Located at Lawn Hill, 377km north-west of Mount Isa in the Lower Gulf of Carpentaria, MMG’s Century Mine was Australia’s largest open cut zinc mine. It began open pit production in 1999 and the final ore was extracted in September 2015.
In its 16 years of operation, Century produced and processed zinc and lead concentrates at Lawn Hill, with product then transferred in slurry form via a 304km underground pipeline to Century’s Gulf port facility at Karumba for shipping to smelters in Australia, Europe and Asia.
Komatsu equipment was on site for the initial infrastructure works, followed by clearing of the natural surface layer to get to the ore body below – with many of those original machines still there until mining operations concluded.
According to Peter Hayward, Komatsu Australia’s major accounts manager for north Queensland (who was involved with Century for much of its history), there were 54 pieces of Komatsu equipment on site during the mine’s peak in 2010. The fleet comprised of 46 trucks (38 830Es and eight 630Es), three wheel loaders (a WA320, WA380 and WA500) and five excavators (PC3000, PC2000, two PC1800s, one PC1250).
Some of that equipment has stayed on site and will remain operational there for the mine’s rehabilitation program, which will extend over the next two to three decades.
‘Launch platform’
Komatsu’s involvement in the mine wasn’t just restricted to supplying equipment. It was also contracted to provide service and maintenance on all equipment – Komatsu and other brands – from the mine’s earliest days until the end of 2004, when the full maintenance agreement ceased.
The processes put in place and lessons learnt from what was Komatsu’s first major maintenance and repair contract in Australia helped form the “launch platform” for its offerings in maintenance, service, fleet management and safety that are in place today.
In the lead-up to the mine’s opening in 1999 (the year of its first shipment of concentrate) Komatsu – then known as NS Komatsu – won a contract to supply mine owner (at the time) Pasminco with eight 630E dump trucks and four WD900-3 wheel dozers, plus some smaller items of equipment for infrastructure and clean-up work.
It also supplied a Demag H285S excavator (later rebadged as a Komatsu PC3000) and various Ingersoll-Rand blast hole drill rigs (for which NS Komatsu was the dealer at the time). These were delivered to the mine site for assembly and commissioning from May 1998.
In addition, the company had a major contract to carry out all on-site repairs and maintenance – not only for Komatsu-supplied equipment but also for other makes.
To carry out development and initial mining, contractors Roche Bros and Eltin formed a joint venture, known as the Roche-Eltin JV, which used the equipment supplied to the mine owner. This JV remained on site until 2005, when the mine owner took over mining and the equipment.
In addition to the original 630E trucks, Hayward said other Komatsu trucks to see service at Century included five 830Es purchased used in 2004, a further five 830Es also purchased used in 2007, and 12 830Es bought new in 2007.
“There were also a number of diggers purchased over the life of the mine, including two new PC1800-6s bought in 2004, a PC2000-8, PC3000-6 and a PC1250-8R purchased in 2008,” he said.
“In particular, those PC1800s have been remarkable machines. One of them has done over 51,000 hours over 11 years, which is a real credit to that size of machine.”
In 2008 Hayward was in charge of a rebuild program for six of the original 630E trucks.
“These were incredible machines, and we rebuilt them at around 54,000 hours,” he said.
“We stripped them all down to the bare chassis, sand-blasted, crack-tested and line-bored them, and upgraded, repaired or changed out components as necessary.
“This investment certainly paid off in terms of productivity and longevity of the trucks. The trucks kept operating until close to the end of the mine’s life, each logging between 70,000 and 80,000 hours as of late 2015.”
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Experiences at century
Rob Venema, currently Komatsu Australia’s national technical support manager for mining trucks, was maintenance manager at Century during the initial machine commissioning and mine development stages.
Venema and others from NS Komatsu worked closely to develop successful and effective fleet management, maintenance and safety programs and procedures.
“Many of Komatsu Australia’s current day systems and processes were born out of our experiences at Century, because we had never run such a large contract maintenance program before – and many of these had to be brought in simultaneously,” Venema said.
“Our history at Century went back to the mid-1990s, when we were awarded the contract by Pasminco. I was appointed maintenance manager at the mine, working closely with Steve Green, our branch manager from Mackay.
“In conjunction with our head office contracts management team, we looked at the people we’d need, the tooling we’d require, and started our hiring and purchasing processes.”
