Komatsu America Corp. first showed off its HM300-5 articulated dump truck ConEXPO earlier this year.

Featuring a net 324-hp (242-kW) diesel engine, the HM300-5 is powered by a Komatsu SAA6D125E-7 engine that is EPA Tier 4 Final emissions certified. Komatsu’s Tier 4 Final engines are based on what it calls "the solid foundation inaugurated in 1996 with the introduction of Komatsu’s Tier 1 engines."

With a 30.9-ton (28-t) payload and a gross vehicle weight of 117,892 lb (53,475 kg), the HM300-5 maintains the productivity and performance of the previous model, and offers improved fuel efficiency.

Through what Komatsu describes as "body design optimization," the HM300-5 has increased body capacity and payload. The low 9’2” (2820-mm) loading height easily matches with 30- to 60-ton (27- to 54-t) hydraulic excavators or 5- to 7.5-yd³ (3.8- to 5.7-m³) wheel loaders. Additionally, the two single-staged body lift cylinders provide a 70° dump angle. Selectable working modes allow the operator to choose between Economy and Power modes to tailor machine performance to the application or work conditions.

The HM300-5 features the Komatsu Traction Control System (K-TCS) that automatically provides optimum traction when operating in soft ground conditions. As ground conditions worsen and tire slippage is detected by the speed sensors located on four wheels, automatic application of the inter-axle lock occurs. If tire slippage continues to be detected, then four independent brakes can be applied to slipping wheels to regain traction.

The HM300-5 is also offered with K-ATOMiCS (Komatsu Advanced Transmission with Optimum Modulation Control System). K-ATOMiCS offers a six-speed, fully-automatic transmission that uses an advanced electronic system to eliminate shift shock and torque cutoff to improve operator and engine efficiency. It automatically selects the most suitable gear based on vehicle speed, engine rpm, and the shift position chosen. This results in powerful acceleration, smooth down-shifting, and synchronized engine speed when climbing slopes. This ultimately minimizes operator fatigue, keeps the load in the body, and increases productivity.

A large automatic retarder allows the operator to select the optimum operating speed on downhill travel and fully loaded hauls, eliminating acceleration generated by the grade of the slope.

An integrated payload meter (PLM) is now standard on the HM300-5. The PLM displays the loaded material weight on the 7-in high-resolution LCD monitor for the truck operator as well as indicates payload information to the loader operator via external display lamps. PLM data is also transferred via KOMTRAX, Komatsu’s standard telematics system, and can be accessed by web.

By integrating selective catalyst reduction, the Tier 4 Final engine further reduces NOx emissions using AdBlue/DEF. The engine uses an electronic control system to manage the airflow rate, fuel injection, combustion parameters, and aftertreatment functions to optimize performance, reduce emissions, and provide advanced diagnostic capability. The result is lower fuel consumption with no loss of performance, says Komatsu, which continues to use a Komatsu variable geometry turbocharger and an exhaust gas recirculation valve for more precise temperature and air management control as well as longer component life.

For product reliability and durability in demanding conditions, Komatsu developed the entire system, including the control software that is critical to the effective operation of the aftertreatment system. This control system is also integrated into the machine’s on-board diagnostics systems and KOMTRAX.

The large cab of the HM300-5 provides a comfortable and quiet work environment. The ROPS/FOPS Level-2 certified cab has a newly designed rounded front dash panel with easy to reach switches. The center mounted high back, heated air ride seat with three-point seat belt that provides the operator with increased visibility during operation. The dashboard and front console provide easy access to all machine controls as well as visibility to the monitor panel. An auxiliary input has also been added to connect a smart phone or other device along with two 12-volt ports that have also been incorporated into the cab.

The high-resolution 7-in LCD monitor offers enhanced capabilities and displays information in 25 languages for global support. Through the monitor, the operator can easily modify settings for items such as the Auto Idle Shutdown or the auto-reversing fan, check operational records, such as driving history or fuel consumption, monitor the KDPF, or check how much time is required before the next maintenance interval. The monitor also provides the operator with the option of using the ECO guidance function, which will provide operational tips to reduce fuel consumption. A rear view monitor system with a separate 7-in LCD monitor is standard with every machine and is mounted on the right hand side of the console for operator convenience.

The HM300-5 provides easier service access in order to reduce costly downtime. The new truck has a light-weight fiberglass engine hood for easy access, increased cooling capacity, and two standard hydraulically driven auto-reversing fans to help keep the radiator and charge air cooler clean. The cab tilts rearward for easy access to the transmission and an electrically powered tilt function is now standard on the HM300-5.

The machine is equipped with the exclusive Komatsu EMMS (Equipment Management Monitoring System), which has enhanced diagnostic features that give the operator and technicians greater monitoring and troubleshooting capabilities. EMMS also continuously monitors all critical systems, preventative maintenance, and provides troubleshooting assistance to minimize diagnosis and repair time.