Blachford Viaduct
near Cornwood, north west of Ivybridge, Devon
Originally built in 1848 to carry the South Devon Railway, and now carrying the Paddington-Penzance line.
See Geograph entry for recent photos and map.
The original viaduct, designed by Isambard Kingdom Brunel and completed in 1848, had thirteen timber spans of 61 ft, supported on slender masonry (rough local granite) piers with a maximum height of 96 ft 6 in. Wrought iron girders were added in 1863.
It was one of five timber viaducts in the area which were strengthened in 1863 and rebuilt as all-masonry viaducts in 1893, when the line was doubled, having been originally built as single track broad gauge. The contractors were S. Pearson and Son, with F. T. Hopkinson in charge of the work, with J. C. Inglis of Plymouth acting on behalf of the GWR. The work was briefly described and illustrated in 'The Engineer'[1]. An interesting aspect was the transport of granite blocks from the quarry at Ivybridge, which involved a locomotive-worked zig-zag railway with a gradient of 1 in 20, and inclined planes with a gradient of 1 in 3.5 worked by a 30 HP portable winding engine. Due to a strike of local stone masons, it was decided to build the arches of brick.
The other four viaducts reconstructed at the time by Pearsons were:-
Bittaford Viaduct
Glaze Viaduct
Ivybridge Viaduct
Slade Viaduct