Loch Thom

In the late 18th century Greenock was a rapidly expanding seaport with industries developing as the Industrial Revolution gathered pace. Its location on the north slopes of hills sweeping down to the south bank of the Firth of Clyde meant that several fast flowing streams provided supplies, and a number of wells provided clean water for domestic use. This was supplemented in 1773 by a piped water system designed by James Watt supplying some areas, but there was increasing demand for water powered mills. On the far side of the hills to the south of the town a natural dip held a freshwater lake known as Shaws Water at a level high above the town. The civil engineer Robert Thom from Rothesay…

From Cornalees Bridge The Cut runs west then turns northward following along the contour of Dunrod Hill which it follows round until running eastwards directly above the town of Greenock at Overton, having come a distance of 9 km. On the way it collects some of the water from streams that cross its path, and a series of sluice gates incorporated an ingenious automatic way of releasing surplus water. As shown in the picture of a restored mechanism, when the aqueduct is over full, water flows down the pipe in the foreground and fills the bucket, which then pulls the chain down over the pulley wheel and lifts the counterweight and the lever opening the sluice gate. Small holes in the bucket…