Anno 1792

Krijtmolen d’Admiraal

Functioning of the mill


Drying barn

The drying barn
The lumps of stone to be grinded are first of all dryed in a so called drying- or wind barn. In former days a number of these large barns stood next to the mill, but at the time of the restorarion in 1967 these had been pulled down because of the delapidated state they were in. In December 2007, a barn was built on the north side of the mill which is partly used as windbarn. The drying-proces can vary from a few weeks in the summer to a couple of months in the winterperiod.





The capstan wheel

The capstan wheel
As with all the wind-powered Dutch mills, before the grinding comes into operation, the cap construction with the sailcross has to be faced on the wind by the miller to make optimal use of the wind. This so called “winding” is done with the help of the tail at the back of the millcap. By means of ropes and hooks which can be shifted on the reefing gallery, the miller can turn the cap with tail and sailcross 360 degrees by turning the capstan wheel.
Setting of the sails and reefing
Depending on the windforce at that instant, the miller can catch extra wind by setting sail. He can also vary the amount of sail on the sails . The less wind, the more clothe the miller shall set. Reducing of the sail because of strengthening of the wind is called “reefing”.
The milling can commence by lifting the brake on top of the “headwheel”. This is done by pulling the rope hanging down from the “brakestick: sticking out at the back of the cap.


The Headwheel, the Wallowwheel and the Kingsspindle

The Headwheel, the Wallowwheel and the Kingsspindle
The rotation of the sails of a mill starts off the interior mechanism. The “sailcross” is secured to the “windshaft” on which the “headwheel” is fitted. The rotation of the sails is transmitted to the “windshaft” and the “headwheel”in the cap. The “headwheel”grabs into a smaller wheel, the “upper wallowwheel”, which is fastened to the upright mainshaft, the “kingsspindle “, running down the interior of the mill. At the other end of the “kingsspindle” the “underwallowwheel” is secured, which grabs into a larger wheel the “stonewheel” . This wheel is found on the “gallery floor”of the stagemill and propels two large upright stones, the “rollercrusher”, on the groundfloor.




The Headwheel, the Wallowwheel and the Kingsspindle
The most impressive part of the mill is the grinding mechanism, the “rollercrusher “. The vertical “rollercrusher” consists of two blue granite stones, an inner and an outer stone, each weighing two and a half thousand kilograms. Both stones roll over a horizontal millingstone, the “bed- or understone”. A walled-up elevation on which the “bedstone” rests is called the “deathbed”. The two stones of the “rollercrusher” are encased in a heavy wooden casement, the “stone window”. Seen from above the upright stones roll clockwise. The crusherstones have some room in the bearings to be able to absorb irregularities. A pair of bent wooden collecting bars, just above the bedstone, ensure that the grinded product is slided back under the crushers.


The Jacobsladder and the boulter
When the stone has been grinded to powder, the miller opens a trapdoor. The stonepowder is caught in the buckets of the “jacobsladder” behind the trapdoor and transported to the “boulter”. The “jacobsladder” is a canvasbelt with buckets at equal distance of one another, running through a wooden pipe with the boulter at the end. The revolving boulter sifts the stonepowder. The sifted “fine sand” is caught in sacks, ready for transport. The coarse particles left behind in the boulter are feeded back to the rollercrusher for a second crushing.

Click here to see historical photo’s





Geplaatst op: 8 januari 2017 door beheerder