Spey Viaduct

Official Heritage Listing Information and Findings

Listed At: Category B

Discussion:

Historic Environment Scotland Number: LB14873

Canmore ID: 16961

Site Number: NJ36SW 20

Description
Blaikie Bros, 1886. Iron girder railway bridge, 350 foot bowed central truss and, on each side, 3 x 100 foot plain truss approach spans carried on circular ashlar piers with granite capitals.

Statement of Special Interest
Built for the Great North of Scotland Railway. Great length of this viaduct caused by wandering nature of River Spey. Bridge now part of Moray District Speyside Walk.

Canmore Notes:

Built by Blaikie Bros, Aberdeen, in 1886 for the Great North of Scotland Railway between Elgin and the Banffshire coast, to a design by Patrick Barnett, this is an awe-inspiring iron structure thrust between river and sky.

Its great length (290m overall) was determined by the Spey's habit of periodically changing channels in the broad level plain near its mouth. The solution was to build a great bowed central truss, 106.6m long and 13m high, with three 30.5m plain truss approach spans on either side, all supported on circular ashlar piers with granite capitals. When completed the bridge was tested with a load of 400 tons of gravel in 20 trucks; the bridge deflected by 29mm.

Now part of the Speyside Way from Spey Bay to Ballindall och, the walker on the bridge can fully appreciate the confidence of Victorian engineering in erecting this cathedral of grey girders and trusses that arch above the ceaseless, turbid Spey.

This viaduct, built from 1883-86, was constructed to carry the Moray Coast Railway, part of the Great North of Scotland Railway, over the Spey and its floodplain 1 mile south of the coast. The river crossing was initially conceived as three separate bridges spanning the disparate channels, but it was decided to divert the river into a single channel to be crossed on a viaduct with embankment approaches.

The viaduct, 950 ft long, was built to carry a single-track railway. It has an impressive 350 ft long wrought-iron lattice bow girder span over the main channel of the river and three parallel-sided wrought-iron lattice girder approach spans of 100 ft at either end. The lattice members of the main arch, 41 ft deep at mid-span, rise from open box girders at each side of the deck. Cast-iron caissons filled with concrete form the piers of the viaduct. These were sunk to bedrock at depths of 25-35 ft except for the piers at the west end of the central span where it was necessary to sink them to a depth of 75 ft.

The viaduct, erected on a forest of staging, was designed by Blyth and Cunningham and Patrick Barnett, and the contractors for the ironwork of the superstructure were Blaikie Bros., Aberdeen. The contractor for the foundations and masonry was John Fyfe & Co., Kemnay.

At the time of construction, the main channel of the Spey ran to the east of the viaduct, and much of the construction work and work on the concrete spine wall to control the direction of the river was done in the dry. On completion of the bridge the river was diverted beneath the central span.