Convair B-36 Derivatives (B-36C)

codeone

ACCESS: Confidential
Joined
Oct 7, 2010
Messages
56
Reaction score
8
Artist concept just posted on Code One Magazine website. Spotlight photo and also put it in the B-36 gallery.

Enjoy.


The B-36C was a modification to the B-36 design proposed in the mid 1940s. The R-4360 engines would be replaced with four Wright Aeronautical gas turbine engines for propeller drive and four General Electric TG-180 gas turbine engines for jet propulsion. The two engine types were paired and mounted in tandem nacelles. The jet nozzles were directed three degrees downward and three degrees outward to so that the hot gasses did not burn the horizontal tail.
 

Attachments

  • 2011_B36C_Illustration_1267828237_9881.jpg
    2011_B36C_Illustration_1267828237_9881.jpg
    213 KB · Views: 1,302

GTX

All hail the God of Frustration!!!
Staff member
Senior Member
Joined
Apr 15, 2006
Messages
3,809
Reaction score
2,320
Website
beyondthesprues.com
Interesting, I thought the "B-36C was to be powered by six 4300 hp Pratt & Whitney R-4360-51 variable discharge turbine (VDT, or turbocompound) engines. In the VDT engine, exhaust gases from the piston engine would pass through a General Electric CHM-2 turbosupercharger which featured a clamshell nozzle that could create a jet thrust by varying the size of the turbine exit. The variable discharge nozzle was to be operated by automatic control activated by a manifold pressure sensor. "

Source


B36Cinfo.jpg

B36Cinfo2.png



regards,

Greg
 

codeone

ACCESS: Confidential
Joined
Oct 7, 2010
Messages
56
Reaction score
8
I have a cutaway graphic of the engine somewhere. Will post it soon.
 

codeone

ACCESS: Confidential
Joined
Oct 7, 2010
Messages
56
Reaction score
8
Posted engine cutaway on our homepage. I'll attach here.
 

Attachments

  • B36C_engine_SM_22.jpg
    B36C_engine_SM_22.jpg
    134.9 KB · Views: 1,196

OM

ACCESS: Top Secret
Joined
Jun 22, 2008
Messages
752
Reaction score
31
Website
www.io.com
...You know, this thread's probably the best place to pose this puzzler: in retrospect, was the choice of pusher over tractor in the B-36's design actually the best choice? What -were- the motivating factors in the first place for Convair's decision in this regard?
 

Stargazer2006

ACCESS: USAP
Senior Member
Joined
Jun 25, 2009
Messages
13,221
Reaction score
856
OM said:
...You know, this thread's probably the best place to pose this puzzler: in retrospect, was the choice of pusher over tractor in the B-36's design actually the best choice? What -were- the motivating factors in the first place for Convair's decision in this regard?

You mean "tractor over pusher", right? ;D
 

JFC Fuller

ACCESS: Top Secret
Senior Member
Joined
Apr 22, 2012
Messages
2,392
Reaction score
1,131
A quick google books search came up with this snippet from Aviation Week and Space Technology:

1947-JB-36C program suggested to Air Staff by converting last 34 of 100-plane program to VDT-tractor versions. Increased costs of B-36C program to be met by cutting total program back from 100 to 95 planes. ...

And according to Robert F. Dorr in '7th Bombardment Group/Wing, 1918-1995'

This version was known as the B-36C and would have gone to the 7th had it materialized. But the VDT engines had bigger problems of their own, and the B- 36C was never built.

I always though it was a shame that they abandoned the original B-29 nose glazing, the B-36 looked much more elegant with that.
 

JFC Fuller

ACCESS: Top Secret
Senior Member
Joined
Apr 22, 2012
Messages
2,392
Reaction score
1,131
So the design in the first post would have had 4 GE/Allison J35's and I assume that the turboprops would have been the Wright J-37?
 

Stargazer2006

ACCESS: USAP
Senior Member
Joined
Jun 25, 2009
Messages
13,221
Reaction score
856
sealordlawrence said:
I always though it was a shame that they abandoned the original B-29 nose glazing, the B-36 looked much more elegant with that.

But wasn't the B-60 supposed to fly at higher altitudes and faster than the B-36? Glazed nose might have been awkward and even dangerous in those conditions.
 

JFC Fuller

ACCESS: Top Secret
Senior Member
Joined
Apr 22, 2012
Messages
2,392
Reaction score
1,131
Stargazer2006 said:
sealordlawrence said:
I always though it was a shame that they abandoned the original B-29 nose glazing, the B-36 looked much more elegant with that.

