But Windmills and Waterwheels Explained by Stan Yorke has changed all that for me.
So fascinating I find difficult to put down, it has taught me that there were innovations in waterwheel design throughout their history.
For example, for thousands of years the central axle of water wheels carried power into the mill building.
Then some bright spark realised that you can bolt a great big gear to the wheel, and mesh it with a little gear to take power into the building.
The new drive shaft runs faster - so less gearing up is needed inside - and can be thinner because it is transmitting less torque.
And, the main wheel axle can now stay still, simplifying its bearing arrangement.
There is also the cunning paddle arrangement of French physicist Poncelet.
He took a huge step away from any-flat-plank-will-do paddles and introduced a brestshot wheel with a curved blade/bucket design that took almost all of the kinetic energy out of the water that struck it.
I rate this alongside the Pelton wheel - a high-pressure high-speed water wheel invented in California in Victorian times.
The spoon-shaped blades of Pelton's design cunningly reverse the flow of impinging water. Once the wheel is moving at its design velocity, water exits the blades stationary, having given up over 90 per cent of its energy to the shaft.
On a cycling trip in California, I was lucky enough to come across one of the first Pelton wheels, a huge one in Grass Valley, which is where I learned that they were invented in the region.
'Alice' alice@electronicsweekly.com
See also:
http://www.strollingguides.co.uk/workshop/darkroom/galleries/
http://www.wheal-martyn.com/historical.html
(Picture - 'Gear2_Big Otter Mill_1#9B4F' by ellievanhoutte, under the Creative Commons Attribution licence)
There is also the cunning paddle arrangement of French physicist Poncelet.
He took a huge step away from any-flat-plank-will-do paddles and introduced a brestshot wheel with a curved blade/bucket design that took almost all of the kinetic energy out of the water that struck it.
I rate this alongside the Pelton wheel - a high-pressure high-speed water wheel invented in California in Victorian times.
The spoon-shaped blades of Pelton's design cunningly reverse the flow of impinging water. Once the wheel is moving at its design velocity, water exits the blades stationary, having given up over 90 per cent of its energy to the shaft.
On a cycling trip in California, I was lucky enough to come across one of the first Pelton wheels, a huge one in Grass Valley, which is where I learned that they were invented in the region.
'Alice' alice@electronicsweekly.com
See also:
http://www.strollingguides.co.uk/workshop/darkroom/galleries/
http://www.wheal-martyn.com/historical.html
(Picture - 'Gear2_Big Otter Mill_1#9B4F' by ellievanhoutte, under the Creative Commons Attribution licence)
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Comments (2)
Working as I do for a well known heritage agency, it was refreshing to see in my in-tray a few days ago, a request for advice on how to convert a water mill in Yorkshire from being on the "Buildings At Risk" register to a functioning generator of electricity. Luckily the owner of said poor building also owns some reservoirs.
Its been done successfully by amongst others the National Trust - it will be interesting to see how far this project gets. There is an interesting web-site that I have looked at called Micro-hydro - http://regensw.co.uk/about-renewable-energy/on-site-renewables/microhydro.php
Posted by Auntie G | July 23, 2008 4:24 PM
Posted on July 23, 2008 16:24
Funnily enough i also work for a well known heritage agency and someone that works there owns a wonderful place near Darlington called Brignall Mill. The mill has an eighteenth century watermill that supplies nearly all the electricty to the property and has a heat pump, solar panels and woodburners and whats even better you can go and stay there and have a close up look. www.brignallmill.co.uk/
Posted by Cushie | July 25, 2008 1:56 PM
Posted on July 25, 2008 13:56