North link and South link, South will learn every way to London (ECML/WCML) plus diversions very extensive route knowledge. Permanent nights (obviously) lodge in London after a UP run say Sunday night, then the DOWn run back home Monday night.
Very little to do between the limited stations calls, as you’ll have an onboard crew who’ll generally do the customer service stuff. It is a role where your with the train until the end, as in if it’s four hours late you’ll be four hours late off duty but obviously 12hrs rest between duties etc.
Last I heard the salary was fairly decent for a guard role, circa £40k.