Isabel and Dulcie are Oliver's coaches. Isabel came with Oliver when they escaped from the Other Railway, and Dulcie was later rescued by Sir Topham Hatt and given to Oliver to help run The Little Western and are usually pulled by him on the Northern Coastline Railway.

Oliver says Isabel is very clever, as she always keeps a good look out when he pushes his trains and can't see where he's going, and talks to him with her bell. He finds them to be funny coaches, and believes that they would not know what to do without him. Despite what Oliver thinks, they are very faithful to him and are easily able to see when he's headed for trouble.