Popular Mechanics (South Africa)
The world’s largest wheeled electric vehicle is a dump truck
WHO SAID electric vehicles can’t do hard labour? Meet Elektro Dumper, the biggest wheeled EV on the planet. eMining AG, a Swiss manufacturer of smart construction equipment, modified a standard Komatsu HD 605-7 truck, an off-highway vehicle used in quarries and mines, to operate entirely with electric energy. Plus, the thing recharges itself using rocks.
At 9.1 m long, 4.2 m wide, and 4.2 m tall, the ‘eDumper’ isn’t an obvious candidate for electrification. But eMining AG didn’t just paint the stock dump truck green. The company also added a 600 kWh battery pack to the vehicle – enough to power six long-range Tesla Model S cars. Those lithium batteries tack on another 4 000 kg.
Here’s how it works: The eDumper weighs approximately 41 tons and ascends a hill at, say, a 13 per cent grade. On the way back down, it’s now carrying 59 tons of
ore. To rectify that scenario, the truck’s regenerative braking system actually recaptures the energy created by going downhill, refilling the battery’s charge for the next time the truck travels uphill.
For a crash course in regenerative braking, think back to high school physics. Kinetic energy is created through motion, and potential energy is stored because of its placement relative to other objects. You can experience this in petrolpowered vehicles, too. The kinetic energy is created by a spark and the ignition, but while rolling down a hill, a vehicle creates more energy due to gravity.
Regenerative braking, then, takes kinetic energy and transforms it into electrical potential energy that is stored back in the battery. Other factors – the truck’s weight, load, vertical position, and gravitational pull – dictate how much energy can be transformed and stored.
The same process is used in a few other electric vehicles, such as the Honda Clarity plug-in hybrid.
‘Rock trucks’ such as the Komatsu HD 605-7 haul marlstone, a type of lime-rich mudstone readily found in the sides of Swiss mountains. The cement trade relies on this raw material – these trucks transport it directly to their factories.
While the eDumper can go days without charging, an eMining AG rep says the truck still needs a good jolt from time to time if you put it through a rigorous workout. Frequently hitting the brakes, for example, may take up too much energy due to the mechanical parts moving.
While EVs are quickly proliferating throughout the US, the serious work in the trades is still done by gas-guzzling diesel engines. And according to the World Economic Forum, an international organisation for public-private cooperation, heavy industry and transport will account for around 15.7 gigatons of carbon emissions by 2050, if left unchecked.
The eDumper is a good start, but it isn’t just a science experiment – it’s already hauling tons of rocks from a quarry on the slopes of the Chasseral to the Ciments Vigier SA cement factory near the Swiss town of Biel.