Need help with Norther Pacific F-3/7 B unit modeling project

Pingman posted:

NP's F-3/7 B units in the Lowey scheme featured "NORTHERN PACIFIC" in individual letters mounted to their sides.  I plan to replicate this on my O gauge B unit, but cannot find a suitable photograph showing how the letters were mounted.  I'm using laser cut letters supplied by Todd Architectural and expect to use a pair of parallel rods on which to mount the letters; and, then mount the rods to the sides of the unit.

Any info on the prototype mounting would be appreciated.

Thanks. 

Have you tried searching the Northern Pacific Railway Historical Society,   www.NPRHS.org  ?

Hot Water posted:

Pingman posted:

NP's F-3/7 B units in the Lowey scheme featured "NORTHERN PACIFIC" in individual letters mounted to their sides.  I plan to replicate this on my O gauge B unit, but cannot find a suitable photograph showing how the letters were mounted.  I'm using laser cut letters supplied by Todd Architectural and expect to use a pair of parallel rods on which to mount the letters; and, then mount the rods to the sides of the unit.

Any info on the prototype mounting would be appreciated.

Thanks. 

Have you tried searching the Northern Pacific Railway Historical Society,   www.NPRHS.org  ?

Thanks, HW.  Yes; twice.  I should have said so in the original post.  I have edited the original post accordingly.

And I've searched the web using every  search term that seemed (to me) relevant.

I know I have seen many, MANY photos of those NP passenger B Units, on Trainorders.com, as well as in the various color books on NP passenger trains. That said, I have no idea exactly how those big letters were mounted on the real B Units, nor what material they were made of. Maybe looking carefully at the many photos could offer clues?

Thanks for following up, HW.  Hopefully, something definitive will show-up.  Whether the prototype method will lend itself to my modeling skills is another issue to be considered.  

I would assume they're mounted on the framing of the grilles. 

That being said, I would model it by sticking the letters directly onto the grilles. This is one of those things that probably will not model well. Couple reasons:

1. I think you're looking at something which, if it was stood off of the grilles, would be at most what? an inch off the grilles? So you'd use .020 plastic (or less) to stand it off. Thats not the easiest stuff in the world to keep lined straight while you're trying to work with it. 

2. I suspect the laserboard is thicker in scale than the lettering probably would be. Not for certain, but I assume the real deal is sheet metal. That combined with the flexibility of the laserboard and the fact that it has a bit of give, you'll overwhelm the .020 thickness of your standoff and the letters will just end up stuck to the grilles anyways, but now with humps where the standoffs are in the way. 

I think you're ahead of the game already by using 3D lettering, rather than something thats just painted on the surface.  Just stick them on.

Carl, many clear & crisp color photos of the B units in the books “Northern Pacific In Color”, Volumes 1 and 2 by Doug Nighswonger (Morning Sun Books). Especially Vol. 2.  It appears that on the F3B’s with the “chickenwire” grills, two metal strips the length of the grill were installed, then the 8” metallic letters were affixed to the strips. For the F7 and F9 B units, already having horizontal metal grilles, it appears the letters were affixed directly to the grill.  

You might also want to check out photos on brasstrains.com of a brass HO NP F7B model. It looks correct to me. I’d post a link if it was easier to do from an iPhone....  Good luck with your project, show us pictures when it’s done! 

Breezinup put up some good photos.  Here's what I see:

1. The F3B, which had chicken wire over the radiator panel, had two bars attached to the chicken wire*, and the letters were mounted onto the bars.
2. Some F7Bs used the GE grilles on the radiator panel, and I believe the photo of the B unit with the semaphore shows an F9B with Farr vertical slit grilles.  Both the GE grilles and the Farr grilles already have two horizontal bars manufactured into them, and the letters were mounted against the bars.
3. NP painted the grilles* on its F7 and F9 units to match the Loewy paint scheme.

I always thought that each letter had brackets welded onto its rear face, that went through the grille and was secured from inside the carbody.  Only once did I have an opportunity to closely examine an NP booster unit, and I do not recall seeing any screws or bolts on the front side of the letters.

* This was a Northern Pacific road-specific modification.

Thank you for all of the photos, information, observations, suggestions, and resources.

Breezinup's third photo was especially helpful since it shows the two bars with letters attached.  I'd previously purchased a package of Evergreen styrene rod to replicate this mounting approach since some of the photos on the web seemed to illustrate this attachment method.

And Number 90's and GN Man's explanations of the different F booster unit letter mounting methods explains what I was seeing in the different web photos I'd found.  The absence of visible hardware Tom observed fits with the photos I've seen, nor have I seen photos of other roads' booster units with similar lettering mounted to the cab. 

GN Man, I wish I had access to the volumes you reference.  The 8" height of the prototype lettering you mention will not be modeled since the smallest lettering I have is 1/4".  Todd Architectural has the correct font, but the smallest available was the 1/4".

Pictures will, of course, be posted.