MINING TRUCKS
protocols, and functional safety to manage vehicle
behaviours safely and productively.
Finally, philosophically Hitachi says it is a
strong advocate for open interoperable systems
and this applies to both fleet and technology
domains. “We’re designing our solutions in
excavators, trucks and software systems to work
with our customers’ chosen systems, fleet and
technology stacks. Other OEM shovels and
loading tools will work with our AHS, subject to
installation of our AHS on-board kit to
communicate with our system.” Like other OEMs
there are plans for full excavator autonomy but
HCM added: “An excavator is the key orchestrator
of load and haul operational efficiency, and HCM
will keep highlighting potential operator-assist
functionality developments and support
mechanisms to customers.”
Caterpillar’s 798 AC broadens wings
Caterpillar continues to make strides across its
electric drive models. This includes a number of
new 794F AC fleets for major projects including
Adani Australia and Anglo American’s Quellaveco
amongst others (Quellaveco will also be the first
autonomous 794F AC fleet).
On this model Cat says: “Overall, customers are
recognising the superior performance of the Cat
794 AC versus other 320 short ton competitors,
even when configured to the same power setting.
This is immediately evident once the 794 AC is
placed in a mixed fleet. Notably, our customers
have elected to make repeat purchases of 794
fleets, which is an excellent indicator of customer
acceptance.”
But a current big focus is also on getting the
new ultraclass 796 AC and 798 AC trucks into the
market. Arguably the 798 AC with a 372 t rated
payload is the largest haul truck in the market
now (not including the BELAZ 75710), and just
ahead of its sister mechanical drive truck, the
797F. The smaller 796 AC has a 326 t payload.
Cat told IM of progress: “The 796 AC and 798
AC programs include several trial fleets in a variety
of applications worldwide to help build product
confidence. Running as part of site production
fleets since Q2 2018, the trucks have accumulated
high field hours in challenging applications. Our
first trial was successful and resulted in the
commercial sale of units to that customer.”
The company would not be drawn on locations,
though two units of the 798 AC are known to have
been trialled at Arch Coal in Wyoming, and units
are now also thought to be running at Antamina in
Peru delivered via dealer Ferreyos as well as units
running with an operator in the Alberta oil sands
delivered by dealer Finning Canada.
The 798 AC shares structural design DNA with
the Terex Unit Rig MT6300AC that joined
Caterpillar through its Bucyrus acquisition in 2010,
but also leverages the engine and drive system
32 International Mining | APRIL 2020
heritage of the 795F AC
A Cat 798 AC working in a
Wyoming coal operation
and 794 AC, along with
the final drive,
suspension, and robust
oil-cooled brakes from
other Cat trucks,
including the 797F. “The
798 AC is a fully
Caterpillar engineered
and sourced product
combining proven
designs, backed by our
world-class
manufacturing, parts,
and service solutions.
We are confident the
efficient, integrated
design of the 798 AC
allows the truck to
achieve size-class leading payload, even after the
addition of customer attachments.”
Caterpillar is also currently commissioning a
796 AC commercial fleet in Australia with
additional units coming in 2021. It says it is
pleased with the early adoption of what is the
most recent addition to the Cat truck lineup.
On results so far Cat says: “Feedback has been
positive for the 796 AC and 798 AC, including the
truck’s ability to meet or exceed customer
productivity, gradeability, speed on grade and
braking metrics. Customers have also
acknowledged the advantages of the simplified
truck design, modular component access and
overall ease of maintenance.”
The trucks are not yet currently available as
AHS fleets with Command for hauling solution but
this is a scaleable design and is currently available
for the 794 AC. The company told IM: “We are
actively working with customers on opportunities
that will allow Cat to expand Command offerings
to the 796 AC and 798 AC trucks.”
Caterpillar remains the only manufacturer that
offers both large mechanical and electric drive
trucks, capable of meeting customer performance
needs and customer drive system preference,
backed by its world-class dealer service and
support. Caterpillar has field evaluated both Cat
mechanical drive and Cat electric drive 250 ton
and 400 ton trucks and still maintains that each
has its place depending on the type of use, haul
road layout etc.
The other major news of 2020 so far was the
announcement of trolley assist availability across
the electric drive range. The statement said the
new Cat trolley assist system for Cat electric drive
mining trucks “is now available for mining
operations seeking a means to reduce carbon
emissions, lower fuel and engine costs, and boost
speed-on-grade for greater productivity. The Cat
trolley assist retrofit kit is currently available for
the 795F AC truck, and the trolley design is
compatible with the three other Cat electric-drive
mining trucks – 794 AC, 796 AC and 798 AC. The
commercial introduction of Cat trolley assist
comes at the conclusion of a nearly two-year pilot
project conducted with four 795F AC trucks using
700 m of electric trolley line at Boliden’s Aitik mine
in Sweden.”
“The Cat trolley assist program at Aitik have
been a real success story” says Jonas Ranggård, a
program manager at Boliden. “Availability has
been high despite the Arctic conditions, and we’ve
had good support from Caterpillar and all other
partners involved. There are few projects that can
show both environmental and productivity
improvements of this magnitude. This is why
Boliden has decided to expand the trolley
infrastructure in Aitik and equip its entire 795F AC
truck fleet with trolley assist systems.”
“We thank Boliden for their work in
demonstrating the capabilities of the Cat trolley
assist attachment. The benefits of trolley can be
significant in the right conditions, and we would
be pleased to discuss site-specific scenarios with
customers.” said Eric Ruth, electrical senior
product team leader with Caterpillar. “We feel that
trolley assist can play a role in achieving mining
companies’ greenhouse gas reduction goals.
Simultaneously, trolley assist boosts productivity
by increasing speed-on-grade. In fact, testing at
Aitik mine has shown that a 795F AC equipped
with trolley assist is the most powerful mining
truck in the world.”
The trolley system significantly reduces diesel
engine emissions at the mine via substitution of
electricity during the most demanding part of the
truck work cycle. Powering a 337 t payload 795F
AC via trolley on a 10% grade as it climbs the ramp
out of the pit saves up to 40 litres of diesel fuel
per kilometre of trolley line. Fuel and engine costs
are reduced by more than 90% while the truck is
on trolley. The trolley system also boosts
productivity. Operating with trolley assist, speed-