Operating one of the Windmills

A description by the writer (RC) for a display at Portland Museum on the Portland Windmills  May 2015 

Operating one of the Portland windmills  was highly skilled but strenuous and dangerous work. Working inside the small tower would have been extremely cramped, draughty, dark and dusty. Upon arrival the grain was manhandled up through the mill and loaded into a hopper above the stones. The mill was anchored to allow the sails to be rigged, one at a time, by climbing the sail bars like a ladder. The sail canvas, rolled up and furled when not in use, was set across the bars and fastened with cords and pointing lines according to wind speed. To reduce the area or reef the sails in stronger winds could be dangerous especially when they were heavy and stiff in cold and wet conditions.

For optimum power from the wind, the cap had to face it squarely. The rear tailpole with its lower end at shoulder height, was braced in the Dutch style to the cap which resting on well greased curb timbers, allowed the miller to turn or wind the mill to face the wind. There may have been a winch on wheels with anchor stones. Turning away from the wind direction or quartering would slow the mill. Details of any internal brake on the head wheel are not known.

The tower's loop lights (open slit windows) faced the prevailing wind giving the miller an idea of its strength and direction. If the latter changed, the mill would have to be turned again or its sails laboriously reefed. High winds could be quite dangerous and if control was lost, the stones could catch the grain on fire.

Once the mill was operating, the amount of grain flowing into the millstones had to be constantly monitored. Flow from the hopper was regulated by a simple gate or spattle in its mouth. The suspended hopper had a hardwood block or rap on its side constantly knocked by a protruding damsel on the rotating quant shaft. A wooden leaf spring held the hopper against the shaft and the grain was thus shaken down within the inclined hopper on every rotation. The damsel got its name as it made more noise than anything else in the windmill !! 

The miller would always have to work with the wind sometimes spending long hours waiting or working late when wind was strong enough. He had to be very skilled at looking and listening to the workings of the mill.

Correctly set millstones would grind with a particular noise and smell. Grain would get burnt if the stones ran too fast or close together, it would only be partially ground if the opposite happened. The critical gap between the stones was manually adjusted by turning a "tentering" screw which lifted or lowered the bridge beam and its bearing on which the upper millstone rotated. The stones were enclosed in a wooden vat from which the ground flour trickled out of a chute into a suspended sack below. The fineness of the flour was checked between thumb  and forefinger and gave rise to the saying "rule of thumb".

Constant maintenance and adjustments were required to ensure the correct running of the shafts and wooden gears. The biggest maintenance item was the millstones. A new 4 foot diameter stone weighed approx 1 ton and would be redressed many times (on both sides) during its life of about 10 years. To enable redressing, the upper stone would have to be lifted off the fixed lower one. Replacement of a stone or windshaft probably required roof removal and external lifting tackle probably borrowed from the stone quarries.