Crosby Tunnel is a tunnel that is located west of Crosby.
It was opened in 1912 after the agreement made in that year to amalgamate the Tidmouth, Knapford and Elsbridge Railway (TK&E) to form the Tidmouth, Wellsworth and Suddery Railway. It became double track in 1915 for the opening of the NWR. Thomas once passed Gordon there when he was going super fast with the Jet Engine.
It appeared in Edward the Blue Engine, when Knapford was located south of the river. It later appeared during the books written by Christopher Awdry, but the tunnel appearing there was an error by the artist, as Knapford was already north of the river after the Knapford Harbour improvement scheme in 1956. In the television series, it appeared in the sixth and tenth seasons, before returning in the twentieth season episode, Letters to Santa.
- When the tunnel returned in the tenth season, the walls were removed and the tracks are curved. In the twentieth season, the tunnel loses its border on the outside.