Calley is a small shunting engine who is Dunbar's and Jackman's assistant as well as the rescue chugger.
Calley has her own set of service cars to perform her many different tasks. For example, with a fuel car attached behind her, she is able to refuel the chuggers. In the event of a fire, she has a fire service car with hoses to put out the flames. And if a chugger ever breaks down, then Calley is also the rescue chugger She loves to use her flashing yellow warning lights when she's out on an emergency. Below Calley's Underground Shed is an underground chamber containing all her rolling stocks. In the event of an emergency, she is lowered underground to a turntable, so that she can quickly hook up to her rolling stock, before shooting off through a network of tunnels that take her under the city.
Calley is loosely based on a Krauss-Maffei ML 500 C diesel hydraulic shunter which were built in Germany.
- Calley is the only diesel engine with buffers.
- She's like a big sister to the Trainees
- She is one of two of the smallest heavy hauling engines in Chuggington. (the other is Hodge)
- In the Interactive version, Calley only has herself in a cuboid shape and a rescue car.
- She is the only diesel chugger with siderods on her wheels.
- She is Dunbar's assistant and helps the trainees with earning their badges or just with everyday jobs.
- To interact with the Chug Patrol, Calley was painted like Jackman, and she recived more flashing lights and a louder siren.