A Mining Company Built A Battery-Electric Train That Never Has To Be Charged Because It Only Carries Its Load Downhill

Iron ore mining is a dirty industry, not just because of the extraction and processing of material, but due to the transportation of it as well. Thankfully, steps are being taken to make ore transportation via train a little cleaner, and perhaps some money can be saved in the process, too. Fortescue, an Australian mining company, just debuted a battery-electric locomotive that charges itself via regen, and it makes a lot of sense.

Full electrification is one of the best ways to clean up railroad operations. Most locomotives that you see out there have been diesel-electric hybrids for the better part of a century, but they still use gigantic, diesel-burning prime movers. The California Air Resources Board says that as of 2022, locomotives in the state were putting out around 29,800 tons of NOx per year and over 640 tons per year of PM2.5. That’s just for the state of California! According to a study published in Nature Energy, diesel-electric locomotives in America produce around 35 million metric tons of CO2 each year.

What I’m getting at here is that it makes sense for railroads to want to reduce their impact. Thus, there have been lots of developments over the years in the further electrification of trains. A lot of rail networks use overhead lines, or catenaries, to provide power to electric trains. Others may use third rails.

But what happens when you want to operate an electric train in a place where there are no overhead lines or third rails? This can be a situation where battery-electric locomotives make sense; they’re a concept that has been around for nearly 200 years. Global mining firm Fortescue, formerly the Fortescue Metals Group, has what could be the best application for a battery-electric locomotive.

Mining Cleaner Transport

Fortescue’s new electric locomotive is destined to descend hills with its heavy load of iron ore and use regeneration to help recharge its batteries. Then, the locomotive unloads at its destination, climbs back up empty, and starts the process over again. In theory, the mining group hopes the train will keep itself charged.

This journey has been over three years in the making. Back in January 2022, Fortescue acquired UK-based Williams Advanced Engineering (WAE) for $221 million. WAE, which was a division of the Williams F1 Group, opened in 2010 as a firm to drive electrification development. Car folks might know WAE best for its links to Formula E. But now, under Fortescue control, WAE, which has been renamed to Fortescue Zero, focuses on decarbonization in the mining sector.

In the press release about WAE’s acquisition, Fortescue announced the Infinity Train project:

FFI and WAE have also commenced development of a regenerating battery electric iron ore train project (Infinity Train) to support the delivery of Fortescue’s industry-leading target to achieve net zero Scope 1 and Scope 2 emissions by 2030. In a world first development, the Infinity Train will utilise the gravitational energy generated on the downhill loaded sections of Fortescue’s rail network to recharge its battery electric systems, without any additional charging requirements for the return trip to reload.

The self-sustaining system will increase operational efficiency, lower maintenance costs, and eliminate diesel and the associated CO2 emissions from Fortescue’s iron ore trains. The regenerative capability will remove the requirement for investment in recharging infrastructure and additional renewable energy generation capacity.

[Ed Note: The concept here is technically sound, so long as the train is significantly heavier going down the grade than up it. The maximum energy that regen could recover is the train’s gravitation potential energy, which is its mass times the height of the hill times the gravitational constant — M*g*h.  Of course, no regenerative braking system is anywhere close to 100% efficient, but that’s fine, because the energy needed to get back up the hill is (M_2)*g*h, where M_2 is significantly lower than M and g and h are the same. This is a fairly basic concept and would work with electric cars, too, so long as you had the payload capacity to create a big enough delta. -DT]. 

Fortescue was pretty upfront about its reasoning. The company has 54 diesel-electric locomotives that pull 16 mining trains, each stretching about 1.7 miles in length. The company says that these trains could carry 34,404 metric tons of iron ore across 244 cars. Yearly, these heavy trains burn about 21.6 million U.S. gallons of diesel fuel and amount to about 11 percent of Fortescue’s Scope 1 emissions.

In Fortescue’s eye, spending $50 million now to develop a battery-electric locomotive is a worthwhile investment to hopefully spend no money on diesel fuel for its locomotives by 2030. Of course, there’s also that side benefit of lower emissions.

Battery Trains Are Rooted In History

Fortescue isn’t entering entirely uncharted territory, either. According to Trains.com, the very first battery-electric locomotive was built in 1842 by Scottish inventor and chemist Robert Davidson. Yep, the battery-electric train has been around for longer than the gas-powered car and even the diesel-powered train. It’s a technology that has proven itself for nearly 200 years, but it’s most often been used in dangerous environments like oil refineries and mines, or as maintenance vehicles in subways.

