|
|
|
Yesterday |
 |
 |
To the
men of yesteryear, to the
engineers confronted with
the difficulties due to a
lack of knowledge
and technical means in the discovery
of a rich lode in a long and
dispersed deposit, and to the
laborers having had to endure
the hardship of working in those
days.
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.
|
Satiric
engraving of the'Proverbes
de Lagniet' published 1657-63,
depicting
the oppression of the
poor by the rich
|
| |
|
Legend has
it that a young shepherd, 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. |
Shepherd
with his goats
|
| |
|
1684
- 1823 : Excavation
The first steps for the recuperation
of salt were limited to tapping
it at the spring. It then became
necessary to proceed by digging
deeper in order to reach the
water at a lower level by means
of stairs. By 1680 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 laborers. This
gave way to some tensions between
the two categories of miners.
If indeed the presence of prisoners
does seem to have existed, child
labor was never used. |
'Cylindre'
|
| |
|
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. |
Start
of the 'Coulat' gallery excavation
at the bottom of 'Escalier
Ruiné'
|
| |
|
In 1725,
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. |
Galerie
Rovéréa
|
| |
|
| As of 1811, 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. |
Example
of extracting saliferous
rock in a grand gallery and
of its transport to the desalination
sites
|
| |
|
|
1823 – 1867
: Exploitation at the desalination
sites
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.
1867 – 1924: Desalination
on a large scale
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. In
due course new techniques and
modernization in the recuperation
of brine rendered the mines
profitable and largely facilitated
the work. This reprieve was
short-lived… |
Portraits
of the 4 founders of the
'Compagnie des Mines et Salines
de Bex' :
Grenier, Chapuis - Veillon,
Beauverd, Laurent
|
| |
|
Towards 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 - 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.
1917
This year 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. |
Salination
by thermo-compression
with the 'Piccard' apparatus
|
| |
|
As
1924: Drilling
The appearance of boring machines
will 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. |
Drillings
for spring water injection
|
| |
|
1943 saw
the installation of the new
electrical power station at
the saltworks.
The commercialization 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.
In 2002 the
company changed its name to
become 'Saline de Bex SA'. The
determination of man, his creativity
and courage over centuries,
make it possible for our canton
to be self-sufficient in salt
even today. |
Our
Specialties
|
|
|
