Rusty is the only diesel engine on the Skarloey Railway.
Rusty came to Sodor to help out in Rheneas and Skarloey's absence. He quickly became an invaluable member of the team, being uncanny in terms of track repair and Quarry work. Rusty has had a variety of accomplishments and adventures, such as saving Duncan from a collapsing bridge and repairing the Lake Line from closure with the help of Skarloey, Rheneas, and Elizabeth. He also out-manuevered a massive boulder that threatened to flatten every little engine in the valley.