Marble of Carrara From Wikipedia, the
free encyclopedia.
The Carrara marble (for the Romans marmor lunensis, "Luna marble") is a type of
marble, quarried in the Apuan Alps of Carrara area, known worldwide as one of
the most precious marbles. History of Carrara marble
The marble caves were probably used during the Copper Age, from the primitive
inhabitants of the area to make tools and various decorative and commemorative
items to be buried in coffins with the dead.
The Romans developed the mining operation itself, and since the time of Julius
Caesar (48-44 BC) supplies the blocks of white marble, the major public
buildings of Rome and several patrician houses.The
export is done through the port of Luni, which was said to Luna marble.
From the fifth century mining undergoes a period of stagnation following the
barbarian invasions.Following
the increased spread of Christianity marble is required in large quantities for
the construction of religious buildings and their interior decoration.The
bustling activity of the quarries is mainly due to Magistri Cumacini, including
Nicola Pisano and Giovanni Pisano, who use it for their work in central Italy.Later
it was the marble used by Michelangelo for his sculptures and came to personally
choose the blocks in which to carry out their work.
In the twentieth century, much use is made of Carrara marble during fascism:
Mussolini gave even the marble for one of two mosques of the Temple Mount in
Jerusalem. The marble quarries
The quarries are places where for many centuries is the quarrying and processing
marble and can be of two types: closed and open.For
the manner in which the marble is drawn, the depth of perspective of the white
walls, wide open spaces, the precision of symmetric steps, the steps seem to
work plans of amphitheatres.The
extraction of the marble quarry has been a constantly evolving document and
dramatic live through the centuries, from the primitive wooden wedges, cut to
the system of the Romans, to the revolutionary coil wire, diamond wire current,
as fast as dangerous,among
the ravines and quarries of white and steep quarry are kept heroism, the
struggles and sacrifices of miners who with tenacity and ability to continue to
this day to demolish these mountains cutting them, and frantumandole smontandole
piece by piece, into small blocks and then sent inworld. Quarrying and
processing marble
The excavation of the marble in the Apuan Alps dates back to very remote ages (I
sec.ac) and has undergone profound changes in the last century.Formerly
the excavation was done with very simple methods and tools, and with great
expenditure of time and effort to achieve modest results.Essentially
manual work was done by a workforce made up largely of sentences of hard work,
and Christian slaves. The first miners exploited the natural fractures in the
rock in which inserivano wedges of fig wood, which then bathed with water,natural
expansion caused the detachment of the rock.In
order to obtain blocks of defined sizes, the Romans resorted to the technique of
"panel", was practiced in the rock chosen, along the cutting line, a deep groove
15-20 cm.in
which they form part of the wedges, then iron, beaten repeatedly and time,
determined the detachment of blocks of 2 m.thick.Such
as mining and processing techniques, such as sawdust hand, remained almost
unchanged even after the discovery of gunpowder, the use of which turned out to
be more harmful than helpful, because the marble was often so crushed to lose
all commercial value.Only
later with the use of mines with the operation called Launched (an event that
left all workers with bated breath) you could detach a large amount of marble
without damaging the product.
The real revolution in the extraction technique took place in late 1800 with the
invention of the coil wire and pulley penetrating.The
steel wire is a cable of 4-6 mm.in
diameter, obtained by the torsion helix with three wires.The
grooves thus determined have the function to transport and distribute, along the
cut made by the cable, the water and the silica sand, originally from
Massaciuccoli, which serve the abrasive action.The
helical wire, placed in a special circuit of pulleys secured to said special
pallets pruned, is long typically a few hundred meters and is moving at a speed
of 5-6 m / sec, while affected by the marble at a rate of 20cm
per hour.The
pulley is a penetrating steel disc features circumferential groove and a small
diamond teeth.By
means of these two brilliant technical the pulley, sliding on a tool rack called
machine that allows the regular and continuous lowering, at the same time
fulfills two functions: while it penetrates into the groove in the marble drag
the helical wire which causes the cutting of the block.
Before starting to cut ahead and start any work on the square, had to leave the
mountain on that side of the rock surface alteration rendered unusable.For
this work, agility and skill which had intervened on tecchiaiolo to examine
closely the marble, freeing the parties precarious: to do this was to descend,
hanging from a rope in front of the quarry face.The
cut at the upstream consisted of isolating from the body marble which
constitutes the reservoir, a huge portion of rock, said cylinder bank, shape and
size defined as a function of the blocks that are to be obtained.Separate
the bank from the rock, the miners proceeded to his reversal on the quarry.This
massive operation had considerable difficulties and its execution entailed
serious risks.On
the square, meanwhile, was preparing the so-called "bed" consisting of a pile of
fine marble detritus mixed with sludge produced by previous, to cushion the fall
of the bank and limit breaks.Once
on the ramp, the bank was washed to be examined by experienced miners who
identify impurities and marked the spots where making any cuts.The
next operation was resizing in blocks of commercial size with the diamond-wire
cutting.Delicate
operation: each error, in fact, was likely to decrease the yield of the whole
cylinder bank and produce blocks of less than the value that the quality of the
marble was hoped.Then
came on the scene riquadratori, that sound of chisel and hammer, trying to give
shape to a square block.It
was a difficult, heavy, and those miners had to be strong, patient and dedicated.
