Meldon Viaduct

A fine example of Victorian engineering prowess

Meldon Viaduct

This is the first of a two-part feature about the two man-made structures built one hundred years apart across the beautiful West Okement valley that runs through Meldon in the north-western fringe of Dartmoor. This piece focuses on Meldon Viaduct, an iconic structure that played a pivotal role in bringing the railway to this part of Devon in the eighteen seventies. The second part examines in some detail the controversy surrounding the decision to build Dartmoor's last reservoir in 1970 by damming the West Okement to create a mile-long artificial lake where there was once a meandering river.

Meldon Viaduct


In the mid 19th Century there were two railway companies contending for the routes from Exeter west to Plymouth and Cornwall: the first comer was Great Western Railway, with Isambard Kingdom Brunel as its celebrated chief engineer. They chose the southern coastal route via Teignmouth and Newton Abbot which was opened as far as Plymouth in 1849 leaving their rivals London and South Western Railways(LSWR) to build and run the route to the north and west of Dartmoor.

A train crosses Meldon Viaduct in the early 20th Century

One of the great challenges facing the LSWR's consultant engineer, W R Galbraith, was to build a viaduct across the deep West Okement valley to the west of Okehampton. The design he chose used frameworks of triangular iron sections known as trusses supported below the level of the viaduct's deck by five wrought iron trestles tapered towards the top, the highest being 120ft from the ground. The first train crossed the single-line viaduct in 1874; the curvature of the track and the exposed location led to the imposition of speed and axle weight restrictions from the outset. In 1878 a second similar viaduct was built alongside and linked to the original to carry the down trains.note1

Closure of the railway beyond Meldon

Following the recommendations of the now infamous 1963 Beeching Reportnote2 on the future shape of the British railway system, through trains between Exeter and Plymouth via Okehampton were withdrawn in May 1968 and the 20 mile section of track from Meldon Viaduct to Bere Alston was lifted. The remaining track was singled and passenger services from Okehampton to Exeter continued until June 1972. The freight service for transportation of material from Meldon Quarry was sustained until operations ceased there in 2011.

Passenger services were given a new lease of life in 1997 with the introduction of a summer Sunday service operated by First Great Western Trains from Exeter to Okehampton targeted at the tourist trade, with the section west of Crediton becoming Dartmoor Railway which was leased to a social enterprise company of the same name. The Heritage Service between Okehampton and Meldon Quarry has been run for several years by the volunteers of the Dartmoor Railway Supporters' Association during the summer on a timetable no longer restricted to Sundays.

The down line track on the viaduct was replaced by a concrete road in 1970 for the conveyance of stone from the quarry to the construction site of the Meldon Dam, though the up line was still in use as a headshunt for trains serving the quarry until the mid 1980s. In 1990 the viaduct was assessed as being no longer strong enough to support a train and the remaining line was removed. The viaduct was refurbished in 1996 prior to it being incorporated into the Dartmoor Way Cycle Route, the Okehampton to Lydford section of which later became The Granite Way.

south side of Meldon Viaduct
South side
north side of Meldon Viaduct
North side

Meldon Viaduct is one of only two wrought and cast iron truss viaducts in the country and is now protected as a Scheduled Monument. The best vantage point from which to view the viaduct in its entirety is from further up the West Okement valley towards Meldon Reservoir:

Meldon Viaduct from near Meldon Reservoir
Meldon Viaduct seen from near Meldon Reservoir.

Looking across the Meldon Gorge from the top of the viaduct one sees the Meldon Reservoir dam, with the hills of the high moor providing a striking backdrop.

Meldon Dam from Meldon Viaduct
Meldon Reservoir dam seen from Meldon Viaduct
Access on foot or bicycle
The Granite Way crossing Meldon Viaduct

There is all-year-round access to the top of Meldon Viaduct by means of The Granite Way, a concrete cycle track and footpath which traverses the viaduct and extends from Okehampton Station to Lydford.

Access by rail

In the summer months a good alternative for the less energetic visitor is to take the Heritage Service train on the two mile journey from Okehampton Station to the viaduct. This short trip, which I took in early August 2014, runs on the last section of track still in place to the west of Okehampton on the original LSWR route from Exeter to Plymouth.

