MAN & Fraunhofer launch noise study for electric trucks
MAN Truck & Bus participated in the ‘Mobility Study on Low-Noise Logistics’ conducted by the Fraunhofer Institute for Material Flow and Logistics IML. A pre-series vehicle of the MAN eTruck was also used to develop standards for measuring noise emissions during delivery operations.
The study, which is funded by the Ministry for the Environment, Nature Conservation and Transport of the state of North Rhine-Westphalia, is intended to develop precisely those standards for noise from delivery vehicles. According to MAN, a pre-production vehicle of the new MAN eTruck, which will be delivered to customers for the first time in 2024, was part of the real-world measurements with selected vehicles.
The study is expected to be published in early 2024. The data for it was collected, among other things, during a series of measurements on the MAN test track in Munich. Experts sent the MAN eTruck and a conventional diesel-powered MAN TGX 18.510 of the same weight class onto the track and measured their noise levels. These were articulated trucks with a total weight of 40 tonnes. Employees of the accredited measurement centre Peutz Consult GmbH carried out the measurements on behalf of Fraunhofer IML. To the right and left of the carriageway, they set up calibrated hand-held sound level meters at a distance of 7.5 metres each.
One result: electric trucks are perceived – especially at low speeds – as only about half as loud as comparable diesel trucks. Specifically, the MAN eTruck was only 1 dB(A)/m “louder” than a passenger car with a combustion engine when driving past at 20 km/h. MAN has published further measured values in the press release linked below.
Quieter electric trucks have further applications
But: combustion engine trucks were also quieter in the measurements than previously assumed in the literature. “Based on the measurements, the eTruck results in a level that is approx. 6 dB lower for the steady pass-by at 20 km/h. If we take into account that the diesel truck measured here is about 5 dB quieter at 20 km/h than the typical approach from the literature, the difference between the eTruck and the literature approach increases to 11 dB. The eTruck is thus about half as loud as a classic diesel truck. For the accelerated approach, there was an even more significant level difference between the two trucks of 12 dB,” explains Michael Wirtz, project manager of the measurements at Peutz Consult GmbH.
“The measurements show: Our new MAN eTrucks could also be used during off-peak hours, i.e., late in the evening or early in the morning,” says Christoph Jeßberger, Product Strategy Manager at MAN. “This means they open up a very wide range of uses and a high degree of flexibility for our customers. This means use up to 24 hours a day, 7 days a week – provided the legal framework is in place.”
Getting new permits for deliveries at night or during off-peak hours is still often difficult today because there is a lack of values to guide the administrations. “By producing a manual on noise emissions from trucks with alternative drive systems during deliveries in urban areas, we want to make the work of municipalities and permitting authorities easier. We have found that they lack data and measured values if they are to decide, for example, on nighttime delivery in urban areas,” says Daniela Kirsch, project manager at Fraunhofer IML.
In the communication, MAN and the Fraunhofer Institute refer to the situation in the Netherlands, where a noise protection standard PIEK has already been developed. In order to obtain certification, for night deliveries, for example, trucks and transport equipment are acoustically tested. They must not exceed the prescribed decibel limits at a distance of 7.5 metres. In Germany, noise immissions are assessed according to the “TA Lärm” (Technical Instructions on Noise Protection). “There is currently no market overview or standardized information on noise emissions from alternatively powered commercial vehicles used in logistics in Germany,” says Kirsch. “That’s why we need a solution like the PIEK certificate that companies can use as a guide.”