Finally came the diamond wire, which is currently in use, the introduction of
which initially create 'issues of job security due to the ease' of release,
issue the correct time. The transport of marble
over time
Once the boxes, the blocks were to go down between debris flows marble called "quarry".Historically,
the descent of the blocks along the steep rocky slopes of the quarries has been
risky business and technical issues, and was carried out with increasingly
sophisticated methods As the economic and social conditions of the region
evolved.The
first rudimentary method of transportation is called "momentum" and was to do
the boulder rolled down the slopes, without any control, until it stops on a bed
of finer debris.The
procedure is widely practiced in ancient times, was so dangerous that it was
prohibited by law when it affirmed the method of "lizzatura".
The lizzatura is a traditional method of transporting marble skid, still
practiced in the early decades of the twentieth century.Basically
the block of marble was firmly fixed to a wooden sled retained upstream by a
system of ropes sliding.The
slide was gradually lowered down the slope by a team of men who loosened the
ropes and controlled the path of the slide.At
lizzatura attended twelve men: it was a very dangerous team.In
front of the slide was placed on the running head, usually the team's most
experienced workers, with the delicate task of controlling the descent proceeded
for the better.The
chief contention prepared the "wallpaper" on the ground in front of the race,
and gave the signal to mollatori to loosen or tighten the cables at the right
time.The
"wallpaper" was sturdy planks of cherry wood, shaving and the youngest of the
company, which were added before loading proceeded hand in hand this down,
allowing it to glide unimpeded.Another
very important figure in the "contention" was the "mollatore", also called "the
man of pyro," which had the task of slowly loosen the ropes that held up the
block, so that the load came downslowly
and gather speed.The
lizzatura was one of the more risky of the entire production cycle: if the load
is freed from the ropes, and gathered speed, it was common for men to overwhelm
one or more of the team, with serious consequences.The
work of lizzatura ended when the cargo arrived at the "hill", that was the place
where the blocks of marble were freed from the ropes and loaded on wagons pulled
by oxen, which had the task of transporting the marble workshops, sawmillsor
at the nearby Port of Marina di Carrara.
Since the last decades of the nineteenth century, said the rail transportation
of marble, by building a dedicated railway line shortly after the unification of
Italy.The
Rail Marble was used for nearly a century to transport the marble in competition
with the traditional lizzatura, convoys of wagons pulled by oxen and the first
attempts of the road transport and road tractors.Built
between 1876 and 1890 the railroad connecting the main centers of the three
storage blocks of Carrara marble basins - Torano, Miseglia Colonnata and - with
the sawmills in the plains, the port of Marina di Carrara and the national rail
network.The
construction of the track represented a significant engineering feat given the
means of the time: they had to overcome a height difference of 450m total length
of 22km and a maximum slope of 6 percent, through a large number of bridges and
railways.
The "marble" long worked to replace the road network, but the construction of
ever more numerous ways of entrenchment and the resulting competition with the
modern means of road transport made it uneconomic.After
a short labor, the railroad ceased its activities in 1964 and his path was
largely dismantled.Some
sections were processed in the streets.
The transport of marbles on the street began to emerge about since 1920, with
the expansion and modernization of roads bound for the extraction basins.The
first means of transport were mechanized "tractor" internal combustion,
traditionally called "ciabattone".From
post-war road transport became predominant, especially with the introduction of
German-made truck Magirus-Deutz.Currently,
all excavated from the marble quarries is transported by truck to the port of
Marina di Carrara, or routed to other destinations. Destination of
the marble quarried
Much of the extract is maintained at the marble block was not processed and sent
directly to the port of Marina di Carrara, which is still managing the majority
of shipments, especially abroad.Almost
all the rest of the marble is extracted rather small slabs of different
thickness and then polished to provide raw material for panels, ornaments,
stairs, marble and other accessories.To
do the sawing and polishing are in operation in the province of Massa Carrara
over a hundred mills which, for equipment and the degree of specialization, work
with marble and granite from around the world.
A fraction of the marble quarried is processed in the laboratories of sculpture
in Carrara, Massa, Pietrasanta and surrounding areas.Employees
in this work are divided among stonemasons, modelers, sculptors and
ornamentalists.In
Carrara has established an "Professional Institute for Industry and Handicrafts
of Marble," which is capable of conferring a specific qualification for workers
in this field.