Battery electric transporter proves faster, safer and more profitable underground leaving diesel rivals struggling to keep pace

Deep underground in the Illawarra, a battery electric transporter called Driftex is rewriting the rules of coal mining by beating diesel on safety, speed and cost.

At the 33rd Mechanical Engineering Safety Seminar (MESS 2025), organised by the NSW Resources Regulator, project engineer Alex Burnside of Peabody’s Metropolitan Mine outlined a three-year journey that took a simple trial of a battery electric transporter and turned it into a transformative fleet initiative. Speaking alongside Jared Gorman, national product manager for DC fast charging, Driftex, and electric vessel propulsion at Ampcontrol, Alex explained how the introduction of the Driftex battery electric transporter is reshaping both operational safety and productivity in one of Australia’s oldest underground coal mines.

The setting: an ageing mine with modern challenges

Metropolitan Colliery, located 30 kilometres north of Wollongong, is Australia’s oldest continuously operating coal mine at 138 years. It produces semi-hard coking coal, PCI, and thermal coal, yielding 2 to 2.5 million tonnes annually from longwall and continuous miner methods.

While its history is a badge of honour for Peabody, Alex was frank about the operational difficulties of working in old layouts with expanding diesel fleets.

“With a growing mine comes a growing workforce and a growing diesel fleet, which means greater ventilation demands,” Alex said. “We’ve upgraded stoppings, increased fan output, and added bunker systems to shorten roadways, but we’re still challenged by ventilation constraints. Many of you would be familiar with the inefficiencies - operators parked up at tag boards waiting for machines to exit, production delays, and potential safety risks if not managed properly.”

It was in this context that the idea of battery electric transporters began to gain traction.

From rumour to reality

Alex recalled hearing early rumours about Ampcontrol’s development of a battery electric transporter. At the time, he was a diesel coordinator looking for ways to ease the strain on fitters and reduce reliance on diesel equipment.

“We aligned a trial with senior management visiting the site. The plan was simple - pick them up in the EV from the car park and drive them down to the muster,” he said with a smile. “When the engineering manager asked the CEOs what they thought, their response was short and clear: ‘I’ll have two.’ Those three words turned what was meant to be a trial into a three-year project.”

Building the Driftex

The Driftex takes a standard diesel personnel carrier and replaces its combustion engine with a full electric drivetrain. Jared outlined the technical specifications:

• Nine and a half tonnes, heavier than its diesel counterpart due to around one tonne of batteries

• Twin 110 kW permanent magnet traction motors with oil cooling, delivering full torque instantly and maintaining top speed on 1-in-4 inclines while fully loaded

• Regenerative braking, upgraded braking systems, and hydraulic steering

• Noise levels around 84 dB, low enough for normal conversations without hearing protection

“The beauty of electric is the torque,” Jared explained. “We can hit top speed straight away, climb grades without losing momentum, and the noise is so low the loudest thing is the tyres on the road.”

The heart of the system is a 60 kWh lithium titanate (LTO) battery, chosen deliberately for safety rather than energy density.

“Not all lithium-ion chemistries are equal,” Jared said. “We selected LTO because it’s inherently safe. It doesn’t go into thermal runaway, it’s certified as intrinsically safe, and it’s capable of fast charging - up to six times faster than many alternatives. In practice, we can charge a Driftex in 10 minutes with the right infrastructure. At Metropolitan, we installed a 75 kW underground charger that takes around 40 minutes.”

With an expected lifespan of 30,000 charge cycles - three times longer than many competing chemistries - the battery is designed to last well beyond typical fleet cycles.

Safety first

Given the coal environment, safety certification was critical. The Driftex employs a combination of protection techniques including Exd (flameproof), Exi (intrinsically safe), and Exs (special protection), with specially designed enclosures that extinguish flames while keeping the overall vehicle weight manageable.

“If ventilation is lost and methane builds up, the onboard gas monitoring system will automatically trip the batteries into a non-operable state,” Jared explained. “That means the vehicle can safely remain underground until conditions stabilise.”

