Hey guys my subject tells the story but I think you should hear the details.
The coal cars in question are Athearn RTR 4 bay coal cars with loads that came in a 6 pack. Now I have checked the wheels for guage and they are all good. Trucks turn free and the wheels roll freely. The wheels are metal BTW. I thought this may be trackwork because one car derails right at a joint the other shortly after but only one direction. They also will derail on a switch going the other way. These 2 coal cars are the only cars in my fleet of about 80 cars that derail on my layout and I checked the joint that the one car derails on and it too is smooth and in guage. I did notice that the wheels seem to roll right over the top of the rail at all locations.
I have tried changing the cars direction, turning the truck 180d, no joy. I am stumped here and want to try fixing this before going out and buying a set of new trucks. Tho I am thinking that that may be my only solution. Does anyone here have any Ideas that I am missing? Also I have run into a similar problem with my 6 axle Athearn locos and that is caused by the wheel not being allowed to slide back and forth enough. Could this be the cause of my coas car derilments as well?
I had a similar problem with my Kato locos and coal cars (N scale). Basically the curvature on the track was too great and since the loco coupler was mounted to the shell as opposed to the trucks, it forced the first car to derail around the corner. So I went to a long shank coupler on the loco.
Hope this helps.
Peter
We have a club member who purchased 4 sets of the Athearn RTR coal hoppers decorated for the Burlington Route and they continually derail. We have checked wheel gauge and coupler height, adjusted the coupler trip pin, and done everything we can think of and these cars simply will not stay on the track – even on straght sections they derail. No one in the club has a similar problem with anything.
Coal cars tend to derail the most because they are light weight. I took a bunch of A-line weights, painted them black, and put them in the bottom of each hopper. The increase in weight vanquished many of my derailments.
Dragenrider is probably right. You said you have loads, so you could probably put whatever is heavy and lying around the house and your problem will (hopefully) be fixed.
I will try adding more weight to these cars. Also they are pretty heavy with the loads in them they weigh more than my Walthers RD4 coal hoppers that never derail.
Yes they even derail on straight sections of track.
I dont think the coupler is causing the derailments These cars derail on 18 and also on 22 in curves and sometimes even on a straight section.
Out of my set of 6 there are only 2 that derail comstantly. The others seem to be fine at least on my home layout.
Thanks for the suggestions if any one else has any I would love to hear them.
If the cars derail on straight track you almost certainly have a wheel dragging on the underframe. Even when these cars were kits they had that problem. The wheel hits on the end with the brake gear. Many people jack the car up with a washer, but I usually carve away at the platform under the brake gear.
ATHEARN has had QC problems. NEM TRUCKS; .088 fine line wheels; have sneaked into production. Example Atlas code 100 flextrack is slightly wide which causes slimmer ‘88’ wheels to mistrack. RP22 wheels are wider and do fine.
THE USUAL things to check:
Wheels in gauge?
Trackwork in guage? (Pre-fabTurnouts are notoriously out of gauge).
Trucks turn freely? Do they have up and down play?
Do cars derail individually, or only when coupled? Coupler problem?
Cars weight evenly distributed? NMRA recommended?
Wheels turn freely when spun?
(MY GUESS is it’s a combination of any of the above).
SHORTCUT: This will probably correct your problems
1.substitute a set of KATO trucks ($4)
2.bring to NMRA wt. (1 oz per car + 1/2 oz per inch).
… but it won’t tell you WHAT was the cause of the as-is car’s “wheels not conforming to the track”.
Sounds like you have covered the bases in trying to solve this mystery. I would look into a twisted truck frames, distorted or twisted frame or cocked bolsters. Even though the trucks move freely, if they are not on the same plain, the slightest variation in trackwork could cause a derailment. I first realized this with Roundhouse, diecast frames. If the frame was bent or bolster(screws) treaded cocked a car could derail even with what I thought was plenty of truck swivel and side play. Hold the car upsidedown and sight the wheelsets. Rock the trucks to see if there is any misalignment. Other than that of what has been already mentioned, the mystery may continue.
Bob K.
I had derailments with my small, red, ore cars until I put about 3 oz of weight in each, near the bottom to keep the centre of gravity low. That improved things greatly. I would add weight before I did anything else.
Set cars on a glass or other dead flat surface and make sure all wheels are making good contact. I suspect the truck mounting screw is too tight or the hole is too small, but there is a slim chance the frame or bolster is out of plumb. Trucks need a little freedom of movement up and down and twisting too, as well as turning. Trackwork is never going to be perfect, and there is no suspension.
Before you swap everything. I had a similar problem and the problem turned out to be wheel alignment. Although the wheels were in gauge, they were NOT aligned in the truck. This was because the wheels were not aligned with each other in the truck. Make sure that when you adjust the gauge, that the wheels are aligned with each other. If the wheels are farther from the end of the axle on a pair of mated axles, it causes the truck to sit cockeyed in the plane parallel to the rails. Ever follow a vehicle down the road and you notice that you can see the whole side of it? That’s because the frame is bent and it causes the vehicle to appear to be rolling diagonally down the road. It’s called ‘dog tracking’. Watch bigger dogs walk down the street, and it’s like the back feet are walking faster than the front ones, make the dog walk diagonally.
After checking your wheelsets for being in gauge, they should line up as shown below.
<=========> <=========>
<=========> <=========>
correct Incorrect
If you notice, that, although the wheels have the same spacing, meaning that they are in gauge, they are not aligned in the same plane as the rails. This creates side pressure on the trucks, which will pu***he wheels off-center. This is especially critical with wheelsets that match RP25 profile, as their smaller flanges will find any defect in the track. If they have the mongo-giganto flanges like IHC uses, they will probably pass.
I use lead shot for weight in hoppers and gons. Turn the car over, bottom side up, and put the shot in areas where it won’t show from the sides. Flood the shot with white glue, let dry, then try it, after doing what the other guys have suggested for the trucks and wheels. Hoppers are light on their feet when they come from the box. [:D]
I am not sure if this would be the case, but I have found the problem on 2 of my cars. The axles are “twisted” in the trucks. If you turn it over and look at the axles all on one plane, say flipping it over and looking to the bottom of the car lining up all the axles as if stareing down a rifle barrel, make sure they are all flat.
I had two that gave me fits and I finally figured out that on axle was “high”, allowing[V] it to float off the rail. Good luck.
Invert the car, pu***he left, or right, wheels hard into their side of the trucks so that the axles are fully seated at their rotating ends (the points), and look from the end of the car, held at eye level, to see if one of the wheels is closer to the truck body than the other.
Have you tried swapping trucks from another athearn car to see if that’s wher the problem is? If it’s a loaded hopper, some extra weight in bottom of hopper won’t hurt, split shot sinkers work also.