Stadler Reduces Tram Vibration By Up To 51% In Tests

Measurements from a German tram network show that vehicle-based technical modifications can reduce ground-borne vibrations by as much as 51% at specific locations. Manufacturer Stadler presented results from December tests in Darmstadt, where modifications were made to the wheels and suspension of its TINA model trams. The investigation addresses vibration transmission to buildings, a persistent issue in dense urban rail environments.

The tests were conducted by an independent, accredited institute following DIN 4150 standards. A modified TINA tram was compared against unmodified reference vehicles across three pre-selected sections of the network operated by HEAG mobilo. These sections had been previously identified in an operator study as having significant vibration differences between TINA trams and older rolling stock. The analysis process, which accounted for natural variations in speed and operating behavior, required several weeks to ensure validated, comparable conclusions.

Data indicates the most substantial improvements occurred on Wilhelm-Leuschner Street, a location that previously registered the highest deviations. At this measurement point, maximum vibration intensity fell by up to 51%, with an average reduction exceeding 33%. On the other two analyzed sections, initial vibration values were lower, and the corresponding improvements were recorded as more moderate.

This vehicle-centric approach to vibration mitigation contrasts with infrastructure-based solutions seen elsewhere in the rail sector. In Spain, for example, the construction of AVE high-speed rail viaducts utilizes self-compacting concrete specifically to reduce vibrations and maintain stability for trains operating above 300 km/h. Stadler’s focus remains on vehicle component optimization.

Following the positive results, Stadler plans to prepare the current technical solutions for implementation in series production. The company is concurrently adapting an additional measure, initially tested in Basel, which targets further vibration reduction at low speeds. This solution is being engineered for the Darmstadt TINA tram and will be deployed if it receives approval from the technical supervisory authority. This process is part of a strategy applied since 2025, which mandates testing solutions on active networks with independent evaluation before fleet-wide rollouts.