Kuhn Schweiz e-Dumper

The e-Dumper is a battery-electric quarry dump truck built by the Swiss company Kuhn Schweiz AG. It is a converted used Komatsu HD 605-7, rebuilt from diesel to electric drive in a project with the Bern University of Applied Sciences (BFH), NTB Buchs and Empa. The Swiss Federal Office of Energy funded the project, and the cost was reported as a seven-figure sum in Swiss francs. The conversion was carried out at Kuhn Schweiz sites in Lommis and Heimberg, with the drive components installed in autumn 2017.

On 20 April 2018 the truck was named “Lynx” (German for lynx) and began work at the Vigier Ciment quarry near Péry in the Bernese Jura, close to Biel. It hauls limestone and marl from a quarry on the slopes of the Chasseral down to the cement plant, on slopes of up to 13%. About 20 trips a day were planned, with more than 300,000 t (330,693 US tons) of rock a year over ten years.

The diesel engine and tank were removed. The electric drive uses a synchronous motor from Oswald Motoren, reported at 634 kW (862 PS / 850 hp) with 12,000 Nm (8,851 lb-ft) of torque. The gearbox comes from Puls Getriebe and the inverter from Aradex. A separate 200 kW (268 hp) motor from Brienzer Motoren powers the hydraulic pumps for the brakes, tipping body and steering. The top speed is reported as 40 km/h (25 mph), and the driver climbs nine steps to reach the cab.

The battery pack sits in four blocks in the engine bay, where the diesel tank used to be. BFH gives its capacity as 600 kWh, Empa and Vigier Ciment as 700 kWh, and a 2025 Galaxus article as 710 kWh. Its mass is 4.5 t (9,921 lb) according to BFH and Empa, while Vigier Ciment’s 2023 release gives 8 t (17,637 lb). Empa’s 2017 project description planned 1,440 nickel-manganese-cobalt cells from Shenzhen Westart with battery software from Esoro. The battery supplier named by BFH is Lithium Storage GmbH. Empa carried out the safety assessment.

The truck has an empty weight of 58 t (127,868 lb) and a payload of 65 t (143,300 lb), giving about 123 t (271,168 lb) fully loaded. It is about 9.35 m (30.7 ft) long, 4.24 m (13.9 ft) wide and 4.4 m (14.4 ft) high, with a wheelbase of 4.3 m (14.1 ft). With the body raised it reaches 8.8 m (28.9 ft). Its tires are almost 2 m (6.5 ft) in diameter.

Braking on the loaded descent recharges the battery. According to the developers’ preliminary calculations, this energy should largely cover the empty return climb, which would make it a “zero-energy” vehicle. Empa’s plan estimated about 40 kWh recovered per descent and a surplus of about 10 kWh per round trip. Later reports speak of a surplus of about 200 kWh a day (77 MWh a year).

The company says a comparable diesel dump truck uses 50,000–100,000 liters (13,209–26,417 US gal) of diesel and emits roughly 131–262 t of CO2 a year. Preliminary estimates put the savings of the e-Dumper at up to 1,300 t of CO2 (1,433 US tons) and 500,000 liters (132,086 US gal) of diesel over ten years.

BFH described the project as setting three world records: the largest and most powerful battery-powered electric wheeled vehicle, the largest battery ever built for an electric vehicle, and the largest CO2 saving by a single electric vehicle. The Guinness World Records 2022 book lists the truck as the world’s largest battery-powered dump truck, according to Vigier Ciment. In a test drive reported in mid-2019, Formula E champion Lucas di Grassi rode in the truck. The battery was reported at 90% at the start, 80% at the top of the climb and 88% after the return.