But wasn't the B-60 supposed to fly at higher altitudes and faster than the B-36? Glazed nose might have been awkward and even dangerous in those conditions.

Erm, who said anything about the B-60?
 

Bill Garvin

ACCESS: Restricted
Joined
Mar 18, 2008
Messages
10
Reaction score
0
...You know, this thread's probably the best place to pose this puzzler: in retrospect, was the choice of pusher over tractor in the B-36's design actually the best choice? What -were- the motivating factors in the first place for Convair's decision in this regard?

The motivating factor was to reduce drag and thus push range up as much as possible. In retrospect, probably not the best solution but given the extent of knowledge at the time, it was an easy mistake to make.

I always though it was a shame that they abandoned the original B-29 nose glazing, the B-36 looked much more elegant with that.

Cost of mounting a twin 20mm turret in the nose. Also, the all-glazed nose on the B-29 caused a lot of problems with instrument layout and reflections off the transparencies.
 

OM

ACCESS: Top Secret
Joined
Jun 22, 2008
Messages
752
Reaction score
31
Website
www.io.com
Stargazer2006 said:
OM said:
...You know, this thread's probably the best place to pose this puzzler: in retrospect, was the choice of pusher over tractor in the B-36's design actually the best choice? What -were- the motivating factors in the first place for Convair's decision in this regard?

You mean "tractor over pusher", right? ;D

...Nope. The way I learned it, if the prop's behind the wing, it's a pusher. Which is how the B-36's butter paddles were mounted.
 

Orionblamblam

ACCESS: Above Top Secret
Top Contributor
Senior Member
Joined
Apr 5, 2006
Messages
8,963
Reaction score
3,494
Website
www.aerospaceprojectsreview.com
OM said:
What -were- the motivating factors in the first place for Convair's decision in this regard?

IIRC, it was so that the propwash wouldn't go over the wing surface and mess up the clean aerodynamics. The B-36 was, after all, designed to be pretty clean... it had to be, since it was meant to fly from the US to Festung Europa and back without refueling.
 

frank

ACCESS: Top Secret
Joined
May 20, 2006
Messages
617
Reaction score
22
A similar situation. I've not flown one personally, but I've heard from several who have, the push-pull Cessna Skymaster flies better on the rear / pusher engine alone rather than the front / tractor engine alone, due to better aerodynamics from being 'pushed'.



Orionblamblam said:
OM said:
What -were- the motivating factors in the first place for Convair's decision in this regard?

IIRC, it was so that the propwash wouldn't go over the wing surface and mess up the clean aerodynamics. The B-36 was, after all, designed to be pretty clean... it had to be, since it was meant to fly from the US to Festung Europa and back without refueling.
 

JFC Fuller

ACCESS: Top Secret
Senior Member
Joined
Apr 22, 2012
Messages
2,392
Reaction score
1,131
Interestingly the model shows 3-bladed propellers whereas the wooden mock-up appears to have a propeller hub with stubs for blades implying a 4 bladed propeller configuration.
 

Howedar

ACCESS: Confidential
Joined
Sep 24, 2008
Messages
58
Reaction score
3
Four blades (or two, or six) would be unfavorable from a vibration perspective, as you'd have a pretty strong mode associated with two blades passing through the wing wake at the same time. Three blades does not have this problem. Neither does five etc, but less blades tends to be more efficient, as long as you're not running into sonic tip or ground clearance issues.
 

JFC Fuller

ACCESS: Top Secret
Senior Member
Joined
Apr 22, 2012
Messages
2,392
Reaction score
1,131
So some random googleing reveals to me (known to most others I am sure) that the Boeing YB-50C and the B-54A production aircraft were to have used the R-4360-51VDT, the existing B-54 threads are here:

http://www.secretprojects.co.uk/forum/index.php/topic,5826.0.html

and

http://www.secretprojects.co.uk/forum/index.php/topic,10693.0.html
 

JFC Fuller

ACCESS: Top Secret
Senior Member
Joined
Apr 22, 2012
Messages
2,392
Reaction score
1,131
It was estimated that an R-4360-51 VDT engined B-36C would have a service ceiling of 45,000ft and a maximum speed of 410mph. The main problems with the VDT engine were the cooling and the control of the discharge nozzle itself.

