower.
I have to look for the correct isue info.

A couple of month ago , I send a drawing to Antonio of a
6 engined 100 ton Douglas bomber proposal.
He put it ons this forum in the Douglas XB-31 heavy bomber file.

The drawing comes from the Dutch pre WWII magazine Avia(1939 I think)
and shows a bomber with clear DC-4E influence...

 

[lark]

Douglas XB-19 early six engined proposal mentioned in:

Air Classics Oktober 1981.

Wings & Airpower March 1975

The Dutch magazine was not Avia but "Vliegwereld" of 29.2.1940.

 

[Skybolt]

My local (milan) library asserts to have the Aviaton Week 1947-1956 collection.... Be patient and I'll undig the 1948 issue. Problem is that in that library specialist magazines collections tend to be patchy...

 

[lark]

Thanks Sky'

My search in the Royal Military Library produced no results.
No Aviation Weeks for 1948 nor for 1958.

The article of 5.12.1958 is interesting since it contains info of unbuilt
Republic designs.
Ref: Overscan and Tony Buttler

The 1948 issue mentioned by Devi is highly interesting since
it is the only source ,so far, who speaks about a B-55 competition.
All the sources I have mentioning this design only as a B-47 development.

 

[lark]

P.S. With my latest note , I think we are far from the XB-19... :-[

 

[Steve Pace]

A few XB-19, XB-19A images from Life magazine.

 

[Jos Heyman]

When you are talking about the 6 engined version of the XB-19, you are really talking about the XBLR-2.
Ordered on 9 July 1935 as XBLR-2, the design had initially 6 engines. In March 1938, by which time the design had evolved into a 4 engined aircraft, the designation was changed to XB-19. At that time no aircraft had yet been ordered. The 3-view is believed to be the XBLR-2. I do not know the source of this.

 

[lark]

Jos,

The 3-view is from the Dutch magazine 'Vliegwereld' 29.2.1940.
There are also a cutaway drawing and some specifications in it.

I suppose the information in this magazine is probably obtained
from a non-Dutch source,not mentioned.

 

[frank]

A bomber development of the DC-4E?

When you are talking about the 6 engined version of the XB-19, you are really talking about the XBLR-2.
Ordered on 9 July 1935 as XBLR-2, the design had initially 6 engines. In March 1938, by which time the design had evolved into a 4 engined aircraft, the designation was changed to XB-19. At that time no aircraft had yet been ordered. The 3-view is believed to be the XBLR-2. I do not know the source of this.

 

[archipeppe]

A bomber development of the DC-4E?

If I remember well also Japanes tried out to sort a bomber version of the original Douglas DC-4E, this particular aircraft should be ended in Japan before the war.

 

[Steve Pace]

I'm with the understanding that the XBLR-1 became the XB-15, XBLR-2 the XB-19, and that the XBLR-3 was an offering from Sikorsky that was never proceeded with... -SP

 

[Arjen]

The DC-4E was developed into the Nakajima G5N Shinzan, I found a picture on http://en.wikipedia.org/wiki/Nakajima_G5N

According to René J. Francillon, Japanese Aircraft of the Pacific War, p. 423-425 six were built. Being overweight and fitted with unreliable engines they were not much of a success. Two G5N1s and the two G5N2s were converted to transports.

[It] retained the wing, powerplant installation and undercarriage of the American transport, but featured a new fuselage with glazed nose and ventral bomb-bay, new tail surfaces with twin fins and rudders, and was powered by four 1,870 hp Nakajima NK7A Mamoru 11 fourteen-cylinder radials.

 

[frank]

That's fine for Japanese a/c, but, see the 3 views here, regarding the DC-4E.

https://www.secretprojects.co.uk/threads/dc-4e.9260/

DC4E was developed into the Nakajima G5N Shinzan, I found a picture on http://en.wikipedia.org/wiki/Nakajima_G5N

According to René J, Francillon, Japanese Aircraft of the Pacific War, p. 423-425 six were built. Being overweight and fitted with unreliable engines they were not much of a success. Two G5N1s and the two G5N2s were converted to transports.

[It] retained the wing, powerplant installation and undercarriage of the American transport, but featured a new fuselage with glazed nose and ventral bomb-bay, new tail surfaces with twin fins and rudders, and was powered by four 1,870 hp Nakajima NK7A Mamoru 11 fourteen-cylinder radials.

 

[Jos Heyman]

I'm with the understanding that the XBLR-1 became the XB-15, XBLR-2 the XB-19, and that the XBLR-3 was an offering from Sikorsky that was never proceeded with... -SP

You are correct:
On 28 June 1934 a contract was placed for one XBLR-1 with serial 35-277. On 29 June 1935, and prior to the first flight of the aircraft, the designation was changed to XB-15. It is not clear if the XBLR-1 design was exactly the same as XB-15.

Also known as project M5-35, a design for the XBLR-3 was submitted on 29 February 1936 whilst a wooden mock up was built in March 1936. The design was rejected in favour of the BLR-2. No aircraft were ordered.

It has been suggested that the XBLR-4 designation was associated with the Martin 145 model that was re-designated as B-16 before the XBLR-4 designation was assigned.

