Een artikel over de molens op de zoutpannen van Trapani.
Op verzoek geschreven voor TIMS
Among other things I am a bit of a wild rover and my most faithful companion on the road is my old van (it already has some 400.000 km. on the clock). It has taken me from home to the North Cape, to Gibraltar, Taranto, as well as many other places, and always brought me back home.
So on 16th May we set off for a tour around the coasts of the island of Sicily in the Mediterranean Sea. On route we would look in on a few little settlements in Italy, such as Rome, Sienna, Florence, Pisa and Lucca. Not many people would give a second thought (or even a first!) to windmills when they think of Italy or Sicily. My female companion had no clue as to my ulterior motives: a good, long look at the salt water basins and windmills of Trapani and Marsala, at the most western extremity of Sicily. On 25th May, driving up to the Museo delle Saline at Trapani, it quickly became clear that not a single mill was intact! It looked like a battlefield after Don Quixote had been through there. Some mills are so badly damaged and are so dilapidated, even our erstwhile Don would have turned up his nose at them (see Fig. 1).
Fig: 1 One of the ruïned Mills
Fig 2: The mill on top of the Museum
This is a museum that houses a few sketches and loose items. Some pieces are almost recognisable: a windshaft, a brake wheel, a wallower, conical gears, an Archimedes screw, a breast beam and some more bits and pieces. Also there are some stone spindles and millstones, as some of windmills often had two pairs of millstones for grinding salt.
The museum mill itself is not open to the public as apparently there`s nothing left inside to be seen (see Fig. 2). According to a miller we met here, there were still two mills nearby at Marsala,
a windmill for pumping seawater into a basin and a windmill for grinding large chunks of salt.
This miller did not seem to mind my having entered the museum grounds or even crawling into one of the mills to take a few photographs of the interior, but at closing time we had to leave.
The technique of obtaining salt from seawater is rather simple: first seawater is pumped into an enormous but shallow basin or pan. This used to be done by windmills supplied with a pump or an Archimedes screw. American windmills with an Archimedes screw were also used for this purpose, and became a common combination (see rear cover). The sun and the wind did the rest, the water was evaporated and hence the salt concentration was increased. The specific gravity of the salt water in the basins is measured with an hydrometer before crystallization has started. Then the water is pumped into the next, smaller basin where evaporation continues and the salt content becomes more concentrated. Complete crystallization and precipitation only takes place in the third and last basin. Here the salt is scooped up and transported onto high heaps by a conveyor belt. These salt piles are covered with roofing tiles to protect the salt from the elements, especially from the rain, which seems logical to me.
Fig. 3: Museum mill near Marsala, details of the wooden poll end and the fastening of the sail stocks
Fig. 4: A derelict cap on a mill at Trapani showing the circular plates used to fasten the sail stocks.
Salt is still being extracted but nowadays electric motors and membrane pumps are being used. Unfortunately, exploiting free wind power does not exist here anymore. We left for Marsala on 26th May, a little downhearted, not expecting much, but to our utter surprise the Museo delle Saline in Marsala was much better than the one in Trapani. The museum mill here has been properly restored and is open to the public (see Fig. 9). According to an inscription the restoration was carried out by Paolo Stampa in 1996. There was no miller or anybody else to give us extra or technical information about the mill and how to operate it, which was a pity. In contrast to what the miller had told me the day before, these mills were not active either (unless I misunderstood him because of my broken Italian). There are two mills here which seem at a first glance to be in good condition, but theyre not! They are only for the tourists to photograph, but at least an attempt is made to keep up appearances (see inside the rear cover). The basins in both areas are filled with all different remnants of the mills, but sorry to say, they show no promise of surviving. Apparently there are not enough people with any interest or money to restore the mills, or even a few of them.
Fig. 5 & 6: A windshaft with compass armed gear wheel (on the left) and a conical lantern pinion wallower and gear wheel (on the right) in the Museum near Trapani.
However, the museum mill is attractive. One can wander through the mill, all the way up and down the floors, and from the gallery there is a lovely view of the salt basins. Most of these round conical mills are built of brick. The conical cap is made of sheet iron work with a protective hood for the breast beam and bearing. Some of the mills are built on a sub-structure which was used as workspace or for storage, etc. Some other mills are built at ground level, mostly with annexes. In some cases an American mill has been placed on such a round mill building, possibly as a replacement for a lost sail cross. Remarkably, all the mills have an intake which is at right angles to the Archimedes screw, which pumped seawater over a threshold into a spillway.
On these battlefields of six-sailers, two ways of constructing the sail crosses can be distinguish. In the first case three steel bars are inserted through the wooden windshaft. The six sails are connected to these bars with U-shaped clamps. Between the clamps bolts have been used to avoid displacement of the sails. In the head of the wooden windshaft is fixed a long steel bar as a bowsprit, together with strengthening around the head of the shaft. Between the top of this bar and the ends of the sails are attached stayropes to avoid too much bending of the sails at high wind speeds (see Fig. 3).
Fig. 7 & 8: Spur wheel suited to accommodate two stone spindles (on the left) and a pair of salt grinding stones (on the right) in the Museum near Trapani.
