Dhe electrification of vehicles can lead to extreme examples. The 58-ton dump truck called Lynx (Lynx in German) is one of them. According to the manufacturer, it is the largest and most powerful electrically powered wheeled vehicle in the world and has the most powerful mobile power storage device, a four-block lithium-ion battery with a capacity of 700 kWh. At 4.5 tons, it weighs about as much as nine traction batteries for the Tesla S. The green monster is powered by a 634 kW synchronous electric motor from the Bavarian manufacturer Oswald, which can develop a maximum torque of up to 12,500 Newton meters. On board is also an asynchronous electric motor with an output of 200 kW from Swiss production, which supplies the hydraulic pumps for the brake system, tilting drive and servo support with the necessary energy.
The Lynx was designed and built by the company E-Mining in Illnau, which belongs to the Swiss construction machinery group Kuhn. The base vehicle was a used Komatsu HD 605-7 dump truck with a conventional diesel engine. It was replaced by the aforementioned electric unit and a two-stage gearbox. This allows the giant tipper to reach a top speed of 40 km/h and climb gradients of up to 14 percent. It is now being used in a quarry near Péry in the Bernese Jura, where it loads up to 65 tons of limestone and marl rock several times a day and transports it to the loading station in the valley.
A residual amount of electricity remains
On a descent with a 13 percent gradient, the fully loaded 123-tonne six-wheeled colossus generates so much electricity by recuperating braking energy that it can use it to make the next ascent. In theory, the Lynx could even make something like a perpetuum mobile a reality. According to the calculations of its designers, it actually generates so much electricity on departure that there is even a residual amount left over after the return trip that could be fed into the grid.
In practice, however, this calculation does not work because the weather often does not cooperate and, for example, when snow chains are fitted, power consumption increases sharply. Like its small four-wheeled relatives, the lynx has to go to the charging station after work.
Nevertheless, it comes quite close to the vision of the zero-energy vehicle. According to a study by the Federal Materials Testing and Research Institute EMPA, it will transport around 300,000 tons of material over ten years of use, saving around 500,000 liters of diesel and up to 1,300 tons of CO2. Then the additional price, which is a considerable factor of 2.5, would have been amortized.