# Restarting a static railway bridge display. (WIP)



## Choobacker (4 mo ago)

I am very grateful for the support already given to me by the Model Train forum members. I have been inspired.

So, as an appetizer for myself, I am going to restart an old project _ a static railway bridge display. It is not of any particular model railway gauge, though it is close to N-gauge. but built to 1:150 scale. However, the rail track I put into it has a gap between tracks of 5mm, based on the 1:150 scale of the narrow gauge used on the Thai-Burma Railway during WW2. Even so, it becomes too narrow for N-gauge.

The steam locomotive used on that particular railway was the JNR Class C56. I originally did not plan to actually have a train in the display, since the display is showing the bridge still under construction. The bridge was being built by POWs on 'The Bridge on River Kwai' (the movie version). But now I wish to include a train, but it's not going to be easy to do so.








I have a few options (so far):

Over the last few days I have been looking for a plastic kit on that train, for static display reasons, but to no avail. The reason for a plastic kit was so I could doctor the wheel base to suit the 5mm gauge.
Buy a cheap used N-gauge C56 and replace the chassis with a scratch-built one by making the wheels closer in.
To replace the track from the bridge would be difficult, but at the moment it's not fully realized if I could until I get a length of N track to compare the measurements, especially the depth (track with sleepers). I will find out for sure when the post arrives in a weeks time (?). 
Scratch build the locomotive as a static display. This would require some extraordinary fine skills, and trickery, on my behalf.
In any case, this project will be a static display. I have no desire to build a running layout of that era and scenario. But I need to finish this project, preferably with a C56 in it.


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## Magic (Jan 28, 2014)

Good luck with the build, keep us posted. 
Loved that movie.

Magic


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## Steve on Cattail Creek (11 mo ago)

Interesting project, Choobacker, and just to be clear, _way_ outside my wheelhouse, so take my comments for what they're worth! 

Of the options you mentioned, it strikes me that by far the easiest approach would be to get a used, hopefully inexpensive, N scale version of the correct type of locomotive and other rolling stock to match your diorama, along with some used N scale track. I believe fitting that track into the model would be vastly easier and ultimately more effective than any of your other options, and once the track is fitted it would more easily support the rolling stock you select (and even allow you to change out rolling stock from time to time). If the ties currently on the used track do not match the track envisioned by or needed to fulfill your plan, it should be possible to detach and reattach the track's rails to the ties you've already fabricated for your model, or you could instead purchase lengths of N scale rail to affix to your ties without having to first disassemble the used track (might be more expensive, though). Maybe it's just me, but of all the items depicted in such a piece, it strikes me that the precise match and alignment of the track is just about the simplest thing to fudge, the most difficult to detect, and one of the hardest things to absolutely finesse. But then again, I model in legacy O scale, so my esthetics are not exactly that of a rivet counter . . . 🙄

In any event, good luck, and I'll be interested in seeing how it turns out. Any pics in its current state?


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## Choobacker (4 mo ago)

@Steve on Cattail Creek , the idea of relocating the rails without the ties sounds very interesting. I will see what I can do about it when I get the track.
I will soon post images of what I done so far, soon.


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## Choobacker (4 mo ago)

Okay, here is 10 photos showing how and where I am with the model.

How I started my estimation of the bridge for scratch building.









Rough display profile plan.


















Tapering 6mm dowels to profile tree trunks.


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## Steve on Cattail Creek (11 mo ago)

Really magnificent work, Choobacker!

One other thought: a simple measurement (and if needed, relocation of one/both) of your existing rails might be all that's needed to display N scale equipment on your model. If this were to be a part of an operating display, there would be a host of additional concerns about providing power and avoiding derailments (all of which have been faced and conquered by the many who have elected to literally lay their own rails!), but it seems to me that for a static display, all you really need is a cheap N scale track gauge, or some sort of home brew template to serve the same purpose.

As I said before, any quibbles about the resulting slight deviations from the prototype would IMHO pale into insignificance against gaining the ability to easily and reliably add (and change) authentic-ish N scale rolling stock! Once you're freed from concern about the trucks and wheels fitting on the rails, you can instead focus on kit-bashing existing N scale rolling stock (or even scratch building shells to go over existing chassis) to better fit the historical and cinematic prototypes you're drawing upon. Good luck, and keep us posted!


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## Choobacker (4 mo ago)

@Steve on Cattail Creek , thanks for kind words and good advice. 
About the track, I will remove all the styrene (and rails). Later, after the n-gauge track is incorporated, I will then know how much to trim all the styrene bits and reglue them into place. I can hardly wait to get the track in the post.

You know, I have not been able to find online any info of what the cross-section profile measurements are of any manufacture n-gauge track. Nor how tall n-gauge steam locomotives are of that period.

However, I found a partial drawing with red notes of a C56. From this I estimated that the model will be about 25mm high. Current clearance on model is 30mm, so I need to trim the two centre dowels, that support the track, to a level as low as possible and level for the styrene (under-boards) to sit on top of the ties.

















5mm clearance out to be okay appearance wise.

Train on bridge.


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## SF Gal (11 mo ago)

Nice work! You have scratch built before, I see. Hope you are NOT thinking about putting an M80 to your pretty creation?!?!


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## Choobacker (4 mo ago)

SF Gal said:


> Nice work! You have scratch built before, I see. Hope you are NOT thinking about putting an M80 to your pretty creation?!?!


