Scania’s mine-specification R 730 shows its ability at 200 tonnes. Images by Nathan Duff
Weipa in Queensland is a bauxite mining town on the west coast of Cape York. While most Australians have certainly heard of Weipa, it’s true to say that not many Australians have visited the town. Located nearly 2500 kms north of Brisbane and 820 kms north west of Cairns, and situated at the end of approximately 480 kms of unsealed road, the town is famous for fishing.
A further 95 kms north of Weipa, ASX-listed Metro Mining Ltd commenced mining operations at its Bauxite Hills Mine in April 2018 and Scania trucks have been an integral part of that operating infrastructure since the mine opened.
There are nine V8-powered Scania trucks in the Metro Mining fleet at the mine, one R 620 and eight R 730s. The R 730s work two 12-hour shifts day-after-day, with half the fleet, running as triples on a 22 km haul route.
Covering 880 km each day, each combination hauls more than 200-tonnes of payload on a direct route from pit floor to port, where the bauxite is screened and fed onto barges for transport up the Skardon River into open sea for on-shipment by bulk carriers to China. The other half of the Scania fleet pulls 90-tonnes of payload in two trailers on a shorter route from a pit nearer to the port.
Aside from the round-the-clock schedule, the climate and fine bauxite dust, the Scania V8s cope effortlessly with the uneven pit floor and the hauls up the inclines out of two creek crossings on their way from the furthest pit to the port.
The triples are Howard Porter made-to-order Hardox steel tippers that carry the 210-tonne payload in 50/80/80-tonne configuration, while Graham Lusty Trailers (GLT) designed and manufactured the two 50-tonne payload ‘bowl’ tippers.
The GLT bowl-side tippers have a 50 cubic metre body, rating at 100 cubic metres for B-double operation in quad-axle configuration. Overall length as a B-double is 25.1 metres, with a trailer width of 3.4 metres and a tare weight of 25.8 tonnes.
Featuring a Knorr-Bremse Electronic Braking System (EBS) and with the aluminium bodies and 700 grade steel chassis’, they feature K-Hitch 13 tonne airbag suspension and heavy duty drum brakes. The tipping cycle time is 30 seconds per trailer.
All-up, the triples are grossing out at close to 300-tonnes, and the fleet transports around 16,000-tonnes each full working day.
The truck operations run on ironstone access roads and recently Metro-Mining decided to speed-limit the trucks down from 80 km/h to 60 km/h to help preserve the road surface, and to reduce wear and tear on the trucks and the trailers to promote even greater uptime availability and productivity.
The lower limit contributes towards operational profitability, as well as giving drivers plenty of time to avoid unplanned interactions with the native wildlife: from wallabies to crocodiles, packs of wild pigs and the wandering cattle sometimes encountered on the haul runs.
The mine harvests three grades of bauxite ore, and quantities are precisely extracted in line with orders from a selection of long-term Chinese customers. The highest-grade is prized for its quality, with blended grades also in strong demand.
Metro Mining is planning to ramp up its production from 3.5 wet metric tonnes (WMT) in 2019 to 6 WMT annually by the end of 2021, with 17 years of production expected to follow at the 6 m/t rate.
The Bauxite Hills mine only uses Scania haul trucks, and the dependence on Scania engineering also extends to the power generation for the entire camp and processing and conveying operation which is handled by is a bank of five Scania 600 kVa generators, each of which also uses the Scania V8 as a base engine configuration. These were installed by Scania agent Shellby Power, based in Brisbane, and deliver high output and low fuel consumption.
“The trucks have been very successful for us,” says Graham Tanner, General Manager and Site Senior Executive at the Bauxite Hills Mine, that is home to 130 workers at any one time.
“They have proven themselves in the first 18 months of operation, pulling up to 210-tonnes night and day, and the aftersales support from Scania has been exceptional. We’re working at about 98 percent uptime which is almost unheard of and unbeatable given the harsh operating conditions.
“Since I have joined the company, we have added a new R 620 and a second-hand R 730 that had been well-used but still performs well. As we expand our output, we will add more Scania trucks to the business. We’re also using the Scania fleet monitoring system reactively at present, to give us insight into how and why incidents may occur.
“We had a trainer come out early on and he assessed all of the drivers we had then. It was well worth it, both from the point of view of identifying potentially bad habits but also explaining how the technology on the trucks works, so that we get the best possible efficiency from them,” Graham says.
Daniel McGillivray, Mining Supervisor, says the trucks don’t get cold.
“Aside from crib breaks during a shift, the trucks are on the road around-the-clock. They are refuelled once per shift, and the trailers are greased once per day.
Scania’s mine specification includes an elevated ride height chassis, a 9-tonne front axle and two 16-tonne drive axles. The 730 hp engine delivers 3500 Nm of torque and is Euro 5 with EEV compliant, using SCR only. The trucks can carry 1050-litres of fuel.
The Scania Opticruise automated gear-changing system features Off-Road Mode to control selection of the 12-speed box and its two additional crawler gears, matched to hub reduction differentials and a 4.38:1 rear axle.
The trucks use drum brakes, backed by Advanced Emergency Braking and ABS/EBS and the Scania R4100 retarder. The suspension runs with parabolic steel leaf springs all round.
The Scania V8s are run on 250, 500 and 1500-hour service intervals and are maintained onsite by a team of technicians, equipped with Scania-supplied diagnostic and computer systems. For the trucks pulling the triples, 500 hours equates to around 18,000 km.
Each of the trucks is thoroughly washed off prior to entering the workshop and undergoing a detailed inspection.
“The bauxite dust is very aggressive, yet the Scania mining specification V8s have stood up to the task incredibly well,” Daniel says.
“We have really seen the benefits of having the Scanias in service on the site and we’re now talking to Robert Taylor and Murray Schneider at Scania Mining about our plans for turning over the fleet at the appropriate time,” Graham Tanner says.
According to Murray Schneider, Scania Mining Services Account Manager, the R-series V8s have performed to expectation.
This is the first greenfield mining site in Australia that is powered entirely by Scania for prime electrical power and haul road work. Essentially without Scania the mine stops. So that’s why we are delighted that the mine has met its production targets and is on track to almost double output over the next two years.
Mining in the 21st century is very much focussed on doing the right thing, culturally, environmentally as well as economically.
Metro Mining has a very strong commitment to employing indigenous workers from the region as well as ensuring that the land is returned to its original condition after the ore is removed.
At Bauxite Hills, the topsoil is anything from 100mm to 300mm deep with a similar depth of overburden. Both are carefully scraped away and then the bauxite ore is exposed. Seams can be 4 metres deep or more, with ironstone below. Once the bauxite ore is extracted, usually in small, round, pebble-guise similar to giant, smooth gravel, the overburden and topsoil is replaced and reseeded.
“We have a computer-controlled loading system for the up to 90 m barges that take up to 6000-tonnes of ore,” Graham Tanner says. “This ensures that the barges are safely loaded and also that no ore is discharged into the river water system,” he says.
Everyone at Metro Mining is encouraged to play their part in caring for the environment, with all waste repatriated to Cairns for processing. Onsite waste is pre-sorted at the point of collection with food, paper and cardboard, aluminium cans and glass all separated.