Martin Model 216 "Flying Aircraft Carrier"

[toura]

Hi all

From"les avions et engins Martin" Minidocavia - Alain PELLETIER.
The project MARTIN 216 .

Who know more ?
Thanks if you know something.

 

[Antonio]

Drawings and some info from pages 26 and 27, The B-52 competition of 1956 by Jared A. Zichek

http://jaredzichek.com/the-american-aerospace-archive-magazine/

 

[toura]

Well ! Thank you Pometablava.
PAUL

 

[PlanesPictures]

But wing is from version 1, fuselage from version 2. Some other source?

 

[Stargazer]

I know that the Martin 216 has been mentioned in several sources pertaining to the B-52 competition, but in my opinion it's wrong. The Martin models listing states that the Model 216 was an "eight engine 500,000 lb flying aircraft carrier" that could lift "1/2 million pounds at take-off." I suppose that refers to what Mr. Pelletier designates as the Model 216-1 pusher flying wing of 1944. As to the Model 216-2 bomber, I find it surprising that it retained the same basic model number, but if what Mr. Pelletier wrote is accurate, then the number was reused for a completely different, heavy bomber design. But does that mean it could be a B-52 contender?

Now speaking of the B-52 competition, what we know of Martin's contender is that it's listed as the Model 236 of 1946. The very interesting point here is that the Model 236 was Martin's entry in a forgotten 1945 competition for a medium, not heavy, bomber. Indeed, the USAAF issued two near-simultaneous competitions in 1945: one for Light Bombers (LB), to which Martin responded with their early Model 234 design (straight-wing XA-45), and one for Medium Bombers (MB), to which Martin submitted their Model 236 design in April 1946 (other known contenders being Consolidated Vultee and Boeing). The winning designs of both competitions received project designations MX-838 and MX-839, respectively. And guess what? MX-839 is the project designation for the B-52 program, which surely is no "medium bomber"... Therefore, in the same way that MX-838 was changed and amended along the way from straight-wing attack to swept-wing ground-support bomber, MX-839 evolved from straight-wing medium bomber to swept-wing heavy bomber.

Back to Model 216-2. It is clear that it is a heavy bomber from the start. So it could not have been submitted in the MX-839 competition, which even though it ultimately resulted in the B-52, wasn't a heavy bomber competition from the start.

 

[Silencer1]

From"les avions et engins Martin" Minidocavia - Alain PELLETIER.
The project MARTIN 216 .

Thanks for sharing!
The overall layout of this project is quite remarkable -a combination of narrow and long fuselage with thick wing, that has center section, equal by height to the fuselage diameter.
The take-off and landing angles are quite low, according to the drawing. And I wonder, what's the reason of such unusual layout.
Comparison to other American big bombers - B-29, XB-32 and B-36 made the Martin 216 project truly "one off"

 

[blackkite]

Model 216-1?
I can see bombs in the wing. I can not see carried aircraft in this drawing.
This wing shape looks like XB-35's wing. I think this swept wing means flying wing.

https://en.topwar.ru/70802-proekt-dalnego-bombardirovschika-martin-model-236-ssha.html

 

[blackkite]

Model 216-2?

 

[blackkite]

Hi! Model 216-1.

Lycoming XR-7755-3, Radial 36 Engine

Type: Reciprocating, Radial, 36 cylinders, nine 4-cylinder banks, liquid cooledPower rating: 3,729 kW (5,000 hp) at 2,600 rpmDisplacement: 127 L (7,755 cu in)Bore and Stroke: 162 mm (6.375 in.) x 171 mm (6.750 in.)Weight: 2,783 kg (6,130 lb)The XR-7755-3 is the largest, most powe

airandspace.si.edu

Lycoming XR-7755 36-Cylinder Aircraft Engine

In 1943, Lycoming began work on a powerful and efficient engine intended to power the next generation of very large aircraft. The 5,000 hp XR-7755 ran in 1946, but such a large engine was no longer…

oldmachinepress.com

 

[blackkite]

Diameter of Lycoming XR-7755 engine is about 1.55m, so the span of Martin 216-1 is about 93m.

 

[blackkite]

Hi! Model 216-1 with F-84.
Perhaps bomb position indicate longitudinal C.G position.

 

[overscan (PaulMM)]

Drawings and some info from pages 26 and 27, The B-52 competition of 1956 by Jared A. Zichek

http://jaredzichek.com/the-american-aerospace-archive-magazine/

Here's the Model 216 drawings in the book.



If by some chance you don't have this book, go here and buy all 5 American Aerospace Archive volumes for just $24.99 -

Jared is clear that Model 236 was the B-52 rival and we don't have any Model 236 drawings. Model 216 drawings are presented as possible designs that might be ancestral to or related to the unknown Model 236.

 

[Stargazer]

Jared is clear that Model 236 was the B-52 rival and we don't have any Model 236 drawings. Model 216 drawings are presented as possible designs that might be ancestral to or related to the unknown Model 236.

Unfortunately, the caption to image #30 claims that it shows the Model 236... I'm always surprised when such typos appear in books, as if no-one had proof-read the final draft before printing...

 

[overscan (PaulMM)]

Unfortunately, the caption to image #30 claims that it shows the Model 236... I'm always surprised when such typos appear in books, as if no-one had proof-read the final draft before printing...

That's not the caption, thats a section heading that happens to be under the picture. The numbered caption (bottom right) correctly identifies it as Model 216.

 

[Stargazer]

That's not the caption, thats a section heading that happens to be under the picture. The numbered caption (bottom right) correctly identifies it as Model 216.

Oh, okay. Now I see what you mean, and I guess by looking at the book proper, I would have identified the red type as a section header. Still, you'll have to admit that positioning the photo number right above the section title is a little awkward in terms of layout.

 

[overscan (PaulMM)]

Oh, okay. Now I see what you mean, and I guess by looking at the book proper, I would have identified the red type as a section header. Still, you'll have to admit that positioning the photo number right above the section title is a little awkward in terms of layout.

Yep, the layout's a bit awkward.

 

[blackkite]

Hi!

 

[Tonton-42]

Hi!

It seems there is a mistake about the power over the B-36 reciprocating engines : 6 x 3800 = 22800 hp, not 15200 ...