sidneySidney is a forgetful blue diesel engine who is good friends with Percy. He often takes goods trains to the Mainland. Sidney started life as a shunter on the Mainland, until he unwittingly followed some diesels onto a steamship boundSidney (often shortened to Sid) is an English given name deriving from the surname, itself of two different derivations depending on the orins of the family. In some cases a place name, itself