This has probably been covered but I'm Posting as a reminder for anyone having a similar problem. I had occasion to make a minor track-plan tweak and ran into a bit of trouble. I went from two Left facing-point-to-facing-point track switches (forming an "S" curve with no straight or easement between):
To two Right face-to-face switches:
I promptly had my first derailment in more than three years when a tank car I was pushing derailed. I was a bit mystified as I had no such problem with the Left-to-Left arrangement which has the exact same geometry. I watched carefully and saw the wheel climb right up over the point. Hmm. So I got out my grinder and bevelled that point nicely. End of problem. The bevelled point can be seen in this pic:
Yes, it is an "S" curve but it works flawlessly now:
The problem area:
There isn't even a "tick" sound when a car is shoved through.
Hope this helps someone.