A new bridge for Phil's RR

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phils2um

Phil S
11 Sep 2015
629
Ann Arbor, Michigan
My latest empire expansion requires a long low bridge over the water feature. I'd been thinking about building something over the winter and just putting a board across the water as a temporary expedient. Last week I was at Menard's (A big box home center somewhat akin to Home Depot and Lowes) to pick up some crushed limestone paver base for the blocks I was putting in. I had not been to Menard's in quite a while as HD and Lowes are much more convenient to me. While looking around I spied these in a rack by the flooring materials. They are 8 foot long aluminum extrusions for transitioning ceramic tile to other types of flooring , but to me, thinking about bridges at the time, they looked an awful lot like trusses.

Trusses - 1 _1_.jpg Trusses - 1 _2_.jpg These are pics of the leftover pieces .

It just happens that 3/8" thick PVC facia board is a perfect fit in the gap of the extrusion as seen in the next pic.

Trusses - 1 _3_.jpg

Two 8 ft extrusions and the 8 ft PVC facia board cost about $65.

The next shot is of my new bridge temporarily installed.

Trusses - 1.jpg

I cut the PVC board into five 300mm pieces plus one shorter make-up segment. One end of each segment will be epoxied into the extrusions and the remaining PVC left to float for the final installation. A small gap will be left between the segments for the differential in expansion and contraction between aluminum and PVC. The bridge will probably be installed upside down from what is shown once I've got the abutments in place. The low "trusses" make more sense for a deck type bridge where they are in tension rather than compression when installed as shown above. But, it is quite sturdy enough to support my heaviest trains as a single span even installed as shown.
 
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Lancer

Lancer

Registered
9 Jul 2017
33
68
United Kingdom
A brilliant idea. Could be just what I'm looking for. I've been looking for ideas for making some bridges.
 
P

phils2um

Phil S
11 Sep 2015
629
Ann Arbor, Michigan
I finally got around to finishing this bridge installation. I wound up shortening it about 12 inches and keeping it with the "trusses" on top.

First a couple of shots showing what I did to finish the bridge span itself. I cut some strips from the leftover PVC facia board to act as walkways. They also keep the track centered. The pics below are of leftovers. I failed to take shots of the actual bridge when I finished it up.

abutments - 1 _10_.jpeg abutments - 1 _11_.jpeg

The facia is molded with one side textured and the other smooth. The walkway strips were glued using standard PVC primer and cement. The strips were glued smooth side down to the bridge platform sections which were installed smooth side up.

Next up was making and installing the permanent abutments. I made these from concrete block. Note: safety glasses and hearing protection mandatory! I marked the bridge width on the blocks then cut a series of kerfs using a dry cutting diamond blade in a Skilsaw. Depth of the kerfs was set so the top of the bridge deck would be even with the top surface of the block.

abutments - 1 _1_.jpeg abutments - 1 _2_.jpeg abutments - 1 _3_.jpeg abutments - 1 _4_.jpeg abutments - 1 _5_.jpeg

Concrete between the kerfs was knocked out using a brick hammer. The cutout was cleaned up by passing the diamond saw blade back and forth to get rid of the remaining ridges. The sole of the Skilsaw was supported on the un-removed top surface of the block to keep the depth reasonably uniform.

The two abutments were fixed in place using quick set mortar. They were put in one at a time. I used half a 55 lb. bag of mortar for each abutment. The temperature was cool enough that I had just enough time to get the blocks in position and leveled while the mortar was still workable. I would have needed set retarder for the mortar if it was any warmer.

abutments - 1 _6_.jpeg abutments - 1 _7_.jpeg abutments - 1 _8_.jpeg

The weather was so pleasant today that I put the water feature's pump back in after I finished installing the bridge.

abutments - 1 _12_.jpeg
 
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dunnyrail

dunnyrail

DOGS, Garden Railways, Steam Trains, Jive Dancing,
25 Oct 2009
17,811
72
St.Neots Cambridgeshire UK
I finally got around to finishing this bridge installation. I wound up shortening it about 12 inches and keeping it with the "trusses" on top.

First a couple of shots showing what I did to finish the bridge span itself. I cut some strips from the leftover PVC facia board to act as walkways. They also keep the track centered. The pics below are of leftovers. I failed to take shots of the actual bridge when I finished it up.

View attachment 263260 View attachment 263261

The facia is molded with one side textured and the other smooth. The walkway strips were glued using standard PVC primer and cement. The strips were glued smooth side down to the bridge platform sections which were installed smooth side up.

Next up was making and installing the permanent abutments. I made these from concrete block. Note: safety glasses and hearing protection mandatory! I marked the bridge width on the blocks then cut a series of kerfs using a dry cutting diamond blade in a Skilsaw. Depth of the kerfs was set so the top of the bridge deck would be even with the top surface of the block.

View attachment 263262 View attachment 263263 View attachment 263264 View attachment 263265 View attachment 263266

Concrete between the kerfs was knocked out using a brick hammer. The cutout was cleaned up by passing the diamond saw blade back and forth to get rid of the remaining ridges. The sole of the Skilsaw was supported on the un-removed top surface of the block to keep the depth reasonably uniform.

The two abutments were fixed in place using quick set mortar. They were put in one at a time. I used half a 55 lb. bag of mortar for each abutment. The temperature was cool enough that I had just enough time to get the blocks in position and leveled while the mortar was still workable. I would have needed set retarder for the mortar if it was any warmer.

View attachment 263267 View attachment 263268 View attachment 263269

The weather was so pleasant today that I put the water feature's pump back in after I finished installing the bridge.

View attachment 263270
Nice work and so good to see the Green Ge6/6. Looks lovely in green out on your railway. Reminds me of my modest sized layout with a HOm Bemo one that I once had on my now sold Swiss Railway.