Carla is a ALCO RSD-4 built in 1946 for the Dock Railway. She's a tomboy, meaning she's idolizes her brother, Carl. Despite that, she's good for both switching jobs and pulling local freights. She has since gone under several engine replacements, the most recent being in 2013. She still works today.
She can be feisty at some times, but she is a great locomotive.
Carla is based on a ALCO RSD-4.