Eads Bridge
Eads Bridge was built in 1874 in the city of St Louis, United States of America. It was named after James Eads, the man who designed and built it. It was the first steel bridge to be made, ushering in a new era of use of steel in engineering, manufacturing, and architecture (Witcher, 2017). To develop, St Louis desperately needed a railroad route across the Mississippi River.
Bridge overview
Eads Bridge is the world’s first steel-truss bridge and an engineering landmark. It is a combined railway and road bridge crossing over the Mississippi River east of St Louis (Kouwenhoven, 2017). It connects the cities of Missouri, St Louis, and Illinois. Eads Bridge was named on the National Register of Historic Places as a historic national landmark.
History and significance
After the Civil war and the need for expansion of the nation’s railroad system emerged, it became clear that if the city of St. Louis was to grow and develop, a bridge across the Mississippi River was important. In 1867, the St. Louis Bridge and Iron Company, a group of City bankers and businessmen, hired James Buchanan Eads (1820-1887) to build one (Witcher, 2017). Eads was a self-educated engineer and had never made any other bridge before. Eads Bridge was essential for St Louis to grow and develop.
Bridge design
The actual construction work of the bridge began in 1867. Giant granite-faced piers support three graceful arches and two decks. It was the first bridge to keep and carry railroad tracks and the first to use tubular cord members, and the first to depend entirely on cantilever construction for its great structure. Pneumatic caissons were used for the first time in the U.S. in constructing its piers, which were sunk to the unprecedented depth of 123 feet (Kouwenhoven, 2017).
Material used
Eads proposed to build an arch bridge using a brand new material: structural steel alloy. Steel construction was not widespread at this time, and in fact, this would be the first steel alloy bridge ever built. As a result, Eads’ steel-truss arch bridge was ridiculed as an impossible structure that would be too difficult to construct over the deep, wide river. Eads’ responded by asking, ‘Must we admit that, because a thing has never been done, it never can be? (Brown, 2014).
References
Kouwenhoven, J. A. (2017). The designing of the Eads Bridge. In Structural Iron and Steel, 1850–1900 (pp. 161-194). Routledge.
Witcher, T. R. (2017). A Pioneering Structure: The Eads Bridge. Civil Engineering Magazine Archive, 87(10), 42-45.
Brown, J. K. (2014). Not the Eads Bridge: An Exploration of Counterfactual History of Technology. Technology and Culture, 521-559.