B-36C productions was allocated serials 44-92065 through 44- 92098.
 

blackkite

Don't laugh, don't cry, don't even curse, but.....
Joined
May 31, 2007
Messages
8,081
Reaction score
4,272
What is this?

http://modernwartech.blog.hu/2016/11/22/a_b-36_vetelytarsai_tovabbfejlesztese_es_az_nb-36h_az_ismerteto_6_resze
 

Attachments

  • This would have been the twin-turboprop version, the B-36 g .jpg
    This would have been the twin-turboprop version, the B-36 g .jpg
    51.1 KB · Views: 1,000

circle-5

ACCESS: Top Secret
Top Contributor
Senior Member
Joined
May 31, 2009
Messages
1,158
Reaction score
232
Another view of this model, currently on display at Fort Worth.
 

Attachments

  • Convair B-60 Turboprop.jpg
    Convair B-60 Turboprop.jpg
    194.6 KB · Views: 814

blackkite

Don't laugh, don't cry, don't even curse, but.....
Joined
May 31, 2007
Messages
8,081
Reaction score
4,272
Thanks!! Excellent information. :eek:
Wright T35 engine.
T35 description.
https://airandspace.si.edu/collection-objects/wright-typhoon-xt35-w-1-turboprop-engine
"Type: Turboprop
Power Rating: 4,451 kW (6,090 eshp) at 7,080 rpm
Compressor: 3-stage centrifugal
Combustor: Annular
Turbine: 3-stage axial
Weight: 2,699 kg (5,950 lb)"

YB-60 with T35 three side view.
http://beyondthesprues.com/Forum/index.php?topic=418.30
XB-52 with T35 three side view.
http://aerothusiast.com/usaf-turboprop-testbeds-yc-97j-yc-121f-yc-124b/

Bottom drawing shows Boeing XB-52 (1948) – The B-52 was originally to be powered by Wright T35 turboprops.

Russian T35 site.
http://military-informant.com/c111-history/letayushhaya-laboratoriya-ev-17g-na-ispyitaniyah-turbovintovogo-dvigatelya-xt-35-typhoon.html

I found two sectional drawing for T35. Two stage compressor type and three stage compressor type.
 

Attachments

  • T35 section.jpg
    T35 section.jpg
    12.3 KB · Views: 244
  • B-17 with Typhoon engine.jpg
    B-17 with Typhoon engine.jpg
    77.1 KB · Views: 272
  • B-17 with T35 Typhoon turboprop engine.jpg
    B-17 with T35 Typhoon turboprop engine.jpg
    59.3 KB · Views: 294
  • Boeing XB-52 (1948) – The B-52 was originally to be powered by Wright T35 turboprops.jpg
    Boeing XB-52 (1948) – The B-52 was originally to be powered by Wright T35 turboprops.jpg
    42.7 KB · Views: 279
  • images.jpg
    images.jpg
    11.6 KB · Views: 635
  • T-35.png
    T-35.png
    43.3 KB · Views: 704
  • Escanear0029_zpsbec6c952.jpg
    Escanear0029_zpsbec6c952.jpg
    120.1 KB · Views: 761

famvburg

I really should change my personal text
Joined
Jul 24, 2011
Messages
362
Reaction score
26
All of the drawings and pics show a 4 engined version, not twin.
 

blackkite

Don't laugh, don't cry, don't even curse, but.....
Joined
May 31, 2007
Messages
8,081
Reaction score
4,272
Hi! Larger image. ;D

http://beyondthesprues.com/Forum/index.php?topic=418.15
 

Attachments

  • YB-60.JPG
    YB-60.JPG
    531.8 KB · Views: 377

blackkite

Don't laugh, don't cry, don't even curse, but.....
Joined
May 31, 2007
Messages
8,081
Reaction score
4,272
Wow!! :eek: What is this unmanned vehicle?
 

LowObservable

ACCESS: Top Secret
Senior Member
Joined
Oct 18, 2006
Messages
2,231
Reaction score
267
Presumably, the Boojum's warhead ensured that the target would softly and suddenly vanish away.
 

blackkite

Don't laugh, don't cry, don't even curse, but.....
Joined
May 31, 2007
Messages
8,081
Reaction score
4,272
Hi!

http://ghostmodeler.blogspot.jp/2014_01_01_archive.html
 

Attachments

  • img736.jpg
    img736.jpg
    342.8 KB · Views: 957

ZacYates

LHX SuperTeam fanboy
Joined
Dec 26, 2012
Messages
87
Reaction score
26
As cool as the swept-wing concepts are, this initial one really took my fancy:
TeddySalad said:
Artist concept just posted on Code One Magazine website. Spotlight photo and also put it in the B-36 gallery.