Ha ha ha, not likely!


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## Steve on Cattail Creek (11 mo ago)

Well, that's _one_ way to obscure any rail discrepancies!


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## Choobacker (4 mo ago)

As I said, I am restarting this project, and my first step, while waiting for the track to arrive, is to strip the tracks off the bridge to its essentials. And then wait for the postman.


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## Choobacker (4 mo ago)

Well, the PECO Code 80 SL-300 track arrived today, at last I was able to get some definitive measurements of its cross-section.
Now the change of plan is to completely take out the two centre poles and ties off the bridge. Then insert two 2mm strips of styrene to raise the Peco track to its required height. That is, the track is to be level with the foot way planking.


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## Steve on Cattail Creek (11 mo ago)

Looks like a plan, Choobacker, but what will the foot way planking rest upon, if you remove the center poles? From your diagram, it looks like they will be attached only to the remaining pole on each side (since they really shouldn't touch the rails), and that seems rather unstable, potentially like a playground see-saw. If there's not enough room to reinstall the poles, perhaps you could run a narrow suitable-thickness strip between the tops of the tie ends outside the rails and the bottoms of the foot way planking, to create an additional support point?


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## Choobacker (4 mo ago)

Steve on Cattail Creek said:


> Looks like a plan, Choobacker, but what will the foot way planking rest upon, if you remove the center poles? From your diagram, it looks like they will be attached only to the remaining pole on each side (since they really shouldn't touch the rails), and that seems rather unstable, potentially like a playground see-saw. If there's not enough room to reinstall the poles, perhaps you could run a narrow suitable-thickness strip between the tops of the tie ends outside the rails and the bottoms of the foot way planking, to create an additional support point?


Ha ha ha, your right. I did not see that. thanks. Yes, I will put another 2mm strip on the ties... I better change that drawing.


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## Choobacker (4 mo ago)

Choobacker said:


> Ha ha ha, your right. I did not see that. thanks. Yes, I will put another 2mm strip on the ties... I better change that drawing.


This time I will put 1mm strips under and top of ties.


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## Steve on Cattail Creek (11 mo ago)

Choobacker said:


> This time I will put 1mm strips under and top of ties.
> View attachment 588953


Yeah, that looks a lot more stable. I wasn't sure what your plan was -- the earlier pic of the planking looked a bit like it might have been spiked through to the poles, but even that method of securing the planking (even backed up with SuperGlue!) seemed a bit tenuous, given the leverage potential, unless you secured both ends.


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## Choobacker (4 mo ago)

I found another image of the train going across the bridge.


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## Berrychon (4 mo ago)

I've seen a topic like this one somewhere else...
Maybe I'm wrong or do I really need bigger goggle ?


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## Choobacker (4 mo ago)

Berrychon said:


> I've seen a topic like this one somewhere else...
> Maybe I'm wrong or do I really need bigger goggle ?


Perhaps you have.


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## Choobacker (4 mo ago)

I received the flexi-tracks but did not think about getting the joiners. I am going to be building an N-gauge/scale layout anyway, so I ordered a few joiners, but I am still waiting for them. In the meantime I decided to test what it's like to solder these tracks. From what I can gather, it is the inside track surface that needs to be free from obstruction. So I simply soldered a heavy gauge copper wire to the outside. It should work okay. What do you know about this idea?


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## Choobacker (4 mo ago)

Painted the ties/sleepers. Those extending from both sides of the bridge were fully painted. It took me a while, but it was worth it.


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## Choobacker (4 mo ago)

I tried finding an aerial view of the movie bridge for a very long time. I know it was made in the mid 1950s, but their was a helicopter over it once and I was hoping. . . to get a better idea of the layout.
PS: A lot of the movie bridge photos, like this one, can be found with the search words 'Ceylon' and/or 'Sri Lanka' (not Burma or Thailand). The movie bridge was built in Sri Lanka.









After close examination of the photos, to see where the rail tracks went, they curved away from both ends. I decided to focus on viewing the bridge from up stream, instead of what we normally see. This aspect will give me a better view of the working areas. Here is a rough plan idea of what is to be built from here on.


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## Choobacker (4 mo ago)

Using 6 and 3mm MDF board, I made the platforms for basing the flat areas and for those steep gorged sides.
I drilled holes, as you will see in photos, in case I may be adding electronics to this project. The holes allow for wiring access.


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## Choobacker (4 mo ago)

Used minimal radius (250 mm) for the track curves.









Pinned the track down at one end first. 
Took photo and provided both actual measurements and what the full scale measurements would be. 
This helps me to get an idea of what and how to implement the POWs and there working area. 
Notice, the red contour lines of the hill.








Not much is happening in this area except for trees and other vegetation.


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## Choobacker (4 mo ago)

Well, the train arrived today. And after unpacking it, I realized why model train fans love their trains. This little steamer came from China (MicroAce). I have not got a controller yet, so I have no idea how it will run... In any case, it won't have far to travel .









The C56-92 looks bigger than I hoped for, but it's close enough for my needs.









The bridge tower cross-beams need to be relocated, to create more clearance.









There is not much space for a driver in this locomotive. 
I'll look into opening the window and have the driver hang halfway out as we often see in real life.









I will be removing those giant couplers later.

Looking forward to seeing this train move along.


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