From cutting costs and emissions to boosting health and safety, electrification of mining vehicles is the way forward.
As a mining engineer by trade, Steve Durkin, founder of mining equipment manufacturer Safescape, had long been concerned about the use of diesel-operated light vehicles on mine sites.
Having developed earlier products to improve safety and efficiency in the sector, such as an enclosed Laddertube escapeway, the next frontier for Durkin was building an electric mining vehicle.
“Prior to starting Safescape and Bortana, I worked as a contract miner on sites with lots of people and equipment, and the light vehicle was always a problem,” he says.
The current commercially available vehicles that can withstand heavy duty roles in underground mines don’t tend to last long and the maintenance costs are high.
But back in 2017, before Durkin could produce an EV of his own, he needed a vehicle to work with – which proved somewhat of a challenge.
“We didn’t have the budget to design a vehicle from the ground up,” he says. “So we were looking around the world to find the right partners to work with, and we couldn’t find anything we could bring in to do the job.”
Eventually, the Bortana team came across a vehicle in Brazil called the Agrale Marruá, which fit the bill.
“It’s a sternly built military vehicle that weighs a lot more than a normal light vehicle due to its strong body and chassis, so it carries a much higher payload,” he says.
The galvanised panels and sealed chassis mean the vehicle has unparalleled resistance to corrosion. Crucially, the vehicle is built to order, meaning Bortana could modify the design after receiving the body and chassis in parts – which is how the ’Bortana EV’ was born.
“We were able to get them to take off all engine mounts, exhaust pipes and fuel-filler cap spots and put in battery and motor mounts during the design process of the vehicle,” he says. “Essentially, it’s built to be an electric vehicle.”
Addressing health and safety concerns
For Durkin, there are many reasons why mining vehicles should go electric.
Around the time he was developing the concept for the Bortana EV, concerns began to arise over Diesel Particulate Matter (DPM), and noise-induced hearing loss for miners is also a significant safety concern.
Noise-induced hearing loss is another safety concern for miners. With vehicle noise a fixture in underground tunnels due to engine and gearbox-shifting sounds reverberating off the walls, operators typically need to pump up their radio volume to hear two-way communications.
However, without internal combustion engines to produce noise and vibrations, EVs are a much quieter option.
“You can therefore adjust that volume right back down to a point where you can easily hear it and carry on a conversation, and you don’t need to wear hearing protection to listen to the radio,” says Durkin.
Durkin says the use of software-driven EVs could also reduce the frequency of accidents.
“By implementing controls within software, drivers can’t break traction, accelerate aggressively, or go faster than the speed limit that’s applied by the operation,” says Durkin.
This function is particularly handy when it comes to traction control. “When you’re travelling downhill in a conventional passenger vehicle 4WD and it becomes very slippery, you’d have to try to match the revolutions of the engine to the speed of the vehicle,” he says.
This can cause the vehicle to skid, requiring strong driving skills to avoid a collision. However, motor control software means EVs can quickly adjust to the terrain, so operators “can’t even tell the road is slippery”.
With its one-pedal driving capability and single gear, the EV can also quickly shift from forward to reverse – which is often a necessity on mine sites.
“No matter how much driving experience a person has, they’re [possibly] going to panic and struggle to get the vehicle into gear to get out of the way of a truck bearing down on them,” says Durkin.
“But with an EV, there’s no stopping, putting your foot on the clutch, and finding that gear in a panic situation. They just press reverse and go.”
Reducing costs and emissions
While using EVs on mine sites provides an opportunity for companies to reduce their scope 2 emissions, there are further benefits of zero-emissions vehicles, including reduced heat generation.
With heat already generated in mines from rock formations, further facilitated by ventilation fans, reducing the heat load on miners is a significant benefit.
Regenerative braking also allows the vehicle to recapture some of the energy expended to move the vehicle, which comes in handy when roving the rugged terrain of mine sites.
“When we’re going downhill, we’re actually generating about half of the energy we use going uphill, and putting it back into the battery for further use,” he says.
But where an EV can have an immediate and significant impact is in energy costs.
“In an underground mine, we are regulated to pump a certain volume of cubic metres of air per second for every diesel engine kilowatt employed within the mine,” says Durkin.
This comes to a cost, based on 10 cents a kilowatt-hour, of around $10,000 a month per diesel-operated vehicle.
“If you replace just one diesel vehicle with an EV, the savings can be enormous,” adds Durkin.
The Bortana-EV prototype, launched in 2020 at Victoria’s Fosterville Gold Mine, and Western Australia’s Long Shaft and Nova Nickel mines – was the first electric vehicle to go underground in these states.
“We thought, ‘we’ll just do it to prove why EVs should be used on mine sites’,” says Durkin.
But after building 10 more EVs to get pre-production experience across a range of different applications, Bortana began to see commercial viability.
“As the years have gone by and we’ve done more, we actually realised we’ve got a compelling vehicle here,” he says.
As Bortana prepares to enter the production phase at the end of this year, Durkin anticipates demand will outstrip supply.
“As is normally the case for local manufacturers of mining, equipment and technology, there’s more interest from overseas than there is from Australia,” he says. “But there’s also plenty of interest in Australia.”
For Durkin, it comes back to improving efficiency to enhance sustainability outcomes.
“While there is one-and-a-half times the amount of steel that goes into a Bortana EV than [some diesel-operated vehicles], it will last 10 times as long,” he says. “So, there are countless sustainability benefits.”