Komatsu also worked closely with Pasminco and local Indigenous communities to develop employment and contracting opportunities.
Venema visited the site for the first time in May 1998, helping to arrange new machine assembly at the assembly pad Komatsu had been allocated.
At that time, Mobil was there putting in the fuel tank systems, and Bechtel was building the processing plant. With the main camp still under construction, Komatsu had to use some of Bechtel’s facilities.
As the Roche-Eltin JV was the mine’s operating contractor, it purchased the machines from Komatsu.
“That meant we were working with REJV directly, and we fairly quickly formed a very good relationship,” Venema said.
Once the machines were assembled and commissioned, and work begun, it very quickly became apparent that the site’s natural surface layer (NSL), which had to be removed before actual mining could start, was extremely challenging to work on.
The ground was very rugged, undulating country, with huge loose boulders, not only on the surface but also below it. The boulders were usually set aside and blasted individually, although from time to time they were carried in trucks.
“At the time, Komatsu was also the national dealer for Ingersoll-Rand mining drills,” Venema said. “We had supplied a number of these to the mine, including the EMC690, DM45 and DMH, which was the largest on the market at the time.
“We had drills operating off hillsides, and we were breaking a lot of drill rods as they hit the buried boulders. We also had to deal with unstable ground and the associated issues.
“As a result, we experienced a fair bit of accidental damage. For the first six months, we had frequent truck body, digger and drill rig repairs coming through the workshop.”
The NSL removal process soon became refined, so the REJV operators would dig out the boulders using the Demag H255S backhoe configuration (now the PC3000), then pop them during the night shift with the EMC690 crew, so the trucks could handle them more easily.
Once the production team got past this layer, it could start properly benching and then extracting the ore.
During the NSL removal stage, the contractor used the WD900-3 wheel dozers to run down after the blasts and race around the pit floor to clean up any shot rock before the next shift could begin. This high speed forward and reverse work quite quickly resulted in a shortened wheel brake life.
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Solutions, innovations
Due to the inadequacy of the shortened wheel brake life, Komatsu Australia engaged with its head office in Japan on a solution.
Komatsu engineers soon came to the site and developed a brake cooling system similar to what was used on the Komatsu mechanical drive mining trucks. This worked so well that it’s now used in all large Komatsu loaders.
The factory had the new cooling system parts manufactured and fitted to these wheel dozers within a few months.
“In my experience, Komatsu has always been very quick to respond to issues such as this on our new model machines in unique or challenging applications,” Venema said.
He said several solutions and innovations that Komatsu developed for Century have contributed significantly to the way Komatsu operates today. These include:
Fleet management systems. At Century, NS Komatsu introduced a number of important systems that it had essentially developed within Australia for this project.
“We were also able to draw on our existing NS Komatsu distributor network at the time for exchange components, as well as our newly developed KOWA oil analysis laboratory and software program,” Venema said.
Maintenance management. As part of its maintenance contract at Century, Komatsu had to set up workshop facilities, offices, computers and machine management systems. Shane Whittington in Mackay, in conjunction with a consultant, designed Komatsu’s Maintenance and Repair System (MARS) using Microsoft Access.
“We did this as there was no specific, cost-effective, easy to use, low computer RAM consumption software available at the time,” Venema said. “I recall sketching up screens and process flows with Shane on the way back and forth from Townsville, travelling in light aircraft at the time.”
MARS was used to record all machine hours, plus defects, accidents, repairs, planned tasks, lubricant consumption, trending of Komatsu PM Clinic diagnostic measurements, electric truck motor brush wear data, and so on.
“We worked to ensure we did not overcomplicate the system by adding financials and labour records, which were handled via our normal mainframe job system,” Venema said. “Jobs numbers were manually recorded as each maintenance case was closed off for cross reference.”
This system was the genesis for Komatsu’s more advanced systems, including its present day global R and M Care systems.
Automatic data transmission. Liquip, the fuel contractor, had a radio communications system that could automatically transmit data between the fuel trucks and Komatsu’s workshop computers.
Whenever a service truck went out to a machine, the truck operator would punch in the machine number, and the amount of fuel and oils used. Then, as the truck approached the workshop, the data would be automatically uploaded to MARS via modem.
Oil analysis. The Komatsu Oil Wear Analysis (KOWA) service was introduced at this time. “The great advantage of our system was that it had a ‘flash filer’ [low RAM use] software process, which meant that even though we had a massive file of oil samples, we could very quickly bring up the machine files we were working on,” Venema said.
