Slender bridge construction to relieve the historic Hirschenbrücke bridge in Schwyz
Strabag is supplementing the listed Hirschenbrücke bridge from Lachen to Altendorf with a new bridge for non-motorised traffic. The construction work should be completed by the end of 2025.
The Schlieren-based construction company Strabag AG is building a new bridge for non-motorised traffic next to the listed Hirschenbrücke dating from 1940. According to a press release, the bridge for pedestrians, bicycles and light vehicles connects the two villages of Lachen and Altendorf in the canton of Schwyz and carries traffic over the train tracks of the Zurich-Chur line. All road users currently use the same bridge. In order to increase safety for slow-moving traffic, the canton of Schwyz has planned an additional bridge to be built next to the existing bridge.
Construction work on the new pedestrian bridge will be completed by the end of 2024, according to the press release. Work on the connecting structures and road expansion will then follow in 2025. It is expected to take until the end of 2025 before the new bridge is opened to non-motorised traffic.
According to Strabag, the new bridge is very slender and has been designed as a three-hinged arch. This echoes the design language of the old Hirschenbrücke, which was designed by civil engineer Robert Maillart in 1940.
According to Strabag, extensive preparatory work such as securing the excavation pit and anchoring the foundations using micropiles preceded construction. The prefabricated bridge was lifted into place at night in just 3 hours and 15 minutes. In August, the civil engineering team lifted the two prefabricated arch elements weighing 27.5 tonnes into place. The work required the closure of the SBB railway tracks, the transmission line, the cantonal road and the railway track. In September, the two edge elements were also installed at night.