Model Railroading > The Bridge

It's a thru truss, but look at the portal ends at the tops that are open. Its marketed by a European model railroad company. I've seen it on a number of layouts including a couple of million dollar plus layouts that are supposed to represent U.S. railroads to the public.

Is there anything like this used by North American railroads?

Victor Baird



Edited 1 time(s). Last edit at 09/18/23 20:41 by wabash2800.

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Victor,

I practiced as a Structural Engineer and an open portal end is not correct.  Stability is required for lateral forces and therefore some type of sway bent is required at major panel points.  I would call this a modeling simplification!

Jeff N
Olathe, KS

I assembled an HO kit like this 60 years ago in Germany.  Believe it was made by Kibri.
jb

This is just on the East side of Platsmouth NE.
[url=http://​https://www.google.com/maps/@41.0014803,-95.8657401,3a,75y,255.76h,88.9t/data=!3m6!1e1!3m4!1sxarfDYVMvlYigZ6hgKZ5ig!2e0!7i16384!8i8192?entry=ttu]Google Maps link[/url]
-Zach

Walthers and Central Valley Model Works each have a nice selection of bridge kits that are North American style and correct per prototype.

Never say never with European bridges - but, this combination of a pony truss at the ends and a (warren?) truss in the middle is not likely in North 
American bridge engineering. As other folks have mentioned there are lots of reasonably accurate bridges available in HO scale.

Just a guess - the model might be that way because European catenary would foul a portal at the ends of the truss.



Edited 2 time(s). Last edit at 09/21/23 10:52 by Lighter.

Folks, I knew that, but if I would have said it's wrong, I would have got a lot of "it's my railroad!" replies.

Victor Baird

Posted from Android



Edited 2 time(s). Last edit at 09/20/23 11:46 by wabash2800.

So if per you this style bridge cant exist. Why does it exist in the real world and support trains.
https://www.dreamstime.com/steel-arch-truss-railroad-bridge-across-river-span-riveted-over-fragment-darnytskyi-dnieper-kyiv-ukraine-image187848852

sfn2633 Wrote:
-------------------------------------------------------
> Victor,
>
> I practiced as a Structural Engineer and an open
> portal end is not correct.  Stability is required
> for lateral forces and therefore some type of sway
> bent is required at major panel points.  I would
> call this a modeling simplification!
>
> Jeff N
> Olathe, KS

You may be asking Jeff, But I would say that is a heavier bridge which also includes more support underneath. I still doubt that you would see anything like this here in North America, as our trains are much heavier than Europeon trains.

Victor Baird



Edited 1 time(s). Last edit at 09/23/23 10:16 by wabash2800.

If you look carefully at the photo you will see an end portal is actually in place.  It is in the form of a K-brace system.  
Whether the bridge has a sloped or horizontal chord, or an arched top chord, is not a factor in the need to provide sway stability to the structure.  

Jeff N