Nothing wrong with nitpickery Justin, it's pretty much automatic if you know anything about the topic. I'm not a NCIS fan but I watched it last night because the episode was shot on an aircraft carrier, and without trying to I spotted a dozen or so glaring errors that showed they didn't do very much research.
I suspect the main problem you'll run into is that railroading is a combination of several different studies, physics, mechanics, electronics, pneumatics, so rather than going into any of that in depth the discussions will assume you already know the basics. For example a railroad wants an electrical maintenance worker they would hire an electrician or electronics tech and teach him the control circuits, they wouldn't hire a kid out of high school and start with Ohm's Law and basic electricity. Same with mechanical, they wouldn't want to teach basic diesel engine theory when they could just hire a diesel mechanic who would already know most of what he needs to know to work on a locomotive engine. So the best place to start learning would be diesel mechanics and electronics, whether it's a loco or a diesel submarine the principle will be very similar.