[Weter]

Well, the last thing, I've going to say, would be about uncoupling of automatic couplers.
During trains sorting (marshaling), there is a need for couplers to be uncoupled.

Doing sorting by pushes, locomotive quickly accelerates a set of cars ahead, then brakes hard.
Uncoupled portion of cars continue rolling through prepared path, defined by switches setting, and arrives to defined siding, where brake shoe is waiting for it, being placed on rail's head - for decelerating and stopping cars, where needed.
For this to be possible, ONE of couplers at defined place (between needed cars) have to be set to "on buffer" mode by train master. So, it allows to push, but lets uncoupled portion of cars to coast further,mas the rest of train is still coupled to shunter, so decelerates quickly, when shunter brakes with locomotive brakes.
Then, rest train backs up, beyond the first switch plus acceleration dustance, next portion of cars is uncoupled, shunter pushes the train towards park again...

On humps, train master's assistants usually operate with long T-handled forks, for uncoupling portions of de-forming train on the fly, as it being pushed onto the hump by shunter. They are walking along wooden pavements, parallel to hump track, so it's very hard and dangerous work. They must not mistake, which cars to uncouple too.