Sidney is a blue diesel engine who lives and works at the Vicarstown Dieselworks. He suffers from short-term memory loss, and as a result is rather forgetful.


Television SeriesEdit

Sidney was brought to the Dieselworks when he had trouble with his wheels, and was suspended up on a hoist inside the main shed. When Percy first came to the Dieselworks, Sidney was one of the diesels that laughed at his joke. (TVS; Day of the Diesels)

Sidney waited a long time for his new wheels, but they never arrived, and two years later he was still waiting for them to arrive. He often jokingly referred to himself as a Christmas decoration, but took this back when Diesel 10 literally used him as one by hanging Christmas tree lights on him. After the Steam Team took their decorations back, Percy asked Sidney how long he had been waiting on the hoist, and was surprised to find out he had waited two years for them to arrive. Percy informed the Fat Controller about this, and as a Christmas present, Sidney was fitted with a new pair of wheels. (TVS; The Missing Christmas Decorations)

Sidney later unwillingly hid from Paxton when Diesel made him and the others hide from Paxton to play a trick on him. This worried Paxton immensely, and when Sidney told Diesel that they had taken it too far, Diesel brushed it off. (TVS; Disappearing Diesels)

Personality and TraitsEdit

Sidney is a rather forgetful engine, and will forget about anything that he is told or does, even if it just happened. Despite his forgetfulness, however, he is incredibly patient and was perfectly content with waiting in the Dieselworks for over two years, as he forgot how long he had even been there. He is also very friendly to the other engines, and never holds a grudge.

Technical DetailsEdit


Sidney is based on the British Rail Class 08 diesel shunter, a widely-produced type of diesel shunter with over eight-hundred engines of this class built. With over sixty members of this class still preserved, the Class 08s are the second most well-preserved class of locomotive in the UK.

It has been suggested that Sidney is based on a Victorian Railway F class, as his livery is relatively similar to one. However, it is unlikely that he is based on the F class, as these were broad gauge engines.


Sidney is painted navy blue with yellow lining. He has yellow hazard stripes painted on his front just under his face, and his bufferbeam and siderods are painted dark red. His cab roof, air vents, ladders and chassis are painted black.


  • It is currently unknown how Sidney managed to survive the fire at the Dieselworks, as since he was on the hoist with no means of escape, he would have surely burned with the building. However, as he was not seen on the hoist in a few scenes, it is likely he was moved to another building at the Dieselworks.
  • Many promotional images of Sidney seem to not show his wheels or siderods.