Sunday, June 12, 2011

Eiffel Tower, Paris

Despite oft-repeated doubts as to its stability, the Eiffel Tower celebrated its centenary in 1989 after a general overhaul lasting eight years. In 1932 it lost its title as the world's highest man- made structure to the Empire State Building in New York (a title now held by Burj Dubai, expect to rise to 2,684 ft upon completion), but is still visited by almost six million people a year. The Eiffel Tower has long been, and still is, the great landmark of Paris.


The designs and calculations for the tower, built for the Paris Exhibition of 1889 which marked the centenary of the French Revolution, were the work of Alexandre-Gustave Eiffel (1832-1923), an engineer from Dijon. He designed the tower in such a way that even under extreme wind pressure the structural weight is sufficient to prevent it from being blown over. Moreover the lattice construction reduced the pressure on the structure by about half, thus giving a double insurance against collapse. Standing 307m/1,007ft high (320.75m/1,052ft to the tip of the aerial), the tower consists of 15,000 steel sections held together by 2.5 million rivets. Originally the structure's total weight of 7,500 tons was distributed in such a way that at ground level the pressure exerted was only four kilograms per sq. centimeter (57 lb per sq. inch), roughly the pressure exerted by a normal-sized adult on the seat of a chair. As individual sections are not replaced by a similar section but by a heavier concrete section, however, the total weight has increased to 11,000 tons. In the course of the recent renovation 1,500 concrete sections were replaced by steel plates.


When the tower was being built there were vigorous public protests, and the construction company was obliged to give an undertaking to meet any claims for damage in the event of the tower collapsing on to surrounding buildings. Thanks to the double safeguards in the structure this has not happened, and the "cleaning-up" during the restoration work of the 1980s has still further increased the security of the tower.

Since the recent modernization the top platform, at a height of 274m/900ft (orientation table), can be reached by lift. From this platform there are panoramic views extending in fine weather for some 70km/45mi. The views from the first and second platforms, at 57m/187ft and 112m/367ft, are less extensive but have the advantage that surrounding districts of the city can be seen in more detail. At these levels there are restaurants, a post office (with a special franking, "Tour Eiffel") and a cinema, with an audiovisual show on the history of the Eiffel Tower. After dark the tower is impressively illuminated.

In spite of the controversy which it engendered in its early days, the Eiffel Tower inspired has numerous artists, including Signac, Seurat, Dauzat, Dufy, Utrillo, Chagall, Legrand and Robert Delaunay, who sought in a whole series of oil paintings to capture the dynamic of the tower's filigree-like structure.

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