As manufacturers race to develop low-emission equipment solutions, Liebherr has announced its first crawler excavator powered by a hydrogen combustion engine, the R 9XX H2.
Based on Liebherr’s generation 8 crawler excavators, the 50-ton R 9XX H2 prototype debuted at the recent Bauma show in Munich, Germany.
At the heart of the machine is Liebherr’s first hydrogen engine, the H966. The engine is based on an intake manifold injection technology, also known as PFI.
Liebherr says that after extensive testing, the results showed strong potential for hydrogen propulsion and the use of such drives in off-road applications. The prototype had the same overall performance as its diesel engine counterpart, both in terms of power output, engine dynamics and response.
The only difference between the prototype and Liebherr’s conventionally powered excavators, the company says, is when it comes to refuelling. The prototype excavator and the refuelling station communicate via infrared sensor for fast and safe refuelling using a standardized high-speed protocol.
“The tests carried out in Colmar were extremely convincing,” said Henrik Weitze, project manager at Liebherr-France SAS. “This technology promises many advantages for us in the future, especially in the most challenging applications.”
The H2 drive in the R 9XX H2 does not require a permanent energy supply and emits extremely low levels of nitrogen oxide and carbon-dioxide.
“Depending on the assessment method used in each case, and whether the entire life cycle of the machine is taken into account, the hydrogen combustion engine can reduce CO2 emissions by almost 100%, when considering ‘tank to wheel’ or by 70%, when considering the ‘cradle to grave’ principle,” Liebherr says.
The company’s components division is working on additional hydrogen-based drive technologies, such as H2 direct injection, which enables a higher power density than the conventional H2 intake manifold injection and is, therefore, well suited for demanding work environments, such as earthmoving and quarry operations.