The South Devon Railway Company built and operated the railway from Exeter to Plymouth and Torquay in Devon, England. It was a broad gauge railway built by Isambard Kingdom Brunel.
The line had to traverse difficult hilly terrain, and the company adopted the atmospheric system in which trains were drawn by a piston in a tube laid between the rails, a vacuum being created by stationary engines. The revolutionary system proved to have insuperable technical difficulties and was abandoned. The line continued as a conventional locomotive railway. The company promoted a number of branches, through the medium of nominally independent companies.
Its original main line between Exeter and Plymouth remains in use today as an important part of the main line between London and Plymouth.
Chronology
1844 South Devon Railway Act passed by Parliament
1846 opened to Newton Abbot
1847 opened to Totnes, atmospheric trains start running
1848 atmospheric trains withdrawn, Torquay branch opened
1849 line completed to Plymouth
1876 amalgamated with the Great Western Railway
Origins
First proposals
First thoughts of a railway connecting Plymouth to Exeter were discussed from 1826, but the first definite proposal came when a meeting of potential promoters in 1840 resolved to build a direct route between the cities. They chose the direct route over two suggested longer routes, which were similar to the Teignmouth and Okehampton routes that were actually built later. Their preferred line was to be 37 miles (60 km) long, climbing to 1,190 feet (363 m) and would pass through very sparsely inhabited terrain; there were to be three rope-worked inclines and two long tunnels, and the construction cost was to be £770,781. This ambitious scheme was presented to Parliament as a Bill on 29 February 1840, but got no further there. Its supporters continued to argue in its favour, but the more practical scheme via Newton soon gained favour.
The failure of this scheme did not suppress the enthusiasm in Plymouth for a railway, and this was heightened as the Bristol and Exeter Railway (B&ER) was constructing its broad gauge line. The Great Western Railway (GWR) and the B&ER were working in close harmony, and were known as the Associated Companies, forming a powerful broad gauge interest in railways. Supporters of what soon became the Plymouth, Devonport and Exeter Railway Company saw that financial support might be available from the Associated Companies, and so it proved, subject to substantial capital (£500,000) being raised locally as well, and that any chosen alignment in Plymouth would be suitable for later extension into Cornwall.
The choice of terminal in Plymouth was a fine point, for the "Three Towns" of Plymouth, Devonport and Stonehouse were independent and fiercely jealous of one another. With Isambard Kingdom Brunel now advising the promoters, a terminal at a neutral location at Eldad was selected. Located away from the centre of any of the Three Towns, it was mocked as being "No Place"; a public house of that name at 353 North Road West on Eldad Hill was extant until recently, and Gregory speculates that it was built in anticipation of the South Devon's Eldad terminus.
A prospectus was issued proposing the line, which with some detail changes, was similar to that actually operating today; the B&ER station at Exeter (St Davids) would be used, and the western terminal would be Eldad, with a branch to the harbour at Millbay. The company's name was changed to the South Devon Railway and a Parliamentary Bill was submitted in the 1844 session; with little opposition, it obtained its authorising Act on 4 July 1844. Share capital was to be £1,100,000 and the Associated Companies agree to subscribe, in the sums of:
Great Western Railway: £150,000
Bristol and Exeter Railway: £200,000
Bristol and Gloucester Railway: £50,000.
The atmospheric system adopted
Although the route was to follow the coast from Exeter to Newton (later called Newton Abbot), from there to Plymouth it would need to run over difficult hilly terrain, and gradients and curvature were challenging. Brunel had planned the route as a double-track locomotive railway, and as late as May 1844 he stated, in reference to the atmospheric system, "I have not been called upon to recommend it or not".