A Bridge Runs Over It

As of this post date, it's one-of-a-kind model: a deck plate girder bridge in T scale. At a mere seven real inches in length, it measures 252 scale feet long, and stands roughly 60 feet, to the rails, at the highest point. It comprises three 84-foot spans, with 12 foot deep girders standing on concrete piers. And it's skewed.



Building the bridge at this point in time became something of a necessity. I'd just finished painting the track (below, using the same techniques as before), and I was cleaning the paint off of the railheads. When I got to the bridge section, I realized it was a risk trying to clean the unsupported track. So, it was time for a bridge.



To be sure, it was a fun little project (well, most any project in T would be "little"), although it got off to a rather slow start. I was going to make the girders the way I had for the through girder bridge I'd built last time, by bonding strip styrene ribs to sheet styrene plates. But when I started doing the math—around 150 ribs to cut and bond!—I decided it would have been a bit more work than I was willing to invest.

And so began the quest for any kind of plastic part or scrap with thin ribs spaced about a quarter-inch apart. Several candidates emerged, including a small N scale bridge kit, board-and-batten sheet styrene, and some Z scale hopper cars. But the detailing on the N scale bridge would have been grossly oversized; the spacing on the board-and-batten stock I had was too narrow; and Z scale hopper cars are not cheap!



After about an hour of searching every box and drawer in my modeling domain, I finally stumbled upon the perfect solution in a most unlikely form: skylight parts left over from an old N scale Model Power factory kit (above). If I believed in fate, I might convince myself I'd saved them for just this project (even though T didn't exist back then). Consider: the rib spacing was exactly correct; they were exactly the length of the spans; and I had six of them, which was exactly how many I needed. Cue the Twilight Zone theme...

The downside to this choice was that the bridge sides would not be continuous parts for strength, as I'd wanted; plus, working with clear styrene is a real bear—it's brittle and doesn't cut cleanly. But I could easily live with these trivial problems considering the amount of work they saved me.



The first step was to remove the bumps and ridges that oriented the parts on the original factory kit roof. After slicing the window parts down to quarter-inch-wide strips, I trimmed them to length, bundled them together, and sanded all of their edges so that they all matched in size (above).





After attaching .010 x .040 inch strip styrene pieces to their ends, I bonded the six parts in sets of three on either side of a .100-inch square styrene strip to make a single, strong assembly. Then I capped the top and bottom edges of the plates with .010 x .040 strip styrene, and added twelve little squares of .010 x .040 strip styrene for pedestals (above). Finally, some flat black spray paint and lots of RustAll pretty much wrapped up the bridge itself.



I tend to assemble bridges in a somewhat counterintuitive manner: from the top down. Before starting on the abutments and piers, I bonded the bridge to the underside of the flex track with thick CA (above); this allowed me to build them to fit, particularly as the piers were different heights.



The wide sides of the piers were cut from .080-inch thick sheet styrene, and laminated together with a spacer at the bottom to create the taper; the narrow sides were .010-inch thick sheet styrene bonded to the edges of the wide parts, then trimmed down to size (above). After sanding everything with medium grit sanding film to kill the sheen and add some texture, I sprayed the parts with Pactra Light Aircraft Grey, and weathered them with powdered chalks (below).





I installed the abutments and piers with Loctite PowerGrab adhesive; this gave me some wiggle room to get everything aligned. The bridge was finished so quickly that I kept wondering what I'd forgotten to do!