D475-(1).pngSaid to deliver ride comfort levels that are equal to or better than any other machine on the market while still maintaining their class-leading dozing and ripping capabilities.

It has also developed a factory-fitted Australian mining spec package, allowing the dozers to be delivered directly from factory to mine site in a "mine-ready" configuration.

According to David Laidlaw, Komatsu Australia's Mining Product Manager, Bulldozers and Excavators, Komatsu mining dozers are renowned as the best ripping and dozing machines on the market but until now have not had the same reputation for comfort and ride.

"Our combination of track configuration and design, transmission and powertrain including the automatic/direct drive transmission on the D375A-6 have meant that Komatsu dozers have a well-deserved reputation for out-ripping and out-pushing any other dozer in the market," he said.

"Now to address perception on comfort and ride, we've made a number of significant modifications to the undercarriage, as well as the cab mountings.

"Following trials in Hunter Valley and Central Queensland coal mines, we can confirm that the ride, vibration levels and operator comfort on Komatsu mining dozers are as good as or better than any other machine," David said.

"We carried out a rigorous independent testing program, comparing a D475A-5EO with the ride enhancement package fitted, one without, and a competitive machine and the results show that we have achieved our ride and operator comfort objectives."

The undercarriage modifications included changes to the bogie and equaliser bar oscillation angles, along with new style cabin mounts to reduce shock loads.

Additional research and testing is continuing into ways of further improving ride and comfort levels.

According to David, Komatsu's factory-fitted "mine spec" option saves considerable time and expense when preparing and delivering dozers to mine operations.

"It ensures that mine specification requirements for our dozers are manufactured and installed to Komatsu's exacting production standards prior to being shipped to Australia, and that they comply to ISO engineering standards," he said.

The factory-fitted mining specification package includes:

Right- and left-hand access platforms with handrails, toerails, access lights and worklights, giving safe, secure access for operators and maintenance crews to the side and rear of the machine, including checking and refilling fuel and hydraulic tanks, cleaning of cab windows, and checking cab mounted lightsHigh mounted HID (high-intensity discharge) headlights for safer working at night

A battery and starter isolator box

Centralised grease points

Manual engine stop switches

Engine bay maintenance light.

The D475A-5EO, which has an operating weight of 108.4 tonnes, is powered by a Komatsu SAA12V140-3 Tier II-compliant engine rated at 664 kW, and incorporating a Komatsu-designed heavy duty high-pressure common rail injection (CRI) air-to-air charge air cooling system.

"It's a totally electronically controlled engine, giving optimum fuel efficiency and power while minimising emission levels, while other changes have been made to further increase service life.

"Komatsu has specifically designed this heavy duty CRI system to meet the needs and demands of large machines in mining applications," David said.

The D375A-6, with an operating weight of 71.64 tonnes, is powered by Komatsu's Tier 3-compliant turbocharged and aftercooled SAA6D170E-5 engine rated at 455 kW.

It is coupled with Komatsu's automatic gearshift transmission, which selects the optimal gear range depending on the working conditions and load on the machine, ensuring the machine is always operating at maximum efficiency plus a lockup torque converter.

"Ripping performance is further enhanced through Komatsu's electronic powertrain control system, which results in a highly efficient drawbar pull, putting more power to the ground where it counts," said David.

In dozing operations, Komatsu's new Fully Universal (Full-U), and Semi Universal (Semi-U) blades allow for increased production without increasing blade width or reducing digging force. A redesigned sectional shape increases load-hauling capacity during dozing operation.

All components in both machines, including engine, transmission components and hydraulics, have as with all Komatsu machines been designed and built from the ground up by Komatsu to work together as an integrated whole.

Brief Specs are:

D375A-6: Operating weight, 71.64 tonnes; engine, Komatsu SAA6D170E-5 engine rated at 455 kW (Net); blade capacity, 18.5 cu m (semi-U), 22 cu m (full-U).

D475A-5EO: Operating weight (with semi-U dozer, giant ripper), 108,390 kg; engine, Komatsu SAA12V140E-3 rated at 664 kW at 2000 rpm; blade capacity: semi-U, 27.2 cu m; full-U, 34.4 cu m; coal, 70-76 cu m.