Stuttgart 21 – Concreting the special chalice

On Saturday the 12.03.2022, a unique chalice-shaped support at the new Stuttgart underground station was concreted. This chalice is exceptionally challenging because the S-Bahn tunnel runs just ten centimetres below the underground station platform. A total of 28 chalice supports comprise the roof of the new, light-flooded platform hall. With its dynamic shapes and characteristic skylights, the white concrete shell structure has never been built in this form before – 450 metres long, 80 metres wide, a complex structure made of anticlastic curved surfaces.

The Stuttgart-Ulm railway extension is one of the largest infrastructure projects in Europe. In 1997, ingenhoven architects won the international competition for the renovation and new construction of Stuttgart’s main train station. An underground through station will replace the existing terminus station. The above-ground rail facilities will be dismantled, reconnecting parts of the city previously separated by the tracks after over 100 years. The new main station will open when the timetable changes on 14 December 2025.