Constructed by Gustav Lindenthal for two years from 1881 to 1883, the Smithfield Street Bridge is one of the most recognizable landmarks of Pittsburgh. The bridge goes over the Monongahela River and links the metropolis? downtown with South Side.
The present day Smithfield Street Bridge is not the first one bridge at this site. In fact, it is the third one built on the same location. The first bridge constructed here is a roofed bridge made from wood which was built in 1818 and substituted a ferry service. This wooden is a pioneering public work since it?s the first bridge in Pittsburgh that crosses a river. Unfortunately, the bridge was reduced to ashes during the Great Fire that hit the city in 1845. The second bridge (wire rope suspension) was conceptualized by John Roebling who was also the designer behind NYC?s iconic Brooklyn Bridge. The bridge became operational in 1847 and was initially a toll bridge up until the city government of Pittsburgh acquired it in 1895.
Skyrocketing vehicular traffic made the new Smithfield Street Bridge to swing which worried motorists and pedestrians. This prompted the city of Pittsburgh to shut down the bridge. The management of the closed down bridge chose the blueprint for the construction of a new bridge made by Austrian born engineer Gustav Lindenthal.
Gustav Lindenthal constructed a lenticular truss bridge, a design that is scarcely used among modern-day bridges. The new bridge features a couple of spans measuring 360 feet and its total stretch measures 361 meters or 1,184 feet. Originally, the Smithfield Street Bridge only had a single lane. An additional deck was constructed in 1889 multiplying the size of the bridge two folds. The second deck featured a pair of rail tracks to accommodate streetcars which were horse drawn. However, these tracks were removed when the bridge underwent renovation from 1994 to 1996 to give way for electric streetcars.
The present steel entrances were conceptualized by Pittsburgh?s city architect Stanley L. Rush and were included in the bridge in 1915. The new portals were made as a replacement for the original wrought iron portals in Lindenthal?s design. The bridge?s color has been gray for the majority of its existence; however, during the renovations which took place from 1994 to 1996, it was brought back to its original hues of royal blue trusses and yellow sandstone shade thresholds. This color earned the bridge the nickname ?blue bridge.?
The Smithfield Street Bridge holds the records of the being the longest of its kind in the United States and the most antiquated bridge in all of Allegheny County. It?s an officially recognized National Historic Civil Engineering Landmark because of its importance in the county?s history and the one-of-a-kind construction techniques that went behind it.