Alex added that Metropolitan went through an exhaustive process of risk assessment, plant safety reviews, and audits to ensure safe deployment.

“One of the biggest concerns was thermal runaway,” he said. “There wasn’t much mining data available, so we drew on automotive sector stress testing and demonstrations at Ampcontrol. We determined the risk sat in the ‘rare’ category, but we knew charging posed the higher risk, so we designed a fit-for-purpose charge bay with fire suppression, ventilation, and gas monitoring.”

Industry recognition

The Driftex innovation has not gone unnoticed. It has won several leading awards, including Health Excellence at the 2023 NSW Mining HSEC Awards and the Health, Safety, Environment and Community (HSEC) People’s Choice Award. Ampcontrol was also named one of Australia’s Most Innovative Companies for 2023 by the Australian Financial Review for its advanced Australian manufacturing of energy solutions - an accolade specifically attributed to Driftex.

These awards underline what Alex and Jared emphasised in their presentation: that the transporter is more than an experiment. It is recognised as a genuine breakthrough in both safety and innovation for the underground mining industry.

Dollars and sense

Electrification does not come cheap. Alex broke down the initial outlay:

• $350,000 for the donor chassis and mechanical components

• $965,000 for Ampcontrol’s electric upgrade

• $270,000 for chargers and charge bay setup

But over a four-year cycle, the Driftex reduces maintenance overheads by around $130,000 per unit. No diesel particulate filters, no fuel bills, and less downtime translate into measurable savings.

And the real kicker came in side-by-side performance trials.

Putting diesel to the test

To benchmark the Driftex, Peabody compared it against a modern repowered diesel transporter dubbed “Predator,” fitted with a 4.1-litre turbocharged engine, upgraded cooling, and particulate filters. Trials were conducted on a hired motocross track, where 23 operators put both vehicles through laps, drags, and endurance runs.

The results were emphatic:

• Driftex recorded faster acceleration to 30 km/h, and the fastest times on 200 m, 500 m, and 1 km circuits

• Noise and emissions were significantly lower

• Operators noted smoother handling and reduced fatigue

“On the one-kilometre circuit, the Driftex was 77 seconds faster than the diesel,” Alex said. “If you extend that to coal haulage, those seconds could translate to an additional $1.9 million in annual revenue. That’s when you start to see how performance and economics align.”

The Predator did score higher on range and reliability in the trials, but the case for electric - particularly in safety-sensitive coal environments - proved compelling.

Lessons learned

Introducing a new technology underground is never straightforward. Alex and his team logged every commissioning fault, from overspeed issues to regen settings, and worked through them systematically. Training packages had to be rewritten, maintenance procedures adjusted, and emergency plans updated.

“We’re still early in the rollout, but we’ve learned that operator training and change management are as important as the engineering,” Alex said. “The technology works, but it has to fit into the broader system - charging, service bays, risk controls, and people.”

The bigger picture

For Alex, the Driftex represents more than just a new vehicle.

“It’s about improved environmental outcomes and a stronger commitment to the health and safety of our people,” he said. “We’ve shown that battery electric transporters can deliver benefits far beyond compliance - they can reshape how we think about underground operations.”

Jared echoed the point. “This project shows that electrification isn’t just a future concept - it’s happening now. We’ve proven you can operate battery vehicles safely in coal mines, with better performance and lower costs. That’s the shift the industry has been waiting for.”

Conclusion

The introduction of battery electric transporters at Metropolitan Colliery demonstrates a decisive step in the industry’s move beyond diesel. What started as a trial to impress visiting executives has evolved into a fully certified, operationally proven fleet asset delivering safety, productivity, and economic benefits.

For mining professionals weighing the balance between tradition and innovation, the Driftex offers a compelling case: safer batteries, faster vehicles, lower ventilation demand, and real-world operational savings.

And as Alex put it bluntly to his audience at MESS 2025: “Don’t just take my word for it - look at the data. The Driftex delivers.”