I know it's secondary world and I can handwave all I want, but if I can get a true to life as possible, it always adds credibility to the story.
My characters are executing a train robbery, and stealing the actual cars. I want my characters to uncouple the last 8 or so train cars of a train, while it's moving. I'm not even sure if this is possible - I'm sure it would be dangerous, but that's beside the point. I'm thinking to say it's a janney coupler, since those would have been in use in the real world in that era, but I've googled variations of coupling and uncoupling janney couplers, aar couplers, etc, and there's a number of videos of them coupling and uncoupling, but not from an angle where I can actually see how it works to describe it, let alone figure out if it could be done on a moving train. There seems to be a pin involved, but the videos move too fast to see it in action.
If it's not possible, I can invent an imaginary type of coupler that makes it possible, just want to do due diligence first.