// Industrial Heritage · Victorian Railway

Meldon
Viaduct

Okehampton, North Dartmoor — wrought iron lattice viaduct, 1874

OS Grid: SX 561 919  ·  Elevation: ~280m ASL  ·  Classification: Listed Structure · Grade II*
▶ Open in Viewer ← Back to Atlas
// Historical Record

Iron Over the West Okement

Meldon Viaduct carries the former London and South Western Railway line across the West Okement river gorge just west of Okehampton — a slender wrought iron lattice structure of remarkable elegance, completed in 1874 and now the most intact Victorian railway viaduct on Dartmoor. It stands approximately 150 feet above the river, carried on five wrought iron trestle piers, and spans 165 metres from abutment to abutment.

The viaduct was designed by William Jacomb, resident engineer for the LSWR extension to Lydford and Launceston. Construction used wrought iron throughout — this was 1874, the cusp of the transition to steel, and Meldon represents one of the later significant uses of wrought iron lattice construction in British railway engineering. A second parallel viaduct was added in 1879 to accommodate double-track working, and the two structures stood side by side until the second was demolished in 1990 when the line closed.

The surviving viaduct is now Grade II* listed and forms part of the Granite Way cycling and walking route across northern Dartmoor. The ironwork retains much of its original fabric, with the characteristic diamond-lattice bracing and the stiffening triangulations of the trestle piers clearly legible.

For Gaussian Splat reconstruction, Meldon is technically the most challenging scene in the archive. The viaduct spans a deep gorge, requiring capture from multiple elevations — below the deck, at deck level, and above — with the river and valley vegetation adding reflective and wind-disturbed surfaces. The payoff is a reconstruction that captures the full three-dimensional lattice structure in a way no photograph can match.

// Site Chronology

Recorded History

1871
LSWR extension authorised — London and South Western Railway gains approval for the Okehampton to Lydford extension. Meldon gorge identified as the critical obstacle.
1874
Viaduct opens — Wrought iron lattice structure completed by William Jacomb. Five trestle piers, 165m span, 46m above the river. Line opens to Lydford.
1879
Second viaduct added — Parallel structure built for double-track working. The two viaducts operate side by side for over a century.
1968
Line closes — Beeching cuts. Okehampton to Bere Alston line closed. Viaduct retained in situ.
1990
Second viaduct demolished — The 1879 parallel structure removed. Original 1874 viaduct survives and is listed Grade II*.
2025
Hylas Spatial survey — 3D Gaussian Splat capture. Multi-level approach: gorge floor, mid-height, deck level, and aerial above. Complete lattice structure reconstructed.