Ganter Bridge (1980) Switzerland
Located near the Simplon Pass in the spectacular Swiss Alpine canton of Valais, the Ganterbrücke (Ganter Bridge) is notable for a number of reasons. It is a cross between a cable-stayed and hollow-box girder bridge, a design sometimes referred to as an extradosed bridge, and it was the first bridge of this type to have its cables encased in triangular concrete “sails” which gives the bridge a stylish geometric appearance.
Designed by noted Swiss engineer Christian Menn, Ganter Bridge is a reinforced concrete road bridge which is currently the longest spanning bridge in Switzerland and comprises a distinctive S-curve structure at an elevation of 1,450m (4,760 ft) above sea level.
There are eight spans supported by two main towers and five piers. The main span between the towers is 174m (571 ft) long and is straight while the other seven are shorter and curved. The bridge has a total length of 678m (2,224 ft) and the taller tower rises 150m (492 ft) above the Ganter River.
A tunnel was originally proposed for this location but the estimated cost of 50 million Swiss francs was considered too expensive. The total cost of Wenn’s bridge was less than half of that at 23.5 million Swiss francs. Construction began in 1976 and the bridge was completed four years later in 1980. Due to climatic conditions construction was only possible for a maximum of eight months each year.
A major programme of refurbishment works was undertaken between 2006 and 2008 after slight movement of the southern piers was detected.
With its spectacular location, unique profile and innovative design the Ganter Bridge is considered to be one of the great bridges of the 20th century.