I can only speak for the TOC I trained with, but it was around 7 weeks in the classroom for PTS (Personal Track Safety) and Rules (with an exam at the end of each week covering that week's topics), then several weeks at my depot with an instructor building up some hours, then back to the school/yard for traction (around a week per Class of train with exams at the end of each, I had four to learn), then back to depot to finish off the required number of hours driving (just over 200hrs in total).
At the end of the training phase, which typically varied from 8-12 months, it was a week-long final exam which covered a day doing out of course workings in the simulator, a day in the yard coupling/uncoupling/fault finding and prepping each class of train (and again written exams on each), a couple of days driving each class of train over several journeys with the examiner, one trip piloting them over a section of route you'd have covered many times based on your depot and instructor's route knowledge, and a final written rules exam that encompassed the six weeks of rules. After that, you were given your key and sent out road learning, the length of time this took varied on how many routes your depot signed in the roster link you were going into. Some depots would assess you on a route by route basis, while others would get you to learn them all in one go and then do a multiple day assessment on them all at the end. After that, you were finally let loose!
Most of us found the pace just about right, although that was by also being sure to revise at home and going over things with our driving instructors during our hours accumulation as not to lose that knowledge between the rules exams at the school and our 'finals' many months later. With the cost of training, it's not in the company's interests to make process unduly difficult and to have people failing. I think some of those I mentioned failed in part due to thinking once they were out of the classroom then they can just switch off and forget about it, or had perhaps already made preconceptions about the role and weren't prepared to put the level of effort in. And as was said to us many times at school, "The only silly question is the one you put off asking". If you go in with the mindset that you are prepared to learn, work with your classmates on breaks (and I guess these days a Whatsapp group to communicate outside of work to help eachother when going over things), and prepared to keep your knowledge up through revision at home and with your instructor, then you'll find the process a lot easier.
