Most Locos are frame mounted, so if you aren’t body mounting on those tighter corners, to loco may have a tendency to lift the car off the rails.
Hi Metro Red Line, My layout is a small branch line railroad with 10" radius curves and Atlas Standard line turnouts. My Exact Rail 50' boxcars with body mounted couplers will derail every time when backed or pulled through two of my back to back Atlas Standard line turnouts. My BLMA 50's gondola's will detail on my 10" radius curves because the wheel rubs the coupler pocket. None of my truck mounted couplers ever derail on my 10" radius curves or when backed though those turnouts. So for me it's just the opposite, zero problems backing my trains with truck mounted couplers and derailments with body mounted couplers. As I explained in my above post, I have a very limited space for my layout. Although it's a switching layout, I also enjoy just watching the train make laps. If I had the room I'd probably be modeling in G scale, but I don't so compromise is the name of the game. When it comes to model railroading, I fall somewhere between a rivet counter and a anything goes person. Things don't have to be 100% realistic or accurate, I get enough of that at work
