Commercial_vehicles_India-02-2017

INTERVIEW: Ravi Pisharody Vinod Aggarwal
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No easy mission
Designed for heavy
duty operations, the
560 hp Astra HD 9
86.56 8x6 with a GVW
of 60-tonnes can
replace a dumper in
opencast mines.
Story by:
Gianenrico Griffini
66 COMMERCIAL VEHICLE FEBRUARY 2017
The Astra HD9 86.56
8x6 is by no means
a conventional offroad
truck. Premiering at
the Bauma fair in Munich,
Germany, which is dedicated
to construction vehicles
and machines, and mining
equipment, the Astra HD9
86.56 is among the top
models in the portfolio of the
Italian truck manufacturer. The
Astra brand belongs to the
CNH industrial Group, and has
been designed for heavy-duty
missions in extreme working
environments typical of the
mining-extractive sector in
which it can replace a rigid
dumper. The opportunity to
test it presented itself recently
in a quarry in Northern Italy
near Piacenza. Equipped
with a Cursor 13 Euro 6
12.8-litre six-cylinder in-line
engine that produces 560
hp at 1,900 rpm, and a peak
torque of 2,500 Nm at 1,000
rpm, the Astra HD9 86.56
looks remarkable.
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Retarder and engine
brake to slow down
safely
Like all Iveco heavy-duty (and
medium-duty too) engines,
the Cursor 13 Euro 6 engine
uses a Hi-SCR system for
pollutants after-treatment, that
does not require an exhaust gas
recirculation circuit (EGR). With
the Hi-SCR solution there is no
need of active regeneration for
the diesel particulate filter (DPF),
a feature that increases the
energy efficiency of the engine
and lowers its fuel consumption.
The Cursor 13 is equipped with
Iveco Super Engine Brake, which
is capable of a maximum braking
power of 463 kW at 1,900 rpm.
The engine, which uses an
electronically-controlled variable
geometry turbocharger (EVGT),
is coupled to a ZF Astronic
16AS 2631 TO 16-speed (plus
two reverse gears) automated
transmission. The transmission,
controlled by an off-road
software, has two operational
modes, namely fully automatic
or manual (sequential).
The powertrain of the Astra
HD9 86.56 8x6 rigid tipper is
coupled to a Steyr VG2700
disengageble transfer case,
which allows a distribution
ratio of the drive torque (front
and rear) of 1: 2.6. Apart from
the Super Engine Brake, the
HD9 86.56 8x6 is equipped
with an hydraulic retarder
(Intarder), integrated to Astronic
automated transmission. Both
the Intarder and the engine
brake are actuated by a 5-stage
www.commercialvehicle.in COMMERCIAL VEHICLE FEBRUARY 2017 67

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multi-function lever (which is
also used for setting up the
cruising speed), located on the
right side of the steering column.
The first two stages activate the
Super Engine Brake, whilst the
remaining three also involve the
hydraulic retarder. Maximum
braking torque is thus provided.
Weighing 24,100 kg, the
HD9 86.56 is equipped with
a 24 cu. m. Cantoni tipper
(specially developed for Astra).
The superstructure is made
of high strength steel, which
has a thickness of 12 mm at
the bottom. The side walls are
8 mm thick. A hydraulic gullwing
tail opening design, the
superstructure (tipper body)
is fitted with an oversized cab
guard. The oversized cab guard
is designed for mining site
operations. Reaching a maximum
tilting angle of 58-degrees, the
tipper body is equipped with
an electronic weighing system,
which shows the relevant data
on a control display placed in
front of the driver’s seat.
68 COMMERCIAL VEHICLE FEBRUARY 2017
Heavy duty
components
The structure of the HD9
86.56 and all the mechanical
components have been
engineered for heavy-duty
tasks. The first drive axle is
a double reduction Kessler
unit with a loading capacity
of 20-tonnes. The third and
the fourth axle are also a
Kessler (double reduction)
unit. They each have a loading
capacity of 20-tonnes. The
10 mm C-section chassis side
members, spaced by 820 mm,
are made of high yield steel
with 6 mm reinforcing internal
C-profiles. The HD9 front
suspension – first and second
axle – feature parabolic springs.
They are supplemented by
hydraulic shock absorbers and
two stabilisers (one for each
axle). Those of the tandem
(cantilever type) have five
parabolic leaves (40 mm x 100
mm) swiveling on a central pin.
The braking system of the
Astra HD9 86.56 8x6 heavyduty
tipper is drum brake
based. There are drum brakes
on all axles with the possibility
of excluding the anti-lock
device (ABS) at speeds below
15 km per hour. The use of
325/95 R24 tyres has the tipper
having a high ground clearance.
This is crucial to the smooth
functioning of the truck as
it will spend much of its life
travelling over uneven terrain
with deep potholes and large
stones. Despite the heavyduty
design of the truck, driver
comfort has been increased
thanks to the correct calibration
of the cab suspension and the
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redesigned interior. The two not
only ensure driver ergonomy
they also help to retain high
level of functionality required
by extreme off-road missions.
At the steering wheel
The HD9 86.56 ZF Astronic
automated gearbox does a
good job in off-road operations.
This is due to the fast (and
higher revs) gearchanging,
managed by the off-road
transmission software. The
automated gearbox, however,
requires some special
precautions, especially on the
most demanding terrain. When
tackling the most demanding
terrain, it is better to use the
gearbox in manual mode,
pressing two times the D (Drive)
button on the dashboard. The
right speed can be selected
using – with an upward and
downward movement – the
multi-function lever on the right
side of the steering column.
Once this operation is done, the
engine is in a position to provide
high torque at low revs (from
1,000 rpm). The same predictive
driving style is needed to engage
in advance the differential locks,
using the knobs on the console
close to the driver’s seat. The
Intarder-enhanced engine brake
provides a powerful braking
action, even when the truck is
fully loaded. A pleasant surprise
is the comfort level of the cab,
due to the good suspension
setting. Remarkable is the
steering angle. It does not seem
to have been heavily affected by
the 8x6 chassis architecture.
CV has been appointed an
associate member of the
International Truck of the Year
(ItoY). Being a part of this
association gives the magazine
exclusive articles, specially
written for CV by IToY jury
members.
www.commercialvehicle.in COMMERCIAL VEHICLE FEBRUARY 2017 69