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July 2015
MODERN MINING
47
OFF-HIGHWAY TRUCKS
AND EXCAVATORS
feature
small to mid-size open-pit mining
ADTs can easily be adapted to a variety of roles. This 35 000 litre water tanker is working at an
emerald mine in Zambia (photo: Arthur Tassell).
bad underfoot conditions, flat and steep grades,
and wet and dry weather, all with equal ease.
“Admittedly, rigids are probably cheaper to
run over longer distances but balancing this
is the fact that – being two-wheel drive – they
require well-maintained, paved haul roads to
operate. One often hears that rigids also offer a
longer life and more reliability – but if they do,
it is because they are not normally subjected to
the same arduous conditions as ADTs. In terms
of initial cost, ADTs are generally cheaper than
similar-sized rigids.”
Gillham adds that a further advantage of
ADTs is that they can easily be adapted to
a variety of roles. “You can turn them into
water bowsers, fuel tankers, service trucks and
explosive trucks, to take the most common
examples. They can also easily be transferred
over to civils applications when mining is in a
downturn. Obviously, this is not a huge factor
for mine owners but it is for mining contractors,
who in many cases are active in both mining
and construction.”
It would be wrong, of course, to believe that
ADTs have no place on larger mines. While
they cannot handle the huge volumes and high
impacts involved in very large scale mate-
rial moving, they often have a role to play in
supplementing the big rigid trucks. It is not
uncommon, for example, to see rigids being
dedicated to waste haulage with ADTs catering
for the (generally) much smaller volumes of ore.
ADTs are also well suited to the satellite-type
operations that often present at large open-pit
mines, which are too small to justify the cre-
ation of well-engineered haul road networks
and which are best served by small trucks with
all-terrain capability.
Gillhammakes the point that current models
from virtually all the big ADT players tend to
be much more fuel efficient than was the case
just a few years ago. “I think the big OEMs have
all put a great deal of effort into reducing fuel
consumption,” he says. “In the case of Bell,
we use Mercedes-Benz engines and these are
renowned for their efficiency – and, for that
matter, their ‘green’ credentials, as they meet
all emission standards.”
Bell, like most other manufacturers, has
one global standard for its ADTs. “We don’t
change the specification for specific parts of
the world, with a high-tech machine for certain
markets and a low-tech version for others,”
says Gillham. “The machine we sell in Africa
is the same as the machine we sell in every
other market in the world. This partly reflects
the fact that mining is a global industry and
that big international mining groups expect the
same standards to be met wherever they work
and will not accept machines that compromise
on safety and environmental standards on their
sites.” He adds that one of the features of Bell’s
A prototype Bell B50E. This
machine will succeed the
ground-breaking B50D.