The 13ft (3.96m) diameter 8ft (2.44m) wide water wheel is made of metal and runs on a large diameter wooden shaft. The wheel is of the low breast shot type and it transfers the river flow into useable energy to power the mill machinery. This means that the paddles on its rim were propelled by water running down a concave curved surface called the ‘breast’, the curve being concentric with the wheel’s rim. The paddles on this wheel are curved buckets similar to those developed by the French inventor Poncelet who realised that curved paddles were more efficient than flat ones. The water flow, and hence the speed, could be controlled by means of a sluice gate in front of the wheel and operated either locally or remotely from within the sawmill. When the waterwheel was in use the water was brought to it by a ‘leat’ from a weir, or ‘lasher’ set sideways to the leat and which controlled the level of water in the leat or ‘head race’ some distance upstream.
The water wheel turns more slowly than required to run the line shafting so a set of gear wheels is housed between the wheel and the workshop. The largest diameter wheel sits in a pit and its 162 wooden teeth were replaced with hornbeam in 2004. By 2014 they were again in need of replacement because the hornbeam had rotted.
When electricity came to the area in the mid-1950s the waterwheel was no longer needed to power the sawmill machinery and in the mid-1970s and, although the tail race still exists, the head race was filled in some years ago to enlarge Combe Yard. Visitors must imagine the river Evenlode running beneath the Mill building.
A bypass sluice was used to control the river flow through the water wheel in conjunction with the sluice gate in front of the wheel.
The waterwheel is now turned by water delivered to the headrace by a six-inch submersible pump in the river.
Recently, with sponsorship from visitors, new teeth were made from oak and fitted in 2019 each bearing a brass numbered disk to identify the sponsor. At the same time millwright, David Empringham, repaired the surrounding timber hurst structure and the winged gudgeons on the ends of the axle tree.
The names of sponsors are recorded below.
