The Luxulyan Valley above St Austell was developed as an industrial site by Joseph Treffry (1782 – 1850). The massive copper mine of Fowey Consols was worked by six steam engines and 17 waterwheels. Treffry linked the mine to the port of Par by a combination of tramways and canal. The valley was also the site of granite quarries which shared the transport network. It was, however, the coming of the railway that catalysed the huge growth in China Clay production.
In 1874 the Cornwall Minerals railway was constructed, providing a network of lines that stretched from Fowey to Newquay. This included, on the line between Par and Fowey, the Pinnock Tunnel – at 1,173 yards the longest rail tunnel in Cornwall. Based in St Blazey, the company lasted until 1896, after which it was taken over by the Great Western Railway.
The Great Western Railway in turn was nationalised in 1948. The line from Par to Fowey was closed to passenger traffic in 1965 and to freight in 1968. In an unusual move the trackbed was converted to a roadway and has been used to this day to transport China Clay to the deep-water docks at Fowey. Around 90% of today’s China Clay production is exported, most of it used to provide the coating on glossy papers.The route still includes the Pinnock Tunnel, now surfaced and lit.
The tunnel operates in one direction at a time and is controlled by traffic lights. It is operated today by ECC’s successor, Imerys. In the past Imerys have allowed occasional visits to the tunnel, normally associated with charity fund-raising.