| Key Facts |
| Bridge Name | Facility Carried / Feature Intersected | Location | Structure Type | Construction Date / Builder or Contractor |
| Carson Street Bridge | Carson Street Over Chartiers Creek | Pittsburgh: Allegheny County, Pennsylvania | Metal Riveted Warren Through Truss, Stationary | 1925 By: McClintic-Marshall Company of Pittsburgh, Pennsylvania |
| Technical Facts |
| Alteration Date | Structure Length | Roadway Width | Bridge Width | Main Spans | Approach Spans |
| 1978 | 144 Feet (43.9 Meters) | 34 Feet (10.4 Meters) | 39.6 Feet (12 Meters) | 1 | None |
This bridge is next to the Carson Street Railroad Bridges, making this a historic scene where two truss bridges, one highway and one railroad, sit side by side, a scene that was once common in this country, but due to demolition, mostly of the highway bridges, is hard to find today.
The Carson Street Bridge was originally built as a pony truss, and in 1978 overhead bracing was added. The braces clearly look out of place and context on the structure, however, it is worth noting that imagining the bridge without those braces one realizes this was one tall pony truss. Given this information, the bridge could perhaps be viewed as a historically significant structure that pushed the limits of the truss bridge, building the largest possible pony truss. Clearly, these limits were push too far for the comfort of 1970s engineers.
Information and Findings From Pennsylvania's Historic Bridge InventoryDiscussion of Bridge The bridge was built in 1925 as a riveted, 6 panel, Warren with verticals pony truss bridge supported on concrete abutments with wingwalls. In 1978 the rolled section top lateral and sway bracing were added, converting the bridge into a thru truss. The bridge, constructed by the county during its 1924-1932 road and bridge building program, is an example of a type and design that had been used with great frequency since the early 20th century. More than 100 Warren truss bridges built between 1905 and 1930 remain statewide. The bridge has no innovative or distinctive details. Neither the bridge nor its setting is historically or technologically significant. It was fabricated by McClintic-Marshall Co. Discussion of Surrounding Area The bridge carries a 3 lane city street and a sidewalk over a stream at the Pittsburgh-McKees Rocks line. Directly north of and parallel to the bridge are 2 Warren thru truss bridges carrying the P&LE main line over the stream. The area does not have the cohesiveness of a potential historic district. At the southwest quadrant is a modern shopping mall and automobile dealership; to the northwest is an older industrial park. To the east is a small WW II monument and a mixed-use neighborhood of early 20th century houses and commercial strip development. Bridge Considered Historic By Survey: No |
