Longer track length improves ride and balance on new Komatsu dozer

Komatsu has released the D475A-5EO mining dozer – a major upgrade to the former D475A-5 – giving significantly improved ride, balance and operator comfort, along with a new engine for reduced emissions.

The main changes are from a seven-roller undercarriage to eight-rollers, increasing effective track length on the ground by 503mm, and the use of Komatsu's tier II-compliant engine, meeting all tier II US and European off-road emissions requirements for mining equipment.

In addition, a bogie-type oscillating front idler has been developed for the new undercarriage, while at the rear of the machine, the height of the final drive above the ground has been raised, allowing for better clearance and increased operator comfort.

Operator comfort is further enhanced through the use of the latest technology air suspension seat which is self-adjusting for operator weight, and giving improved low-frequency support.

The D475A-5EO's dozer's eight-roller undercarriage is about 250 mm longer than its nearest competitor, and increases machine weight by about 1 tonne.

New undercarriage

According to Komatsu Australia's mining dozer national product manager David Laidlaw, the revisions to the D475A-5EO result in a greatly improved ride, better fine blade control and increased operator comfort.

“Komatsu has developed a completely new style undercarriage that improves ride drastically, as well as providing dramatic improvements in fine grading control,” he said.

“At the same time, the longer track length on the ground and increased weight gives better traction and stability, an improved centre of gravity and a better `feel' when operating.”

In addition, a new Komatsu-designed high-tech seat further reduces vibration and shock loads to the operator.

“Combining the new undercarriage with this new seat means a significant advance in operator comfort in large mining dozers,” Laidlaw said.

The other major change on the D475A-5EO is the introduction of the new Komatsu SAA12V140-3 tier II-compliant engine.

“This new engine incorporates 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,” he said.

All Komatsu

All components including engine, transmission components and hydraulics, have – as with all Komatsu machines – been designed and built from the ground up by Komatsu.

“This dozer represents the peak in dozer technology, with the most advanced components and systems available on the market,” said Laidlaw.

The first dozer arrived in Australia in early November 2005, and has been delivered to a mine site in Queensland's Bowen Basin, fitted with a 70m3 coal blade. And in early 2006, the first four of a fleet of six were delivered to Mount Thorley Warkworth's mine in the NSW Hunter Valley.

Brief specs: Operating weight (with semi-U dozer, giant ripper), 108t; engine, SAA12V140E-3 rated at 664kW net at 2000 rpm; powershift transmission with lockup clutch; maximum speeds, F/R, 10.9/14.3 km/h; drawbar pull, first gear, 1km/h, 120t; blade capacity: semi-U, 27.2m3; full-U, 34.4m3; coal, 70-76m3 (dual skin/ strengthened blades standard on semi U and full U); maximum ripping depth, giant ripper, 1.8m.