History

Meldon Viaduct, a Scheduled Ancient Monument, is a superb example of Victorian Engineering and is one of only two in the country of this type of construction. Built in 1874 for the London and South Western Railway main line between Waterloo and Plymouth, it was widened to double track in 1878 and closed to trains in the late 1960s.

The widening was achieved by constructing a second viaduct along side the first, using an almost exact copy of the original design. Over the years the two structures have been tied together in an effort to reduce sway when trains crossed the viaduct. The structure underwent a major refurbishment in 1996. Although the trains have long gone it is still a significant landscape feature that it is now available to walkers and cyclists.

Meldon Viaduct – Detailed History

The spindly wrought and cast iron trestle construction Meldon Viaduct was built by the London South Western Railway under the direction of their Consulting Engineer W R Galbraith for the opening of the line between Okehampton and Lydford on the 12th October 1874. It spans the West Okement valley as the line makes it way high around the north western edge of Dartmoor. Its maximum height above the valley is 150ft with a rising gradient of 1 in 77 towards the west on a 30 chain radius curve.

The original viaduct was built for single track but in 1878 the line was doubled by building a second similar viaduct on the down side. The two viaducts were linked by extending the deck construction and bracing between the tops of the trestles, but the lower ends of the trestles were only interlaced. However the exposed position during adverse weather and the forces exerted on the structure by trains traversing the bend resulted in speed and weight restrictions being imposed. In 1938 braces were added between the lower ends of the trestles then in 1944 to allow heavy wartime traffic across the viaduct the outer trestle legs were weighted with additional concrete. The viaduct was further strengthened between 1959 and 1960 by the inner trestle legs also being weighted and the up road trestle bracing being replaced with stronger section members.

The line was singled between Meldon Quarry and Meldon Junction signal boxes (junction for North Cornwall line to Halwill thence Bude/ Padstow /Barnstaple) on the 24th April 1966 and thereafter trains used the recently strengthened original up trestle. When services west of Okehampton were withdrawn on the 6th May 1968 the track on the bridge was for very many years (at least as late as the middle 1980s) used as a locomotive headshunt for the adjacent Meldon Quarry. The down side of the viaduct had a concrete road laid upon it in 1970 and this was used for construction traffic whilst the nearby Meldon Reservoir was built. The track was lifted in 1990 when the structure was judged to be too weak to support the weight of a train. It became a listed building in 1997.

Supplied by kind permission of Paul Rendell, Local Historian and Author