The canal, including an aqueduct and this tunnel where designed by the civil engineer John Taylor. Construction started in 1803 and by 1816 the first, specially designed, 200 ton barges were used to ship copper ore from Dartmoor to Plymouth. In addition to copper ore, the barges were also used to transport slate, limestone and other goods downstream.  The largest engineering feature of this canal, was actually the construction of the 2.5km long tunnel. The tunnel, of small bore, was cut through rock, and at it deepest point is more than 100m below the surface. Taylor used towo types of pumps during the construction, one to keep the tunnel drained and the second to provide clean air to the workforce. Both of these were powered by water wheels, driven by the canal water.  When cutting of the tunnel began, copper ore was discovered close to the upper end, and this became the a copper 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.

I have seen quite a bit of Devon above ground but never had such a hike, or should a say wade, covering such a long distance below Devon. Although the views are not quite as nice down below, this was nevertheless an exciting explore, courtesy of the Devon & Cornwall Mine Explorers (who let me tag along a second time). I am eternally grateful to them for lending me a caving suit as well, otherwise this could well have been a miserable trip. I slowly start to think that there a no dry mines in Devon. Apart from wading through the tunnel, we crawled along several adits that branch of the main canal and crossed a flooded winze on two metal pipes. I guess this is what constitutes a bridge down here. Unlike the previous time I actually managed to use my DSLR camera this time having stuffed it into a dry-bag. However, I definitely need to figure out how to use the camera properly withouth drowning them into the murky water. Having used my a powerful torch I managed to get some hand-held shots…