Den and Dart
First Appearance Thomas Helps Out (cameo)
Basis Den: Rolls Royce Sentinel Diesel-Hydraulic 0-4-0

Dart: 4w Diesel-hydraulic shunter

Livery Den: Dark blue and orange with cream lining

Dart: Yellow and red with white lining

Voice Actor Den: SodorsNWRSteam

Dart: ThomasWoodenEpisodes

Den and Dart are two fiesty and intelligent diesels who work at the Sodor Dieselworks.


Den and Dart were bought by P.T. Boomer to work at the Vicarstown Dieselworks. After the Vicarstown Dieselworks were bought by the North Western Railway and became the Sodor Dieselworks, Den and Dart transferred over to Sodor and started work on the North Western Railway.

Den and Dart helped search for the culprit during the Pirate fiasco. 

Den and Dart helped shuttle materials back and forth during the Narrow Gauge Expansion Project.

Den and Dart currently do odd jobs around the Island of Sodor, but mostly work at the Dieselworks. They have a running feud with James. The two are very loyal to Diesel 10.


Den is stately and deeply thoughtful. He often overthinks things, and tends to worry about things more than he should. Den is a hard worker and is well respected among the diesels for this. Den is not devious per se, but he is often roped into schemes by his fellow diesels.

In some ways, Dart is the opposite of Den. Dart is very intelligent, but is quite impulsive and can be arrogant at times. He does not listen to anyone other than Den, P.T. Boomer, Norman, and Diesel 10. Dart is not extremely devious, but can be grumpy, gruff, irritable, and cheeky. However, despite not being the most devious diesel, he is more than happy to cause trouble for the steamies.