60.000 liters of water per minute
With a favorable wind a mill pumps up 60,000 liters of water per minute.
And you can experience that now, because the 400-year-old mills still work!
A whopping 52 (!) Watermills were needed for dry-cleaning the Schermeer. In every thatched mill, type octagonal inner barrel, there was a huge six-meter long paddle wheel. This allowed the polder water to be pumped up about one meter, the so-called head.
Thanks to the sails, the miller could respond to the volatility of the wind force. And by turning the hood he could follow the shrinking and clearing of the wind. Because the better he could use the wind, the more water he could pump up.
The rods (the base of the sails cross), the ashes and the scoop wheel were all made of wood at the time. That material had a limited life span and ensured a high cost item. Fortunately, various technical improvements have been made over the centuries. The wooden rods and upper shafts have been replaced by replacing (cast) iron ones. From 1850 a start was made with what was the most important improvement: the paddle wheel through a mortar – a large-scale project that took a total of 25 years.
The technique stood for nothing …
Thanks to this innovation, the three-stage drainage (with scoop wheel) of the inner atria was replaced by a two-stage drainage (with auger). In a test with the current Museummolen it turned out that the head of a mortar was so much larger than that of a paddle wheel: the drainage could be performed less with two mills – one step. And because the jacks worked so well, switching to steam milling was postponed. Wind-drainage – according to a report from 1876 – was much cheaper than steam drainage.
Because the wage costs continue to rise and the Working Hours Decree of 1915 limits the working hours of the millers, the polder board decided in 1924 to switch to electric pumping. The biggest advantage of course was that people were no longer dependent on the wind. And so it was that in 1929 the last mills were put out of use. The water in the polder was now maintained by three electrical pumping stations (Emma, Juliana and Wilhelmina). (Many decades later – late last century – these were replaced by two computer-controlled electric pumping stations, which – according to the current tradition – are called Beatrix and Willem-Alexander.
They are only tools …
Because the mills were ‘only’ tools, it was decided in 1929 to sell them individually as soon as they were no longer usable. Blessing in disguise. In the Second World War several mills were made ready for use again in order to be able to grind again in an emergency – which also happened. After that, the water board had to keep a number of mills ready for operation in the early 1950s – thanks to the W ate Protection Act in Wartime (BWO Act). Two mills were also kept in the context of the housing shortage. In the end, 17 icons have been retained, of which 8 can still pump 60,000 liters of water per minute. Just like 400 years ago.
Schermer mills on Facebook