Enjoy.


The B-36C was a modification to the B-36 design proposed in the mid 1940s. The R-4360 engines would be replaced with four Wright Aeronautical gas turbine engines for propeller drive and four General Electric TG-180 gas turbine engines for jet propulsion. The two engine types were paired and mounted in tandem nacelles. The jet nozzles were directed three degrees downward and three degrees outward to so that the hot gasses did not burn the horizontal tail.
Are there any other drawings/models of this one out there?
 

blackkite

Don't laugh, don't cry, don't even curse, but.....
Joined
May 31, 2007
Messages
8,081
Reaction score
4,272
ZacYates said:
As cool as the swept-wing concepts are, this initial one really took my fancy:
TeddySalad said:
Artist concept just posted on Code One Magazine website. Spotlight photo and also put it in the B-36 gallery.

Enjoy.


The B-36C was a modification to the B-36 design proposed in the mid 1940s. The R-4360 engines would be replaced with four Wright Aeronautical gas turbine engines for propeller drive and four General Electric TG-180 gas turbine engines for jet propulsion. The two engine types were paired and mounted in tandem nacelles. The jet nozzles were directed three degrees downward and three degrees outward to so that the hot gasses did not burn the horizontal tail.
Are there any other drawings/models of this one out there?
I will try this. Perhaps it takes long time. ;)
 

blackkite

Don't laugh, don't cry, don't even curse, but.....
Joined
May 31, 2007
Messages
8,081
Reaction score
4,272
Hi! Another one. Powered by eight T-35 engines?(Or eight R-7755 engine with skin cooler?)

http://beyondthesprues.com/Forum/index.php?topic=418.0;all

"Not as "high-tech" perhaps as eight XT35's, but eight XR7755's would have had the same horsepower and likely could've used the same propellers. The radiators would've required some nacelle design changes, but nothing major compared to what's already shown here."

http://www.ebay.com/itm/PLS-144002-1-144-B-36-Peacemaker-strategic-bomber-Full-Size-Scale-2xA1-Plans-/272559700700

Deatail drawing with Russian language is here.
http://www.airwar.ru/other/draw2/b36aiv.html
 

Attachments

  • B-36B2_zps5a4d975f.jpg
    B-36B2_zps5a4d975f.jpg
    118.4 KB · Views: 792
  • B-36B1_zps77169140s.jpg
    B-36B1_zps77169140s.jpg
    107.5 KB · Views: 768
  • s-l1600.jpg
    s-l1600.jpg
    874.2 KB · Views: 762
  • s-l1600r.jpg
    s-l1600r.jpg
    933.6 KB · Views: 726

RAP

ACCESS: Top Secret
Top Contributor
Senior Member
Joined
Jan 29, 2008
Messages
706
Reaction score
521
Some info from 1950 Convair report.
 

Attachments

  • B36 parasite.jpg
    B36 parasite.jpg
    853.6 KB · Views: 293
  • B36 payload.jpg
    B36 payload.jpg
    552 KB · Views: 301
  • B36 performance.jpg
    B36 performance.jpg
    559 KB · Views: 270
  • B36 swept.jpg
    B36 swept.jpg
    380.4 KB · Views: 253
  • B36 rpt cover.jpg
    B36 rpt cover.jpg
    154.2 KB · Views: 203

RyanC

Crazy Researcher
Top Contributor
Senior Member
Joined
Dec 19, 2006
Messages
893
Reaction score
278
Website
www.alternatewars.com
NARA II, College Park, MD
RG 342
Entry P-26
Box 3685

Folder: 452.1
Consolidated B-36
Confid 1945-46-47-48

Declassified via NND 917647

----------------------

IN REPLY ADDRESS BOTH COMMUNICATION AND
ENVELOPE TO COMMANDING GENERAL, AIR MATERIEL
COMMAND, ATTENTION FOLLOWING OFFICE SYMBOL:
MCPPXA3/TPG:ICW/3-1334

HEADQUARTERS
AIR MATERIEL COMMAND
WRIGHT-PATTERSON AIR FORCE BASE
DAYTON, OHIO

(Undated)
(Filed Date)
25 [illegible] 1948)

SUBJECT: B-36 Program.

TO: Chief of Staff,
United States Air Force,
Washington 25, D. C.

Attention: Deputy Chief of Staff, Materiel.

