random derailment

[jboot111]

ok i was running my layout and and it was running smoothly... until the end of my tunnel
i checked my track and it was fine
anyone have any ideas why

P.S. my track is temp not permanent

[Doneldon]

jb-

Could things have shifted around enough that your
trains are making contact with the sides of the tunnel?

                              -- D

[mf5117]

Is it coming threw a curve . Do you have a loose rail joiner or an offset in your rails  .  Is the engine derailing or the rolling stock , possibly a hose to low on one of your couplers . Did you try running your string in the opposite direction to see if it derails going the other way . Do you have a mix of different manufacturer's rolling stock . Could you possibly have a light flat or tanker in the mix or middle of the string that gets pulled off the rails . It can be a number of things from worn wheel flanges ,Wheel sets out of gauge ,couplers not gauged . Also put the heavier pieces of rolling stock you have to the front of your string and the lighter ones to the back . Also try turning your rolling stock around the one that derails .

Also depending on your environment if your track is not permanent .It will move around due to temperature changes

I have ran my trains all day long with no derailments and 2 days later every 5th or 6th time around a derail so it makes me go threw and check the small things that mean alot .

[mf5117]

Also if you go to the "search" icon and type derailments there is alot of good reading and learning there .

regards MF5117

[jboot111]

jb-

Could things have shifted around enough that your
trains are making contact with the sides of the tunnel?

                              -- D

that is possible

[Len]

Did you add a new car to your rolling stock that's longer than the previously operated cars? If so, and the tunnel portal is on a curve, the over hang of the new car could be side swiping the tunnel portal.

That's one of the drawbacks to the Woodland Scenics "Layout in a Box" kits, they put single track tunnel portals on 18in radius curves. This really limits the length of the cars you can run unless you enlarge the portal opening, or replace them with double track portals.

Len

[jward]

18" radius limits the length of cars you can run anyway. i haven't had trouble running cars through single track portals on 18" curves, but i limit myself to cars and locomotives of 55' or less (about the length of a gp40 or b23-7.)

i have to wonder is this derailment truly random. does it happen at random spots on the layout, with raodom cars or locomotives? or is it just one spot with random cars & locomotives? (carefully checque the track in this case.) or does it only affect certain locomotives and cars, at random spots on the layout? (if so, checque the wheel guage, truck rock and swivel, and couplerheight and operation of those pieces.)

when troubleshooting, the more information you can give about the problem, the more likely you are to get a solution.

[jboot111]

i only have one train opperating but now i moved the tunnel(aka my old thomas table) over a little bit and it worked fine