Sawing with wind power

Sawmill De Ster’s (The Star) location at the river Leidsche Rijn to the west of the Utrecht city centre is typical of early sawmills which needed to be close to rivers or canals to more easily transport logs to and sawn boards from the mill. After the tree trunks arrived, they were kept in water-filled ditches ('beam holes') for at least two years. This allowed the sap to flow from the trees, a process that strengthened the wood.

When the logs were ready, they were hauled from the water along the slipway into the factory part of the mill by wind power. Inside, the miller and his assistants loaded the log on a large sled which was then pulled through the sawing frame. This frame was moved up and down by wind power as well. The sawn wood was then transported outside by lorries to dry in one of the open sheds next to the mill.

The invention of the crankshaft around 1590 enabled wind-powered sawmills to be developed. The crankshaft converted the circular motion of the turning sails into the vertical movement needed for sawing. This invention greatly increased the pro-ductivity of sawing factories over hand sawing. The crankshaft had many appli-cations and contributed to the onset of the Industrial Revolution in the 19th century.