Modification of Entrances to Trams Operated by Basler Verkehrs-Betriebe

Basler Verkehrs-Betriebe BVB
The Swiss Federal Act on the Equalization of Persons with Disabilities (BehiG) calls for flush access to public transport so that passengers with disabilities can enter without assistance. To comply with this requirement, Basler Verkehrs-Betriebe (BVB) raised the platform level of their stops and adjusted their vehicle entrances accordingly. As part of the project, Helbling designed a modification to the steel structure of the approximately 25-year-old Be 4/4 and Be 4/6s series trams.

The steel structure to be developed for the trams not only had to comply with the new geometric constraints to the entrance area and the underlying principles of valid regulations, but also needed to be economically feasible. As an internationally active development and innovation partner to the rail vehicle industry, Helbling had all of the qualifications it needed to solve this problem. Helbling has many years of experience and proven expertise when it comes to modernizing and retrofitting rail vehicles.

  • Retrofitting the trams will ensure that disabled individuals can enter and use the vehicles unaided

  • Renewal: On older trams, the underbody is the load-bearing element. The superstructures themselves are not load-bearing. Now, however, the steel structure is to become load-bearing. That called for complicated structural integrity assessments.


  • Developing a concept for the steel structure in entry areas

  • Developing a validation concept compliant with EN 12663 as a basis for calculating the retrofit

  • Presentation of the validation concept to the Federal Office of Transport (BAV)

  • Close cooperation with BAV as the approval granting authority on coordinating regulations and boundary conditions

  • Developing an FE model of the structural element for FEM calculations with 3D CAD

  • Agreeing the developed solutions with the customer’s production experts

  • Producing the production drawings after completion of design work and proof of durability

  • Documentation of serviceability in an assessment report to BAV

Result / Success

Thanks to the close collaboration between Helbling and BVB as well as the systematic approach applied during the design and calculation work, an economically sensible and regulation-compliant tram retrofit solution was developed within a short space of time. The trams are now properly equipped for another 15 to 20 years of operation.

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