https://youtu.be/yCcjBMBOXyI
Imagine this going on at a tourist RR or museum, but apparently it happens every day here. I'd heard about how you can see sparks at night in the winter time when this daily local switches there, but I'd never seen it before yesterday.
About 4 cars never got hooked up and one had it's hand brake set before being pushed into this siding.
I'll never think of flat spots on wheels again in the same way.

Putting air on a car will not release a set hand brake. If you're moving cars with or without air all hand brakes on cars that are to be moved must be released.

Needless to say all wheel chocks and skates on cars that are to be moved must also be removed.

Phil Mulligan