The series is set in the fictional island of Sodor, located in the Irish Sea. Sodor is depicted as located in Cumbria, near the historical town of Barrow-in-Furness Thomas the Tank Engine is an anthropomorphic steam locomotive, with a design loosely based on the LB&SCR E2 class (1913-1963). Thomas and his associates work at the North Western Railway, the main standard gauge rail network of Sodor. The series focuses on their work relationship.