Bridge Over Troubled Water

Time to get to work on the signature scene of The Hills Line, the Iowa Interstate’s deck-girder bridge over the Iowa River.

The first detail needed are the cutwater retaining walls that wrap around each of the bridge piers. I searched for a suitable commercial product, but all were too bulky to simulate the prototype.

A plea for help on the Proto-Layouts list directed me to Plastruct’s G-Scale Corrugated Roofing. Turned over, the sheets do an excellent job of replicating sheetpile. One package gave me more than enough to complete the project.

Despite being designed for G-Scale, the sheets are thin enough to be cut with scissors. I didn’t worry about leaving rough edges post cut since it would match the weather-beaten look of the prototype.

I lucked out by being able to bend the material on the seams when shaping the wall. This minimized the cuts and joints needed while maintaining some sense of structural integrity.

Where I did need to splice the wall together, I made sure to line up the seams. Once painted, weathered, and glued the joints should disappear.

The prototype walls have what appears to be a length of I-beam along the side of the long walls. I cut out a single section of corrugation and glued it to the wall. The strip provides further support and prevents it from sagging.

The walls were painted with Rustoleum Bright Coat Aluminum spray paint, which is rapidly becoming my go-to color for simulating steel and metal.

Out come the PanPastels and India Ink washes! I’m getting better at using PanPastel colors for weathering, but continue to struggle to get the powder to adhere to all surfaces. Rustoleum’s Clear Dead Flat Spray does seem to provide more tooth for the pastels to adhere to than Testor’s Matte Lacquer Spray.

Once dry, the walls were attached to both the riverbed and the piers using construction adhesive. Talus and other riprap will be added to the base of the walls and along the banks when I begin scenery construction.