Germany, Switzerland: Nine-section Urbanliner Flexity trams from Alstom in Berlin and five-section TINA family vehicles from Stadler in Darmstadt and Basel are encountering commissioning difficulties.
In February, the introduction of Berlin’s longest trams, the Urbanliners, was again postponed indefinitely. Capital operator BVG has cited the need for further regulatory approvals without disclosing specific reasons.
Urbanliner Flexity from Alstom in Berlin. Source: Daniel Prusseit
According to Urban Transport Magazine, the primary issue is the M4 line’s infrastructure not being ready for these vehicles. A fully loaded Urbanliner weighs 100 tonnes with an axle load of 10 t, far exceeding that of the 1990s-era GT6N trams currently in use.
The new trams were originally scheduled for service in 2023, but the first vehicle began testing only a year later. Subsequent delays stemmed from incomplete documentation, software shortcomings, safety systems and other issues. Under a 2020 contract and 2025 option, 65 nine-section units are now on order.
Meanwhile, Stadler must upgrade 50 TINA-platform trams for Darmstadt and Basel at its own expense, including new bogies pending regulatory approval.
Bogie of the Be 8/10 tram by Stadler for Basel. Source: Benjamin Wieland/bz
Darmstadt operator HEAG mobilo previously halted acceptance of ST15 trams over noise and vibration complaints. An independent survey in early 2025 confirmed that vibrations from the ST15 were 25% higher in nearby buildings than from older trams. Similar issues emerged in Basel with the related Be 8/10 model.
Last spring, Stadler identified redesigned bogies as the culprit. To maximise the low-floor proportion, they were made as compact as possible but proved insufficiently balanced. The manufacturer has retrofitted them with extra yaw dampers and new wheel profiles. Test bogies are reported to have performed well on two trams in both cities. Stadler has also developed and successfully trialled a low-speed vibration suppression system in Basel.
