Duncan means well but will "Rock 'n Roll" whenever the mood takes him. He tends to have a mind of his own which makes him obstinate and rude on occasions. He has a great big heart but is a little misguided. Duncan is now part of Sir Topham Hatt's narrow gauge railway of which he feels he is very overworked.

Duncan first went to the Narrow Gauge Railway to help out when Peter Sam after he'd had an accident