# Making a Bridge in the house



## TrainHigh (Mar 1, 2009)

Maybe someone here can give me some ideas. I want to make a bridge to go between two walls that are 9.5' feet apart. I don't want it to hang from the ceiling because the ceiling is raised and this will only be about 8' off the ground. Has anyone built a bridge like this and what did you build it out of? How did you attach it to the walls? I was thinking something like a 6"x6" piece of wood and cut a slight curve into the bottom to make it look better and then painting it the color of the trim. What do you think?


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## nkelsey (Jan 4, 2008)

How about something like this.......not mine, a fellow club member's indoor layout


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(Image excedes 800 pixels in width changed to link, SteveC)[/i]


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## TrainHigh (Mar 1, 2009)

Thanks for replying. That is nice looking bridge. But not quite what I'm looking for. That is mounted to the wall, I need to cross in the middle of a room so it has to be an actual bridge, but each end can hook to the wall. Also I want it to blend in to the house so that it looks more like a structure of the house like trim rather than an actual train bridge.


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## SoCalStu (Dec 27, 2007)

In that distance you'll need nothing less than a 2'x6' on edge or two 2'x4's in a "T" formation with the roadbed mounted on the top. A single 2'x4' may flex too much. I did a 14' tabletop layout without any center supports and the 2'x6' worked out fine. Then you can paint it, stain it, cover it with sheet rock, decorate it with crown molding or put your 'flying' bridge along the top of it.


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## TrainHigh (Mar 1, 2009)

I went to the hardware store and found that a 1x8x10 has no bend in it when supported on both ends. I bought that and some railing to go along the sides which will also give it strength. I'm going to give that a shot. If I find it bends I'll put a 1x6x10 on edge on each side of the 1x8 to give it support. I'll report back once I have it built, which may be a month or a couple before I get it done.


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## coyote97 (Apr 5, 2009)

hm...i see....

...but i dont understand why you want it like this.

Dont let me be misunderstood: everyone on his own! 
But there are hundreds of railroaders who would be happy to have a "real" place for a bridge, covered and therefor save from weatherconditions, and u tell u are looking for something that does NOT look like a bridge.

Thats just a view out of "normality", i dont want to say anything bad with that. It just "fell into my eye" and i didnt understand. For more: wehn it has to look like housestructre, just take a beam.....ready!

Me, I like bridges very much and i want to try to give u a thought about installing a "real" RR-bridge. Just want to make u think about the "jump" on the opportunity of a great place for a bridge.
G-scale bridges are great, and there are LESS places where we can look from an "underview". Would be worth thinking, wouldnt it?

...and for more....i DONT think about selling a bridge to you. Bigger bridges arent affordable to be send over the big pool.
I am thinking about one of eaglewings constructions. The look good and seem to be worth money.

My "bridge-motivation" is a question of basics. I LIKE bridges. I wouldnt let out an opportunity to set a nice one in. 

BUT:
IF it is just like a storage where the track moves along, just take a simple beam!


Greetings 

Frank


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## Torby (Jan 2, 2008)

Beware: It's not above a brat to sell you a bridge









"Now that bridge is going to be worth a lot of money to us some day!" -- Oliver Hardy


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## Pete Thornton (Jan 2, 2008)

that a 1x8x10 has no bend in it when supported on both ends
Wait until your first train gets to the center.









Seriously, I think you need to consider this as an engineering problem. There are lots of prototype bridge designs that would fit you needs. Dropping the suspension bridge type (too unsightly) the other arch types, and the Howe truss, that leaves you with a simpler king or queen truss (one or two uprights and a stressed member from the end, over the two uprights, and terminating at the other end - just like a freight car underframe.) A simple upright under the center and two wires, one at each side, should immensely stiffen it. 

Alternatively, the box girder is quite attractive - a simple box where the side elements support the upper flat and the bottom acts as a stressed member. A strong, square-section gutter down-pipe wouldn't look bad. The 'Brittannia Bridge' in the UK ran the trains through the center - which might be another option for you: build a tube of a 1x6 top and bottom and something light (1/4 ply, 1/8 plastic sheet) for the sides.


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## Al McEvoy (Jan 3, 2008)

To put it in perspective, find a U.S. prototype railroad bridge that has at least a clear 228 foot span with no piers/trestles underneath. 9.5 ft x 24 (assume 1/2 inch scale for now) = 228 ft. I would think that to maintain clear space underneath, this would require cable-stay suspension attached from each wall out to the center similar to the Wuhu Yangtze River Bridge in Anhui, China. That structure uses cable stays for a clear center span that is 312 m long between uprights. See second and third pix down page: http://bridge-maximumcard.blogspot....ridge.html


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## kormsen (Oct 27, 2009)

that is about a long, as a soccer field. 
there must be lots of bridges that span more than that.


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## Madman (Jan 5, 2008)

I agree with the box girder design, for simplification, and weight consideration. It's amazing how ridgid and lite weight a box girder bridge can be.