“Having KOWA on this site really demonstrated to everyone involved how, when you have an effective oil sampling system in place, you have very minimal unplanned failures.
“This was a big change at the time, away from the traditional system of just troubleshooting once a problem became evident during machine operation, across to much more predictive maintenance planning.”
Component exchange. As the Century project progressed and machines aged, there was also a much larger volume of exchange components coming out of Komatsu’s relatively small, Brisbane-based East Coast Rebuild Centre.
This larger volume ultimately resulted in the development of Komatsu’s Reman program and its dedicated facilities (now in both Brisbane and Perth).
“Having all these support systems operational within a very short time of going on-site at Century meant that we had very good management of our machine maintenance records, and could respond quickly to the changing site conditions,” Venema said.
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“Our maintenance team was able to provide the JV with very detailed reports on each piece of equipment at all times.
“This detailed monthly cost breakdown allowed REJV to then adjust production techniques and plan machine maintenance days more accurately, paying off in higher availability and lower running costs.”
Safety management. When the Century project commenced, the industry was rapidly embracing much higher levels of safety management.
Komatsu as a company in Australia was quick to examine the best systems available across the industry and adapt them to its company culture.
“From my point of view, this and other major projects we were engaged with at the time really helped Komatsu in Australia to be at the forefront of this change, introducing this culture via programs like Take 5 and detailed risk assessments,” Venema said.
“As part of this change, Komatsu spent a lot of money early on to purchase the correct manual handling systems and equipment, for example, so that our people were not using incorrect manual handling practices.
“Also introduced at this time were toolbox talks and suggestions boxes, which took some time to manage but brought very good ideas to the fore. Pasminco found this approach aligned well with their expectations in terms of WHS management.”
The mined ore contained large amounts of lead and cadmium, so Komatsu had to be very careful to stay on top of seals and cabin pressurisation to safeguard the operators. This also meant hand washing before eating (and smoking at the time) – not only to remove bacteria from people’s hands, but also potentially harmful chemicals.
Operator training was carried out in cycles to ensure safe, efficient mining practices. Other risk factors at such an isolated site included fatigue due to 12-hour shifts, the four weeks on/one week off roster, and off-site road travel. To minimise these risks, Pasminco developed rigorous procedures in relation to road travel, work hours, recreational activities and fatigue management.
Community engagement. A satisfying element of the Century project was the opportunity to engage with the local Indigenous communities. Pasminco, REJV and Komatsu worked closely with community leaders – several of whom had close family operating the machines.
“From our point of view, we wanted to ensure the local community were able to gain benefit from us working in their region, and also that our people respected their special sites and culture while off site in the local area,” Venema said.
“We also helped build up a good business for a local Aboriginal-owned company, Kings Transport, transporting parts, consumables and small components between Mt Isa and the mine – a distance of 377km.
“Kings Transport had a small fleet of Toyota utes and light trucks, and we found them very quick and flexible compared to major truck companies in this remote area, and ended up using Kings exclusively for these critical local logistics.”
The next phase
As the mine operations began winding down in early 2015, surplus equipment was progressively parked up and either cannibalised for parts to keep other units working, or cut up for scrap.
“There are still around six 630E trucks staying on site for the mine rehabilitation program over the next few decades as required,” Peter Hayward said.
“The longevity, reliability and availability we got out of the equipment at this site, whether trucks or diggers, is testament not only to the quality of our equipment, but also to what can be achieved with proper fleet maintenance scheduling.
“It’s also a tribute to the national and local support Komatsu Australia was able to supply to the mine over its 16-year life span, across quality of component rebuilds, truck refurbishments, spare parts, technical service and back up.
“The company has been able to work closely with our clients to help increase the reliability, availability and productivity of each of their Komatsu investments throughout this period.”
Both Hayward and Venema described working at the Century Mine as a great honour.
“Personally, it has been a privilege to be a small part of this,” Hayward said. “Will there be another Century Mine? I would love to think so!”
Venema said the Century Mine maintenance contract, along with other projects Komatsu was involved in across Australia at the time, “really matured the company in Australia in the world of contract maintenance. They helped inspire our people to build in-house systems and procedures to provide the best service and value to our customers, with a strong focus on safety. This attitude certainly continues in what we do today.”
Source: Komatsu Australia