On departing from Okehampton Station, very soon the western fringes of the town disappear from view to be replaced by the dense verdant foliage of the former Okehampton park, the hunting ground of the nobility in Mediaeval times until it was disparked by Henry VIII at the time he ordered the dismantling of much of nearby Okehampton Castle.

Okehampton Station
Okehampton Station
Okehampton Castle seen from the Meldon train
Okehampton Castle seen from the Meldon train
Meldon Quarry
Meldon Quarry workings

In the park's heyday the earldom of Devon was held by successive generations of Courtenays whose main residence was in Tiverton; when the season was right they would bring their entourage west, setting up temporary lodgings in Okehampton Castle from where they could indulge their passion for the chase. As the train pulls out of the woods the castle can be glimpsed in the distance among the trees.

On emerging from a short tunnel the substantial workings of Meldon Quarry are plainly visible on the left. This was opened in 1874, principally to provide ballast for railway tracks but also lump stone for walling and aggregate for concrete. Production continued until May 2011 when the site was mothballed as demand declined. The only viable means of transporting stone from the quarry was by rail, providing a lifeline for the former LSWR track as far as Meldon following closure of passenger services to Okehampton in 1972. The quarry rail sidings and an engine shed are used today by the volunteer workforce of the Dartmoor Railway Supporters' Association as a base for the refurbishment of rolling stock.

Meldon Quarry Halt, early 1960s
Meldon Quarry Halt station

The original station serving the quarry, Meldon Quarry Halt, was opened in the 1920s for the use of railway workers and quarrymen families, many of whom lived in cottages on the site. It didn't appear on railway timetables and trains stopped there by prior arrangement only; it was closed in 1972 when the passenger services ended. As can be seen, the platforms were very narrow. The close proximity of the quarry to the rail lines necessitated certain precautionary measures:

No charges were permitted to be fixed until Meldon Quarry signal box had assured the quarry operator that no train was approaching on the the main line. At times the Meldon Quarry signalman had to erect blast screens over his signal box windows.[1]

Heritage Service train waiting at Meldon Viaduct
The Class 205 unit "Thumper" waiting at Meldon Viaduct station

The quarry halt was replaced by the current station that serves as the terminus for the Heritage Service from Okehampton. It is somewhat further from the viaduct than the halt was, and it has just one wider platform that was renamed Meldon Viaduct in 2014.

A new imperative for reopening the North Dartmoor rail route
Storm damage to the West Country mainline at Dawlish, Feb. 2014

The severe storm damage to the Dawlish section of the main rail line between Exeter and Plymouth in February 2014 forced its closure for several weeks during repair work. In the aftermath of this there was much talk of making the West Country rail link resilient to such extreme weather events. One option that came to the fore was the possible reinstatement of the old LSWR line to the north of Dartmoor. Indeed, BBC news reported at the time that this was Network Rail's preferred option. In considering this option, several threads on railway discussion groups questioned whether Meldon Viaduct in its current condition would be strong enough to support trainsnote3. The Secretary of State for Transport commissioned Network Rail to produce a report to consider in depth the various options. This was published in June 2014; the LSWR line reinstatement was deemed feasible albeit at considerable cost (£870 million including a 66% uplift for contingency, somewhat less if the line was mostly single track). The conclusions based on the report's cost-benefit analysis on re-using this route presented a more lukewarm endorsement of this option than was implied in the BBC piece. In particular, the report remarked that the existing Meldon Viaduct was not currently in a fit state to carry trains and its replication would add appreciably to the estimated cost of reopening the line:

Meldon viaduct, an 165 metre long and 46 metre high listed structure located immediately south of Meldon quarry, is too badly deteriorated for re-use. A new structure would be required, adjacent to the existing viaduct.note4


For a more technical description of the construction of Meldon Viaduct, see Our Transport Heritage [return].
A scan of the original Beeching Report is available in pdf format on the Railways Archive. [return]
Some interesting points regarding Meldon Viaduct in relation to the re-opening the LSWR line as a relief route are given in this thread on [return]
Extracted from the report commissioned by the Secretary of State for Transport, Patrick McLoughlin: West of Exeter Route Resilience Study, Network Rail, Summer 2014 [return]


Devonshire Railways by Colin Maggs, Halsgrove, 2010. [return]