- "Dizzy diesels!"
- ―Dart's catchphrase
Dart is Den's fiesty assistant who shunts trucks with his friend at Vicarstown.
Dart and Den arrived on Sodor to help out with the shunting work at Vicarstown.
Later, Den and Dart teased James about being cold, despite being twice as cold as anyone else!
Dart then was sent to work at the Kellsthorpe Refinery during its construction, and has continued to work there with Den upon its completion.
Dart is a young diesel that listens to the advice of other engines, even though it isn't always the best decision to make! Besides this, Dart is typically kind-hearted and willing to fix any diesel engine in distress! He is rather proud at times, and doesn't always like to admit his problems.
- Season 1: Lift Bridge, Swagger and Swerves (cameo), Splatter (cameo), Snow Blind (cameo), Shepherd's Pie (cameo), Buffer Bashing (cameo), Scruff's Scaffolding (cameo), Wilbert the Lumberjack (cameo), Rendezvous with Disaster, Will Power, Conspiracy Theory (cameo)
- Season 2: Two Hearts Burn Together (cameo), Scot-free (cameo), Mavis and the Tornado (cameo), James Goes on a Trip (cameo), Rock-Star, Pummeling Percy (cameo), Munitions (cameo), Swan Dive (does not speak), Aura of Menace (cameo), Swashbuckler
- Season 3: Logan Leaves his Mark (cameo)
- Web Clips: Walter Sliggs - Meet the Characters! (does not speak)