# Building Bridges



## JohnnyB (Jan 16, 2011)

I am adding an HO layout to my newly constructed movie room. I plan on adding a few bridges to the layout. I have built a few bridges in the last few years for some clients, but they have been mostly 1/24 scale. I used solid maple for most of the bridge projects. I would like to incorporate the bridge in below picture. It has many details that would be difficult to construct in wood. Is there a better material other than wood or metal to use for this detailed bridge? I thought about constructing a mold and casting it in plaster. What ideas or suggestions do you have.











The pictures below are from a bridge that I did for the Caesars Palace Hotel in Las Vegas, some years ago.


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## sstlaure (Oct 12, 2010)

Faller makes some stuff that looks similar

http://www.walthers.com/exec/productinfo/272-120488

Marklins got a decent arched bridge

http://www.walthers.com/exec/productinfo/770-2548

If you kitbash a few kits together along with some sheet styrene I'd bet you can get pretty close to what you're looking for. Nice LV bridge BTW.


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## JohnnyB (Jan 16, 2011)

Thanks for the links. Yes, there are some nice looking premade bridges out there, but I would like to make it myself. It will be a custom size to fit an area of the layout. 

I've never worked with styrene before. Wondering how to cut it. Can you cut it with a razor blade or does it require a powered saw of some sort. Also, how well does it sand. Will need to cut arches and then sand smooth. Can you use filler on styrene to smooth out the rough areas?

Wondering if if a dense foam board material would work. Maybe cut it out and use filler to cover the raw foam.

After looking at some of the pre made bridges, I am thinking my scale may be off. From the lowest support column to the highest part of my bridge I am looking at approximate. 20". Do you think I should shrink it a little for HO scale?


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## sstlaure (Oct 12, 2010)

You can score and snap it with a hobby knife. Pretty sure you can use body filler, etc for smoothing. It sands just fine (I use fine grit to smooth out glued joints - I use a solvent that melts the plastic together rather than gluing - makes for an undetectable joint once sanded.)

You could always make it out of wood or foam board then coat with a layer of plaster and sand smooth as well.


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## NIMT (Jan 6, 2011)

If you want to make it look like the picture, you need to make a mold.
you would only need to make one side of it. The other side is the same.
The shape of the bridge done in styrene would be to exact.
Styrene is structural shaped plastic, like I beams and that when glued together look just like steel.
Your going to spend a lot of time carving a mold to do a one off production, some times it's best to get it close and call it good.
You said you worked with maple, build the skeleton out of maple and form the rest on to the skeleton. with either clay or plaster. 
You could carve it out of clay.


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## JohnnyB (Jan 16, 2011)

Yes, I am leaning towards building the base of the structure out of wood and adding details with an alternate material such as plaster, balsawood or similar material. As an alternate to the expensive maple, I can use light weight MDF.

How about the scale. As mentioned above I am looking at 20" from the lowest to highest part of the bridge. Do you think I should shrink it down a little for HO scale?


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## sstlaure (Oct 12, 2010)

That's a tall bridge - you could get close to the same effect shrinking it down a little, but if you've got room for the elevation - go for it. That will be one nice structure when you're done - a real showpiece. 

Looking at the picture again - if it's 20" high it will probably be at least 5-6 feet long for the proportions to be correct. That's a lot of real estate.


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## JohnnyB (Jan 16, 2011)

Yes, I have it at 20" tall and a little over 6 feet long.


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## sstlaure (Oct 12, 2010)

That's a Kick-a__ bridge if you've got the space....very cool.


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## JohnnyB (Jan 16, 2011)

I plan on building one side of the main structure this weekend. I will post up progress pictures in this thread.

It will be set up against a wall, so I only need to fully detail one side, which will save a lot of time.


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