Another system has two round iron plates attached to the long iron bar (bowsprit) which is fixed in the head of the windshaft. Between these plates are fixed the iron or steel bars on which the sails are connected (see Fig. 4). All the surviving sails have double frames which are sometimes known as butterfly sails. The sail bars are inserted through the stocks and are fixed to the hemlaths. They are very tightly fixed because I could not discover any jointing material here. Between the stocks and the hemlaths there are two uplongs parallel with the stock. The technology used in these mills are not very different from other mills we know. They are not very large and the construction of the machinery is simple and light.
From the ladies in the museum I could not get any technical information how winding the cap was achieved. I suppose that a long and strong wooden pole or beam was used which could be attached to the wooden construction sticking out on top of the mill building. Inside the cap, the anchor chains must be set free and then the cap could be winded by pushing. The cap lies with the cap circle direct on the dead curb. In between the cap circle and dead curb there is only grease for lubrication. The whole construction is supported on a brick flange in which the keep flange is fixed. In the inner circle of the dead curb there are round holes into which fit the steel pins to which the anchor chains are fastened. On the outside the sails were anchored with thick ropes tied to wooden pins in the mill building. I did not see any lightning conductor on the outside of the mill. In both areas, Trapani and Marsala, I have not seen any sail cloths. I think that setting the sails, reefing etc. was carried out as anywhere else in the World.
Fig. 9: The salt grinding mill and museum near Marsala with salt workers in the foreground.
Fig. 10: One of the attractive windmills situated among the salt pans near Marsala
From top to bottom the construction of the mills is roughly as follows: Inside the cap we see the breast beam and a tail beam. These beams are anchored between cap sheers. There are also tie beams and bridle irons for strengthening. The wooden windshaft lies in a stone neck bearing and the tail lies in a bearing which is constructed in the tail beam. The cogs of the inclined main gearwheel drives a conical wallower (see Fig. 5 & 6). This wallower is fitted to the steel main shaft which is divided in several parts which are connected to each other with claw couplings. The gudgeon of the main shaft is fixed in the upper bearing which is mounted on the sprattle beam. As it passes through each floor the main shaft is supported by a hard wooden block which is smeared with grease. On the storey below is the brake. This is quite remarkable being a big wooden drum constructed around the main shaft. A thick rope is wound around this drum with two or three turns and one end is anchored in the wall. The other end is led to the floor below via pulley. Pulling the rope will cause the it to tighten around the drum thus stopping the mill. I think it worked very well in this type of mill. I wonder if such a construction would work in a big windmill like at Kinderdijk.
Below the brake drum are three beams anchored in the wall that meet in the centre of the mill where there is a bearing for the main shaft. This arrangement probable prevents bending of the main shaft during braking. On the next floor there is the spur wheel (see Fig. 7). Usually this wheel drives two stone spindles via two stone nuts. There is also a square framing of beams. This framing has two spindle beams which support the shaft ends of the stone spindles. Just below this frame is a cross beam on which is housed the bearing of the main shaft. At ground level there are two pairs of millstones. In the smaller mills on the basins there is usually only one pair of millstones. On top of the runner stone is a hopper in which the salt chunks can be thrown. The salt is ground between the millstones and falls into a kind of tub on which the bedstones are placed (see Fig. 8).
The stone spindles are led through these bedstones, passing through a wooden bearing to a steel construction under the bedstones. In this construction the end of the stone spindle is fixed in a bearing. By lifting or lowering the runner stone the distance between runner stone and the bedstone can be adjusted in a similar way to that used in grain mills. Unfortunately, I was unable to photograph this construction. The back of the runner millstones are curved as in the very old days. In the museum mill we could enjoy a film about obtaining salt and how this system worked when the mills were in operation. The system is still the same, but nowadays electric motors are used. In this museum are also a lot of technical drawings and photographs from the old times which present a good picture of the salt works in operation in the past. One exhibit, a hand operated Archimedes screw was quite remarkable. I think that this was used to pump out small amounts of water from the basins where the salt is shovelled up. Because many of the mills were in ruins, these visits could not be considered as a highlight of this trip around the island.
Sometimes there were tears in my eyes, but maybe that was because of salt in the air. I wonder if there are any TIMS members or mill enthusiasts in Italy or on Sicily who could do something for these mills. It would be a shame if this cultural heritage were to be lost forever. But maybe that is a task for Europe that seems to rule almost anything these days. Certainly, the salt basins deserve a place on the list of World Heritage Sites, just like Kinderdijk, among others. This report is made by an eyewitness who could only use his own observation and the background knowledge he has obtained as a Mio (in Dutch this means Molenaar in opleiding, or in English Miller in training). There was no adequate information available at the sites, despite the fact that language was not a big problem. So it is possible that on some points I have jumped to the wrong conclusion, or I have used the wrong word. Therefore I wholeheartedly invite any (Italian) experts to provide any additional information or corrections if necessary.
Because the lack of Italian equivalents for all parts of the mills, I have had to choose the English terms from the well-known TIMS Dictionary of Molinology. The author can be contacted at www.janalthofweb.nl and further photographs can be accessed at: https://www.flickr.com/photos/151756040@N07/albums