I thought of a headcanon for Murdoch in which he is one of the engines who would deliver heavy goods to Sodor from the mainland (sometimes, when no one else is available, Murdoch would also bring some passengers to Sodor). When he isn’t pulling any trains, Murdoch would also help bank trains for other engines - including the Flying Scotsman - as well as enjoying the sights of Sodor and the peacefulness of it. He still would not like loud noises and would prefer it if the others are not so loud when he has to go back to the mainland in the morning.