Sigrid of Arlesdale

Sigrid of Arlesdale is a diesel working on the Arlesdale Railway who has not appeared in The Railway Series books, but is mentioned in The Island of Sodor: Its People, History and Railways. She is painted a two-tone blue livery.

She has however been seen on the Ravenglass and Eskdale Railway: her real-life counterpart, Shelagh of Eskdale, is now dressed up with a face to represent her at "Day out with Thomas" events, whereas formerly they named her "BoCoBo", after the locomotive's wheel arrangement. Not much is known about her.