The station was enlarged during the 1870s and in 1880 received trains from the Midland Railway following the commissioning of a south-to-east direct curve to the Furness and Midland Joint Railway that created a triangular junction. The L&CR was taken over by the London and North Western Railway (LNWR). Carnforth Station was operated under a joint management by the Furness and LNWR compnies - the Midland having Running Powers into the station. Station personnel wore a uniform with the initials CJS for Carnforth: Joint Station. The Furness Railway erected a distinctive stone-built signal box to the north-west of the station in 1882, used until 1903, and this survives preserved as a listed building.