South Devon Railway Company

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.

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.

[note 1] 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.

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".

The tube is slotted at the top to enable the piston bracket to pass, and a continuous leather seal prevents unwanted admission of air.

The system appeared to be a solution to the difficulties: greater traction was possible, not relying on steel wheel adhesion, and avoiding the necessity to carry the weight of a locomotive and its fuel over the steep gradients.

It was asserted that only a single line (instead of double track) would be needed to work the traffic by the atmospheric system, and that steeper gradients and sharper curves were feasible compared with locomotive operation, saving construction costs.

[2] Gregory records that: "The Chairman [Thomas Gill] admitted that at first he thought it unwise to use it, believing that it was unsuited to the particular circumstances of this neighbourhood, but after witnessing what he did on the Dublin & Dalkey Railway his prejudices were entirely removed.

This alone involved a vast rock cutting operation by blasting, as well as six tunnels and two "covered ways",[note 2] and extensive sea wall protection.

[12] Sekon records that, "The first experiment of the atmospheric system on the South Devon line was made on 26th February 1847, when a train of two carriages went from Exeter to Turf and back, upon which occasion Mr Brunel said everything gave him full satisfaction.

"On 17th December ... some service trains were worked for the first time by this method as far as Newton ... and on 23rd February [1848] the changeover [to full atmospheric operation] was complete.

Concerned about the tractive capacity, Brunel had substituted a 15-inch (380 mm) tube, and "the machinery was clearly being heavily taxed even on the level section for all but the lightest trains.

[18] Operating costs were substantially higher than promised; this was particularly the case for fuel for the stationary engines, and daily attention to the tubes and the sealing flap.

At some stations an 8-inch (203 mm) auxiliary pipe was provided at the lineside, from which the train could be towed by rope, but in many cases it is likely that horses were used for shunting and marshalling, and human power to move individual vehicles.

An automatic release mechanism used the air pressure ahead of the piston after it had passed the main pipe to the engine house, to open the valve.

The alarming news was revived that on 4 May 1847 the London and Croydon Railway had decided to abandon the atmospheric system on their line, due to insuperable technical problems.

Promoted by a deputation the previous day led by George Hudson,[note 10] the doubts resulted in a resolution to delay expenditure west of Totnes until after the next meeting.

In fact the decision was to suspend until Samuda put the system into working order, but it was obvious he was not in a position to do so, and the last atmospheric train was an up goods arriving at Exeter at 12:30 in the small hours of Sunday 10 September 1848.

The Plymouth and Dartmoor Railway (P&DR) crossed the path of the SDR there and ran on alongside the River Plym to wharves near Laira Bridge.

The South Devon Railway Act 1844 included powers to purchase this section of the P&DR, subject to agreeing terms with the owners, but the negotiations were frustratingly slow.

The short section incorporated an exceptional number of engineering structures; at Newton the branch ran alongside the main line for a mile to Aller.

The line opened on 4 July 1866; it was 12 mi (19 km) long and climbed steadily from Newton (Abbot) to Moretonhampstead, gaining 550 ft (170 m) on the journey through Teigngrace and Bovey.

However its main line was single track only with difficult gradients and it had expended its financial resources on the abortive atmospheric system, and very soon rapidly increasing demand became the dominant problem.

In the same period layout improvements were made at the crossing places at Dawlish, Teignmouth and Kingsbridge Road, and at Totnes, this work being completed in 1856, and in August 1856 the Chairman announced that it was not planned to double any further sections of the route.

A further series of capacity improvements took place from 1874 to 1875, when a third track was laid from Newton to Aller, restoring the independent access to the Torquay branch; and Starcross to Dawlish was doubled.

When the Cornwall Railway was nearing completion, the Plymouth station was expanded to accommodate that company's traffic, an apportionment of the capital and running costs being agreed.

Shortly after the amalgamation the London and South Western Railway (LSWR) arrived in Plymouth and a joint station was opened at North Road.

The next section dealt with from Rattery to Hemerdon was more challenging, involving five large new masonry viaducts as well as Marley Tunnel; the double line was opened in stages progressively in 1893, completing on 19 November 1893.

From there the line follows the north bank of the River Plym, passing through a tunnel near Mutley, running to the present-day Plymouth station.

[1][36][37][35] Exeter to Plymouth Torquay branch The company hired locomotives from the Great Western Railway to haul their trains until the atmospheric system was ready for operation.