Stronger for longer

Underground mining contractor Byrnecut is achieving the “magic number” for engine life with the Cummins QSK19.

Epiroc and Cummins have worked together closely to extend life-to-overhaul of the 760-horsepower (hp) QSK19 in underground haul trucks, which have one of the toughest jobs in mining.

High engine load factors are the norm when operating underground, with trucks operating at full power for long periods on punishingly steep grades at fully loaded weights in excess of 100 tonnes.

Byrnecut, one of Australia’s largest underground mining contractors, operates 27 Epiroc MT65 underground trucks among its massive fleet of equipment, which also includes hundreds of trucks, loaders and development and production drills.

Acclaimed as the industry’s first 65-tonne payload capacity truck, the MT65 was introduced in 2016 with Cummins’ QSK19 MCRS engine, and Byrnecut’s 27 units are now hauling gold-bearing ore at the Golden Grove, Carosue Dam, Deep South and Hamlet underground mines in Western Australia.

Jamie Armstrong, Byrnecut’s maintenance reliability coordinator, is concise in describing his role.

“I just look at the data – the facts and figures – before making recommendations,” he said.

Cummins’ QSK19 MCRS engine.

Magic number

Armstrong believes Byrnecut has proven it can deliver what’s needed with these underground trucks.

“When we look at engine life, 16,000 hours is the magic number and the evidence is that we can now achieve that with the QSK19,” he says. “Reliability has improved considerably over the last four years, and today we are very comfortable with the product.”

Armstrong pointed out that longer engine life, as well as improvements to the MT65 itself, have been critical to reducing lifecycle costs, with Byrnecut now able to extend truck life from 24,000 to 30,000 hours.

Byrnecut’s knowledge of the product has continued to grow, resulting in improved skillsets at a servicing level.

Engineering support provided by Cummins is rated highly by Armstrong.

One example of this strong support came when fluctuating oil pressure was causing premature bearing wear, a problem detected by PrevenTech, Cummins’ real-time digital monitoring and reporting system. The cause was found to be oil sump overfill, and Cummins developed a calibration to warn the operator if this has occurred.

“The QSK19 is the benchmark for reliability and durability in underground mining,” Cummins mining business manager for Western Australia Dave Abbott said. “In fact, in some operations in Australia, we’re seeing the engine reach the 18,000-hour mark.”

Drivetrain updates

An upgraded MT65 – designated the MT65 S – will be seen in Australia late this year. Epiroc said the optimised drivetrain of the MT65 S combines high ramp speed with improved energy efficiency.

Among the key updates are a diff ratio change to ensure the engine is constantly operating in the ‘sweet spot’ for improved performance and fuel efficiency. In addition, upgraded software for the transmission helps to ensure gear shifting takes place at the right time while also providing improved retardation.

The is MT65 S is part of Epiroc’s ‘Smart’ series, which makes it prepared for sixth sense functionality such as automation and remote control.

This feature appeared in the September 2023 issue of Australian Mining.

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