Battery-powered heavy haul locomotives are a more recent concept that leverages modern developments in battery technology. Now, EV tech isn’t anywhere near capable of entirely replacing diesel-electric yet. In 2021, the BNSF Railway operated an experimental locomotive from Wabtec that had a range of around just 50 miles.

A few years ago, Metra, Chicagoland’s passenger rail operator, was investing in converting three EMD F40PH-3s diesel-electrics into battery-electrics. Those locos were targeted to get 150 miles of range. A newer Metra plan calls for battery-electric railcars that have 65 miles of range.

The catch with the locomotives I just mentioned is that they do have to be parked to be recharged, just like your car would need to be. However, companies are finding that all-electric vehicles can go a while without a charge thanks in part to regen.

In 2022, Caterpillar talked wrote a press release about its first battery-electric 793 large mining truck, noting:

 Fully loaded to its rated capacity, the truck achieved a top speed of 60 km/h (37.3 mph). The loaded truck traveled one kilometer (0.62 mile) up a 10% grade at 12 km/h (7.5 mph). The truck also performed a one kilometer (0.62 mile) run on a 10% downhill grade, capturing the energy that would normally be lost to heat and regenerating that energy to the battery. Upon completing the entire run, the truck maintained enough battery energy to perform additional complete cycles.

Fortescue Zero also has a mining truck like this. Its beast has a 1.4 MWh battery, recharges on down slopes, and can reportedly fast-charge in as quickly as 30 minutes, and the idea of using gravity to recharge batteries is also being employed by the diesel-electric logging trucks of Edison Motors, which I’ve written about here.

The Train

This train might sound crazy, but it makes sense. The first so-called Infinity Train has been completed and was shipped about 683 miles across Australia to Fortescue’s operations in the Pilbara region. There, Fortescue operates three mining hubs and has 472 miles of trackage.

What really helps Fortescue here is elevation. The hubs sit as high as a thousand feet above sea level, where the ore gets delivered. In theory, Fortescue believes, its train will load up at a hub, use tons of regeneration on the way down to sea-level, unload its iron ore, and then use batteries charged through the regeneration to climb back up to the hub while empty.

Fortescue hasn’t released data about what batteries are housed in its sole prototype, Fortescue Zero Locomotive 001. The company also hasn’t stated just how long of a route along the mainline that the locomotive is expected to cover. Loco No. 001 is currently expected to undergo yard testing and trials before being put into service later this year.

The body design of No. 001 is pretty interesting. Diesel-electric freight locomotives often have bits I’d best describe as “growths” to fit intakes, fans, and ventilation for their diesel engines, but none of that is needed here. So, No. 001 looks all smooth, similar to an EMD-based passenger locomotive, which is neat.

Also, if you were wondering just how something like this is shipped, Fortescue has a video showing the locomotive’s trucks being mounted to a pair of rails. Then, the locomotive was lifted onto the deck of a massive truck trailer, where it was then hauled out. It’s not uncommon to ship locomotives in this manner; sometimes, a railcar or locomotive shipped by road will have its trucks removed so that the locomotive can fit under bridges and other overhead obstacles.

Railroad CSX Corporation and the EPA quote an Emissions Factor – a rough value that attempts to relate a quantity of pollutant released during the commission of an activity – of 10.21 kg (22.51 pounds) CO2 per gallon of diesel burned. Let’s say, just for the sake of argument, that Fortescue’s 54 diesel-electric locomotives use an equal amount of diesel to reach 21.6 million gallons burned a year, and that their emissions fit that Emissions Factor. Just one locomotive alone would be responsible for burning around 400,000 gallons of diesel, emitting somewhere around 9,004,000 pounds of CO2. The whole fleet would be responsible for 486,216,000 pounds of CO2, or 220,543 metric tons a year.

Fortescue claims to release more than 2.5 million metric tons of carbon dioxide each year. So, making the entire train fleet all-electric would, in theory, help the company cut down on emissions. Of course, the company would also benefit from not having to buy diesel fuel or spend money on diesel maintenance.

At any rate … now we wait. Fortescue has been talking about this train for over three years now, and now it’s time for the company to deliver. Will the Infinity Train actually deliver a load and return to the hub without needing to be plugged in along the way? You know I’ll be paying attention to find out.

Hat tip to Electrek!