The Sodor and Mainland Railway is a standard gauge railway opened in 1853. It runs from the harbour at Kirk Ronan to Ballahoo via Rolf's Castle and Crovan's Gate, but never reached the mainland due to some misfortunes plus Queen Victoria's difficulty with British Parliament and the Prime Minister, the 4th Earl of Aberdeen. A plan to make a tunnel once was a failure to reach the mainland when some excavations through Ballahoo Ridge collapsed and a scheme to build a bridge across the Walney Channel was stopped by the Admiralty contacting from London (which became a driving force behind the unification of NWR and the completion of a link to the mainland).

In 1910, the Sodor and Mainland Railway's finances collapsed and finally the company joined with the Tidmouth, Wellsworth and Suddery Railway to officially become the NWR in 1914, the year that the First World War had started in Europe. The S&M did at one time try to expand operations to Peel Godred, but this came to nothing with the Mid Sodor Railway operating from 1880 to 1937 and from today electric engines on the Peel Godred branch because the line was now part of the NWR. Only one part of this railway became the NWR's official link to the main line from Tidmouth to Barrow.