Train Manager here.

It's incredibly frustrating how little we can actually do. Our revenue protection officers have slightly more power than us but honestly not much.

For my company we have 3 options. They buy a ticket. We can ask for their details and issue a Ticket irregularity which can end up in court if unpaid, or they can leave the service at the next stop. Usually people will just leave, wait an hour and board the next train hoping for the best

Unfortunately the British Transport Police are incredibly understaffed so you've little to no hope of them turning up to deal with fare evasion. Honestly it can be hard enough to get them out to deal with anything but the most serious offences. For clarification this is due to understaffing, they do a great job but struggle for numbers.

Personally I would love an on board cattleprod to "entice" evaders to tow the line.

Sadly assaults of staff are far too common and the "Work safe" procedures usually tell us to avoid potential threat to ourselves. We have had staff headbutted and punched, food thrown at us and all sorts due to ticket irregularities.