GARABIT VIADUCT BRIDGE MAP

GARABIT VIADUCT BRIDGE MAP

Crossing Truyere River, near Saint-Flour, France Designer/Engineer Gustave Eiffel Completed 1884 Span 541 feet (165 meters)

Material Steel Type Arched viaduct

Eiffel harnessed the wind, a feat that inspires engineers to this day.

Gustave Eiffel’s best-known worksthe armature of the Statue of Liberty, the dome of the Nice Observatory, and his ultimate creation, the tower that bears his nameare such landmarks that they overshadow his considerable achievements as a bridge builder. The hundreds of bridgesportable bridges, military bridges, railway bridges, and footbridgesEiffel would build and perfect over a lifetime were a prelude to his last and most significant bridge, the Garabit Viaduct.

“This is therefore a double success for me, first for my pride and second for the importance of the work which is exactly the type to put me among the companies to be reckoned with,” wrote a proud Eiffel to his mother in 1867 after winning his first big contract to build two viaducts at Neuvial and Rouzat. He went on to build a number of railway viaducts, needed by the rapidly expanding mining industry in the iron-rich, though topographically inhospitable, Massif Central region in the South of France. The railroad viaducts that Eiffel designed between 1869 and 1884 exemplify a method and an aesthetic that found their ultimate celebration in the design of the Eiffel Tower.

Eiffel’s challenge in crossing the deep valley over the Truyere River was to create a structure that could withstand, despite its great height, the strong winds that swept through the Massif Central’s steep gorges. Having set up meteorological stations throughout France to collect data on aerodynamics, Eiffel had vast empirical knowledge of wind forces.

At Garabit, Eiffel proposed a parabolic-arched viaduct similar to the Ponte Maria Pia (1877), which he had built over the Douro River in Porto, Portugal. The recent availability of cheap steel (by the 1870s its price had fallen 75 percent) made feasible the long spans of both viaducts. As at Douro, the Garabit bridge crosses the ravine in five spans. The two short spans on either side of the valley are supported by metal piers on masonry bases shaped like truncated pyramids; the tallest of these piers is 294 feet (90 meters). The 541-foot (165-meter) central span is supported by an arch shaped like a crescent moon. Each half of the arch was suspended by steel cables from the deck while its components were fastened together and built out to midspan. Standing 400 feet (122 meters) above water, the viaduct was for many years the tallest bridge in the world.

Aerodynamics continued to engage Eiffel’s brilliant, persistent mind. Five years later the lessons learned at Garabit would inspire the Eiffel Tower. In 1912 he built the first aerodynamic laboratory in France, where he continued to work until his death in 1923.

His expressive mastery of metal earned Gustave Eiffel (1832-1923) the appellation “iron magician.” Eiffel et cie, the firm he opened with Theophile Seyrig in 1868 to provide metal structures, would endure for a hundred years. By 1880, Eiffel was working on projects in a dozen countries. This photograph is by Nadar, who specialized in portraits of nineteenth-century French intelligentsia.

Built as the centerpiece of the 1889 Exposition Universelle in Paris, the Eiffel Tower is a dizzying web of twelve thousand pieces of wrought iron, each designed independently to reflect variable inclinations and bear different loads. Eiffel’s achievement at Garabit was essential to the design for his immortal tower.

The Ponte Maria Pia has a 525-foot (160-meter) central span. On the basis of its acclaimed design, Eiffel won the Garabit contract.