Penstock and Pentrough

The penstock is a vertical gate used by the miller to control the quantity of water flowing from the pentrough onto the overshot waterwheel which in turn controls the rotational speed of the waterwheel and of the runner millstone. A second sluice gate is installed upstream of the pentrough to control the amount of water entering the pentrough, or to completely stop it off.

Our penstock and pentrough were renewed in 2014 to replace those installed in the 1970's, which had deteriorated beyond repair.

The penstock control is located inside the mill, close to the meal bagging area and within easy reach of the miller. It is attached to the penstock by an unusual roller and chain mechanism. The lever is moved around the semi-circular board, which rotates the penstock chain drum and thereby raises or lowers the penstock in the pentrough outside. The miller then pins the lever in place at the desired level.