Aerodynamic measurements of the new ÖBB nightjets

For 10 December 2023 the Viaggio Next Level non-powered multilple units (NMUs) built by Siemens are scheduled to start passenger service in Austria and Germany. PJM was commissioned with the overall approval in cooperation with ÖBB (as announced in October 2022).

As an accredited test laboratory according to ISO/IEC 17025, the Austrian system specialist was in charge of the design and production of the measuring wheelsets as well as for the approval tests in the areas of running behavior, fatigue strength, acoustics and aerodynamics. PJM carried out the approval tests, the measuring wheelsets were designed and manufactured in its headquarters in Graz.

The aerodynamic vehicle tests according to TSI LOC&PAS, EN 1467-4 and 14067-5, were performed at speeds of over 200 km/h in the tunnel and 230 km/h at open track. In the course of these measurements, compliance with the permissible aerodynamic stresses was checked on the  platforms, on the open track and in tunnels, including determination of pressure fluctuations and using ultrasonic anemometer for airflow measurements

The required boundary conditions in Austria can currently only be executed on the Westbahn HSL, which is why the test runs took place between Wien and Linz. One of the measuring points was at the Sittenbergtunnel at Ybbs a. d. Donau. Flexibility and precise preparation were required in advance so as not to interfere with the tight timetable of the frequently used Westbahn.