I have several log and coal dump cars. When I push the button on the UCS track to dump the coal or logs, the car also uncouples. How do i not get the cars to uncouple?? I believe i have 2 different coal and 2 different log dump cars from different dates. One is a 3459 and 3469. The 3459 uncouples that cars but the 3469 does not. Seems like the 3459 is older than the 3469. I have no idea why it would uncouple. Let me know how i chould fix this problem. thanks.
What you are seeing is normal, however undesirable it may be. The operating mechanism in these cars is connected between the uncoupler shoes. For uncoupling, the controller connects both shoes to the center rail. Each coupler sees track voltage; but the mechanism sees nothing since both shoes are at the same voltage. For operating, the controller connects one shoe to the outside rail and the other to the center rail. The mechanism then sees the full track voltage. One coupler sees zero voltage; and the other coupler sees track voltage. So it uncouples.
The difference between the two models is that the earlier 3459 has electromagnetic (coil) couplers, making it vulnerable to the problem that I described, while the 3469 has magnetic couplers, with no electrical connections, making it immune to the unwanted-uncoupling behavior.
You could replace the 3459’s trucks with the same type as used on the 3469 (and other later operating cars).
I would like to keep it all orginal. Guess I have to couple the cars back together. thanks.