Next visit to the Bex Salt Mines
"Kilometres of underground galleries, a train in the mountains ... For once, the children were literally transfixed! "
Things to do in the Bex Salt Mines
Plenty of adventure and lots of stories.
The Salt Mines of Bex is now a vast underground labyrinth, several kilometres of which are open to the public. A unique attraction in Switzerland! Take a ride on the miners’ train and discover the most spectacular and the most characteristic elements of the various mining techniques used since the first gallery was first dug out in 1684, right up to the present day.
A meal, an event
Would you like to organise a unique and memorable event that is, let’s say…. 1,500 metres underground? Whether it's a conference, a seminar, a training day, or perhaps a drinks reception, a meal or an evening do, we can offer you the setting for an exceptional experience, far away from the trials and tribulations of everyday life!
For the more daring among you: Why not go on an adventure and discover the old galleries away from the standard tour circuit and enjoy the mine’s fascinating stories as retold by our experienced guides!
The history of the Sel the Alpes
Explore over 500 years of history, perseverance, ingenuity, skill, hard work and passion in the Bex Mines.
The history of the Saltworks and Mines at Bex is linked directly to the important discovery of salt springs in the Canton of Vaud in the XVth century. At that time salt was a rare commodity, difficult to transport. It permitted the mighty of this world to gain immense profit and power. And the Swiss having no salt of their own, were therefore dependent on foreign suppliers.
on the Earth originally came from the sea. The way our planet was formed 4.6 billion years ago is directly linked to the presence of salt in our oceans, which came from the erosion of the surface layer of the Earth's crust, lithosphere and volcanic gases.
the end of the Triassic, 200 million years ago, the land that would become the Switzerland of today was completely covered by the sea. When it receded in the early Jurassic, the salt remained trapped in the rock of the Alps, perfectly pure and protected from pollution.
in the region of Chablais since the XV century.
According to the legend, a young shepherd, Jean du Bouillet (nicknamed Bracaillon), when taking his goats to pasture towards Panex, not far from Ollon and towards Le Fondement just above Bex, noticed that the animals preferred drinking water from two particular springs. Out of curiosity he tasted the water, and finding it salty, took a cauldron full and boiled it. When the water had evaporated, he discovered that salt crystals had formed. Prosaically, it seemed indeed that livestock, greedy for salt, preferred the springs on the right bank of the Gryonne at a locality called 'Le Fondement'.
It was the Bernese invaders of the region, who in 1475 started the exploitation of these slightly salty springs by boiling the brine in pots over a fire, a process called evaporation. This procedure continued for almost 200 years.
around the Bex mine sprang up in early 1554. All attempts to recover the salt were still done on an artisanal basis. It was not until the following century that major works were undertaken for the start of true industrial exploitation.
that the Saltwork of Bévieux was established, the only one still in operation today.
Duirng htis same period, the springs had diminished and galleries had to be dug in view of emptying the immense reservoirs of salt water which were imagined to be in the mountain. A labyrinth of shafts, stairs and galleries was excavated over more than a century. This gigantic piece of work was carried out at first with hammer and chisel, and later on with gunpowder. According to a communication in 1686, rumor had it that prisoners had been used in the mines side by side with the local population of traditional labourers. This gave way to some tensions between the two categories of miners. If indeed the presence of prisoners does seem to have existed, child labour was never used.
The Bernese government acquired the operation in 1685.
Between 1684 and 1691, an important excavation was carried out: the Coulat Gallery. A main gallery called 'Principale du Coulat' was begun on the left bank of the Gryonne. A tunnel 700 meters long had to be dug in order to reach the 'Cylindre'. The latter was thought to be a reservoir containing the precious salt water; and without any real reason they attributed to it a cylindrical form.
In order to speed up the operation, it was decided to dig a stairwell for ventilation. This descending excavation was an arduous and perilous operation for the miners. They had to dig lower than where they stood under the feeble lights of oil lamps, with insufficient ventilation. The debris had then to be carried up on their backs. At that time, the work in a horizontally dug gallery advanced by four meters per month, vertically at a much slower rate. The stairway of the 'Coulat', called 'Escalier Ruiné', has 458 steps.
