Love that photo of the PRR coal drag under the waterbridge. Thanks for posting the pic and the project. I was unfamiliar with these structures.
My last post on this thread was a Bob Hall custom-built CB&Q Mountain. Bob built at least eleven CB&Q steamers. Many were models of prototypes that the Q had a lot of, such as the O-1A Mikado. Bob built three of these: one for Richard Garberson, one for Jim Seacrest, and one for himself. He did however build a few less common locomotives. My favorite is this Class T-2 2-6-6-2, shown here on my workbench for inspection, cleaning, and lubrication:

I was very happy to find that the gearboxes turned freely and the locomotive ran smoothly on a short straight track. As such, this one did not stay on the workbench very long. Here it is running light on the layout at the OKC show:

Most of the layout is parallel double-track. The locomotive is running on the inside main, which of course has tighter curves (the track in front is a yard lead). I was hoping that, being a short articulated with six drivers per engine, it would negotiate the tight curves. It ran fine on the 60" curve seen here, but that wasn't the acid test. We haven't finished the layout upgrade yet, so for now the inside main passes through the diverging track of a #5 switch and then a #6 S-curve. I failed to get video of the T-2 snaking through these, but it ran for about an hour with not a single problem.
I do have some video of it on the rest of the layout, though, and will post soon.
Jim