Switzerland – Graubünden (Chur, St. Moritz) September 18, 2019
Swiss Tectonic Arena Sardona WHS. In the northeastern part of the country, this 32,850 ha area has seven peaks above 3,000 m. The Glarus Overthrust demonstrates mountain building through continental collision and tectonic thrust where older, deeper rocks are carried onto younger, shallower rocks. The site shows the three-dimensional exposure of the fault. The Glarus Alps are glaciated mountains with narrow river valleys.
Pont sur la gorge du Salgina (Salginatobel Bridge or Maillart Bridge). A tentative WHS, this 132.3m long bridge crosses the Salgina Brook gorge. Built in 1929-30, it is a marvel of 20th-century bridge construction. Designed and built by Robert Maillard and his company Prader, it was the cheapest bid of 19 others by making the sparing use of reinforced concrete which was very expensive at the time.
Maillart was one of the most significant civil engineers of his time, designing innovative and trend-setting structures. He developed the beamless flat slab (mushroom floor) and he built structures in Spain, France, Italy, Finland, Egypt, and Russia, where he was caught by surprise while building a giant factory when WWI broke out. In 1918, he returned penniless to Switzerland and began a new career as a consulting engineer. The three-hinged hollow-box girder arch and the deck-stiffened arch bridge construction systems developed by him are outstanding in the history of engineering.
Scaffolding was erected in the steep ravine by only 6 workers in the late summer of 1929. The concrete was cast in 1930 in an unbelievably short time of only 3 months. All the materials for the concrete were mixed by hand and transported by wheelbarrow. The most delicate phase was casting the thin arch plate, which had to be done absolutely symmetrically from both sides without interruption. After 40 hours of strenuous work, it was completed. In the middle of August 1930, the scaffolding was removed, and the bridge opened for traffic. The bridge deck is only 3.5m wide, allowing single-lane traffic. The span of the arch is 90.04m, and rises 12.99m. Dimensions of the arch slab – .4m x 6m at the support hinges and .2m x 3.8m at the crown. It is 90m over the river and cost a total of CHF 180,000.
As an outstanding engineering feat and modern work of art, it has had an almost magical attraction to experts and artists alike. In 1991, the American Society of Civil Engineers declared it a world monument (joining a select group of 30 of the world’s most significant engineering creations including the Eiffel Tower, the Statue of Liberty, Forth Railway Bridge in Scotland, Aqueduct of Segovia in Spain and the Ifugao Rice Terraces in the Philippines. In 2001, the renowned British trade journal voted this bridge the most beautiful bridge of the century.
Reach the bridge on a 4km narrow, switchbacking road above the town of Schiers up to the remote location. There is a tiny parking space with room for only 2 vehicles at the south end of the bridge with a picnic table and these signs. There is a trail down the hill to a viewing platform. The bridge still has a very modern look with clean lines.
The bridge doesn’t appear to go anywhere and deadends: it ascends from its elevation at 873m on a switchbacking road to Schuders, a restaurant at 1272m, then ends up giving access to walking trails.
