Post mill

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Rebuilt post mill in Krippendorf, Thuringia
Post mill, rebuilt in the museum village of Cloppenburg . The mill from Essern , Nienburg / Weser district , was probably built in 1638 according to the inscription.

The post mill (also column mill , box mill or German windmill ) is the oldest type of windmill in Europe . The main feature of this type of mill is that the entire mill house stands on a single thick post (the “house tree”), which is fastened vertically in a wooden support frame (the eponymous “trestle”) underneath the actual mill. On the trestle, the entire mill machinery can be turned into the wind by means of the leverage of the outer beam. However, this method is not ideal and very cumbersome when the wind directions change.

History of the post mill

Structure of a post mill:
1  frame, 2  stairs and feet, 3  codend / sterz, 4  comb wheel, 5  wing cross, 6  house tree, 7  flour bars, 8  stone floor, 9  flour floor, 10  saddle

The earliest mentions of post windmills are in Belgium and northern France at the beginning of the 11th century. They appear more frequently in Germany since the beginning of the 15th century and were normally used for grinding grain . Post windmills were gradually displaced by Dutch mills in northern Germany since the 16th century .

The name comes from a base, the "trestle", in which the actual mill house (or mill case) is stored. This rectangular mill housing, mostly made of oak, can be rotated together with the grinding gear, the gearbox and the milling machines around the vertical “house tree” (about 65 centimeters in diameter) or stand. The mill box is turned by means of a boom, the so-called codend , so that the mill blades are "in the wind", that is, the wind blows on the blades from the front and sets them in motion. This turning of the entire mill case with the attached wings is supported by piles driven into the ground around the mill: the mill can be turned better into the wind by means of a pulley system between the piles and the codend.

English post mills had mostly a large wind rose on the back instead of the manually operated codend. It was mounted on a wheel-based suspension (chair) that sat at the bottom of the access stairs. The box of English post mills was - more like the Titzer mill - often surrounded by a mostly round stone building (Rundbau, English roundhouse ).

A staircase at the back of the housing led into the mill interior. The whole mill could be dismantled relatively easily and rebuilt in another location.

Special forms of the post mill

A look into the mechanical inner workings of a Swedish post mill on the island of Öland

A further development of the post mill is the Paltrock windmill , in which the wooden mill house and the mill technology are no longer mounted on a trestle or house tree, but are rotated on a roller ring. This gives the mill additional storage space and its external dimensions can also be increased.

Since the beginning of the 15th century, the post windmills had competition from the coker windmills developed from them in Holland , from the 18th century from the more well-known Dutch windmills and in the 19th century from the stone tower windmills , where the entire mill house no longer had to be pivoted. Nevertheless, there are still a little over 100 historic post mills in Germany today. The largest is in the Penkun district of Storkow .

The post mill in Langenhagen deserves a special mention . This mill was originally built in 1602 a little further north between Bissendorf and Wennebostel and moved to its current location in Kaltenweide in 1878 . It is one of the oldest mills of this type. Deviating from the usual structure, the frame is 110 cm above normal height and the wings have an oversized length of 21 m. The mill is privately owned and open to the public. It is considered the landmark of the village of Kaltenweide.

See also

literature

  • Torsten Rüdinger, Philipp Oppermann: Small mill customer - German history of technology from friction stone to industrial mill , Berlin 2012 (2nd edition), Edition Terra

Web links

Commons : Post windmills  - Collection of images, videos and audio files

Individual evidence

  1. Thorpeness post mill in Suffolk