Cost pressures and challenges in Australia's mining industry mean that mine operators are under increasing pressure to "do more with less" which includes getting the most from existing equipment even as it ages.
The challenge for miners is to ensure that production doesn't suffer even as equipment hours extend well beyond has traditionally been regarded as their normal design life. An example of this trend is Rio Tinto's Mt Thorley Warkworth (MTW) mine near Singleton in NSW.
MTW operates a mixed fleet, including 47 Komatsu 830E haul trucks with part of that makeup being a fleet of twelve 830E DC drive trucks delivered in 1996 under a Repair and Maintenance Contract (MARC) with Komatsu Australia. MTW is currently running 11 of the 12 original trucks.
This MARC concluded in 2009 at 60,000 hours, with maintenance of the fleet then taken over by MTW's Maintenance Department.
Careful management of the trucks' repair and maintenance program has meant 11 of MTW's 830Es are now on track to achieve at least 120,000 hours.
According to Craig Burgess, Komatsu Australia's Branch Manager at its Mount Thorley Branch, this push to significantly extend equipment life is very much a "sign of the times".
"Historically, customers would operate trucks such as these for between 60,000 and 75,000 hours before changing them over for new machines, but market conditions have forced them to look at ways of extending that significantly," he said
Simon Triggs, MTW's Mobile Maintenance Superintendent, said that managing the 830Es to extend their life out to 120,000 hours was aided by a number of factors, including rigorous inspection and maintenance procedures by the mine, a long-term relationship with Komatsu, and the reliability and durability built into the truck chassis and frame.
"Because we'd had the trucks for a long period, and had ongoing support from Komatsu over that time, we found it very easy to work together to develop a strategy to work out what we needed to do to extend the trucks' chassis lives," he said.
"We repowered the trucks in 2010-2011, and at the same time stripped each of them down to the chassis, then refurbished any areas that were cracking or rusting.
"We then repainted and assembled the trucks, and then continued the processes we'd applied from when they were new, including learnings Komatsu shared with us as well as those we'd gained from our site operations.
"When we did the repowers at 60,000 hours, we were confident we'd get to 120,000 hours for the trucks," he said.
"Now we are aiming for 120,000 hours, and we think we can do that comfortably, engaging with Komatsu to help with the maintenance and repair program on the chassis and frames."
Simon said MTW also had experience with other brands, and had found that Komatsu machines seemed to be able to get over 100,000 hours easier than others although he cautioned it still took discipline and work to get there.
"An important factor is the simplicity of the Komatsu frames and systems, which makes them easy to manage and therefore to push out the projected life. But a good chassis is the necessary base to start with."
He said changing industry conditions had been a contributor to efforts to significantly extend the life of the trucks.
"When we did the repowers in 2010, we had a view to keep using the trucks, and get the extra life to take them out to 110,000 hours.
"At the time, we could see the chassis were in good condition, plus we have the advantage of a tight pit and a good layout."
While Simon describes MTW's pit as "challenging" that is a factor that has actually worked to the mine's advantage in extending equipment life.
"Because we have got a challenging pit, due to the amount of material we have to move in a tight site, we have always had a focus on costs and fleet performance and that is what drove some of our behaviour.
"At the time of doing the repower in 2009, we asked ourselves: instead of spending $100 million on a new fleet, could we spend $20 million, push the trucks to two engine lives, and get another 10 years from them?
"We were confident we could achieve that, because of our fleet management capabilities, our site conditions, plus how well the chassis are built.
"Now with the current market conditions in the industry, we are pushing components a bit, and because of the conditions the chassis are in, we are in good position to get to 110,000 hours," he said.
MTW has a rigorous inspection and checking program in place, which includes:Having equipment inspectors fully check each machine between service intervalsCarrying out thorough inspections each timeUsing comprehensive service sheets designed to ensure inspectors are checking the right areas, ensuring that each truck has have been maintained properly and is still in good condition.
"This whole process involves working closely with Komatsu and ensuring our service sheets are followed properly," said Simon Triggs.
Komatsu's Craig Burgess said that what MTW was achieving with its eleven 830E DC trucks was an excellent example of how mining companies and OEMs could work together to significantly extend equipment working life, and substantially reduce capital equipment costs.
"Every mining company bought a lot of equipment during the boom period, and they have all continued to run these," he said.
"However, now with the drop in the coal price, there is no longer any capital expenditure budget to buy new machines, so they have to manage existing machines for a longer duration.
"Having said that, if you service your Komatsu machine as and when you are supposed to, if you use Komatsu genuine parts, and if you take advantage of our service support offerings, there is a good chance you can successfully achieve significant extensions of machine operational life," said Craig.