|Trenance, Cornwall Viaduct|
The original Cornish viaducts / bridges were indeed wooden - built on masonary piers.
I found the photo below (in the public domain) of the Truro Railway Carvedras Viaduct from 1859. This shows the wooden construction supporting the railway lines. At the time this was done to save money, but was a false economy as stronger stone viaducts had to be built in 1899.
The original stone piers remain next to the newer viaducts.
|Truro, Cornwall Viaduct|
|Truro Viaduct today|