Any chance the Atlas rerailer section was left in the sun? Heat exposure might be enough to narrow the gauge through the plastic section and cause the cars or a long-wheelbase steamer to bind up.
A "loop" usually means a return loop reversing a trains direction to US modelers/ To British modellers, it means a passing siding.
A loop? As in a return loop?
I would examine if there is something sticking up somewhere, a track nail or something physically catching the affected rolling stock. I'd check track gauge too, since its easy to do. Flange clearance? A sharp raise in gradient? A high spot perhapse in ballast that is catching coupler "hoses"? Good places to start. Dan
My layout is L shaped, nickel silver, Code 83 Atlas track with a loop at one end. Total track length is about 150 feet. I inserted 6 power feeds along the run. During the course of construction and reconstruction I feel like I can now apply for a railroad pension. I've encountered another problem.
At one point most of my rolling stock and locomotives go smoothly. Other rolling stock will derail. One car actually grinds when it goes over the spot. The other hinky thing is, even tho' there's a soldered power feed at this point, some of the locomotives stall. One loco, a Nickel Plate Berkshire, just sits there and buzzes.
Would I be better off just replacing that stretch for a foot or two? It starts at a 9" Atlas rerailer section and would end as part of a 3 foot Atlas flex track.