South Devon Railway

The South Devon Railway (SDR) was a British pre-grouping railway incorporated by Act of Parliament on 4 August 1844 to build an extension of the broad-gauge Great Western Railway from Exeter to Plymouth. Engineered by Brunel, the SDR's most famous and unsuccessful experiment was the use of the atmospheric railway system, in which trains were propelled by the differential air pressure in a continuous pipe between the rails. The atmospheric system worked from 1847 to 1848 between Exeter and Newton Abbot before being abandoned because of corrosion of the leather flap valve, and the line was converted to conventional locomotive traction.

The SDR's curving, steeply-graded line through the South Hams (the so-called 'sea wall' along the Dawlish coast and the South Devon Banks at Dainton, Rattery and Hemerdon) was a particular challenge for its locomotive department. Many of the SDR's celebrated saddle-tank engines were built at Newton Abbot Works, where G. J. Churchward later served his apprenticeship.

The SDR was absorbed into the GWR on 1 February 1876, completing the GWR's monopoly on the West of England broad-gauge mileage. The Dawlish sea wall remains a heavily-photographed and operationally-vulnerable piece of British railway infrastructure today.