The Metropolitan Railway (Harrow and Uxbridge Railway) constructed the line between Harrow-on-the-Hill and Uxbridge and commenced services on 4 July 1904 with, initially, Ruislip being the only intermediate stop. At first, services were operated by steam trains, but track electrification was completed in the subsequent months and electric trains began operating on 1 January 1905. The formation was made wide enough at Ruislip to enable another pair of tracks to be constructed as passing loops or additional platform roads. Neither has ever occurred.