Isaac Gamaliel de Rovéréa, the then director of the Mines, decided to undertake an even more audacious operation. His project was to dig a gallery leading out of 'Bouillet'. A distance of two kilometers separated the starting point from the famous 'Cylindre'. There also a second attempt was made from a stairwell of 735 steps. But the Bernese government, alarmed by the magnitude of the task and by the expected duration, took the decision to close the site. At this stage 202 meters of gallery had already been dug, and the 'Grand Escalier' (grand stairway) was already finished. The government held to its decision, after having consulted with an engineer from Saxony, the Baron de Beust, who recommended the excavating of a shaft in order to test the 'Cylindre'. These new experiments were a deception. Salinity seemed to diminish. The future of the mines looked somber, to such an extent that Bern considered closing them down altogether.
It is then that in 1768, que the son of de Rovéréa took over his father's plans and saved the site for a first time. Specialists then realized that the 'Cylindre' is in fact a thick layer of subvertical schist and dark sandstone which has nothing of a cylindrical form. Mr de Rovéréa proposed to dig a gallery along this layer from which crossings were to emanate. The first of these transversals led to the discovery of a good source of saline water. Two other trials also led to results which allowed the saltworks to operate for more than 60 years.
the excavation of the Bouillet gallery resumes with the arrival of a new protagonist, Jean de Charpentier. The works last for twelve years. A massive saline rock ('Coulat'-pocket) is uncovered, while a whole series of galleries as well as two desalination sites are excavated. This mass of saline rock was cut up in the underground superimposed quarries. These blocks were then grouped by twos or threes and transported into caverns: the desalination sites. It is here that the salt was liquefied by washing of the blocks. The brine was brought to saturation by a rotating system. Then this saturated brine was dispatched to the saltworks of 'Bévieux' through pipes made of trunks of larches. But this expensive form of exploitation required a large work force. The salt of Bex could therefore not compete with foreign salt from the time that transportation by rail was made possible.
During the revolution, the region was restored to the people of Vaud, but the problem remained. In 1836 large deposits of almost pure salt were discovered at Basel; they were much easier to exploit than those at Bex. And in 1865 the 'Vaudois' once again considered closing down the mines which they judged to be unprofitable.
As of 1867, the citizens of Bex united to save their industry. Four of them, namely Messrs Grenier, Chappuis-Veillon, Beauverd and Laurent created the Compagnie des Mines et Salines de Bex, and instituted a new mode of exploitation. They conceived the idea of flooding the existing caverns and galleries. The water which infiltrates everywhere transforms into brine. It then suffices to pump it out. Slowly but surely, new techniques and modernization in the recuperation of brine rendered the mines profitable and largely facilitated the work. This reprieve was short-lived…
Around 1877, the wood-burning stoves were abandoned and replaced by a new technique: salination by thermo-compression with the Piccard apparatus (named after the inventor who was at the time manager of the 'Papeterie' at Bex) and which was built there. This system, steadily improved with time, is today still in use worldwide. It works on the same principle as the heat pump. Brine is brought to boil in evaporators using live steam generated in boilers. Then the steam is compressed, increasing its temperature, before conveying it to the evaporator, where it serves as heating agent. All this happens, of course, in a closed circuit.
In recuperating the heat contained in the steam, this new technique saves a considerable amount of energy. From 1867 to 1913, the two caverns 'Coulat' and 'Bouillet' furnished 164,486 tons of salt. Within a century, thanks to the various processes used, production at the saltworks increased tenfold whereas energy consumption was reduced to less than a tenth of what it used to be.
is marked by an important event: the Société Vaudoise des Mines et Salines de Bex replaces the old company. The Canton becomes a 50% shareholder and renews the concession until 31.12.1969.
Interestingly, it was in 1924 that the regulations of the Canton of Vaud that imposed the introduction of iodine in salt.
The appearance of boring machines as from 1924, make it possible to save the mines. First used for prospecting only, the drillings will later, around 1960, allow the desalination of saliferous rock by direct injection, a technique still used today.
The Salt Mines of Bex were not spared by accidents due to firedamp. Reliable means exist nowadays to detect the presence of this odorless and dangerous gas capable of exploding at the slightest spark.
1943 saw the installation of the new electrical power station at the saltworks.
The commercialisation of salt was at first handled by the Canton of Vaud. Only in 1997 the latter entrusted this task and the control of the salt monopoly (salt tax) to the Société Vaudoise des Mines et Salines de Bex.
the company changed its name to become what it is known as today, Saline de Bex SA. At the same time, the Bex Salt Mines Foundation was set up, its purpose: to bring the tourist attraction to life and preserve the extraordinary heritage that had been developed from generation to generation through the sheer determination, creativity and courage of the Swiss pioneers in salt. In 2014, the company Saline de Bex SA joined the Swiss Salt Group SA, guaranteeing the supply of salt for all Switzerland.