 

[Stargazer]

On 28 June 1934 a contract was placed for one XBLR-1 with serial 35-277. On 29 June 1935, and prior to the first flight of the aircraft, the designation was changed to XB-15. It is not clear if the XBLR-1 design was exactly the same as XB-15.

Someone recently suggested (was it you?) that the Boeing Model 294 was first called XB-15, then XBLR-1, then XB-15 again... Or was it the other way round? Can you confirm that, Jos?

Also known as project M5-35, a design for the XBLR-3 was submitted on 29 February 1936 whilst a wooden mock up was built in March 1936. The design was rejected in favour of the BLR-2. No aircraft were ordered.

The Sikorsky bomber was a handsome design (see attachment for profile comparison — couldn't find any of the XB-16, sorry). Shame it never made it to prototype form. I believe it was also the last non-flying boat aircraft Sikorsky studied before going all rotary.

It has been suggested that the XBLR-4 designation was associated with the Martin 145 model that was re-designated as B-16 before the XBLR-4 designation was assigned.

Very interesting. First time I've ever read about this theory, and that would have been very logical indeed.

 

[Stargazer]

And the top views...

(NOTE: all these are for design comparison purposes and not necessarily exactly to scale).

 

[Arjen]

@Stargazer2006:
The first drawings I have ever seen of the Sikorsky design, thanks!
As for the XB-15, the in-house designation was model 294, the Army designation was XBLR-1 at the time the contract was drawn, changing to XB-15 in July 1936 (1).

@frank 7 dec 07:29:16 pm:
Initial design of the DC-4E started in the second half of 1935 (2), Douglas started preliminary design of the XBLR-2 on 31 July, 1935 (3). Francillon writes that development of the XB-19 was considerably delayed because Douglas was forced to spend more of its own funds than expected, and design personnel being needed on other projects4. Eventually the DC-4E was completed in May 1938 (4), whereas the XB-19 was completed in May 1941(5). Both designs show obvious Douglas-features, but in my opinion this is more likely to stem from parallel development in a common environment rather than one design (XB-19) being derived from the other (DC-4E). After the DC4-E had been acquired by the Japanese in late 1939 (6), it was first assembled by Douglas personnel in Japan, only to be dismantled just months later by Nakajima when its wings were used in the construction of the Nakajima G5N-prototype (7).

1 Peter M Bowers, Boeing Aircraft since 1916, Putnam 1989, p.228.
2 René J Francillon, McDonnell Aircraft since 1920, Vol. I, Putnam 1988, p.265
3 Francillon, p.308.
4 Francillon, p.309.
5 Francillon, p.267.
6 Francillon, p.310.
7 Francillon, p.268.

 

[Stargazer]

Both designs show obvious Douglas-features, but in my opininion this is more likely to stem from parallel development in a common environment rather than one design (XB-19) being derived from the other (DC-4E).

Ah, but I think he refered to the OTHER Douglas design, the one that was posted as "BLR-2" and which is not only very different, but pretty similar to the DC-4E's configuration.

 

[Arjen]

According to Francillon the XB-19 was a re-designated XBLR-2:

Finally, as funds were made available, construction of a prototype - now re-designated XB-19 - was authorized on 8 March, 1938.

Francillon does not mention any six-engined XBLR-2 design, I was pleasantly surprised by the drawing.

The XBLR-2 as seen in the drawing is very different from the XB-19 as built, but as the XB-19
- was the final product of a development of which the six-engined variant was an earlier stage
- a development that started at about the same time as development of the DC-4E
- the XB-19- and XBLR-2-designs were considerably larger than the DC-4E
in my opinion the XB-19 was no bomber variant of the DC-4E. <edit> Having said that, if anyone digs up a link between the XBLR-2/XB-19 and the DC-4E, I would love to hear of it. Live and learn . </edit>

Come to think of it, with its all-new fuselage and tail-assembly, neither was the Nakajima G5N.

 

[Jos Heyman]

Here are the redesignation dates I have in my files:

"Studies for a heavy bomber began in April 1934 followed by a contract as XBLR-1 on 28 June 1934. On 29 June 1935 the design was redesignated as XB-15"

and

"The XB 19 four engined heavy bomber was originally ordered as XBLR-2 and redesignated in March 1938."

Sources for this? No idea. I have collected data over the past 45 years of all US military aircraft and did not and can not afford the storage space for all detailed references. Be assured that 'weird data' (such as the suggested XBLR-4) is labelled as such in my files.

 

[lark]

From the French 'AirMagazine' No.47 Sept.Oct.2009.

A fourteen page article "Un Géant précoce:Le Douglas XB-19"
by Rene J.Francillon.
Translated text on page 6.

...Douglas recommend on 30August 1938 to abandon the program for the benefit
of a less complex machine,the DB-4,derived from the first DC-4,the one with the 3tailfins
who would become the DC-4E. The Material Division opposed because the Army Air Corps
wanted the first machine as a flying testbank...
So far :Rene J.Francillon.

 

[Stargazer]

Sources for this? No idea. I have collected data over the past 45 years of all US military aircraft and did not and can not afford the storage space for all detailed references. Be assured that 'weird data' (such as the suggested XBLR-4) is labelled as such in my files.

