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…........................--- Bridges/Culverts & Roadbed ---

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Been working with Fusion 360 to design some bridges and culverts that can be used where tracks cross small streams or in my case a dry wash, which are numerous in the west.

I see a lot of short girder bridges across dry washes here in Utah. Hard to see but the resin printer was able to print the rivets on the bridge also.

The bridge is wide enough plus just a bit to place cork roadbed on it and ballast it. If you already have the road bed in place there are also print files where the bridge can be printed as two sides. Then dig out under the roadbed a ways from each side and insert them as is shown with one of the culverts below.

Since concrete culverts are also numerous in the west I designed two sizes to use (10 ft and 13 ft wide at the mouth (13 ft above).

I marked where the foam needed to be dug out and ...

….. cut it out with an X-Acto knife and a hot wire foam knife.

I haven't added water to the paver sand at this point to set it up (it has its own adhesive) as the culvert still needs to be painted. The other culvert on the far side will be installed the same way. Having only one side of the culvert printed allows you to use culverts with different retaining wall angles on each side and to also cross one or multiple tracks.

In the area above I'll probably use the 10 foot wide culverts. Three different options for each size can be printed. One has both the retaining walls at the same angle and the other two angle the retaining walls off to either the left or the right depending on the direction the waterway approaches the culvert or leaves it.

I'll also put up bridge files for a single span and two span girder bridge along with only one side of the single and double span girder. Use the single sides if you want to install under existing roadbed or if there is more than one track.

Spent a little time and added roadbed to the upper level above. One track coming off the bridge (left) proceeds through the tunnel to the left and around the other side of the backdrop where there will be a sawmill. Past the sawmill the track will come back through the tunnel to the right and back to the bridge and cross it and after crossing leave the first track and go to the far side of the layout. So some imagination is needed to see that the high bridge is actually two separate bridges with one being further along the main.

The scene above will also represent a summit with a siding where helper engines could be left for the next train going down if that is the case.

Next a rasp will be used to flatten the cork and knock down the shoulders. Then Spackle will be applied and the roadbed sanded (will take about 30-45 minutes to do that). More on using the rasp and spackling ( HERE ). Then I'll add the rock and other landscape main features in front of and behind the track to the backdrop.

A few more pictures on how to use the plate girder bridge halves if you print them instead of the complete bridge with the deck. If you don't have road bed down printing the complete bridge might be easier but....if you need more than a single track or if the road bed is down using the separate bridge sides can be of benefit.

I carved out a piece of 1” foam board for this example. If the track it in place work in from both sides. You probably don't have to make a cut all the way through if you can't see under the bridge when it is installed.

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I haven't progressed with the final landscaping since this was a piece of scrap foam and not the layout.

Above is the double span bridge. You can also print the side files for the single span and do the same.

You can find the print files for the 10 foot concrete culverts ( HERE ).

You can find the print files for the 13 foot concrete culverts ( HERE ).

You can find the print files for the different plate girder bridges ( HERE ).

For all my thingiverse.com print files go ( HERE ).

A link to this whole build ( HERE ).

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