Duke lived on an unnamed narrow gauge railway with several engines including Stuart, Falcon and briefly Smudger, until the line went bankrupt and Stuart and Falcon were sold. Duke, however, was sheeted until a group of adventurers found his shed, buried under soil that had washed down from the mountains. Skarloey and Rheneas took him back to the Skarloey Railway, where he was soon returned to service.
- Season 1 - Luke and the Special Party
- Season 2 - Don't Be Late!, Duncan's Predicament, Welcome Smudger, and Sir Handel and the Ghost Engine
- Season 3 - Duke's Final Run
- Season 4 - Trapped
- Season 5 - The Fastest Engine in the Hills and Thomas Runs Away
- Season 8 - Materialization
- Season 9 - Icelandic Engines