I know exactly what you're talking about. I have collected aircraft designations since I was 7, filled copybooks and notepads with notes taken down in libraries... and could NOT bother to specify the sources for each particular one!
And I also do the same as you: any dubious or uncircumstanciated piece of information is duly marked as such.

 

[Stargazer]

...Douglas recommend on 30August 1938 to abandon the program for the benefit
of a less complex machine,the DB-4,derived from the first DC-4,the one with the 3tailfins
who would become the DC-4E. The Material Division opposed because the Army Air Corps
wanted the first machine as a flying testbank...
So far :Rene J.Francillon.

Very interesting. The DB-series is sort of shaping up, with DB-1 being the B-18 Bolo, the DB-2 a derivative prototype with a nose turret, the DB-4 a proposed version of the DC-4E and the DB-5 a proposed version of the DC-5... (I suspect the DB-3 must have been the B-23 Dragon, although I never actually found evidence of this).

For some reason, the B-19 didn't get a DB- designation (at least none that I know of). It is found as design DS-167C, and has been variously refered to as "Project D", "Hemisphere Bomber" and "Hemisphere Defender". As XB-19 it fell under specification X-203, while the XB-19A conversion with Allison V-3420-11 engines fell under MX-309.

 

[Arjen]

Slightly off-topic. I found an XB-16 picture in wikipedia (of all places): http://en.wikipedia.org/wiki/XB-16
This picture is also featured in MARTIN AIRCRAFT 1909-1960 by John R. Breihan & Stan Piet & Roger S. Mason - which is out of print. Drat. http://www.amazon.co.uk/MARTIN-AIRCRAFT-1909-1960-Mason-Breihan/dp/0913322032/ref=sr_1_1?ie=UTF8&qid=1291900644&sr=1-1

 

[Stargazer]

Yep, it's the most circulated image of the XB-16. However, it's only Model 145, one of two configurations proposed. The other one, Model 145A (strangely submitted before the twin-boom one), was radically different and more conventional (see attachments).

 

[Arjen]

Breihan/Piet/Mason(p.120) write:

The Martin Model 145, a very long-range bomber projected in 1936 as the XB-16, was initially similar to Boeing's XB-15; both were designed for four Allison V-1710 liquid-cooled engines. The XB-16's wingspan was to be 140 feet and the loaded weight 65,000 pounds. The following year Martin proposed the Model 145A, a most unconventional six-engine bomber with twin booms, a span of 173 feet and a weight of more than 100,000 pounds. It was expected to attain 256 mph. Neither design went past the drawing stage, although the Air Corps purchased the engineering data and later publicized a four-engine version of the 145A as one of its "Airplanes of the Future".

This is the book's caption of the picture I posted:

This "4-engine bomber of the future" was based on the second XB-16 design, which had six engines rather than the nacelle guns shown.

... so I understand the picture was produced by the Air Corps, not by Martin.

Just to confuse me, page 121 shows a 3-view drawing of a design very much like the model in Stargazer2006's pictures - also labeled Model 145A.
http://www.marylandaviationmuseum.org/history/martin_aircraft/10_bombers.html ...is where you can find even more information, including a pdf with model 145/146 specs: http://www.marylandaviationmuseum.org/pdf/146_spec.pdf

 

[Stargazer]

Either one should rename this topic or split it in two, because we are now waaaaay off topic... Let me continue in a separate thread, okay?

 

[Arjen]

OK.

 

[Stargazer]

I have created a new topic about the Martin 145 designs... and you're in for a couple of surprises!

http://www.secretprojects.co.uk/forum/index.php/topic,11590

 

[Stargazer]

The posts specific to the Sikorsky XBLR-3 are now in a separate topic here:

http://www.secretprojects.co.uk/forum/index.php/topic,16564.0

 

[Orionblamblam]

XB-19 artwork from: http://www.flickr.com/photos/x-ray_delta_one/7689302716/in/datetaken/

 

[Stargazer]

Magnificent! Thanks for sharing, Scott.

 

[Apteryx]

XB-19 artwork from: http://www.flickr.com/photos/x-ray_delta_one/7689302716/in/datetaken/

Wow, nice. I once saw this picture on a commemorative plate in an antique store.

 

[redstar72]

XB-19 drawing by Stanislav Smekal, from L+K 26/1988:

 

[sienar]

Nice little data file on the xb-19

http://www.alternatewars.com/SAC/XB-19_Technical_Report_-_18_July_1942.pdf

 

[sienar]

And how about the b-19 carrying torpedo armed P-39s

http://www.ebay.com/itm/Douglas-B-19-Bomber-Aerial-Cruiser-A-Comparative-Survey-Douglas-Aircraft-Co-/272105437278

 

[RAP]

http://www.ebay.com/itm/Pilots-Handbook-of-Instructions-for-the-Operation-of-the-Douglas-XB-19-Bomber-/281909614784?hash=item41a31f58c0:g:nssAAOSwqrtWmDLk

XB-19 fight manual, current bid $500. I'd love this but out of my reach.