Wooden Howe Truss Bridge, part 2
The SPJRR Howe Truss Bridge kit usually has stringers for track laid during the construction of the deck. I decided to take a different approach. I wanted a more realistic depiction of the type of stringers real railroads used on wooden bridges and trestles. And, I was going to take advantage of the much more detailed track-work possible in 1:20.3 scale by hand-laying track, including using tie plates under the rail. I also plan on having custom old-style fishplate castings made for each simulated rail joint at 18” intervals (about 30 scale feet, slightly under the prototype 33 feet, but nicely divides each 6-foot piece of rail into four sections).
The rail I am using is Llagas Creek code 215 aluminum. I “blackened” it with JAX Aluminum Blackener, and then painted it with a light coat of red oxide primer. Tie plates and spikes are Ozark Miniatures items.
I made a jig out of styrene to assure correct tie spacing, shown here with the first run of spiked ties. Note the stops at each end to position the rail in the center of the deck.
Here it is, positioned for another run of ties. It takes me about 2 hours to spike each foot section.
For stringers, I’m using 3/8 x 1/2″ lumber, which scales to about 8×10″ for 1:20.3, which looks good but is not prototypical. I searched for spacers that would work in brass, because the weathered patina looks really nice, but no luck. So I made “packing washers” by 3D printing through Shapeways in plastic.
I had custom Brass Rods made to secure the stringers by SPJRR, because I like brass. Here are the bags of parts, and the packing washers on a bamboo skewer ready for painting (in red oxide) and then painted. I used sharp scissors to separate the pieces, which worked better than an X-acto knife.
After attempting to use a hand drill to drill the stringers, which was a total fail, I purchased a small drill press, and that was very successful. I made a jig to center the piece, and set the hole positions. There was one near each end, and two in the center to mate with other staggered stringers.
Within about 1 hour, I had made the jig and drilled all the stringers. Note the hand-drilled pieces in the back, which will be used as center pieces.
The stringers are best assembled with the center always overhanging both outside pieces, so you’re never trying to fit a stringer between existing pieces. Note the spacers on each of the rods on the piece ready to attach.
Here’s the finished stringer sitting on the bridge, with the track resting on it. It’s going to look great!
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