|First Appearance|| Thomas Helps Out (Cameo)
Culdee Crosses the Border (First Full Appearance)
|Basis||BR Class 46 "Peak" 1 Co-Co1|
|Livery||Blue with yellow warning panels and a gray roof|
|Voice Actor|| NWRWS01
D199 was built to shunt and pull freight trains, as well as pull passenger trains, on the Other Railway. He worked closely with his friends D261 and Diesel 10. The two eventually became Diesel 10's right hand men in causing mischief and trouble around the railway.
After Culdee and Hiro unknowingly entered the railway and later escaped after taking some of their secrets, Diesels 199 and 261 gave chase, but ended up stranded on Sodor. Sir Topham Hatt sentenced them to the Sodor Dieselworks under the jurisdiction of P.T. Boomer. When Diesel 10 and his new right-hand men, Splatter and Dodge were brought to Sodor, they were reunited and once again started causing havoc around Sodor.
D199 currently works at the Sodor Dieselworks under P.T. Boomer and works closely with Diesel 10, Diesel 261, Splatter, and Dodge, causing mischief whenever they can. The engines mostly sulk around in the Ironworks and rey to avoid work as much as they can..
D199 is pompous, rude, and arrogant. He, like many other diesels, believes that diesels are better than steam engines. He is not a very hard worker and enjoys causing trouble around Sodor.