Mystery Derailment

I’ve been chasing derailments lately, and making steady progress until I came up against this one on the Pembroke Milling Company switch. Here the first truck of 1120’s tender consistently chooses the diverging path, rather than the normal route. Interestingly, this has been only happening for about a year. Prior to that, northbound trains arrived at the depot without incident.

I could find nothing wrong with the point itself, and indeed, a free truck flies through flawlessly. So I ran the engine back and forth, watching the wheels carefully, and discovered that the far wheel floats above the rail long before it arrives at the switch. Curiously, the drivers, which present a much longer rigid chassis, do not behave the same way.

I’m three long evenings into the puzzle, and the solution is still in my future. I’m just hoping it’s not too far in my future!