Liebherr mobile cranes comply with Euro VI c standard in real driving conditions
Much of the public debate about diesel engines and their emissions is focused on trucks and cars, which are subject to standards such as the Euro stage VI c which specifies the limit value for truck exhaust emissions. A part of the regulation includes measurements of the real vehicle in real driving conditions.
Mobile cranes, in contrast to trucks, are subject to off-road standards such as the Euro stage V, regardless of whether they are being driven on the road or are on a construction site. Modern mobile cranes have a single engine for both road travel and site operations. All diesel engines built in 2019 onwards, which are installed in mobile cranes and are licensed in EU countries, Switzerland or Norway, must satisfy the Euro V emissions standard. These requirements are similar to those for the Euro VI c on-road standard. The Euro stage V regulation specifies emissions limits for mobile machines and equipment not designed for road traffic.
Compared to trucks, there are fewer mobile cranes in operation around the world, and they cover significantly lower distances, an average of 10,000 kilometres annually. Despite their smaller carbon footprint, could mobile cranes or any other of-road equipment achieve or be expected to achieve the same emission targets as those of on-road vehicles?
Liebherr aims to achieve the same emission limits for its on-road and off-road equipment. By using their latest engine and gearbox technologies, combined with a sophisticated, efficient emissions treatment system, Liebherr has demonstrated that their mobile cranes can comply with the stringent Euro VI c on-road standard in real driving conditions.
Dr. Ulrich Hamme, technical director, Liebherr-Werk Ehingen, said: “We have been conducting research for over 20 years and a significant part of our development budget is spent on reducing emissions. During this time, we have managed to reduce nitrogen oxide and soot particles, or fine dust, in stages by around 97%. Before our fleet was converted to emissions level V, we conducted a field test with Biberach-based crane hire company ESB over a period of several months to observe and improve the diesel particulate filter and urea dosage system in real-world conditions.”
Liebherr has been conducting extensive portable emission measurement system (PEMS) tests during the last few months in collaboration with experts from TÜV NORD and IAV. The PEMS equipment is a mobile emissions measuring device for real-world driving. In order to determine the emissions by means of PEMS on public roads, the in-service conformity procedure (emissions during use) is also used. For the ISC test, the vehicles are equipped with the PEMS technology for mobile emission measurement and tested in real road traffic for the limits of nitrogen oxides (NOx), carbon monoxides (CO) and hydrocarbons (HC).
The tests compared the emissions from a 60t Liebherr LTM 1160-5.2 crane and a laden 40t Mercedes Actros 1842 truck in real driving conditions. Both the vehicles were driven on the same route around the cities of Ehingen and Ulm in Germany and subjected to similar on-road and off-road conditions including urban traffic.
TÜV NORD and IAV monitored the entire trip and conducted the PEMS tests including tailpipe measurements, and they documented the results independently.
After three months of testing, the results revealed that the emissions of the off-road stage V Liebherr cranes matched the requirements of the on-road Euro VI c PEMS standard in real driving conditions.
Dr. Martin Goschütz, project manager, TÜV NORD, said: “Both the nitrogen dioxide emitted by the crane and the carbon monoxide were in the comparable range to the emissions of the truck while the hydrocarbons were even lower than those measured in the truck.”
Dr. Hamme explained: “The results of these measurements, even by comparison with modern trucks from renowned German manufacturers, are another pioneering, forward-looking milestone in our steady development of engines and gearboxes for our cranes. The PEMS test results indicate that our mobile cranes can definitely match the emission limits of long-haul trucks.”