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## TrainHigh (Mar 1, 2009)

Great ideas. My reason for not wanting a real looking bridge is I like my trains to blend into the house. I don't have any real layouts other than a makeshift N scale layout on my fireplace mantel. I think it's cool if the track is kind of hidden and then a train just comes through the room. 

I agree it is an engineering challenge, but also an looks challenge. I want it to blend in with the walls and trim as much as possible. I like the beam idea, if I could find a 6"x6" or 8"x6" beam that would probably be the way to go. But if I can't find a beam like that I like the box design. That's kind of what I had in mind except for not putting a bottom on it, and cut the bottom of the two sides up into an arch. I drew a pic in paint I'll try to post it.


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## TrainHigh (Mar 1, 2009)

Here is what I was thinking, but now I like the box idea. 

Without railing. Top piece is 6" wide, bottom pieces are 1x6 and on edge to provide strength, and a curve cut in them. 
 

With railing. Top piece is 8" wide and the rails put on the edges, the bottom is the same as above.


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## coyote97 (Apr 5, 2009)

Oh, o.k.!
Got it!

For the "not real thing" there is an idea between "it-looks-just-like-a-part-of-the-house" and "wow-like-a-real-bridge".

Shops for room-equipment, sometimes furniture-shops have some kind of lattice-piles or girders. They are quite simply constructed: just 3 pipes with ...say half or 3/4 inch dia, to make the edges of a triangle-shaped girder. the pipes are connected with zig-zag-rods which are welded to the pipes-sides. I think the piles should be 5 or 6 inches in width, are quite light and looking not bad. I have seen them in painted black, coated wthite or in some aluminium or zinc-plated style

I have no clue if this thing has a name....often it is used to put in lights and lamps and gives a living-room some kind of "industrial" look. 

That would make a good "bridge" of a disign, that is not "g-scale"-prototypical, but has the attributes of a bridge. Like i said: its a thing "between".


Frank


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## Pete Thornton (Jan 2, 2008)

I like the beam idea, if I could find a 6"x6" or 8"x6" beam 

You can easily make an "H" beam using a 1x6 top and bottom and a 1x6 upright. An 'engineered' rafter used in modern homes is basically the same. It must be well glued though. 

I can see you like the 'arch' approach. If you make it a box by gluing a piece of plywood onto the curve underneath it will be much stronger. 

The other thing it reminded me of was a cantilever. Here's an elegant concrete box version: 
http://encyclopedia.farlex.com/_/viewer.aspx?path=hut&name=0016n035.jpg 
and the definition with drawings: http://www.absoluteastronomy.com/topics/Cantilever

A couple of flat boxes anchored to the walls and resting on plinths at the edge of the open span would then meet in the middle of the span. As in the above pic.


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## Al McEvoy (Jan 3, 2008)

TrainHigh I guess I did not read thoroughly enough before my prior reply. If you want the "bridge" to blend in with the house, then, considering the photo of your room you linked to in photobucket showing that your house has a contemporary interior, any add-on structural component would require paint-to-match else it risks sticking out, visually. Sounds like the box structure is best to blend in, although I really liked your arched side concept and agree with Pete's suggestion to add the curved bottom board for strength.


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## Madman (Jan 5, 2008)

Posted By TrainHigh on 06 Feb 2010 12:12 AM 
Here is what I was thinking, but now I like the box idea. 

Without railing. Top piece is 6" wide, bottom pieces are 1x6 and on edge to provide strength, and a curve cut in them. 
 

With railing. Top piece is 8" wide and the rails put on the edges, the bottom is the same as above. 


Good idea. Now what is the span of the bridge? You will need to keep enough meat in the 1" x 6"s at the center point to prevent sagging.


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## TrainHigh (Mar 1, 2009)

Yes I had planned on painting the bridge white to match the trim of the house. I definitely have a lot to learn about bridges. I haven't thought about the "H" beam idea, I had thought about a "T" beam but don't know how that will look as far as blending in. I think the box or curve would look the best. This bridge will be 9.5" if I can ever get it built.


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## Madman (Jan 5, 2008)

Posted By TrainHigh on 08 Feb 2010 05:59 PM 
Yes I had planned on painting the bridge white to match the trim of the house. I definitely have a lot to learn about bridges. I haven't thought about the "H" beam idea, I had thought about a "T" beam but don't know how that will look as far as blending in. I think the box or curve would look the best. *This bridge will be *9.5"[/b] if I can ever get it built. 


Did you mean to write 9.5'


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## TrainHigh (Mar 1, 2009)

Yes I meant 9.5'.


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## Paradise (Jan 9, 2008)

Trainhigh, 

If you end up with a potentially sagging wooden design which could be the case in the arch center, you could install a truss rod under the deck made with allthreead which can be tightened if any sagging occurs over time - like how a guitar neck works. 

Andrew


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