Whitehaven slashes costs with Cummins repowers

Reduced maintenance costs and quality service support are the key reasons Whitehaven Coal is repowering five Hitachi EH3500 haul trucks with 2000 hp Cummins Inc. QSK50 MCRS engines.

The original engines, from another manufacturer, are being replaced in the EH3500s while Hitachi carries out a 32,000-hour refurbishment program on the trucks at its facility in Gunnedah, NSW. The repower project will be completed in early 2024.

The repowered trucks, which have a gross weight rating of 322 tonnes carrying a 181-tonne payload, are working at Whitehaven Coal’s Maules Creek mine in the New South Wales Gunnedah Basin, which has production approval for 13 Mt run-of-mine (ROM) coal per annum.

Whitehaven, noted for producing high quality thermal and metallurgical coal, has four operating mines in the Gunnedah Basin which achieved ROM production of 18.2 Mt in 2023. More than 100 high horsepower Cummins engines are involved in its three open-cut operations.

Whitehaven recently announced its intention to buy two major Queensland coal mines from BHP – Daunia and Blackwater – in a multi-billion-dollar deal that will transform it into a leading supplier of metallurgical coal for export markets with pro-forma, ROM production of around 40 Mtpa.

Cummins’ involvement in the Maules Creek operation – currently Whitehaven’s largest mine which shipped its first coal in 2015 – is significant with 61 engines in service, a mix of QSK50 MCRS and QSK60 MCRS powerhouses spanning 1944 to 2850 hp, all certified to Tier 2 emissions level. 

They are powering a range of Hitachi equipment, including 45 ultra-class EH5000 haul trucks with a 296-tonne payload and five 800-tonne EX8000 excavators. Maules Creek is the first mine in the world to implement Hitachi’s autonomous (driverless) haul truck system. Two autonomous Hitachi excavators are also operating at the mine.

“We’ve had a long, healthy relationship with Cummins,” says Mark Irwin, Whitehaven’s maintenance manager at Maules Creek, commenting on the reasons behind the repower project. “We’re familiar with the Cummins product and we get high quality support. So when the opportunity arose to increase the Cummins footprint at Maules Creek we jumped at it. 

“We can log issues with Cummins and we’re confident those issues will be addressed. There’s a fair bit of comfort in that.”  

Cummins Tamworth’s on-site support at Maules Creek is headed up by Phil U’Ren who is also leading the repower project, a first globally for Hitachi and Cummins in that there has been no previous QSK50 repower experience with the EH3500.

“We’ve worked closely with Hitachi on the design, installation and commissioning and it has proved a very successful project,” says U’Ren. “We had to compile a significant parts list and some parts had to be manufactured by Hitachi in Japan specifically for the project.” 

Total cost of ownership

When Cummins first got involved in the Maules Creek project, during the tender stage to supply engines, it was emphasized by Whitehaven Coal that the mine was a low-cost business model and that total cost of ownership and local service support were the critical elements.

To meet the life cycle cost requirement for the trucks, collaboration resulted in one engine change-out and one midlife being eliminated from the 90,000 to 100,000-hour life of the chassis.

All the engines at Maules Creek incorporate Cummins’ high-pressure modular common rail fuel system (MCRS) technology for longer life-to-overhaul and reduced fuel consumption and emissions.

“We had high expectations from the start based on our conversations with Cummins and those expectations are being met,” says Mark Irwin decisively. 

He points out that the life-to-overhaul “starting point” for the QSK50 is 32,000 hours; experience at another mine site is that 35,000 hours can be “comfortably” achieved with the 50-litre, V16 Cummins in the EH3500.

Discussing life-to-overhaul of the QSK60 rated at 2850 hp in the 500-tonne EH5000, he reveals 32,000 hours are being achieved “comfortably” at Maules Creek, and that “we’re exploring pushing that out further”. 

“We have to make sure these hours line up with the rest of our maintenance strategies. For example, we do a QSK60 change-out at 24,000 hours in the EX8000 excavators and that lines up with the second change-out of their hydraulic pumps for the life of the engine.” 

Minimal midlife component change-out is another major cost reduction benefit with the QSK50 and QSK60. The MCRS fuel injectors are achieving full engine life. “We have over two million hours’ experience with our EH5000 fleet and in that time there has only been single digit injector replacement before life,” Irwin reveals. “The MCRS injectors are extremely reliable.”  

Low-emission engines are a key requirement at the mine which operates under strict environmental standards. For that reason, all the Cummins engines are Tier 2 emissions compliant. A fuel consumption improvement in excess of 3% is calculated for the QSK50 over the engine it replaces in the EH3500, and this results in a significant greenhouse gas reduction for a truck doing 5,000 to 6,000 hours a year.

PrevenTech™ remote monitoring

Another key benefit of repowering with Cummins is the availability of Cummins’ remote engine monitoring system, PrevenTech™, which is connected to all Cummins-powered trucks and excavators at Whitehaven mines.

PrevenTech works by applying connectivity, algorithms and analytics to a machine's engine hardware, helping a mine identify and diagnose issues faster and more accurately. It works with Internet of Things (IoT) technology and global security standards.

Mark Irwin saw PrevenTech as a “logical step” for integration in the fleet while the system was being trialled at Maules Creek. 

“During the trial period we only had 10 engines connected but still prevented a couple of potentially significant downtime events. The machines were diagnosed and then repaired in a short period so as not to interrupt production,” he reveals.

“Anything that helps us trend data and get ahead of issues is important,” he says. “We’ve gone from looking in the rear-view mirror to learn from the past, to looking forward and making informed decisions with the real time data we’re getting from PrevenTech.

“In other words, we’re now being more proactive, and less reactive, with our maintenance practices and that means reduced operational and maintenance costs.”