Calley is a small German shunting engine who is Dunbar's and Jackman's assistant as well as the rescue chugger.
Calley is a brave rescue engine who serves as the right-hand "chugger" to Jackman, Chief's Engine to the Crotoonian Fire and Rescue Squad. Brave, motherly, and always out to help others, Calley is always encouraging other engines to do their best, and never to put themselves down whenever things go awry. Calley is often placed in charge of special details when rescues aren't about, such as delivering emergency supplies to stations or shunting equipment in the HQ's Yards.
Calley is loosely based on a Krauss-Maffei ML 500 C diesel hydraulic shunter which were built in Germany.
- She is good at using the Chug Patrol Karts.
- Calley is the only diesel Chugger with buffers and coupling rods.
- She is one of two of the smallest heavy hauling Chuggers in Chuggington (the other being Hodge).
- She is Dunbar's assistant and helps the trainees with earning their badges or just with everyday jobs.
- As of Season 4, Calley is a member of Chug Patrol. She was repainted in Chug Patrol Livery, and received more flashing lights and a louder siren.
- Her role for the seasons were as a teacher, Rescue Chugger and assistant of Chug Patrol.
- Both she and Asher are based on German locomotives.
- In Polish, she is called "Kaja".
- She travels far faster in the television series than her basis is capable of.
- She is currently the only Chuggington character to appear in the series to retain her voice actor.