The Works Diesel rescued James after his injector failed, and managed to change James' opinion of diesels with his charismatic persona. He then brought the Christmas tree for Thomas from the Other Railway. In 1986, Donald mentions that there are other diesels at the works. The Works Diesel was later seen talking to Gordon at Barrow-in-Furness in 1992.
Although the Works Diesel has not spoken, he is described as being friendly and is impossible to not like - even James, who retained a hearty dislike of diesels, could not help but befriend him before the two had even reached the Works.
The Works Diesel is based on a BR Class 47 "Brush" Co-Co diesel locomotive. 512 members of this class were built from 1962 to 1968. 32 of these engines are preserved, while another 30 are still used on the national railway network.
The Works Diesel is painted in the British Railways' Rail Blue with yellow warning panels. He lacks the BR logo and has a indiscernible number painted on his sides in white.
- Really Useful Engines - Triple-Header (indirectly mentioned)
- James and the Diesel Engines - Deep Freeze (does not speak)
- Gordon the High-Speed Engine - High-Speed Gordon (mentioned)
- Henry and the Express - Out of Puff (cameo)
- Thomas and the Missing Christmas Tree (does not speak)