The technology of the Eiffel Tower
Straddling the city of Paris, instantly recognizable, the Eiffel Tower is the symbol of both Paris and France. Three hundred meters high, it’s visible from all parts of the city. Encircled by wheeling flocks of pigeons, soaring above a great plaza filled with tourists, beggars and trinket-sellers, the tower’s four massive piers enclose a 2.5- acre space. It was the highest structure in the world for forty years, until the Chrysler Building was built.
Designed by Gustav Eiffel, the tower was intended to last for only twenty years despite being built for the ages. Its construction required the assistance of fifty engineers, architects and draftsmen. Built of “puddle iron,” which is virtually indestructible when kept carefully painted, the tower is scrupulously repainted every seven years. All paint is by long custom applied by hand using brushes (no paint guns). Its color over the years since construction has ranged from Venetian Red to yellow-brown. During the two years that it took to build the tower, constant criticisms were launched against it by prominent men of arts of that era, including Charles Garnier, architect of the Paris Opera, and the author Guy de Maupassant. Some of the epithets launched against it included: “this truly tragic street lamp” (Léon Bloy); “this belfry skeleton” (Paul Verlaine); “this high and skinny pyramid of iron ladders, this giant ungainly skeleton upon a base that looks built to carry a colossal monument of Cyclops, but which just peters out into a ridiculous thin shape like a factory chimney” (Maupassant); “a half-built factory pipe, a carcass waiting to be fleshed out with freestone or brick, a funnel-shaped grill, a hole-riddled suppository” (Joris-Karl Huysmans).
The elevators that carry tourists to the top are in constant use and are checked and maintained daily. Their annual up-and-down trips combined are equal to two and half times around the world. Visitors can sign up for a special tour that focuses on the below-ground bunker that contains the original elevator machinery, restored and still useful today.
The height of the structure made it ideal for experiments with early radio, cordless telegraphy and (eventually) television. During the First World War, receivers at the Eiffel Tower intercepted secret German transmissions that were decoded and resulted in successful counterattacks. “Thanks to the Eiffel Tower’s [radio] station…spies were exposed, among them Mata Hari,” says the Eiffel Tower’s official history page (http://www.eiffel-tower.com/everything-about-the-tower/themed-files/95-la-tour-eiffel-et-lhistoire-des-transmissions.html)
In recent years the tower has been covered with a colored light show that sparkles and pulses. [ See http://www.youtube.com /watch?v=vCDnMd4bwHA] Those who frown on “disco-lights” should note that imaginative lighting at the tower has a long tradition. Even at the beginning, at its opening in 1889, ten thousand gas street lamps illuminated the tower. Two projectors on the top aimed spotlights at the city below. These beacons, tinted in the national colors of blue, white and red, were considered the most powerful in the world at that time. Between 1925 and 1936 the tower carried an ad for Citroen that was sculpted from 250,000 colored lights that were visible for 30 kilometers; and in the 1930s a huge chandelier containing ten kilometers of fluorescent tubes was installed on the first floor. At times during recent years the tower has been bathed in scarlet, green, blue and other colors. During recent years the nocturnal light show has been programmed to sparkle for five minutes at the beginning of each hour.
The building is one of the most reproduced and recognizable shapes in the world. Paris’ most-visited monument, it attracts nearly seven million visitors each year. Once you stand beneath it and look up, you’ll know why.