Smithfield Street Bridge, Spanning Monongahela River on Smithfield Street, Pittsburgh, Allegheny County, PA

Significance: Designed by Gustav Lindenthal, one of America's most famous bridge engineers, as a two-lane bridge. One lane was erected in 1883, and another was added in 1891. The span is Pittsburgh's most graceful and makes use of a double lenticular truss, patented in America by Edwin Stanley in 1851.
Unprocessed Field note material exists for this structure: FN-4
Survey number: HAER PA-2
Building/structure dates: 1883 Initial Construction
Building/structure dates: 1890- 1891 Subsequent Work
Building/structure dates: 1911-1915 Subsequent Work
Building/structure dates: 1934 Subsequent Work
Building/structure dates: 1966-1967 Subsequent Work
National Register of Historic Places NRIS Number: 74001745