Needing a railroad bridge crossing the Mississippi River at St. Louis, St. Louis bankers hired engineer James Eads to build the world’s first steel-truss bridge. Construction began in 1867 and it was dedicated in 1874. Giant granite piers support three arches and two decks. The top deck is the roadway and the bottom deck was for the railroad (now Metro Link mass transit). Pneumatic caissons were used for the construction for the piers, which were sunk 123 feet through mud to the rock bottom of the riverbed.
The caissons were pulled down in place using steel wire rope, manufactured on site. Seeing the usefulness of the wire rope several companies started manufacturing the rope for use in various types of construction. Not only did the bridge further open the West. Products developed for its construction helped build the West.
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