Sidney is a diesel engine who works on the Island of Sodor.
Not much is known about Sidney's past (he has probably forgotten most of it). He arrived sometime prior to 2010. At some point, he needed new wheels and went the Dieselworks, but for some reason it took years to repair him. It is unknown what was done with him during the fire as he clearly survived it. He eventually gained his new wheels in Christmas 2013.
Sidney's model is a reskin of a BR Class 08 by donaldthescottishtwin (DTST).
- Painful Memories (cameo)
Sidney was also supposed to appear in one of the Original Pilots.
Sidney's model was used in Smuggling from Scotland as a diesel pulling trucks, but is not intended to be him.
Sidney first appeared in the 2011 Thomas and Friends special Day of the Diesels, though it was a small cameo. He wouldn't appear again until the Season 17 episode The Missing Christmas Decorations. He was voiced by Kerry Shale in both the American and British dubs of Day of the Diesels while Bob Golding has voiced him since season 17. He then appeared in seasons 18, 20, and 21