So should I make it look like concrete along the outer rim, then use sifted sand to simulate gravel and paint the cobbles individually? Then use some weathering powders to finish it off?
I’m open to suggestions.
The apron (rim) might best be done in asphalt, perhaps with wood strips defining the flangeways. If it were concrete, all the radial tracks would have to be formed into it, or the tracks would have to be laid up to the edge on top of the concrete, as if on an abutment, and the bridge raised slightly to match.
The walls would be cobbled, and the step at the bottom that carries the ring rail should be concrete. You can have fun deciding how the ring rail would be adjusted if part of its foundation settled over time… you would not necessarily be able to adjust bridge-roller height to compensate evenly.
All the pit at the bottom between the ring-rail support and the center support of the bridge would likely be gravel, so water and lubricants dripping off the engines would not make a mess. Especially if you have Baldwin diesels, there’s all kinds of prospective fun with replicating this…
The alternative would be concrete or asphalt, with defined grading and drains. The concrete would be like light paving, not structural, and would probably not be smoothly struck off and jointed.
I think the interior part is supposed to just be a coarser concrete. On a quick online search, I couldn’t find any images of anyone making the turntable look like the inside part was gravel or dirt. They’re all painted and weathered to look like concrete.
