Komatsu has released two new articulated dump trucks, the 28-tonne capacity HM300-5 and 40-
tonne capacity HM400-5, both powered by low-emission Tier 4 Final engines and featuring
Komatsu’s advanced truck transmission system.
The 28 tonne capacity HM300-5 is powered by Komatsu’s SAA6D125E-7 engine rated at 242 kW net,
while the 40 tonne HM400-5 is powered by the SAA6D140E-7 rated at 348 kW net.
Both engines are US EPA Tier 4 Final emissions certified, cutting both nitrous oxide (NOx) and
particulate matter (PM) emissions by 90% compared with their Tier 3 equivalents, while delivering
up to 14% lower fuel consumption compared with previous models.
These engines incorporate an advanced electronic control system that performs high-speed
processing of all signals from sensors installed in the vehicle, providing total control of equipment in
all conditions of use.
Engine condition information is displayed via an on-board network to the monitor inside the cab,
providing all necessary operating data to the operator.
Additionally, this data can be accessed and managed via the KOMTRAX telematics remote
monitoring system (supplied as standard on all Komatsu construction and utility machines), ensuring
owners and fleet managers stay well on top of all maintenance requirements.
According to Richard Feehely, Komatsu Australia’s National Business Manager, Quarries, Komatsu’s
new Tier 4 engines monitor and transmit far more detailed data about engine conditions and
operation, giving unmatched visibility into the health of equipment – and any potential issues.
“And through our in-house development and production of engines, electronics, and hydraulic
components all designed to work with each other, Komatsu has achieved major advances in
technology, providing high levels of performance and efficiency across all applications,” he said.
“Because of this integrated design approach, we have been able to achieve further reductions in fuel
consumption with these new trucks,” Richard said.
“These include the use of variable displacement piston pumps that use engine power only as needed
to eliminate unnecessary PTO inefficiencies, along with design improvements to the drive axles and
transmission systems that reduce parasitic driveline losses.”
Both new trucks feature Komatsu’s advanced truck transmission system, including its electronically
controlled K-ATOMICS countershaft transmission which is also used on large mining trucks, and the
Komatsu Traction Control System (KTCS).
“Both these features are unique to Komatsu articulated dump trucks and, combined with our
hydraulically controlled wet multiple-disc brakes and retarder system, provide unrivalled traction,
braking power and safety in all types of operation,” Richard said.
K-ATOMICS incorporates an electronic clutch modulation system that ensures proper clutch pressure
when the clutch is engaged.
“This total control system controls both the engine and the transmission by monitoring the vehicle
conditions, ensuring smooth shifts with minimal shock and thus maximises powertrain life,” he said.
“KTCS, which we have derived from our extensive experience in traction control systems in dozers
and rigid dump trucks, was developed by Komatsu to ensure maximum machine performance in soft
and slippery ground conditions.
“This system, which is automatically activated and deactivated, monitors wheel speeds on the front
and middle axles, and if it detects wheel slip, will automatically engage the inter-axle lock to improve
“If the machine continues to detect wheel slip, it will brake the wheel that slip was detected on,
continually monitoring wheel speeds and engaging the brakes as necessary,” he said.
Both trucks also incorporate Komatsu’s exclusive hydraulic braking and retarder system, which
ensures complete control even when doing downhill fully loaded.
“Large-capacity, continuously cooled, wet-multiple disc brakes, which have been proven on other
Komatsu rigid dump trucks, also function as a highly responsive retarder, giving the operator full
control when travelling downhill,” said Richard.
Retarder absorbing capacity (continuous descent) is 392 kW on the HM300-5 and 510 kW on the
They also both come as standard with a payload meter (PLM), which displays payload tonnage as the
truck is loaded. This information is visible to the operator, and is also transmitted to owners and
fleet management via KOMTRAX.
Both trucks feature large ergonomically designed ROPS/FOPS cabs with air suspension seats and
hydro-pneumatic front axle suspension, while the centrally located operator seat and short-bonnet
design ensures excellent visibility of the working area. A rear-view camera and in-cab monitor are
also provided as standard.
Maintenance requirements have been made easier on the two trucks through features such as
ground-level fuel filter access, power-tiltable cab, reversible engine cooling fan, battery disconnect
switch and an electric fuel priming pump.
“Since we introduced our HM400-3M0 in Australia in 2014, it has proven itself as a highly
productive, efficient and safe articulated hauler across a wide range of applications,” said Richard.
“Now with our launch of these latest low-emission versions of the HM300-5 and HM400-5 trucks,
customers can take advantage of the benefits of the latest Komatsu technology for their haulage
Brief specs of the two trucks are as follows:
HM300-5: Payload capacity, 28 tonnes; body capacity, 17.1 cu m; engine, Komatsu SAA6D140E-7
engine EPA Tier 4 Final emissions certified, rated at 242 kW net at 2000 rpm; transmission, automatic countershaft with lockup torque converter, 6F/2R speeds; maximum speed, 58.6 km/h; tyres, 23.5 R25; loading height, 2830 mm; width, 2900 mm; overall length, 10,275 mm.
HM400-5: Payload capacity, 40 tonnes; body capacity, 24 cu m; engine, Komatsu SAA6D125E-7
engine EPA Tier 4 Final emissions certified, rated at 348 kW net at 2000 rpm; transmission,
automatic countershaft with lockup torque converter, 6F/2R speeds; maximum speed, 55.9 km/h;
tyres, 29.5 R25; loading height, 3164 mm; width, 3450 mm; overall length, 11,105 mm.