Bridges and viaducts › Glenfinnan Viaduct

Glenfinnan Viaduct

The curved concrete viaduct at Glenfinnan on the West Highland Line, opened in 1901: 21 semicircular arches of 50 ft (15 m), 1,248 ft (380 m) long and 100 ft (30 m) above the River Finnan.

Opened
1 April 1901 (the Mallaig Extension; built 1897-98)
Line
West Highland Line (Fort William to Mallaig)
Kind
Concrete arches (mass concrete)
Length
1,248 ft (380 m)
Arches
21 semicircular, each 50 ft (15 m)
Height
Up to 100 ft (30 m) above the River Finnan
Width
18 ft (5.5 m) between the parapets
Train drawn
ScotRail Class 156

unverified Some of these figures haven’t yet been checked against an official source or a published history. What’s in doubt ↓

Glenfinnan Viaduct, schematic side elevation at 1 px a metre, with a ScotRail Class 156 crossing
A ScotRail Class 156 crossing. Schematic side elevation at 1 px a metre, a tenth of the scale of the train drawings: proportions from the published figures, details simplified.

Four times larger

Glenfinnan Viaduct, schematic side elevation at 4 px a metre, with a ScotRail Class 156 crossing
A ScotRail Class 156 crossing. Schematic side elevation at 4 px a metre: proportions from the published figures, details simplified. Scroll sideways to see it all.

Close up

At 10 px a metre, the scale of the train drawings, so the train is the size it is on its own page. Each is cut from the same drawing.

Glenfinnan Viaduct, close-up: The west (Mallaig) end, the higher one.
The west (Mallaig) end, the higher one.
Glenfinnan Viaduct, close-up: Thick pier 8 and the tallest piers, 9 and 10, over the River Finnan.
Thick pier 8 and the tallest piers, 9 and 10, over the River Finnan.
Glenfinnan Viaduct, close-up: A ScotRail Class 156 behind the parapet, on the gradient.
A ScotRail Class 156 behind the parapet, on the gradient.

Sources

How we source figures →  ·  Spotted a mistake? Tell us → (opens in a new tab)

