Fergus is a railway traction engine, who works at the Cement Works.
Fergus knows the rulebook off by heart, and his catchphrase is "Do it right!" His insistence on doing everything absolutely according to the rules can annoy the other engines, but he is a decent engine at heart and will not hesitate to help others in trouble.
Fergus is based on the Aveling and Porter 2-2-0 'T9' class railway traction engine No. 9449 "Blue Circle", which is the only one left in the world. Since Fergus' introduction, "Blue Circle" has been dressed up as Fergus on special occasions on its home line, the Battlefield Line in Leicestershire.
Fergus is painted royal blue with gold boiler bands and red wheels.
- Steven Kynman (UK; one-hundredth season onwards)
- Christopher Ragland (US; one-hundredth season onwards)
- Ryōtarō Okiayu (Japan)
- According to the official website, Fergus' flywheel can be used to power tools such as a saw, drill, or pump. It has also powered a generator in the past.
- Fergus has never been seen with a fireman.
- In a SiF interview with Chris Lloyd, it was mentioned that Fergus' model was damaged during the filming of Bill, Ben and Fergus. His model still worked, but the flywheel couldn't turn anymore, nor could he puff steam. This was fixed on his CGI Series model.
- Fergus differs slightly from his basis: his smoke box is larger to accommodate a face. His bufferbeam is also missing a large section for the same reason.
- According to Robert Gauld-Galliers's concept art, Fergus was originally going to have oval shaped buffers.
- Fergus incorrectly has black buffers on many of his promotional artwork.
- When Fergus returned in the one-hundredth season, he gained a few changes, these being:
- Season 100:
- He gained a permanent lamp and tail-lamp.
- His buffers changed from bronze to silver.
- He gained a frame around his coupling hook.
- Season 100: