Architectural History
The invitation to tender took place in the summer of 1928. Two months later, the cantonal building authority had received 19 projects for a Salgina ravine bridge. The authorities preferred the most reasonably priced offer by the Prader company, although they did not completely trust the unusually slender construction.
This project had been designed by Robert Maillart, who had once again succeeded in finding the most economical bridge solution, using reinforced concrete – a very expensive material at the time – as sparingly as possible. The construction order was placed for the quoted lump sum of CHF 135,000.
The almost completed scaffolding of the Salginatobel Bridge. Foreman Konrad Flütsch carried this postcard in his jacket pocket throughout his life as a reminder of the dangerous yet magnificent work - hence the damage to the picture. (Photo J. Hitz, Pany/Archive A. Kessler).
The highly acclaimed scaffolding by Richard Coray cost an additional CHF 45,000. It was joined on a gigantic floor by just six workers near today's community hall and erected in the steep ravine in the late summer of 1929. The amount of timber required was around 700 m³ and could be extracted from the community's own forests. The concrete was cast in 1930 in the amazingly short period of only three months. All the concrete components were mixed by hand and transported by wheelbarrows. The most delicate phase was the casting of the thin arch slab, which had to be carried out absolutely symmetrically from both sides without interruption. This was completed after 40 hours of painstaking work. In mid-August 1930, the scaffolding was lowered and the structure was opened to traffic.
The Salginatobel Bridge has long been a milestone in the history of bridge building. Its revolutionary construction has set new trends and influenced civil engineers in all parts of the world.
The three-hinged arch structure forms a rigid box girder from the quarter points to the apex: vault, side walls and carriageway form a slender entity. In reverse, huge recesses in the side walls taper the arch towards the supports. The visual effect is captivating - like a giant greyhound, the bridge leaps against the perpendicular face of the rock.
The unadorned clarity of the form, composed of thin slabs and discs, enthralls experts and laymen alike and appears timelessly modern. Never before has reinforced concrete been used in a more economical and elegant way.