Liebherr L 556 - Manual (Page 12)

12 // Quarrying
The roots of the Holemans Group go back to the year 1873 , and
the head office is in the town of Rees directly on the Rhine. Its
core business is the quarrying and marketing of gravel and sand,
and 95 % of this is delivered to the construction industry, where
it is used as raw materials in the production of concrete. The
family business is now in its third generation and employs 130
people. It’s not just the customers who benefit from the
company’s activities. Many protected species of animals and
plants find new homes in the gravel pit lakes that are created.
And the people in the region enjoy the watery recreation areas.
The companies of the Holemans Group deliver some 4.4 million
tons of high-quality gravel and sand every year, mainly to
manufacturers of concrete components, concrete transporters
and construction materials traders. “Sand and gravel can be found
everywhere, for example in buildings, footpaths, roads, bridges
and pipes, to name just a few,” says Thomas Derksen, technical
manager of Holemans GmbH. “Solar cells and microchips also
contain sand.”
Sand is made up of grains of between 0.00025 and 0.08 inches
in diameter. Gravel grains are between 0.08 and 1.26 inches in
diameter. “Sand and gravel are also split up into various size
categories. The individual fractions are separated using different
processes and then mixed in precisely defined ratios for the
specific requirements of the customers. “Today, concrete
manufacturing is a science in itself. As the industry develops, the
requirements on the raw materials are increasing,” says Thomas
Derksen, commenting on trends in the sector.
The Holemans Group performs mining and recultivation
in stages, many of them in parallel. Embankments and paths
are laid, waterside areas fortified and trees planted. Ten Liebherr
machines are used in these operations: eight wheel loaders, two
wheeled excavators and one crawler.
Holemans has been placing its trust in Liebherr excavators and
wheel loaders for many years. The crawlers employed to date
include a PR 743. From December 2012 until July 2013, a
preproduction machine of the type PR 736 was tested. The tasks
of the crawler included shifting and depositing gravel fields and
top soil and shaping the topography of the terrain. Some 2100
operating hours were accumulated.
The PR 736 features an unprecedented electronically regulated
travel control with integrated “eco” function and proactive power
adjustment, which offers the choice between high power out
putand maximum efficiency. “The important thing for us is that
we have power for pushing. That makes up 90 percent of our
operation,” explains Thomas Derksen. “And the power available
is really impressive compared to the predecessor model. Despite
this, fuel consumption is on a similar level.”
Other positive aspects for the drivers were the comfort and clarity
of the cab, which has been developed completely from scratch.
All-round vision provides for additional efficiency and safety –
even in the area around the door – thanks to edges that drop
“Service over the entire lifetime of the machine
plays a decisive role for us. With Liebherr, we
know that we can rely on a quick response and
good work.”
Thomas Derksen, technical manager of Holemans GmbH
Thomas Derksen, technical manager.
From gravel to sand
and on to new lakelands
Many gravel pit lakes on the lower Rhine are former quarrying fields of the Holemans Group. Here in the region
between the Ruhr and the Netherlands, companies of the Holemans Group have been extracting gravel and sand
before recultivating the areas affected for many decades. For six months, a PR 736 was in use as a practical test
machine for the new crawler generation 6.
Feature: Holemans GmbH