The culvert carries the mine spur across the Allt Creag na Còsaig and is as simple and low-tech as the railway could get away with. Two 4" × 8" beams cross the stream and the sleepers are simply laid upon them.

As this spur sees traffic of a single wagon and lightweight loco once or twice a week, and axle loads are restricted to 1½ tons, this was deemed perfectly adequate by the Works Engineer.

The mine spur is laid with 12lb/yd rail (Code 143), necessitating lightweight fishplates. I use 30 mm sections of 2 mm × 1 mm for the outside and 0.5 mm thickness for the inside plates; I gently file one side of the inner ones longitudinally to ensure a snug fit against the rail web, but even so in the 12'-radius curves the wheel flanges strike the bolt heads of the fishplate on the outside rail (they are slightly thicker than scale), so once in place I grind their tops down by 0.5 mm, which solves that problem.

Here Doctor John holds an inside and outside fishplate to demonstrate the different thicknesses.

As I would be building the culvert into the layout I built it directly onto the template with cutouts for the stringers. The sleepers which will rest on the stringers are not glued to the template; once glued to the stringers the template was cut away more-or-less where John is standing.

The final 9' panel of track at the mine itself is on its own template; this section is level whereas the culvert is part of the 1-in-25 climb up to the station. As a result the fishplates connecting these two pieces could not be fitted at the workbench but had to be assembled in situ. By now I have mastered this, so it took a matter of minutes only.

Note I have not followed the Templot timber spacing here: I could not figure out how to vary timber spacing for differing rail weights and decided it would be easy enough to do on the spot, and in this scale it is.

The completed rail joints connecting the culvert to the mine spur end. The stringers are mounted into slots cut into the baseboard; their original abutments have disappeared over time.

Note that I distressed these sleepers to varying degrees using a wire brush. They have been stained and will remain more-or-less this colour, as the sleepers on this spur have not been regularly creosoted—in fact, they have never really been maintained at all. I still have to weather them accordingly.

The completed culvert. The sleepers are not bolted to the culvert. The fishplate bolts still have to be trimmed.

The opposing 1-in-25 gradients of the mine spur and the branch line create a sense of vertical space on the layout.