derailment questions???

[pdlethbridge]

My brother and I built his layout about twenty years ago, Code 100 Atlas track, using custom line #6's on the mainline and #4's in the yard. We have switchmaster switch machines, a bowser turntable and DPDT center off switches to control two cabs. We just installed an NCE DCC unit on to the left side of the toggles only. While running the BLI N&W "A" pulling 8  athearn heavy weight passenger cars around the layout it ran beautifully with the normal right rail direction, but when I switched over to Left rail operation, Ala C&NW, it constantly derailed everywhere. What gives? Are the tracks wearing a certain way? This seemed strange as right rail operation is almost derailment free and has been for twenty years, but running the wrong way has  been a headache.

[Yampa Bob]

Are the derails just on curves, or everywhere?

To see if any wear or dynamics are coming into play, have you tried temporarily turning the cars around? 

I suppose wheels do wear more on one side, or so we have been told.  I wouldn't know as my cars don't have many miles on them.  If so, then they should all be rotated occasionally to even up the wear.  If the wear is excessive, it might be necessary to just replace the wheelsets, at least on one car that is the worst offender for a test.

A bit of systematic troubleshooting should lead you to the cause.

[pdlethbridge]

It depends on the direction the train goes on the mainline. Turning the cars around does not help. The derailments seem to be anywhere the train goes. This is a 20 year old layout with lots and lots of mileage. I think it is more a track problem. It happens on switches, straights, curves, everywhere! We have facing and trailing point switches, crossings, crossovers and grades. Same problem running in one direction only.

[Jim Banner]

It sounds to me like a layout that was always run in the same direction and now you are trying to reverse that direction.  Layouts run in one direction show up the track faults for that direction only, and those faults are the only ones that ever get fixed.  After a while, the layout runs beautifully in one direction because all the faults in that direction are fixed.  Trying to run trains in the other direction is very frustrating by comparison.  So guess which direction the owner runs his trains in the future?  Twenty years later, the layout still runs fine in one direction and poorly in the other.

[pdlethbridge]

you're right on the money. Except for using a crossover coming into or out of the yard, it has always been run right rail. We never really had any problems running that way right from the start, but the other direction has always been a problem

[ebtnut]

I would observe the loco very closely as it goes around the layout.  It may in fact be derailing at one spot, but does not actually come completely off the rails until later.  My first thought would be that the curves on the "left" side may be right at (or just below) the minimum radius for the loco.  The curves on the "right" side may be just OK.  On tight curves, a driver may ride up on top of the rail, but not jump off until it changes direction or hits something like a turnout or crossing.