Rusty is a Diesel who does maintainence work on the Skarloey Railway.
Rusty is the only diesel engine on the Narrow Gauge railway. He is a very self-assured and dedicated worker with a huge heart. Rusty loves adventure and has a unique two-toned horn. 
Rusty was built by Ruston and Hornsby Ltd. He was bought by Sir Handel Brown direct from the builders in 1957 to assist Sir Handel and Peter Sam. While they handled passengers and goods, Rusty was paired with CME Mr. Ivo Hugh to repair the aging trackbed along the line.
When Sir Handel pretended to be ill, Rusty was asked to assist Peter Sam with the slate trucks and later that day had to perform a rescue operation at the quarry when Peter Sam had his accident on the incline. Following the return of Skarloey, Rusty was put back on maintenance duties, but had an argument with Duncan about taking care on a "bad bit" of track south of Cros-ny-Cuirn.
Rusty is usually helpful and kind, but initially refused to help Duncan after he derailed. In the newer television series, he is occasionally impatient, careless, and prone to procrastination.
BasisEditRusty is based on the Talyllyn Railway's Midlander.
- A major continuity error occurred in the original American broadcasts of the 9th season, where Rusty was referred to as female by Michael Brandon. While Rusty was clearly slated as being male in the original books, not once in the television series had he been referred to in gender-specific terms until then. Nonetheless, the two episodes that contained this error, Tuneful Toots and Duncan and the Old Mine, were edited for their DVD releases, now identifying Rusty as male.
- Rusty is actually named after his makers, Ruston and Hornsby, not his orange colour.
- When the narrow gauge engines recieved large scale models in the 5th season, Rusty's face became larger.