In 1844 Cheam was on the planned route for the London to Portsmouth atmospheric railway. The section of line between Croydon and Epsom was part of the London & Croydon Railway, who promoted the Clegg and Samuda atmospheric principle. The project failed, and Cheam station became part of the London Brighton & South Coast Railway in 1847. Pumping stations were built at Portland Road, Croydon and Dartmouth Arms. The latter station was opened by the original L&CR on 5 June 1839, and named after the local inn; it is still open, but is now called Forest Hill station.