Blokweer Museum Windmill grinds to a halt – for now
Due to issues with its main axle, The Blokweer Museum Windmill is temporarily put on standstill. Even after repairs are completed later this month, it will take this polder mill some time to be up and running in perfect shape again.
The front bearing on the main axle of the mill, which dates all the way back to 1630, is no longer working properly. “It’s caused by the shape of the axle, which has become oval instead of perfectly circular at that end,” Ad Wisse explains in his capacity as maintenance supervisor in Kinderdijk World Heritage. “It’s supposed to be round. Its current oval shape speeds up the process of wearing down the whole mechanism. The axle is cast out of steel, but the bearing is made of bronze. Due to the oval shape, the system isn’t running smoothly at all. In addition, the axle heats up beyond safe limits after just about thirty minutes of activity.”
These technical issues have prevented the mill’s sails from spinning for several weeks now. “Why, yes, of course that’s a pity,” Yvonne, one of Blokweer’s millers confirms. Even so, she finds that hardly any visitors have complained about it. “As soon as we explain what the problem is, they think it’s a very interesting story instead.”
Starting in the second half of October, Goltens Rotterdam BV from nearby Spijkenisse will be leading the effort to fix this specialist job. They will be supported by De Gelder Millwrights & Contractors from Sliedrecht along the way. Wisse explains: “They’re going to fix a device onto the axle to get it back in its original round shape. It works a bit like a pencil sharpener, using a chisel to grind it down to its former proportions, bit by bit. Work is set to commence by October 22. We expect the experts to finish the job in about two weeks.”
This approach has several benefits, according to Wisse. “You could use other methods to try and fix the problem, you know. One way would be to set up a cutterblock along the axle and then set the windmill in motion. This would involve greater risks, though; especially when the wind picks up. Another advantage of our current approach is that it’s much cheaper.” Wisse estimates the overall costs of the repairs at about 10,000 euros. This includes a brand-new bronze bearing. Replacing the axle altogether would easily cost 40,000 euros by Wisse’s calculations.
The repairs will largely go unnoticed as far as tourists are concerned. Once they’re completed, the Blokweer mill is up for a slow and steady start. “We’ll be very careful when we start milling again. The axle needs to find its way again, so to speak. All the parts will have to readjust to the new situation. At first, the millers will need to climb up every other hour to check if everything is working properly.” Experienced as our veteran millwright may be, discovering an oval axle is definitely a first. What could have caused it is anyone’s guess. “There’s always the possibility that it’s been like this since the day the mill was built.”