On the SJR&P many of our C-19 locomotives have battery packs in the tender for the purpose of DCC backup power. One side effect of this is that the tenders are heavier than stock tenders.
Yesterday the tender of one of our C-19 locomotives kept derailing, a condition we have not seen before.
On close inspection I found that the rear truck side frames were hitting the tender frame interfering with the trucks ability to rotate through curves. While the truck side frames are intended to have some play, the play on this truck was excessive.
On disassembly I found that the single spring that is inside each side frame had collapsed. I replaced these springs with springs Bachmann uses on its 1:20 freight trucks. After replacement the tender truck now operates like new.
This particular C-19 was one of the first to receive a battery pack. Inspection of other C-19s with battery packs showed several that were beginning to have excessive sideframe play but not the extent the problem one had. Each will have its springs replaced as well as a preventive measure.
Below is a photo of the collapsed spring next to a new one.
Stan
Good warning and solution Stan.
What was the additional weight of the batteries? Normally LiIon is pretty light unless you want a mega pack.
Does Bachmann sell springs only?
Did you look at the parts store.
Yes.
As light as the loading on the spring should have been, it does seem odd that it would completely collapse like that. Normally I would just pull that spring back to a longer length and think nothing of it, but it seems that old spring lacks adequate temper!?!?
As Stan runs DCC on the track, i suggested to him that he had had a short thru the springs, causing the lack of temper.
How would that happen? The C19 has plastic trucks on the tender I believe... correct me if I am wrong.