Dennis is a lazy diesel engine, and the twin brother of Norman. He is a lazy engine who tries to do whatever he can to weasel his way out of work, even manipulating the other engines into doing his jobs for him.


Thomas & Friends

When Dennis first arrived on the North Western Railway, he was given the job of delivering a train of tiles to Bluff's Cove for the school. However, he struggled to move the trucks by himself, and required help from Thomas, which Thomas was happy to do.

After Thomas left, Dennis stayed in the yard until he returned and asked him the way to the schoolhouse, as he did not want to take the train by himself. When the two engines arrived at the junction to Bluff's Cove, Thomas tried to leave, but Dennis pretended to overheat so that he could help him. Instead, Thomas left to find another engine, much to Dennis' chagrin.

Dennis then decided to leave the trucks on the Main Line and ran away, but went too fast around a bend and derailed, damaging both his engine and fuel tank. When Thomas returned, Dennis was forced to admit his mistakes, and after being re-railed, he and Thomas delivered the tiles to Bluff's Cove. (TVS; Thomas' Day Off)

Dennis was later present at the Quarry when the diesel engines were informed that Thomas had been found after he went missing in Morgan's Mine. (TVS; The Great Discovery)

Personality and Traits

Dennis is lazy, indolent and sluggish, hating to do any kind of work which would require effort. He likes to manipulate the other engines into believing that there is something wrong with him so that they can do his work for him, but his plans rarely succeed, and backfire on him regularly. Dennis will always apologize for his behavior, but whether or not he means it is uncertain.

Technical Details


Dennis is based on No. 11001, an experimental diesel shunter built at Ashford Works in 1949, which has been credited as being the first diesel engine put into service on British Railways. 11001 was in service from 1950 to 1959, when it was withdrawn from service and scrapped at Ashford Works.[1] Norman is also based on this engine.


Dennis is painted in a two-tone grey livery. His cab and the sides of his bonnet are painted light grey, while the rest of him is painted in a darker shade. His bufferbeam and crankshaft are painted red, and he carries his number on his sides in white writing.


Thomas & Friends



  • According to a magazine article, Dennis is said to live at the Vicarstown Dieselworks with the other diesel engines.




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