1. Reference is made to Hqs. USAF directive dated 5 December 1947 which approved the B-36 VDT production program. The Air Materiel Command has reexamined this program because increased engine cooling requirements preclude meeting the original estimated performance. The B-36 engine installation is critically affected by increased cooling requirements due to location of the engines in the rear portion of the wing and the high altitude at which the airplane is designed to operate.

2. The basic causes of airplane performance loss are:

a. Additional horsepower required to drive higher capacity cooling fan with resultant loss of 49 MPH cruising speed.
b. Additional airplane weight empty increases caused by the latest power plant installation requirements.
c. Increased drag estimates based on wind tunnel tests amounting to 9 MPH cruising speed penalty.

3. In accordance with the Contractors latest performance estimates, which are concurred in by the Air Materiel Command, the VDT airplane has a maximum range of 7,250 nautical miles at an average cruising speed of 228 knots. The B-36B Airplane has a cruise speed of 248 knots for the same range, and its maximum range is 8,620 nautical miles at 180 knots. Therefore, the Air Materiel Command recommends cancellation of the VDT program. (Comparative performance curves are contained in Attachment "A").

4. In view of the foregoing, it appears advisable to again evaluate the B-36 program based on operational requirements. One of the four following courses of action can be taken:

a. Revert to the original B-36 program; 22 B-36A and 78 B-36B Airplanes, This program can be completed by February 1950. At the present time, it appears that the 100 B-36A and B-36B Airplanes can be completed within funds available on the airframe contract. An additional cost of approximately $1,500,000 will be required to reinstate Government Furnished Property procurements and cover costs incurred to date on B-36 VDT GFP development and production.

b. Terminate at 61 airplanes, thereby cancelling the airplanes scheduled for VDT engine installation. If termination of a quantity of B-36 Airplanes is contemplated, the 61st airplane is the most economical point at which to terminate, since a large amount of the airframe and GFP components has already been stopped at 61st airplane pending release of engineering information for the VDT program. Termination at this point will allow recovery of approximately $92,000,000.

c. Terminate all but 41 B-36 aircraft. This program would obtain for the Air Force the 18 B-36B Airplanes which are currently included in the "GEM" program, one test B-36B, and 22 B-36A Airplanes. (A tentative requirement has been established by Hqs. USAF for modification of 12 B-36A aircraft as tankers to refuel the B-36B aircraft included in the "GEM" program.) Termination at this point will allow recovery of approximately $133,000,000.

d. Terminate the B-36 program delivering only the 22 airplanes which are essentially shop completed. One of these airplanes has already been delivered for static test. The additional 21 airplanes require incorporation of late change requirements and flight test prior to delivery. Termination at this point will allow recovery of approximately $167,000,000.

Note: A breakdown of estimated costs and funds recoverable in support of the above alternate plans is set forth in Attachment "B".

5. Early decision of Headquarters, USAF is required in order that a revised program may be instituted at a minimum cost.

/S/
JOSEPH T. MCNARNEY,
GENERAL, USAF,
COMMANDING.

Incl. Attachments "A" and "B".

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Attach A attached as VDT.gif

B not done so far.

------------

Basic Com. fr Hq AMC, Wright-Patterson AFB, Dayton, Ohio, undated, subject: B-36 Program.

1st Ind.

HQ UNITED STATES AIR FORCE, Washington 25, D. C. 25 June 1948

TO: Commanding General, Air Materiel Command, Wright-Patterson AFB, Dayton, Ohio

1. It is directed that such action be taken on this program as was decided upon at the conference in the Office of the Secretary of the Air Force on 24 June 1948. General Wolfe represented your Command at this conference.

BY COMMAND OF THE CHIEF OF STAFF:

/S/
H.A. CRAIG
Lt. General, U.S.A.F.
Deputy Chief of Staff, Materiel

2 Incls.
n/c

7-13-48 - The decision made by higher authority in the conference referenced above, is to the effect that the 34 B-36 type airplanes, comprising one YB-36C and 33 B-36C airplanes, be cancelled, and that in lieu thereof there be procured 34 additional B-36B airplanes. This will make the program for B-36 airplanes, which is covered by contract W33-038 AC-7 read as follows:

22 B-36A airplanes
73 B-36B airplanes
95 Total

The previous cancellation of 5 airplanes from this program under authority of TI-2036, Addendum #10, which action was taken at the time it was contemplated procuring 34 B-36 series airplanes, will remain the same.

/S/
K.B. WOLFE
Major General USAF
Director, Procurement and Industrial Planning
 

Attachments

  • VDT.gif
    VDT.gif
    116.6 KB · Views: 116

Similar threads

Top