Show the 15 sources from Historic Environment Scotland, Highland Historic Environment Record, Wikipedia and 12 more
  • Glenfinnan Viaduct (listed building LB310, Category A) Historic Environment Scotland, read 8 November 2026opened 1901; 21-arched concrete viaduct on a curve; 'thicker pylons flank centre portion of continuous semi-circular arch rings'; 416 yd; Scotland's longest concrete viaduct
  • Glenfinnan Viaduct (MHG17226, from the National Monuments Record of Scotland record) Highland Historic Environment Record, read 8 November 202621-span curved viaduct, 1,248 ft (380.5 m), 21 semicircular arches, concrete pylon construction
  • Glenfinnan Viaduct Wikipedia, read 8 November 202621 semicircular spans of 50 ft; 100 ft above the River Finnan; 18 ft between parapets; a 792 ft curve; built 1897-98; Simpson & Wilson, Robert McAlpine & Sons
  • Passion for construction bridges the centuries Sir Robert McAlpine, 17 June 20241,250 ft; 21 arches of 50 ft; an 800 ft radius; the piers tapered in plan for the curve; two hollow 'stop' piers
  • Glenfinnan Viaduct (location page and photograph captions) Railscot, read 8 November 2026piers 8 and 13 more substantial than the others; the piers taper to keep 50 ft spans on both sides of the 12-chain curve; 1 in 50 from the viaduct to the station; 1 in 60 up to the viaduct
  • Glenfinnan Viaduct (Canmore site 22436) Canmore, Historic Environment Scotlandthe two 'king' piers are hollow
  • OpenStreetMap OpenStreetMap contributors (ODbL), read 8 November 2026length 1,249 ft (380.7 m; 1,249 ft); curve radius 810 ft (247 m; 12.3 chains, a circle fitted to the way); the river 544 ft (165.8 m) from the west end; maxspeed 30 mph (48 km/h)
  • EU-DEM v1.1 (25 m) digital elevation model, served by OpenTopoData European Union Copernicus programme (EU-DEM), via OpenTopoData, read 8-9 November 2026the ground's profile along the viaduct
  • Glenfinnan Viaduct (photograph, long lens) Neil Aitkenhead, via Wikimedia Commons, 2010long-lens view of the whole south face: the arch count, the thick piers 8 and 13 and their widths, the pilasters on the odd piers, the piers' batter, the crown and parapet; the drawing's overlay
  • Glenfinnan Viaduct (photograph) Chris Morgan, via Wikimedia Commons (geograph.org.uk), 2021the south face from the viewpoint: the thick piers 8 and 13, the pilasters' places, the colours (sunlit)
  • Glenfinnan Viaduct 1 (photograph) Daniel Kraft, via Wikimedia Commons, 2021arches 16-21 from the river bank, level: normal pier width, no batter, crown, ring, parapet, pilasters on piers 17 and 19, the east abutment
  • Glenfinnan Viaduct (photograph) Michael Garlick, via Wikimedia Commons (geograph.org.uk), 2026the east half from the valley floor, sunlit: the pilasters on piers 13-19 and their width, the crown and parapet, the colours
  • Arches of Glenfinnan Viaduct (photograph) Jim Smillie, via Wikimedia Commons (geograph.org.uk), 2022close from below: pilasters on alternate piers rising to the coping, normal pier width, no impost band
  • Glenfinnan Viaduct (photograph, panorama) Liam Drew, via Wikimedia Commons (geograph.org.uk), 2013a pilaster close: its cap at the deck joint and its block level with the coping; no string course
  • Glenfinnan Viaduct, Glenfinnan, United Kingdom (photograph from Unsplash) Thomas Tucker, via Wikimedia Commons, 2016the curve from the viewpoint hill (above rail level): not measured
unverified
  • The ground under each pier comes from the EU-DEM (82 ft (25 m), smoothed) hung from the formation, put 100 ft above the valley floor at the river. On the photographs the piers east of the centre stand shorter than the DEM gives (piers 15-19 by about 10-25 ft on Aitkenhead's and Kraft's photographs, the same fall on Morgan's), and the west piers by about 5-14 ft; the feet may be hidden by bracken and humps, so the ground is left as the DEM gives it until Kyle says otherwise. The river's channel is not in the DEM; its width (30 ft) is an estimate.
  • The abutments' 22 ft 6 in each is what the published 1,248 ft leaves after the measured piers; on the photographs both ends run into trees and the embankments (at least 16-21 ft of wall shows beyond the last arch at the east end).
  • The formation is put at the joint line where the white leaching starts on the face, 5 ft below the coping's top (Kraft 4.9 and 6.3, Garlick 4.3, Aitkenhead 5.2); the deck itself can't be seen from outside. There is no projecting string course on any photograph: the 0.3 ft band drawn is that joint.
  • Pier 1's pilaster is drawn by the pattern (pilasters on every odd pier, 3 to 19, on the photographs); pier 1 is hidden by trees on all seven. Each pilaster has a small moulded cap at about the deck joint, left off at these scales.
  • The gradient: 1 in 50 rising west, from photograph captions (Railscot: '1 in 50 between Glenfinnan Viaduct and the station', and '1 in 60 up to Glenfinnan Viaduct' from the east); where the change falls is not known. The DEM's end heights agree with a rise to the west; the photographs can't show it (the curve and the camera heights hide it).
  • The embankments' end slopes (1 in 1.5) are estimates: both ends are in trees on every photograph.
  • The line speed, 30 mph (48 km/h), is OpenStreetMap's maxspeed on the viaduct; no Network Rail document was found.
  • One stone colour is drawn for the whole face (the median of the lit face); on the photographs the pier faces read paler (#959591) than the spandrels (#5F6164 to #7D7E80), and the parapet darker.

Know a source for one of these? Send it to us → (opens in a new tab)

Top