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Tavistock Canal
The Tavistock Canal is a canal in the county of Devon in England. It was constructed early in the 19th century to link the town of Tavistock to Morwellham Quay on the River Tamar, where cargo could be loaded into ships. The canal is still in use to supply water to a hydro-electric power plant at Morwellham Quay, and forms part of the Cornwall and West Devon Mining Landscape World Heritage Site. It is unusual for a canal, as it has a gentle slope over its length, resulting in a considerable flow of water.〔(UK Rivers Guide )〕
==History==
Morwellham Quay is on the River Tamar, and although it is about from the sea, the river is still tidal there. The quay was the furthest point inland to which the river was navigable, and it had served Tavistock as a port since the twelfth century. Ships of 200 tons were using the quay by 1800, and there was a growing trade in copper, which was being mined locally, particularly since the Wheal Friendship mine had opened around 1797. In 1802, John Taylor, a local civil engineer with interests in the mining of metal ores,〔(Towpath Treks )〕 surveyed the route for a canal to run from Tavistock to Morwellham, and it was discussed at a meeting held in March 1803 in Tavistock. The canal would be wide and deep, and the Millhill slate quarries would be served by a branch from the main line. It would carry copper ore, both the Wheal Friendship and the Wheal Crowndale mine which had recently opened nearer to Tavistock. Other cargo would include slate, limestone and general goods. The canal would be suitable for tub-boats, and would be built entirely on land owned by the Duke of Bedford, who approved of the project. The estimated cost was £40,000, which included provision for testing any mineral lodes which were found during its construction, and the rights to those minerals, together with dues payable to the Duke for their extraction, were negotiated before the project began.
An Act of Parliament was obtained in 1803 which gave the proprietors the power to raise £50,000 in £50 shares for the construction of the canal. The land was donated by the Duke, who took 125 of the 1000 shares. Taylor, who also managed Wheal Friendship mine, acted as engineer, and work started in August 1803. The largest engineering feature of the canal was a tunnel under Morwell Down. When cutting of it began, copper ore was discovered close to the Tavistock end, and this became the Wheal Crebor mine, which was managed as a separate project. It had its own entrance, by the tunnel entrance, and used water-powered machinery, driven by water flowing along the canal. The canal from Tavistock to the tunnel mouth, including an aqueduct which carried it over the River Lumburn, was opened in 1805. The tunnel was cut through rock, was of small bore, and required Taylor to construct two types of pump, one to keep the workings drained, and the other to clean the air.〔〔 Both were powered by water wheels, driven by the canal water.〔 The tunnel, which was driven through elvan rock and killas clay-slate, is below Morwell Down at its deepest point, and it was finished in 1816.
At the tunnel's southern end, the canal was on the contour, and Taylor constructed an inclined plane to drop the level by to the quay at Morwellham. There were two tracks, one running to the quay, and a second which ended some higher at ore-chutes above the Lower Copper Quay. The rails were initially "L" shaped cast iron plate rails, spaced apart between the flanges, although trough-shaped rails were used in places on the quay, particularly where roads crossed the tracks. Four-wheeled tipping wagons which had larger wheels at the front than at the rear were used on the twin tracks, which operated independently. The system was powered by a large overshot waterwheel, in diameter and wide, situated alongside the winding house at the head of the incline, which was fed with water from the canal. It drove a declutchable winch, to which the wagons were attached by chains. Wagons arriving at the top of the incline passed onto a sloping platform, which moved to a horizontal position due to the weight of the wagon, and this disconnected the waterwheel from the drum holding the chain. The rails were later replaced by wrought iron edge rails, and the chains by cables.〔R. Waterhouse, Morwellham Quay Archaeologist.〕
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