The windmills of the Trapani salt pans: what are they for?

The windmills stand out imposingly among the salt pans in the panorama of the Trapani salt pans. These stone giants that dominate the landscape of the salt pan have become over time one of the most recognized symbols of this magical place.

Introduced around 1750 thanks to the industrial modernization of salt production, the windmills of the Trapani salt pans are built in Favignana tuff covered with a light and robust mortar. In the upper part of their truncated cone shape are the blades (traditionally 6) that once captured the force of the wind to set in motion the gear mechanism inside the structure of the mill.

Before then, the processes in which the mills were used were carried out through animal traction. These processes are essentially two: the transfer of water between the salt pan tanks and the grinding of the salt. The windmills of Trapani worked differently depending on the function they were designed for.

Windmills for lifting water

The mills used to move water in the salt pan are usually found between one basin and another in the salt pan. They were medium-sized constructions, and were used both to fill the basins and to dry them. In spring, in fact, the windmills pumped the water from the winter rains out of the salt pan and, after cleaning, the sea water was pumped back in.

At each change of tank, the mills were activated to transfer this increasingly salty water from one part of the salt pan to another.

The entry or exit of the water through the mills occurred by simply opening (or closing) doors placed inside the structure, aided by an ingenious device called Archimede's Screw.

The Archimede's Screw is an engineering work by the Syracusan inventor from whom it takes its name. It is a large wooden and iron tube composed internally of a central core around which spirals with a concave surface are wrapped. The Archimedean Screw was positioned horizontally under the mill, in a slightly inclined position and with the two ends placed in correspondence with two different tanks.

Through an external extension of the core on the highest part, the screw was hooked to the windmill mechanism, which allowed it to rotate with the lowest end on the surface of the water. Thanks to the rotation and the system of internal spirals, the water was transferred from one tank to another with ease, leaving the muddy sediments and water residues not to enter the new tanks during the transfer.

Innovation in the mid-1900s: "American" windmills

In the 1960s, new modernizations arrived to modify the structure of the salt-water windmills for pumping water. While the blades of the mills were dismantled in the approach of the winter months, the cylinder to which these structures were connected, typically made of wood, remained exposed to the elements and often suffered from failures. Replacing such a complex and expensive mechanical element was often a considerable economic effort.

In search of more efficient solutions, windmill models made with blades and mechanical elements in steel were imported. Specifically, the new model of the “American” Mill required fewer motor elements and was equipped with 24 blades to capture the force of the wind. These changes improved the working conditions of the millers and reduced the maintenance costs of the mechanisms.

Windmills for grinding salt

Unlike water mills, windmills for salt are majestic constructions of considerable size, built on large sheds and warehouses to be as close as possible to the place where the product is collected and stored.

Internally, the mill is composed of a system of gears and a shaft that transfers the driving force of the blades moved by the wind to the lower part of the structure. Here, two limestone stones positioned one above the other act as a millstone: with a funnel the collected salt was poured from above into the center of the upper stone (hollowed out internally).

This stone, in rotary motion on the lower stationary one, grinds the salt that comes out laterally through friction. From here the ground salt was collected in a tub, ready to be stored in the warehouse. This grinding operation produced a coarse salt used for salting fish or for preservation, while fine salt was produced at home in a mortar from this thicker grain base.

Visit a real windmill with Saline Culcasi

The fascinating giants of the salt pans are now in disuse and rare to find. Saline Culcasi in Nubia (TP) holds a treasure within a treasure. The ancient seventeenth-century baglio together with its grinding windmill are perfectly preserved. Inside the mill, you can visit the Salt Museum, a collection of work tools and historical photographic testimonies that tell the story of the processing of salt over the centuries and the life in the salt pans of the men and women of Trapani.

The Culcasi family will be able to guide you to discover the traditions of Trapani linked to salt and its production on this journey into the history of the area. You can visit the museum and the mill by contacting us as you prefer.