1818: a covered wooden bridge
1846: (Bridge Hunter)1883: (Bridge Hunter; Historic Bridges; HAER; pghbridges, has links to photo galleries; BrooklineConnection, a significant amount of information and photos; no B&T; Satellite)
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| HAER PA,2-PITBU,58--30 (CT) GENERAL VIEW FROM SHORE, WEST OF ENTIRE BRIDGE - Smithfield Street Bridge, Spanning Monongahela River on Smithfield Street, Pittsburgh, Allegheny County, PA |
1818
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| BrooklineConnection "The Monongahela Bridge in 1832 after being damaged by a runaway boat." It was the first bridge to cross the Monongahela River. The 1846 bridge was built because the Great Fire destroyed this bridge in 1845. |
1846
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| BridgeHunter-1846 |
I did not realize until I saw this image that the bridge was a sequence of suspension bridges.
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| BrooklineConnection "John Roebling's Monongahela Bridge spans the river in this scene from 1857." This was John A. Roebling's first highway bridge. Because the piers survived the fire, this bridge reused the 1818 piers. It also was a successful toll bridge because it was still the only crossing of the river. "The light-weight suspension bridge carried the heaviest kind of street traffic, including the horse cars, steam rollers, and eight-horse teams pulling heavy trucks loaded with iron, coal and machinery. Despite the added strain, the bridge performed well." [Note that this image was made back when smoke was considered a sign of prosperity and artists were sure to add a lot of it.] |
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| Bridges Now and Then posted "Smithfield Street Bridge (1846-1883) over the Monongahela River as it appeared in 1880. Engineer: John Augustus Roebling" (Photograph from the Pittsburgh City Photographer Collection, 1901-2002, AIS.1971.05, Archives Service Center, University of Pittsburgh) |
1883
Gustav Lindenthal designed this 1883 lenticular trusses bridge. "The bridge is made of steel, which was a relatively unknown material in the early 1880's. It remains today as the original and oldest steel bridge." [BridgeHunter-1883] Historic Bridges disagrees about this being the oldest steel bridge. It cites the 1979 Glasgow Railroad Bridge as older. The 1874 Eads Bridge that used steel is probably not considered because it used steel only where its strength was needed. It used iron for some of the other members.
"With its two 360 foot spans, the Smithfield Street Bridge displays the longest lenticular truss spans known to remain in the United States." The steel was produced in a mill that Andrew Kloman helped create. "Kloman and his mills would later become associated with the famous Carnegie Steel Company." [HistoricBridges]
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| Street View |
"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." [HAER-data]
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| HAER PA,2-PITBU,58--12 12. May 1974. GENERAL VIEW OF BRIDGE FROM THE NORTHEAST SHORE FROM THE NORTH. - Smithfield Street Bridge, Spanning Monongahela River on Smithfield Street, Pittsburgh, Allegheny County, PA |
The bridge we see today had another truss line added, and it is more than twice as wide as the original.
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| transactions via HistoricBridges, p24 |
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| transactions via HistoricBridges, p30, the original single-lane structure Also in BrooklineConnection Lindenthal designed the piers so that the bridge could be widened with a third truss on the upstream side. A third lane was added in 1891 and Lindenthal's vision of a four lane bridge was realized in 1911 by moving the third truss further upstream. [BrooklineConnection has many construction photos and describes several projects including a deck replacement with aluminum in 1933 and a year-long reconstruction in 1994.] |
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| BrooklineConnection "Looking at the southern portals of the Smithfield Street Bridge in 1900." [Since this was between the 1891 and 1911 expansions, there is only one lane on the upriver side. The old portal was not removed until the 1911 expansion. I wonder what building is being constructed in the left background.] |
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| David Gulden posted A.B.SHEETS [The bridge in the background is the Panhandle Bridge.] |
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| Photo taken by Royce and Bobette Haley in July 2016 via BridgeHunter-1833, one of many |
Built up lattice beams and pin connections. At first, I thought the 1994 reconstruction used rivets instead of bolts. But then I realized that the reconstruction did not have to replace many rivets because I spotted a couple of bolts near the bottom of the foreground vertical member. It looks like the bridge's design has plenty of parallel tie-bars to have redundancy. The lack of tie-bar redundancy is one reason the Silver Bridge collapsed.
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| Bill M, Aug 2020 |
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| Street View |
As with other big bridges, some of the approach spans can be significant. The P&LE right-of-way used to be wider than just two tracks.
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| 3D Satellite [Is the monument in the lower-left corner a blowing engine, a press or something else?] |
These overpass spans are not of significance because of their size, but because of the construction technique used during the 1911 bridge expansion. This is another example that ABC (Accelerated Bridge Construction) is not a 21st Century development as some contractors imply. Note the prebuilt truss on the right side of the photo. Obviously the 120.5' trusses were built on the side of the right-of-way and then lifted into place to reduce the downtime of the PL&E railroad. In fact, the text says the derrick moved into position between trains. The train shed of the PL&E train station is in the left background.
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| Digitized by Google |
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| Bridges Now and Then posted Pittsburgh's Smithfield Street Bridge during construction in 1882. Note the old Roebling Bridge in operation under the new span. (Brookline Connection) Jimmy McPleasant shared |
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