Alice and Mirabel are two Great Western autocoaches pulled by Duck on his branch line. They were rescued from scrap by the Fat Controller, along with Dulcie, and given to Oliver to use on the Little Western.
Around the time of Oliver, Isabel, and Toad's arrival on Sodor, the Fat Controller was in the of re-opening the Little Western line between Tidmouth and Arlesburgh. He assigned Oliver and Duck to the line, but the only coach was Isabel. The Fat Controller was able the rescue three more autocoaches like Isabel. Two of the coaches, Alice and Mirabel, became Duck's coaches while Dulcie JOINED Isabel and Oliver.
Alice and Mirabel are based off Great Western Autocoaches, which were used in push-pull service on branchlines. The autocoaches were efficient because it elimated the need for the engine to run around to the other end of the when it needed to turn around.
Alice and Mirabel are painted in the Great Western's chocolate and cream livery for coaches.
Alice and Mirabel also appeared in the My Thomas Story Library books, Duck and Bulgy They were also recently mentioned in a 2014 magazine file fact featuring Duck. In the television series, they aren't mentioned by name, but are depicted as regular red and cream Express Coaches in the third season.