Emery is the Rapid Transit train often seen on elevated lines or in underground tunnels. He is based on the Urban Transportation Development Corporation Intermediate Capacity Transit System Scarborough RT-type electric train. He likes tricking and harassing other trains into thinking that they have a problem. He is the only engine who carries an additional carriage or truck with him permanently, although in at least two episodes, he disconnects his carriage to go faster.^[12] He often announces his actions with transit announcements. His right eye is green and his left eye is blue.

Old Puffer Pete is the oldest chugger in Chuggington, a steam locomotive who is apparently 150 years old. Pete loves passing his wisdom on to the trainees or anyone who is willing to listen. He drives them mad with his endless stories (which often get him confused), and can never seem to remember the chuggers' names, but they are very fond of him. He works at the central distribution centres for Chuggington: The Drop Load and Freight Yard. He is a cross between Union Pacific No. 119 and a DRG Class 62.

Koko (voiced by Imogen Bailey in the UK and Brigid Harrington in the US), is an electric engine, modelled on the bullet train. She is green and purple, and was built for high speed, being one of the fastest Chuggers in Chuggington. She loves to explore and have adventures, and to challenge her friends to a dare or a race. Although she can get into mischief, she always means well and knows when to apologise.

Emery is the Rapid Transit train often seen on elevated lines or in underground tunnels. He is based on the Urban Transportation Development Corporation Intermediate Capacity Transit System Scarborough RT-type electric train. He likes tricking and harassing other trains into thinking that they have a problem. He is the only engine who carries an additional carriage or truck with him permanently, although in at least two episodes, he disconnects his carriage to go faster. He often announces his actions with transit announcements. His right eye is green and his left eye is blue.

Olwin is an older motherly steam locomotive resembling the British streamlined train LNER Class A4, who refers to the "trainees" as her "little chugg-a-chuggs". Instead of a tender, Olwin's coal is stored just forward of the cab making her a tank locomotive.

Wilson, (voiced by Morgan Overton in the UK in Series 1, 2 and 3, Edward Sharpe in the UK in Series 4 and 5 due to Overton's voice maturing and Tony Terraciano in the US), is a lively red engine based upon an EMD F-unit. His enthusiasm is opposed by his short attention span, and most of his adventures are in Chug Patrol.

Brewster (voiced by Charlie George in the UK in Series 1, 2 and 3, Toby Davies in the UK in Series 4 and 5 due to George's voice maturing and Miles J Harvey in the US) is a strong diesel-electric locomotive built for heavy loads. He is British Railblue with yellow face; Brewster is similar to a BR Deltic diesel engine, but with a single end-cab. He is a member of the Chuggineers, the building team on Chuggington. He likes to haul heavy loads on pick-ups, and often picks up too much load. Other Chuggers may rush when given a task, but Brewster asks questions if he is unsure. He is dependable, respectful and can be relied on when there is trouble.