Stadelhofen Station is located in a dense urban area between Stadelhofen Square and the Hohenpromenade Hill; once a bastion of the old cityıs fortifications. Calatrava's challenge was to accommodate a new third track along the curved railway line running around a hillside in the town center.
Options for accommodating a third track were a tunnel, the more intricate, less intrusive approach, and an open excavation, the more rapid solution. Calatrava proposed a compromise, a sweeping yet contained intervention, which would undercut and redefine the hillside to create an open platform while respecting the slope of the terrain.
The old retaining wall was demolished and the hill supported by a concrete box-beam, with convex soffit, supported by an anchored and piled wall to the rear and a series of triple-point, slanting and tapering columns to the front. This structure develops as a continuous 270-meter section, following the curve of the tracks mid-radius 400 meters under the hill.
A promenade above the box-beam is covered by a cable trellis, creating a transparent green
"canopy" that softens the station's intrusion into the surrounding environment and relates to the green of the 19th-century area behind. From the promenade travelers can access the platforms via stairs, elevator or across bridges which span the tracks to the lower side. A transparent glass canopy, extending the entire length of the open platform, ensures a feeling of spaciousness and maximizes the effect of light, which filters down to the subterranean passage.
To maximize commercial use of the site the underground passages were connected to create a subterranean shopping mall. In its construction, concrete supports were cast in place using one-piece formwork that, for each new casting, was then moved and adjusted to the geometrical gradient. At each point of entrance, where the supports have been omitted not to interrupt passenger flow, the structure is held by clad tension-rods. The exposed concrete ceiling is one continuous, undulating surface. To illuminate the shop fronts, daylight filters down between the supports through prefabricated glass-brick elements laid in the platforms.
The requirement for closing the station at night resulted in the development of hydraulically activated devices to shut that entrances and in some cases protect them from the weather.
Client: Swiss Federal Railways, Berne
Landscape Architect: Werner Rüeger