La Tour Eiffel
Some words about the Tower: The Eiffel Tower, an immense tower of exposed latticework supports made of iron, was erected for the Paris Exposition of 1889. It was named after its builder, the French structural engineer Alexandre Gustave EIFFEL, who was assisted in the design by the engineers Maurice Koechlin and Emile Nouguier and the architect Stephen Sauvestre. Built to celebrate the science and engineering achievements of its age, the 300-m (984-ft) structure consists of two visibly distinct parts, a base composed of a platform resting on four separate supports (called pylons or bents) and, above this, a slender tower created as the bents taper upward, rising above a second platform to merge in a unified column.
This unprecedented work, the tallest structure in the world until the Empire State Building was built about 40 years later, had several antecedents. Among them were the iron-supported railway viaducts designed by Eiffel and a design for a circular, iron-frame tower proposed by the American engineers Clarke and Reeves for the Centennial Exposition of 1876. Eiffel knew and publicly acknowledged this influence; he was no stranger to the United States, having designed (1885) the wrought-iron pylon inside Frederic Bartholdi's Statue of Liberty.
Eiffel was the leading European authority on the aerodynamics of high frames. In the construction of the Eiffel Tower, the curve of the base pylons was precisely calculated so that the bending and shearing forces of the wind were progressively transformed into forces of compression, which the bents could withstand more effectively. The superskyscrapers erected since 1960, such as the World Trade Center, are constructed in much the same way.
And now, some words about the Tower's builder: Alexandre Gustave Eiffel, b. Dec. 15, 1832, d. Dec. 28, 1923, was a French engineer best known for designing the Eiffel Tower, built in 1889 for the Paris exhibition. Before beginning work on the wrought-iron tower, Eiffel had gained a reputation as a noted builder of bridges and viaducts. He designed an arch bridge over the Douro River in Portugal that had a span of 160 m (525 ft). In 1884, Eiffel designed the iron pylon for the Statue of Liberty and the next year began work on the cupola of the Nice observatory. He later became interested in aerodynamics and wrote The Resistance of the Air (1913).
Once again, Paris.org has some pages about La Tour Eiffel
by: Erik J. Barzeski
iacas@erie.net
