De Modderige Bol is a Hollow Post mill in

Goëngahuizen Goëngahuizen () is a hamlet in Smallingerland in the province of Friesland, the Netherlands. It had a population of around 58 in January 2017. The village was first mentioned in 1573 as Gonyehuisen, and means "settlement of the Goinga family". Go ...

Friesland Friesland ( ; ; official ), historically and traditionally known as Frisia (), named after the Frisians, is a Provinces of the Netherlands, province of the Netherlands located in the country's northern part. It is situated west of Groningen (p ...

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

which has been restored to working order. The mill is listed as a

Rijksmonument A (, ) is a national heritage site of the Netherlands, listed by the agency Rijksdienst voor het Cultureel Erfgoed (RCE) acting for the Dutch Ministry of Education, Culture and Science. At the end of February 2015, the Netherlands had 61,822 l ...

, number 34001. (Click on "Technische gegevens" to view.)

History

The date that ''De Modderige Bol'' was built is unknown. The earliest record is its appearance on a map dated 1848. Until 1952, the mill drained the polder Adamse, which had an area of . The mill was restored in 1954 and 1969. A further restoration was undertaken in 1978 by

millwright A millwright is a craftsman or skilled tradesman who installs, dismantles, maintains, repairs, reassembles, and moves machinery in factories, power plants, and construction sites. The term ''millwright'' (also known as ''industrial mechanic'') ...

s Bouwbedrijf Van Zuiden of Tjerkwerd. On 9 November 1978, the mill was sold to

Stichting De Fryske Mole The Stichting De Fryske Mole (; ; ) is a foundation for the preservation of windmills in the Dutch province Friesland, owning 42 of the 124 windmills in Friesland and closely co-operating with the Gild Fryske Mounders with which it publishes a q ...

(). The mill was restored again in 1992–93.

Description

''De Modderige Bol'' is what the Dutch describe as an ''spinnenkop'' -. It is a hollow post mill on a single storey square roundhouse. The mill is winded by tailpole and winch. The roundhouse is clad in pantiles and mill body is covered in vertical boards, while the roof of the mill is boarded and covered in felt. The sails are Common sails. They have a span of . The sails are carried on a wooden ''windshaft''. The ''windshaft'' also carries the ''brake wheel'' which has 43 cogs. This drives the ''wallower'' (21 cogs) at the top of the ''upright shaft''. At the bottom of the ''upright shaft'', the ''crown wheel'', which has 31 cogs drives a gearwheel with 30 cogs on the axle of the Archimedes' screw. The axle of the Archimedes' screw is 250 millimetres (9¾ inches) diameter. The screw is diameter and long. It is inclined at 24°. Each revolution of the screw lifts of water.

Public access

''De Modderige Bol'' is open by appointment. (Click on "Informatie" to view.)

References

{{DEFAULTSORT:Modderige Bol Buildings and structures completed in the 19th century Windmills in Friesland Hollow post mills in the Netherlands Windpumps in the Netherlands Rijksmonuments in Friesland