Convair NB-36H Crusader

[daveculp]

I've been wanting to do this build for a long time, ever since I read David Carpenter's book about the NX-2 nuclear powered airplane.  Since the NX-2 was never built most of the book is about the test programs created to gather data for the nuclear powered aircraft program.  The "ground" part of the testing took place in the desert of southern Utah, and the flying part involved the Convair NB-36H (also known as the XB-36H).  One B-36H, which was damaged in a tornado, was converted into a flying test bed for a one megawatt reactor.  It got a whole new front end with lots of lead and rubber shielding.  The reactor was hoisted up into the aft bomb bay with a hook and plugged into the monitoring, control and cooling systems installed for the test.  All this was done by remote operation.  The reactor didn't power anything.  Waste heat was dumped into the atmosphere through the cooling system.  

 

 

I've seen this done in a reasonable 1/144 scale, but you know what they say, "Go big or go home", so I'll do it in 1/72 scale.  The biggest part of the conversion is the fuselage front end.  I considered 3D printing my own, but I found one available at Shapeways, and even though it's pricey I figured the time savings would be worth it.  The other conversion parts needed are the scoops for the reactor cooling system.  Those are also available at Shapeways, but I need to print something, so the scoops are it.

 

 

I'll also need to add the aft bomb bay doors - I want both bays open, with associated bulkheads.  I have in mind a diorama, actually a partial diorama given the huge wing span, which shows the reactor being winched up into the aft bomb bay from it's underground bunker.

 

Naturally you can't start a project like this without at least considering where in the #$&& am I going to put it.  I'm hoping I can give it to the local Atomic Energy Museum, if they'll have it.

 

When the project is completed I expect to be adept at NMF and panel line rescribing since that's where much of the sweat will go.  So, to start with I'm rescribing panel lines using the original raised panel lines as a guide.  I'll first do all the lines that don't cross the fuselage halve seams.  I'll save the rest for after the fuselage halves are joined, just to make sure the lines meet properly.

 

[Out2gtcha]

Wow, what a project!

[LSP_Kevin]

18 minutes ago, Out2gtcha said:

Wow, what a project!

 

That's what I was thinking!

 

Kev

[daveculp]

It's tricky to figure out where to cut the nose of the bomber off.  The available diagrams and photos don't seem to agree on this, so I picked one and started cutting.  I found if I cut the radome off first the fuselage will fit snugly in my miter box (or mitre box, depending on which side of the Atlantic you reside).  Lucky!  The cut still came out a bit crooked because the fuselage radius is slightly larger than the height of the miter box.

 

 

 

After cutting you need to sand off some raised features on the inside of the fuselage halves.  Then the test fit of the new nose from Click2Detail (https://www.click2detail.net/)

 

 

Deciding where to cut the bomb bays open is another guessing game.   Here are the end points I decided on, and also the center point where a bulkhead will go between the two bomb bays.

 

[Out2gtcha]

Great work! Wow, those parts are nice................but HELLA expensive!!! Holy Jam-ole...........I looked at some of their 32nd stuff too, and its utterly ridiculous price wise. 

 

This is going to be super cool (and unique) project for sure!     Looking forward to more. 

[daveculp]

1 hour ago, Out2gtcha said:

Great work! Wow, those parts are nice................but HELLA expensive!!! Holy Jam-ole...........I looked at some of their 32nd stuff too, and its utterly ridiculous price wise.

 

Yeah, it's pricey alright, but I was afraid of burnout, especially after deciding the whole kit would have to be rescribed.  I know I had earlier decided to print my own cooling scoops, but they were available at a reasonable price from the same maker so I bought them also.  The only thing I'll be printing now is the reactor itself.

[daveculp]

First print of the reactor is complete.  I used a resin I've never tried before, a semi-transparent blue-green resin called Siraya Blu.  I don't know if I'll keep this print or try again with my usual resin grey resin.  The print looks cool, but it has a couple spots that could be better.  First photo is of the CAD design.

 

 

Next photo is of the part being cured in a UV curing box. (only included here because it looks cool)

 

 

Next photo shows the print with a photo of the real reactor.

 

 

Next photo is the reactor next to the B-36 fuselage.  All that fuss over such a little object!

 

 

I'll primer it and do some more sanding, then decide if it's a keeper or not.  The final reactor color will be all silver.

[daveculp]

1 hour ago, Jennings Heilig said:

Is the reactor visible from the outside of the aircraft??

 

Normally no, but I'm going to display it with the reactor in the process of being winched up into the aft bomb bay, so it will be visible.

[Out2gtcha]

Just watched a special on the B-36 the other night................very interesting!  They even showed clips from Jimmy Stewart's "Strategic Air Command" from 1955, as well as some good photos and vids of NB-36H.

 

12 minutes ago, daveculp said:

Normally no, but I'm going to display it with the reactor in the process of being winched up into the aft bomb bay, so it will be visible.

 

 

That's going to make for a BIG dio! 

[daveculp]

Just finished phase one of the re-scribing on the left fuselage half, then cut out the full length of the bomb bays (26.4 cm).  The reactor needs one coat of primer then silver paint.  It's taken a couple sandings/primings of the reactor to remove the 3D printing artifacts.

 

[Gazzas]

Great looking project! Dave.   Looking forward to more.

[RadBaron]

Wow, wow, wow!!! Nice to see someone taking the plunge with the conversion. Those parts looked nice, but as said multiple times above, yowza on the price! It all comes down to how badly you want to build it 

 

Awesome progress sofar, shes going to be a beaut when shes finished!

[daveculp]

10 minutes ago, Jennings Heilig said:

Where ya going to source markings?

 

I'm going to have to make my own.  Not looking forward to it.  I have the AOA set for the common-to-all B-36 markings, but I don't have specific NB-36H markings. 

[daveculp]

Reactor ready for clear coat and black wash to bring out the details.  This one is printed using the trusty Ellego grey resin - the colored semi-transparent prints look pretty, but they weren't the results I wanted.  ( my work space is awfully dusty  )

 

[daveculp]

The scoops are printed by Shapeways - excellent fit!  In fact the fit is so good that I can glue them on after the fuselage is completed.  In this photo they have their first coat of primer.  It will take at least a couple primer coats with liberal sanding in between to remove the 3D printing surface artifacts. 

 

The part at far left is the bulkhead between the two bomb bays.  I printed this as a partial bulkhead since no one will ever look up into the bomb bays (the model will be attached to the diorama base).

 

The curved tabs are printed alignment tabs for the fuselage.  For some reason the fuselage halves are missing some alignment pins, so these tabs will help when gluing the fuselage together.

 

At top is an earlier attempt at building the exhaust vents for the heat exchanger system.  In the NB-36H the aft crew compartment was re-purposed as the reactor heat exchanger.  Cooling air came in through the scoops (mentioned above), through the heat exhanger, then out the exhaust vents.  The vent outlets are what used to be observation domes for use by the gunners.  The domes were removed making the vents outlets always open.

 

Landing gear is OOB.  They look solid enough, and the kit will not be handled once it's in the diorama.