De Oudkerkermolen, or Oudkerkemolen (English: Old Church Mill) is a smock mill

Smock mill

The smock mill is a type of windmill that consists of a sloping, horizontally weatherboarded tower, usually with six or eight sides. It is topped with a roof or cap that rotates to bring the sails into the wind...

 in Aldtsjerk

Aldtsjerk

Aldtsjerk is a small village on the highway from Leeuwarden to Dokkum. It is part of Tytsjerksteradiel, Friesland, Netherlands, Europe and has around the 693 citizens ....

, Friesland

Friesland

Friesland is a province in the north of the Netherlands and part of the ancient region of Frisia.Until the end of 1996, the province bore Friesland as its official name. In 1997 this Dutch name lost its official status to the Frisian Fryslân...

, Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

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

Rijksmonument

A rijksmonument is a National Heritage Site of the Netherlands, listed by the agency Rijksdienst voor het Cultureel Erfgoed acting for the Dutch Ministry of Education, Culture and Science.-History and criteria:...

, number 35674.

History

De Oudkerkermolen was built in 1864. On 13 March 1955 it was badly damaged in a storm. Repairs cost ƒ6,734, including new sails at ƒ3,200 and a new Archimedes screw at ƒ1,950. The repairs were carried out by millwright

Millwright

A millwright is a craftsman or tradesman engaged with the construction and maintenance of machinery.Early millwrights were specialist carpenters who erected machines used in agriculture, food processing and processing lumber and paper...

 De Roos of Leeuwarden. Further repairs were made to the mill in 1963.

The mill drained the 160 hectares (395.4 acre) Oudkerkerpolder until 1970. A diesel engine formerly provided auxiliary power. It was restored in 1975. Although in working order, the mill just pumps water in a circuit to demonstrate the process.

Description

De Oudkerkermolen is what the Dutch describe as an "achtkante grondzeiler". It is a smock mill whose sails almost reach the ground. The mill has a single storey brick base. The smock and cap are thatched. The mill is winded by a tailpole and winch. The four Common sails, which have a span of 15.68 metre, are carried on a cast iron windshaft. This was made by millwright H J Koning of Foxham in 1910. The windshaft also carries the brake wheel which has 50 cogs. This drives the wallower (29 cogs) at the top of the upright shaft. At the lower end of the upright shaft the crown wheel (37 cogs) drives the wooden Archimedes screw via a gear wheel with 34 cogs. The Archimedes screw has an axle diameter of 320 millimetre and is 1.24 metre diameter overall. It is inclined at 19½°. Each turn of the screw lifts 537 litres (118.1 imp gal) of water.