# Might be scratch building a diesel, need some advice



## San Juan (Jan 3, 2008)

I'm thinking about a winter scratch building project of a 1:22.5 scale version of the US Army Transportation Corps narrow gauge diesel #4700N. She looked like this:











A friend kindly sent me some scale drawings for this loco: 












I also have the correct font for the Army Corps, so making custom decals is no issue. 


But before I get into the project, I have a few questions that maybe you could help with. 


*1 *Any ideas on what motor blocks to use? I'm not too familiar with the offerings from Aristo and USA for diesel motor blocks so I appreciate any info you could provide.

*2* What about the truck sideframes? Are there any that might be close to the ones seen on the prototype? I'm not looking for a perfect rivet counting job, just a representation. 


*3* Does anyone offer castings for some of the parts like headlights, etc... Maybe Ozark?

*4 * Any other ideas, suggestions, tips?


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## Spule 4 (Jan 2, 2008)

Hmm, the trucks are odd, a mix of the AAR type and the snub nose switcher type? 

http://www.irm.org/dieseldept/technicaldata/EMD/SW7/cbq/paintdiagrams/cbq-sw7-side-details1sm.jpg 

http://trainiax.net/drawings/cd/cd-rkemdgp30milw.gif 

With that, your options would be a 1:29 SW switcher or for the AARs some sort of 1:29 ALCo road diesel (RS3 for example). 

....and then, maybe see which of these gives you a close hood/underframe also?


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## Spule 4 (Jan 2, 2008)

No idea why neither of those links work, you will ahve to cut and paste, the wonders of MLS!


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## Gary Armitstead (Jan 2, 2008)

I think you have to do the links through the ADD REPLY box, not QUICK REPLY. Just a guess.


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## Bruce Chandler (Jan 2, 2008)

That should be a pretty neat project.

The wheelbase is 6'11" - in 1.22.5 that equates to 3.68". The Aristo ART29351 looks to be 3.8125" - just a bit too long, but I don't know of anything closer.


I don't know what the wheel diameter is or what it should be. This one indicates a wheel diameter of 1 3/8" - which would be about 31" in 1:22.5.


This is a shot of the truck: 









So, you might have to modify it, depending on how close you want to be. Some of it might be easily done via adding styrene strips or parts.


How much scratching do you want to do? For instance, the headlights could be made with some styrene tubes.


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## GN_Rocky (Jan 6, 2008)

*Another good shell to start with might be the USA S-4 switcher. 
It has the grill work on the side that's closer than the RS-3. Also, the front is more square like what you'd want where the RS-3 is more rounded. 

Rocky *


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## Spule 4 (Jan 2, 2008)

....and gives you the correct trucks for that matter.


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## San Juan (Jan 3, 2008)

Thanks for the tips,

I'll look into the USA S4.


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## Scottychaos (Jan 2, 2008)

Posted By Spule 4 on 28 Aug 2010 07:34 AM 
....and gives you the correct trucks for that matter. 




well..correct-ish. 
probably the best trucks to start with though, if you arent going to scratch build the truck sideframes..
the S4 shell isnt much help IMO..not really anything in common with the Army diesel..
the S4 could be useful for the trucks, frame, and end frames (pilot, steps) though..
then scratchbuild the shell, everything above the frame.

Scot


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## Scottychaos (Jan 2, 2008)

Matt, 
you have probably already seen this, but in case you havent: 

http://utahrails.net/loconotes/rs4tc.php 

When looking at the photo, I assumed it was a GE..its actually a Davenport!  

(From the link above) 
Road Number - USA 4700N 
Builder Number - Davenport 3427 
Builder Date - Nov 1953 
Length - 38' 11" 
Height - 11' 3" 
Weight - 57-1/2 tons 
Fuel - 500 gallons 
Disposition - Note 3 

Note 3 - . USA 4700N was scrapped at Tooele Army Depot Rail Shop, Hill AFB, Utah, in about November 1973.


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## jonathanj (Jan 24, 2008)

The USA trains GP7/F3 truck/block is a little bit shorter than the aristo29351 (scale 4 inches in 1/29) - in metric it's 94.5mm wheelbase, with 28.5mm wheels - about 1mm over length in 1/22.5, but looking at the prototype, I'd guess the wheels were way too small (should probably be about a scale 3ft?). NSWL do replacement larger wheels for the USAt trucks, but they ain't cheap, and I don't think there's anything as large as you'd probably need. I'd probably go with the aristo blocks Bruce suggested, ignore the extra 4mm wheelbase and cut down the sideframes to make them look more like 4700N's. The aristo wheels are about 35mm, probably still to small, but closer than the supersmall USA ones.


I've been wondering about this loco myself on and off for a couple of years - in 1/20.3, where the ART29351s are fractionally undersize, maybe even selling a bodykit - but I've never seen a drawing that felt right. The one posted above is better than most, but the louvres/grilles next to the cab don't look right to me - in the photo they look more like a duplicate of the set of the one at the other end of the hood (four in a pair of doors next to the main radiator grille). And if that's what they need to be, does that mean that the intermediate doors have been squeezed up to make room for the bigger cabside grilles in the drawing? Incidentally, has anyone ever seen a photo of the other side of the loco?


Jonathan


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## Trains West (Oct 4, 2008)

wondered if you knew that aug 2010 railroad model craftsman did a build of this loco in HO scale starting with a NW2 shell ....

you should be able to get a copy or I still have some for sale at the store


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## San Juan (Jan 3, 2008)

Posted By jonathanj on 02 Sep 2010 12:20 PM 
Incidentally, has anyone ever seen a photo of the other side of the loco?




There is a photo of the other side in one of the following books: 
_Narrow Gauge Pictorial Volume 1, Rio Grande Southern and D&RGW Motive Power_

or

_Narrow Gauge Pictorial Volume 11, Locomotives of the D&RGW_


I have both but can't remember which one has the photo. I'm guessing it's volume 1. Both books are at our place in Colorado (and I'm back in California now) so I can't check the books.

I do remember that in the photo some of the side panels are opened obscuring some detail.


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## jonathanj (Jan 24, 2008)

Posted By San Juan on 03 Sep 2010 12:03 AM 
Posted By jonathanj on 02 Sep 2010 12:20 PM 
Incidentally, has anyone ever seen a photo of the other side of the loco?




There is a photo of the other side in one of the following books: 
_Narrow Gauge Pictorial Volume 1, Rio Grande Southern and D&RGW Motive Power_

or

_Narrow Gauge Pictorial Volume 11, Locomotives of the D&RGW_


I have both but can't remember which one has the photo. I'm guessing it's volume 1. Both books are at our place in Colorado (and I'm back in California now) so I can't check the books.

I do remember that in the photo some of the side panels are opened obscuring some detail. 

Thanks - haven't got either, but at least I know what to keep my eyes open for now. J.


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