Liebherr L 556 - Manual (Page 17)

Quarrying // 17
The “Carrière des Grands Usages” quarry covers an area of 173
acres and is owned by the companies Eurovia and Colas. It is
located just a few miles from Bourges, France. At present, 74
acres are being used to produce material for road building and
concrete production. “We offer the full range for the construction
industry, with grain sizes 0/10, 0/20, 0/30 and 0/60 plus 4/10
and 10/20 for the production of concrete,” explains Alexandre
Favin, operations manager of the Carrière des Grands Usages
quarry, or CAGU for short. Other products include filling sands,
drainage materials with 40/70 grain, as well as blocks of rock
from 3.9 to 7.9 in and even 19.7 to 39.4 in. “All of these are
prepared according to the customer’s wish, for example, for
fortifying embankments or as decoration for landscape architects,”
the operations manager adds.
The most important customers of the CAGU quarry are the
members of the syndicate that own the quarry. These include
the locally based companies Eurovia and Colas, but also civil
engineering companies and two ready-mixed concrete plants
in Bourges. The Carrière des Grands Usages quarry includes
the Morthomiers limestone seam, which is very well known in
the region. The excavation permit allows 402, 344 tons per year
to be quarried until 2034.
“Prior to excavation, we have to clear 7.9 to 11.8 in of spoil and
then a 19.7 in to 6.6 ft deep layer of material. Depending on its
quality, the latter layer may either be sold or used for filling on the
quarry grounds,” explains Alexandre Favin. Drilling and blasting
are outsourced to a subcontractor.
A crawler excavator from 2005 was used in the quarry until June
2013. The excavator loads a rigid-frame dumper truck that trans-
ports the limestone to the charging hopper of the processing
machine. The material is conveyed by an apron conveyor to a
scalper where the stone is separated and sieved. Material larger
than 4,7 in is carried to the primary impact crusher which produces
material of grain size 0/31.5, 30/70 or 30/150 and 70/150. A
second impact crusher produces material of grain size 0/4, 0/20,
4/10 and 10/20.
The materials from the machine are taken to the stocking bays
by a rigid 30-ton dumper truck. Besides the production of con-
struction materials, the quarry is also able to take earth from
construction sites. “Customers tip their earth onto a platform
specially provided for this purpose and we spread it with a crawler
loader to fill the quarry grounds,” explains Alexandre Favin.
“With 11,500 operating hours, the crawler excavator had already
reached a ripe old age,” Alexandre Favin tells us. “Moreover, this
55-ton excavator was somewhat oversized in view of the eco-
nomic development,” he adds. “More than anything we wanted
a smaller excavator.” The operations manager at the quarry was
really looking for an excavator of about 44 tons.
He compared the offers of the different manufacturers, including
Liebherr. He asked Liebherr if he could test the R 946. Fabien
Denis, technical customer consultant at the SOMTP Centre, the
contractual dealer for Liebherr in the region, recommended the
R 950 SME (Super Mass Excavation), a new machine that was
launched in 2012. “That is the quarry version of the R 946,” Fabien
Denis says. “It has the turntable of the R 946 and the undercar-
riage of the R 956. Its boom and bucket arm are reinforced and
the ballast weight is higher. The driver’s cab and the tilt cylinder
feature safety devices, and the windows are made out of armored
glass. The underbody is protected by a thick guard plate.” In
contrast to the R 950 SME, neither of the competition models
that were considered was specially designed for work in a quarry.
“In our region, we are heavily involved in the Eurovia companies,”
Fabien Denis adds. “But this is the first R 950 SME within the
Eurovia Group,” Alexandre Favin explains. The Construction
Machines department of the road building company is monitoring
the testing of this model at the CAGU quarry with interest. Another
advantage is the vicinity to the Liebherr contractual dealer SOMTP
Centre. This is just a few miles away from the quarry.
That’s how the R 950 SME came to find its place in the quarry’s
machine fleet. It is equipped with a Liebherr backhoe bucket with
semi-delta cutter and 3 yd
3 capacity without special wear protec-
tion as the material is not especially abrasive. “This procurement
was part of a partnership,” Alexandre Favin tells us.
R 950 SME: The right excavator for
“Carrière des Grands Usages” Quarry.
When the time came for the 50-ton excavator at this limestone quarry to be replaced, the operator
selected the R 950 SME – an excavator of the right size that is specially designed for working at the
face yet versatile in its operation.
The R 950 SME flexibly performs
its tasks on the excavation front.
Quarrying in profile: Carrière des Grands Usages