Cornwall Railway viaducts
The Cornwall Railway company constructed a railway line between Plymouth and Truro, England, opening in 1859, and extended it to Falmouth in 1863. The topography of Cornwall is such that the route, which is generally east-west, cuts across numerous deep river valleys that generally run north-south. At the time of construction of the line, money was in short supply due to the collapse in confidence following the railway mania, and the company sought ways of reducing expenditure.
On the advice of the Victorian railway engineer Isambard Kingdom Brunel, they constructed the river crossings in the form of wooden viaducts, 42 in total, consisting of timber deck spans supported by fans of timber bracing built on masonry piers. This unusual method of construction substantially reduced the first cost of construction compared to an all-masonry structure, but at the cost of more expensive maintenance.
Replacement of the timber viaducts by all-masonry structures began in the 1870s but a few remained in service until the 1930s.
The Cornwall Railway linked Plymouth with Falmouth. The section from Plymouth to Truro was opened on 4 May 1859, and the remainder to Falmouth on 24 August 1863. Although the line had been designed by Brunel, this was after his death and the construction under the supervision of R P Brereton. It was built as a single-track 7 ft (2,134 mm) broad gauge line.
The 70 miles (110 km) of railway crossed 45 rivers and deep valleys. Of these 43 were spanned by viaducts of various types built partly or entirely from timber. Workshops were established at Lostwithiel where timber could arrive on barges to be preserved and cut to size. The offcuts from the timbers used for the viaducts and track were then used for the construction of the railway's buildings.
...
Wikipedia