Windmill Development

Windmill Operation

There are still a small number of working windmills in the UK.  Maud Foster in Boston, Lincolnshire is one of them.  See the mill stones in action on a YouTube video clip by our Research Team, video link also on the Commercial Operation page.

The Crusaders brought Arab windmill technology back with them from their attempts to conquer the Holy Land. It was a particularly useful addition in hilly areas where suitable rivers and streams were in short supply. Post Mills where the windmill rotated around a central post came first, such as this one at Avoncroft Outdoor Museum. Smock mills and brick tower mills came later.

Ashton Windmill

Ashton Windmill, Chapel Allerton, Somerset

The windmill tower is 25 feet (7.5 metres) high with a diameter of 12 feet (3.5 metres).  The windmill was built between 1760 and 1774.  For more information read:

• Ashton Windmill information on the Sedgemoor District Council website

 

Technical Information

After a period of disuse the windmill was renovated in 1958, yet by the early 1970’s the wooden stocks that held the sails had rotted.  New steel stocks were filled in 1979 and are still in position today.

From 1894-1927 a portable steam engine powered the windmill.

It took an hour to grind four sacks of grain.  Each sack weighed 244 pounds (17.5 stones or 111 kilograms), the weight of a heavy man.

Stembridge Mill

Stembridge Mill, High Ham, Somerset

Stembridge Mill is about a dozen miles east of Taunton.   It is the last remaining thatched windmill in England.

The windmill comprises four floors and is 26 feet (7.9 metres) high.  It is built on a walled mound that keeps people and animals away from the sails.  The mill was built in 1822.  More information about the mill is available by clicking:

• Wikipedia Stembridge Mill
• National Trust Stembridge Tower Mill

 

Turning The Cap With A Wheel And Chain

To turn the sails into the wind the miller has to use a wheel and chain mechanism, the looping chain uses a number of gears to turn the cap.  The miller therefore has to regularly check the wind direction.

Hough Mill has a fantail which automatically turns the sails into the wind without any intervention by the miller.

Carew Tidal Mill

Carew Tidal Mill, Pembrokeshire

Carew Tidal Mill is build on top of a dam across the Carew River a little to the west of Carew Castle.  When the tide is coming in the gates underneath the mill are opened to allow the water into the 23 acre mill pond.  The gates are closed when the tide turns.  When the tide has receded sufficiently, the gates are reopened to allow the water from the mill pond to flow into the main part of the river.  This flow of water turns the water wheel and the mill is able to operate.

Technical Information

It is interesting to compare the impact of the different power sources on the millers:

• Windmills – The miller is completely dependent upon the strength of the wind to work the mill.  It is possible to go for weeks at a time without their being sufficient wind to power the mill.  This is why many millers had alternative occupations such as farmers and publicans.
• Watermills – The miller is able to decide when to open the mill race and release the water to turn the water wheel.  The miller could choose when to work the mill.  Only in rare long dry spells might the miller run short of water for the mill.
• Tidal mills – The miller’s working hours are dictated by the time of the low tide.  Unlike upstream rivers the sea does not run dry, so the miller has a reliable source of power.

Carew Tidal Mill is enormous compared to windmills and watermills and could run several sets of stones at the same time.  Apart from the power source the technology is very similar to the windmill.

Weald and Downland Open Air Museum

From the outside a watermill is very different from a windmill.  But once inside the technology is very similar.

The museum also has a wind pump on its lake, another example of how the technology can be used for different purposes.

Foreign Stones

Sibsey Trader Windmill has a Dutch Sickle Stone on display.  Dutch mills turn quicker than British mills, yet the grain needs to stay between the stones long enough to be properly ground.  The solution is curved channels in the stones thus making it a longer journey before the grain emerges between the stones as flour.

Dobsons Windmill has a German stone that has been dressed on both sides.  The reason for the second set of lines is not known.

Windmill Galleries

Many windmills have galleries part way up the windmill.  This makes it easier and quicker for the miller to go outside and dress the sails.

Windmills built from hard bricks tend to leave the brickwork open to the elements.  Windmills built with softer bricks paint them with a protective coat.  Black tar coated windmills are a good example.  Once painted the windmill needs to be regularly repainted, otherwise the tar coat breaks down and rain water gets behind the tar but cannot escape.

Miscellaneous Developments

Getting The Grain In

Some windmills have steps loading to a platform outside the entrance.  The platform is the height of the cart, thus making it easier to offload sacks of grain and load sacks of flour.

Other windmills have a door part way up the wall.  A hoist can be used to raise sacks or replacement stones.

A millwright would use a sail winch on the inside of the mill to haul sails up to the top of the mill.  The rope would go from the winch up through the mill and emerge through the pole end where the sails were attached.

A stone dresser would lift the stones with a bar and insert wooden stepped supports to hold them in a raised position.