Non-derailing switches

Agreed, that non-derailing is beneficial without any downside (as long as coil-type switch motors are protected from burnout).

All Fastrack track switches are non-derailing, even the manual-throw ones. All Realtrax switches are non-derailing.

What exactly does it mean when a switch is "non-derailing"?

I know that it probably means that the switch won't derail a train but what makes one switch non-derailing?

When a train approaches the points-end of a track switch the train will take whichever way the switch points lead it. If a train approaches a switch from the opposite direction the points must be thrown the way that permits the train through. If the points are set the wrong way the locomotive wheels will be forced up and over the rail at the point where the points-rail and running-rail come together in a V, thus derailing the train. A non-derailing switch either (1) has spring-tensioned points that an approaching train can force open to allow the wheel flanges to pass or (2) has an electrical feature which causes the switch motor to change the points to the correct alignment.

I think I've asked that question before but I like the way you explained it.  I am curious, in the real world, do the switches do the same thing if a train approaches an improperly thrown switch from the opposite of the points leading edge? 

bobotech posted:

I think I've asked that question before but I like the way you explained it.  I am curious, in the real world, do the switches do the same thing if a train approaches an improperly thrown switch from the opposite of the points leading edge? 

There are spring switches used at siding exit ends  to allow a train to exit without needing to throw switch.  From my reading signal books, power switches are part of a cTc systems under dispatcher control, and do not change position like model trains (of course I am sure there could be an exception), but I believe some power switches models can allow the points to move then spring back.  However power switches are interconnected with signal systems and forcing the points over I think should cause signal indication changes and maybe reflected on the dispatchers board/monitor.

The term is running through a switch. The wheel flanges will force the point rails over and the train will not derail but the switch will be broken in the process and require repair.