Ok, I know the most basic cause of a stringline derailment is weight (mainly lack there-of for one car, with more-so behind it).
Another issue is train-handling (mainly poor).
Ive also seen where a stiff coupler can pull cars off the rails, though that can pull either direction.
But, any other causes?
Reason - I have a 60' Boxcar, that, any amount of weight behind it, it will derail every time, to the inside of any curve, therefore a stringline derailment. (Even one lighter than normal car will cause this.) Yet, this car will not jump off if there is zero weight trailing it. (Even with horrible train handling, attempting to derail it.)
While it does not quite hit NMRA recommended weight, everything else (wheelset gauge, coupler height and freeness of travel, etc...) checks out.
Other than making it a designated EOT car, (with a EOT flashing coupler included), any ideas?
Ricky W.
HO scale Proto-freelancer.
My Railroad rules:
1: It's my railroad, my rules.
2: It's for having fun and enjoyment.
3: Any objections, consult above rules.
Other than the usual suspects of weight or having too many heavy cars behind lighter cars, and sharper curves etc.... the only other thing I can think of is are the trucks really wobbly and have way too much "play". I like to remove trucks and file the lip down enough so that I can snug the screw enough to stop the truck from pivoting and then back it off so the truck swivels freely and has perhaps a tiny bit of rock, but not much. That may or may not be a factor.
Rio Grande. The Action Road - Focus 1977-1983
Having experienced this myself on a friends layout with some passenger cars, the swingout on couplers can be a factor. Seems like when the couplers align outside the guage of the track, they would generate a derailment.
Do the couplers swing nicely from side to side in a generous arc? The trucks may pivot easily and smoothly when you hold the item in your hand, but with the trucks on the rails and the car body and frame bearing down on them, maybe one or both snag on something under the sill.
I would fix any of those problems if they are there, double check that the wheels and flanges are NMRA compliant for the scale, that the axles are properly mounted into the side frames, that the wheels are placed on the axle correctly (not both slid toward one end so that the axle doesn't track well), add some weight, and see if that doesn't make it behave.
Besides the trucks being to loose and sloppy they could be too tight thus not allowing the car to turn properly. Check the wheels also. They might be the problem. Do they roll freely. Are they out of guage? Try a different set of wheel and trucks and see if that helps. Test ones from another car that you know works and see if that fixes the problem.
Ok, first, thanks for all the tips.
I had to add some details in the Diner thread, so I will add them here as well.
Loco pulling the train was a Alco C430.
Car started in car spot 1 of 10, derailed on curves. (Not the same spot each time.)
Car would derail at any speed, from slow to mainline (40 sMPH) speeds.
Placing car in spot 10 of 10, no derailments.
Placing another car in behind it, now 11 cars, car 10 (60' boxcar in question) derailed to the inside of the first curve it hit.
(New car 11 was lighter weight than boxcar is.)
I do have a couple things to check, so I will check on those items, just to try to rule out something easy to fix.
EDIT: I will be checking to make sure no details are catching on either the couplers nor the trucks. I will also be checking to see if I can add a bit more weight as well.
What is the radius of your curves?
George In Midcoast Maine, 'bout halfway up the Rockland branch
22" mainline, 18" yard lead.
Put a car in front of and in back of the prooblem car, then holding the problem car, slowly roll the combo into a curve. If there is insufficient coupler swing, you will feel the pressure ont he car starting to push it off the rails. I doubt it is stringlining in the traditional sense, rather it's either a bit too long or the couplers are a bit too stiff for your radius curves. On the club layout, something like 28" + radius curves, I've run trains with empty flat cars right behind the loco (unbder NMRA weight) with loaded open hoppers (with the loads installed, over NMRA weight) behind it and had the whole thing stall suddenly, and the leap back into action when the sort was cleared and never have I had it pull the lighter cars off the rails.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I had the same problems with my road railers, I discovered if I also added weight to the center of the car it solved the problem, maybe just the equal weight distribution will cure yours also.
I presume you also thoroughly checked each wheel to see if there were any defects in the flange or wheel tread.
ricktrains4824While it does not quite hit NMRA recommended weight
Why not bring it up to NMRA weight?
Autonerd ricktrains4824 While it does not quite hit NMRA recommended weight Why not bring it up to NMRA weight?
ricktrains4824 While it does not quite hit NMRA recommended weight
Well, for whatever reason, the manufacturer glued both the roof (normal), and the floor (odd) to the shell....
And, to update -
I have ruled out trucks/Wheelsets as I took those off and replaced with known "good" (never derails) trucks and wheelsets. Still derails...
The trucks and wheelsets from the question car, were placed onto the known good car, and it does not derail. (Still.)
So... More trouble shooting after w*^k tonight.
Try replacing the couplers with longer shanked versions or looser springs.
- Douglas