Bridges, Viaducts and Aqueducts
The expansion of the mining transport network meant dramatic changes had to be made for the landscape to be navigable. Replacing mules with tramroads and railways was the beginning, but access was still needed across bodies of water. This led to the construction of some of the region’s most technically advanced bridge structures.
After inheriting the estates of the Treffry’s family in 1813, Joseph Austen (later Joseph Treffry) had begun to take advantage of the Luxulyan Valley by building a new artificial harbour and canal to link up by inclined plane to Lanescot Mine and Fowey Consols.
Treffry Viaduct stands at 198m long and 30m high. It was the most advanced engineering project in the western peninsula at the time.
For the tramroad which was later built across the valley, a high-level crossing of the river was required. The solution was this 198m long, 30m high viaduct – the most advanced engineering project in the western peninsula at the time.
Calstock Viaduct was built to carry the East Cornwall Mineral Railway at high level over the River Tamar. It stands 37m high with 12 18m-wide arches and was built between 1904 and 1907 following the construction of the Brunel Bridge.
Penponds Viaduct was built by the West Cornwall Railway in 1857 to replace an inclined plane that had been built 20 years before by the Hayle Railway. Penponds is situated close to Camborne.
As many of the area’s mines were relatively close to navigable water, canals were generally a less practical option for transportation. However, there were exceptions – most commonly in eastern parts of the Site.
John Taylor’s intention in constructing the Tavistock Canal was to link the copper mines he managed in the Tavistock area to the River Tamar, the principal transport route to the sea from Plymouth. Building started in 1802 and on completion in 1817 it stood at 7.2km long.
Liskeard & Looe Union Canal
This canal linked Moorswater with Looe and opened in 1827. It became a popular route from the Caradon mines following the discovery of copper ore at South Caradon Mine in 1836. Eventually it was proving to be insufficient for the volume of mineral output from the district and so the railway connection was extended down to Looe in1860, rendering the canal redundant.
Opening in 1829, the Par Canal was constructed to connect Par to the foot of Penpillick Hill and later to Ponts Mill. This connected by inclined plane to Lanescot Mine and Fowey Consols and was part of the development of the Luxulyan Valley initiated by Treffry.