November 30, 2020

Why do old windmills turn left and new ones turn right?

Filed under: Architecture,General,History,Nature by Orangemaster @ 2:37 pm

Every once in a while it’s good to ask ourselves some deep questions, and this one popped up as news recently. Why do old Dutch windmills turn left and newer ones turn right? It has nothing to do with the wind or with most millers being right-handed – let’s get that out of the way now.

The material that older blades are made from provide a more precise explanation. The two rods that form a cross to which the blades are attached are made from a tree trunk. As it was growing and needed sun to do so, the trunk would rotate to the right because the sun rises in the East, then moves to the South and sets in the West, and the tree would follow.

By turning the blades to the left, counter-clockwise, it would turn avoid splintering the wood. The wood needs to be super solid and ideally be of high quality, which could sometimes come from trees that grow very straight in forests, but not all the time.

Taking physics into account, there is no reason why modern-day windmills should have a preferred rotation direction. For example, wind turbines are manufactured in factories that use the same type and angle of blades, making them standardised and so they turn the same way – to the right. They could all be made to turn left if for some reason the world decided to do so.

Old Dutch windmills were not standardised and unique, which makes them nice to visit.

(Link: nu.nl)

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May 16, 2015

Windmills that generate twice the power of traditional windmills

Filed under: History,Technology by Branko Collin @ 9:27 pm

windmill-leiden-branko-collinAlthough windmills are an iconic representation of the Netherlands, they haven’t actually been used much for the past two centuries.

The ‘invention’ of the practical steam engine by James Watt in the 18th century made short work of the Dutch reliance on windmills. The use of wind power for pumping water out of polders saw a sharp decline in the 19th century.

Ironically, the abandonment of windmills did not stop the development of these devices in the Netherlands. According to Low Tech Magazine:

In the 1920s and 1930s, however, when windmills had stopped working almost everywhere in Europe, the Dutch started a research program that led to the final development of the classical windmill. In 1923, the “Dutch Windmill Society” was founded, with the mission to improve the performance of windmills generating mechanical energy. Among the members were famous millwright builders like the Dekker Brothers. The results were spectacular.

[…]

[While] a traditional windmill could be worked for around 2,671 hours per year in the Netherlands, the new streamlined design could be operated for 4,442 hours per year – more or less doubling the annual energy output.

(Link: Making Light, Photo: regular windmill De Put in Leiden by me)

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March 27, 2015

Dutch spies thwarted by German windmills

Filed under: Sustainability,Technology by Branko Collin @ 2:58 pm

don-quixote-gustave-dore-pdGerman windmills are disrupting the proper spying on Dutch citizens by the Dutch military secret service MIVD, or so the latter complains.

The Ministry of Defence has complained to the municipality of Vreden (Germany) about the fact that it allows the placement of wind turbines so near to its spying antennas (14 kilometres), Ravage reports. Vreden has already limited the height of its turbines and is currently amending its rules for the placement of new turbines.

According to Webwereld, 25 Dutch citizens lost their jobs in 2009 and 2010 when the Ministry of Defence destroyed their employer’s business model of providing medium distance, high speed wireless internet (wimax). After the ministry had told Worldmax that it was forbidden to roll out its services in the entire north of the Netherlands, the wimax provider had to close its doors, losing dozens of millions of euro in the process.

Vreden is planning a farm of 24 wind turbines in or near the Crosewicker Feld nature reserve and is getting some resistance from its citizens, according to Münsterland Zeitung. The locals don’t share the concerns of the Dutch military, but are unwilling to have to look at the turbines all day. They want the distance from the turbines to their house increased from the proposed 400 metres to at least 500 metres. (This has led to an interesting legal paradox where the council members who live too close to the proposed wind farm are not allowed to vote on what constitutes ‘too close’. The Germans call this conflict of interest Befangenheit.)

Illustration: renowned windmill fighter Don Quixote by Gustave Doré, 1863.

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July 23, 2008

Old mills being put back to work

Filed under: Architecture,Food & Drink by Branko Collin @ 11:26 am

The New York Times is taking a look at old Dutch windmills that are being used again for their original purposes:

Some of the renewed interest in mills is driven by the search for traditional food and drink. Patrick Langkruis, whose bakeshop, Het Bammetje, features 28 different kinds of bread and 35 different rolls, uses only flour ground by a traditional mill. “The taste is fuller, there’s more flavor,” he said. “It’s also because the grains are ground slowly.”

His supplier is Karel Streumer, who has been grinding out ordinary and exotic grains for the last eight years at his mill, De Distilleerketel, or distillery pot, in Delfshaven, on the edge of Rotterdam. He uses technology — huge mill stones and enormous wooden gears that make visitors feel they’re inside an immense and ancient clock — that has not changed since the mill was built in 1727.

De Distilleerketel caught fire in 1940 during fights between the Dutch army and the Nazis. It wasn’t rebuilt until the 1980s after much hemming and hawing. Because of the delay, city planners had already planned houses almost right next to the mill, which was subsequently moved 11 metres, according to the Nederlandse Molendatabase (Dutch).

Photo of De Disitilleerketel by M.Minderhoud, distributed under the GNU FDL 1.2.

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