Miner gears up to keep show on road
Alcoa World Alumina Australia has recently bought a $40m equipment package that includes 12 Komatsu 730E dump trucks, four WA900-3 loaders and other Komatsu loaders, graders, articulated dump trucks, dozers and skidsteers.
Also, in a world first, Alcoa is using the AcuMine HaulCheck driver guidance system to ensure its larger trucks work safely on restricted-width haul roads.
Financed through Komatsu Australia Corporate Finance, the package is part of an equipment replacement program at Alcoa’s Willowdale and Huntly mines, south west of Perth in Western Australia.
Alcoa mining engineering manager Steve Pyburne says in moving to the 190t-capacity 730Es, the company is aiming to achieve a “step change” in lowering its mining costs.
“Our previous trucks at the two mines were 90t Komatsu HD785s and 105t HD985s,” Pyburne says.
“By moving to the larger trucks, we are looking to reduce our haulage, labour and maintenance costs,” he says.
Of the 12 730Es, four have replaced seven HD985s at Willowdale and eight have replaced 17 HD785s at Huntly.
“At the same time, we have re-arranged our mining operations at our largest, Huntly mine, reducing our haul road distances significantly, moving our crushing plants and extending conveyors, as part of a $100m upgrade project,” Pyburne says.
“One of our biggest challenges in this project was whether we would be able to go for the bigger trucks.
“We have a network of haul roads through the jarrah forest, which is managed for multiple land uses including conservation and water catchment.
“That means we are always aiming to minimise our impacts on the environment, and we did not want to increase our haul road clearing widths,” he says.
The challenge of moving to substantially larger trucks while still using roughly the same width haul roads was solved by adopting the AcuMine HaulCheck driver guidance system.
The system, developed at the University of Sydney’s Centre for Autonomous Systems, uses an onboard monitoring system to create a “virtual corridor” within the haul road by measuring the relative distance from PVC markers placed along the side of the road.
If the truck strays too close to either side of the 20-22m-wide haul road, the driver is alerted by means of a multi-level series of visual and auditory alarms. In addition, operators of other trucks are alerted to the potential hazard.
The monitoring device, fitted to the left-hand side of the truck, uses a scanning laser sensor to measure the distance from the PVC markers, which are placed preset distances apart along the left-hand side of a haul road.
If the truck veers out of the virtual corridor, the driver is alerted. In addition, the system logs all alerts so drivers in at-risk situations are notified and managed.
The system also incorporates a GPS so the locations of any problem areas are easily identified.
“The AcuMine HaulCheck system provides very accurate guidance to our drivers that they are within the safe haul lanes,” Pyburne says.
“It also makes an excellent fatigue management tool, alerting drivers and mine management to any fatigue-related issues. This system was delivered and installed in early February, and has been working very well for us.
“Komatsu Australia has committed to guarantee the availability of the HaulCheck system, and we are still working jointly with Komatsu on further improving it,” he says.
Prime loading units for the 730Es are two Komatsu PC1600 excavators at Willowdale and two other excavators at Huntly, with four WA900-3s – also delivered over the past 18 months – used as back up loading tools. One of the WA900s is at Willowdale and the other three are at Huntly.
With three of the WA900s delivered before Alcoa’s decision to opt for 730Es, these were converted to high-lift configuration to handle the larger trucks, although the final WA900 was delivered as a high-lift unit.
“The Komatsu trucks offered us the lowest whole-of-life costs, taking into account all factors, including owning and operating costs,” Pyburne says.
“We are not just an open-pit operation; we have many small pods of ore around the mine situated in the jarrah forest, so our haul trucks need to be suited for long hauls and our loading equipment needs to be suited to frequent relocation around the mine.”
For these orebodies, Alcoa uses WA900s as its loading tools; hence the need for compatible truck/loader combinations.
In addition to the truck/WA900 purchase, Alcoa has bought two WA500 loaders and two HM400-1 artic trucks fitted with ejector bodies as part of a trial of a new method of removing overburden material from on top of the orebody.
“Our existing overburden operation involves the use of twin-engine scrapers, but we are carrying out a trial using the WA500s and ejector-body HM400s in an effort to remove some of this material more efficiently and safely,” Pyburne says.
Other equipment delivered by Komatsu under this package includes two GD825A-3 graders for haul road and pit floor maintenance.
In addition, Alcoa’s refining operations have taken delivery of a WA600-3, a PC300-7 excavator and four Komatsu skidsteers: two SK714s, an SK820 and an SK1020.
More info: 1800 566 287
16-Aug-2005