Over the centuries, the Mines at Bex have been visited by famous people. Among them Jean-Jacques Rousseau, who passed by in 1754 and Alexandre Dumas, who visited the mines on September 28, 1832. The latter walked the route, nowadays done by train, before climbing the 'Grand Escalier' (grand staircase), visited the 'Chambre de la Roue' (Chamber of the Wheel) and exited by climbing the steps of the 'Escalier Ruiné'. During the first exile of Napoleon I on the Island of Elba, Empress Marie-Louise herself also walked through the mines. The 'Grand Reservoir' carries her name in homage of her visit.
Alexandre Dumas (1802 -1870)
Alexandre Dumas was thirty years old when he visited the Bex salt mines.
It is the year 1832. 'Henri III' and the 'Tour de Nesle' have just recently been a triumph. Fleeing Paris which was in the throes of a cholera epidemic, the young writer, who had travelled by stagecoach, finally reaches the foothills of the Dents du Midi.
A miner leads him into the bowels of the earth: this frizzy-haired giant (Dumas was the grandson of a Haitian slave) proved less intrepid than his 'Three Musketeers' !
With great humour, Alexandre Dumas recalls his adventure in the mines: scuttling down ladders 'like a beetle down a blade of grass', asking his guide if 'this foolishness’ was nearly at an end, and dropping his lamp which his eyes followed 'until finally a dull thump could be heard as it made contact with the water, signalling to me that it had arrived at our final destination before we had.'
Retrace the steps of the illustrious author by taking part in the TrekkMines Adventure!
Impératrice Marie-Louise (1791 - 1847)
'Gathering her blond hair under a black hood', Empress Marie-Louise entered the Bex salt mines ...
'Walking in front of her, torch in hand, the miner took her on a journey through a subterranean underworld...
Around the corner from a deep well, the young woman discovered a vast room of columns covered in gypsum crystals, the reflection of which could be seen in a salt lake.
Admiring the boldness of this feat of human engineering, all thoughts of her husband Napoleon exiled on the island of Elba, and her infant son, whom the French called 'L'Aiglon' (the eaglet) vanished that July day in 1814.
Share the emotions of the young empress by visiting the Réservoir Marie-Louise!
The origin of the Sel des Alpes
For over five hundred years, the Sel des Alpes has been extracted from the mountainous rock in the Bex Salt Mines, by dissolving in the glacial spring water then by evaporating. The precious crystals preserve all their purity and mineral wealth.
Channelling pure water from the glaciers to the Salt Mines
Water from the glaciers of Azeindaz and Diablerets, is primarily completely pure snow that has accumulated since the Pleistocene, long before any human activity, and has been preserved in the form of ice for thousands of years. The instant it returns to its liquid state, it is routed to the Bex Salt Mines, where a new destiny awaits.
Extracting the Sel des Alpes from the saliferous rock
An important step involves drilling into a saliferous vein. Once the research has been conducted, a tube measuring 5 cm in diameter is inserted fully into the probe hole. This tube is perforated along its entire length. A second, narrower tube is inserted inside this larger tube, it too is perforated. Meanwhile on its lower part. It is through this inner tube that the water from the alpine source is injected under pressure. As the water seeps into the rock, it gradually dissolves the salt in the rock over a radius of 400 metres. The pressurised water, without any outlet points, rises back through the outer tube in the form of brine (salt water).
The pure brine that is extracted in this way from the mountain is channelled through pipelines into the Bex Saltworks below. Rich with around 300 grams of salt per litre, the solution is close to saturation (i.e. the maximum amount of dissolved salt that water can contain before it re-crystallizes and can no longer be transported in this way).
Desalination through thermocompression
Desalination is the process of retrieving the salt content from the brine. Since the first excavations at the Bex Mines, the salt has been recovered by means of evaporation. Naturally, over the centuries, the techniques have evolved. Thermocompression has replaced the wood-burning stoves used at the beginning. Moreover, the method of thermocompression was developed at the Bex site by Antoine-Paul Piccard (great uncle of Bertrand Piccard). Revolutionary for its time, this technology led to substantial energy savings compared to the open evaporation process over a fire source. The little energy that is required for the process is today provided by our own hydroelectric plant on the Avançon, certified naturmade basic.
Packaging the crystals
Once the salt has been recovered, it is carefully dried to eliminate any residual moisture before being weighed and packaged directly into the bags you see at your local grocers.