I need to build two bridges on a curve that are triple track. Track is Peco code 55 flex. I plan on just spreading ballast over the plastic base of the spans, no cork roadbed.

One is short, around 6" in length, not a huge problem. The other is 16" in length that will have a offset center support. I plan on using 1/8" black ABS plastic for a base and custom extended length sections of Peco truss girder bridge sides (NB-38) for the upper support. Not any prize winner, it surely won't make the cover of MR.

Attached are photos of the two bridges from the side and aerial shots with the longer span with track in place. The trusses you see have not been lengthened. Nothing is attached or secured, just placed there for a overall idea what it would look like. That curved turnout is a approximate location on the short span. I'm also think since I have ample of vertical clearance of adding I beams or some type of narrow channel below. Also, that white center support will be changed due to lack of side clearance. It was a piece of 3/8" ply scrap left over from the table.

One question; will running traffic over a plastic base as what I plan be noisy w/o any cork roadbed?

Questions? Suggestions?

Bruce, if this was my project I would do those sides with girder brige pieces .They are easy to bash to just about any length you might want and would also make the ballasted deck more prototypical looking.The plastic you are using for the deck is plenty thick enough to glue the sides to.To make the sides I would use the large Evergreen Tile or sidewalk .

Here is a pic of one of two girder bridges I did for my Z layout,it may help you understand what I am fumbling to say about the construction.except for the deck the whole bridge is Evergreen sidewalk stock,angels and strips.



These are suggestions only and should be taken only for what you may think they are worth.

Funny you posted that as I bought a couple of sets of plates similar to what you show.
But, the height of those pieces is still the issue as it looks unrealistic due to the length of the span. I really need a 2x higher panel like a truss bridge would have, but I couldn't find any.

If you look at the 2nd attachment, that one piece was 'bashed' from two pieces to extend the length for that shorter span which should look ok.

videobruce Wrote:I need to build two bridges on a curve that are triple track. Track is Peco code 55 flex. I plan on just spreading ballast over the plastic base of the spans, no cork roadbed.

1. With a through truss span, there is usually no closed deck to ballast. You see this done with a through girder bridge.
2. In most cases, there is much less "train noise" on bridges, than anywhere else.
3. Your side trusses,( or girders ) need to extend from "support to support", as it is the trusses/girders that carry the load.

That's a pretty ambitious set of bridges...!!!

Where would I find girder plates without the rest of the bridge elements..?? This is for HO...

Gus:

Central Valley makes HO 72 foot long girders # 210-19031.

Howard

I second the idea of using plate girders for this project, the tuss looks unrealistic.

Wouldn't those HO scale CV plate girders be too large for N scale appearance wise even though the span is longer than what would be in the prototype??
You are referring to this?;
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Ok, how about this. From a Atlas single track truss bridge. The pieces are just 'sitting' there, they would have to be cut down in length.
Though, I don't know what to do about the top cross supports.