Allegheny Aqueduct

The Pennsylvania Canal was an engineering triumph that crossed the state with a spectacular 37-mile railroad portage over the Allegheny Mountains, and for half a century between 1820 and the Civil War packet boats pulled by mules traveled through it. Canal boats crossed the Allegheny River to Pittsburgh on the world's first successful cable suspension aqueduct, or water bridge. After the original canal aqueduct collapsed into the river, John Roebling was hired to build a new one in 1844. He later became famous as a bridge designer for the 1879 Brooklyn Bridge, and after his experiment here he used his invention of wire rope, a strong iron cable, in all his bridges. His aqueduct had a wood trough filled with water and suspended from two iron cables that were strung in place wire by wire and anchored in eyebars embedded in masonry. The structure was 160 feet long and held 2,000 tons of water, allowing six boats loaded with passengers and goods to cross the river at the same time. When it was first filled with water, more than 10,000 spectators gathered and 100 guns saluted the first boats to float across. As canal technology became obsolete, the aqueduct was demolished in 1861 when the expanding Pennsylvania Railroad put the canal out of business.

Pittsburgh, Pennsylvania · United States