Bertram (nicknamed The Old Warrior) used to work in a series of mines with other "little engines". His fate was unknown to many after the mine's closure, and it was assumed he was left to rust. However, Toby found him whilst watching over the quarry one night, and has since befriended him. He now works at the restored mines, taking passengers to the fairground within.
- Bertram's name is erroneously spelled as Bertrum on his box and tanks.
- His ERTL prototype is a direct repaint of Duke's model, including Duke's face.