Rusty is a small diesel engine that works on the Skarloey Railway. He is based on the Midlander on the Talyllyn Railway in Wales. Rusty is painted orange with yellow and black details.
Rusty is a trusty, tame, friendly little diesel. He is a dedicated worker, often maintaining the line, while understanding and respecting the importance of his duties. He also has a rather distinctive two-tone horn. Rusty is quick to remind others with regards to proper conduct, particularly Duncan, who was initially very suspicious of the little diesel.