Month: March 2026

Installing a Bridge

Installing a Bridge over the Los Angeles River

Installing a bridge over the Los Angeles River was high on my list, since river bridges have always fascinated me in model railroad layouts. In addition, bridges are a great way to add vertical variation to an otherwise flat urban setting, especially on a layout like the Burbank Branch in N scale .

Cutting Benchwork

I started by measuring and cutting the plywood subroadbed support of my N scale layout.

Installing a bridge over the Los Angeles River
Cutting the benchwork

Then, I used styrofoam to shape the riverbed and the riverbanks, cutting it with a hot wire cutter.

Cutting foam with a hot wire cutter.

I glued the riverbanks to the riverbed with acrylic glue.

Installing a bridge: riverbed and riverbank made out of foam board.

Next, I applied a few coats of ultra-flat gray spray paint to seal the foam and create a solid base for the final color, and masked the banks.

Installing a bridge: Painting the foam riverbed and river banks gray

I started painting the riverbed with a coat of Tamiya XF-8, then I progressively added light layers of Vallejo Camouflage Medium Brown (71.038), and Vallejo Light Green Chromate (71.006) to get some variation close to the riverbanks.

Painting the riverbed

I painted the concrete riverbanks with a flat gray finish using an inexpensive spray can.

Expoxy Resin Water

The riverbed and riverbanks are now painted. Therefore, they are ready for a layer of 2-part epoxy resin to achieve a realistic water effect.

Installing a bridge: 2-part epoxy resin.
2-part epoxy resin cups

Always wear protective gloves when handling resin. After all, that material is incredibly sticky!

Mixing the 2-part epoxy resin.

Additionally, I incorporated a few drops of Vallejo Dark Olive Drab (71.316). This gives the water a subtly greener, more natural appearance.

Adding drops of Vallejo Dark Olive Drab to the resin mix.

Once the resin had cured, I painted some subtle wave effect using Liquitex Gloss Medium. Then, I installed the riverbed in its final position on the layout. To ensure a perfect fit, I first test-fitted the riverbed and then marked the cutaway along the fascia with a pencil.

Subsequently, I cut the fascia accordingly with a saw. I then used a rasp and a file to fine-tune it.

Finally, I glued the riverbed to the benchwork. Following this, I applied a layer of putty to smooth out the joints, creating a seamless transition.

LA River

Installing a Bridge: Final Steps

Then, I assembled an RSLaser 60-foot girder bridge kit and test fitted it in its final location.

Installing a bridge: test fitting the RSlaser kit.

Afterwards, I scratchbuilt the retaining walls from tiny pieces of wood and painted them a warm gray tone using Vallejo Concrete and Vallejo Gull Gray. In the photo below, I’m test fitting them in place.

Retaining walls
Painting the retaining walls
Installing a bridge

I glued the bridge to the abutments using Liquitex Matte Medium. Then, I secured the wooden retaining walls with more matte medium.

Glueing the bridge down with Liquitex Matte Medium
Retaining wooden walls glued

To keep everything aligned, I inserted a small piece of EVA foam to press the wall against the bridge. Afterwards, I placed a couple of metal weights on top of the bridge and let the glue dry.

Installing a bridge: keeping the bridge in place with metal weights

I added some papier-mâché terrain behind the retaining walls and painted everything a tan color.

Papier-mâché terrain behind the retaining wall

I prepared the bridge track with the correct tie spacing and soldered the feeders. Then, I carefully measured the section to install it in place of the temporary flex track I had used before the bridge was ready.

Installing a bridge: trackwork

Once the track was in place, I connected all the feeders to the main bus, cleaned the rails, and tested the track.

Installing a bridge

Here is the final result. It is still missing some terrain and vegetation around the edges, but overall the scene already feels much more complete.

Installing a Bridge