Pennsylvania Railroad Bridge
Why it's listed
Spanning the Allegheny River at Eleventh Street in Pittsburgh, this double-decked steel through truss railroad bridge replaced an earlier span built in the middle of the nineteenth century. Pennsylvania Railroad engineers designed it, and the American Bridge Company built it between 1901 and 1904. The structure has five spans totaling 861 feet, carried on six massive stone and concrete piers, with open web trusses, huge girders and cross braces forming its main section. Its builder traced its lineage to the Keystone Bridge Company, Andrew Carnegie's first major industrial enterprise. Its significance rests on its engineering: the nomination holds it to be among the most powerful and rugged of Pittsburgh's bridges and an unadorned structural form that reflects the city's role in the American industrial expansion of the late nineteenth and early twentieth centuries. The bridge was raised in 1918, when a reinforced concrete cap was added to the piers.
Significance in brief: The nomination argues the bridge is among the most powerful and rugged of Pittsburgh's steel bridges and a clear expression of American industrial engineering of the early twentieth century. It is described as a pure structural form free of nineteenth-century Romantic ornament. The document also ties it to the Keystone Bridge Company and Andrew Carnegie's industrial enterprise.
Machine-generated summary. This summary was generated by a language model from the official nomination document and has not been reviewed line by line by an editor. It may contain errors. Check the source document before relying on any detail. Source: nomination document (PDF) · National Archives catalog entry. NRHP reference 79002160, listed August 13, 1979. Summary generated October 2026 (model claude-haiku-5-5, prompt v1.1-2026-10-29, confidence medium).
Key facts
| Address | 11th St., Pittsburgh |
|---|---|
| County | Allegheny County |
| Listed | August 13, 1979 |
| Reference number | 79002160 |
| Resource type | Structure |
| Period of significance | 1901-1904 |
| Architect / builder | Pennsylvania Railroad engineers (design); American Bridge Company (builder) |
| Criteria |
|
| Areas of significance | Engineering, Transportation |
| Level of significance | Local |
| Status (as stated in the nomination) | The document states the bridge has been in continual use since it was raised in 1918 and is in good condition, altered. |
| Acreage | 1.2 |
| Coordinates | 40.44947, -79.99695 (NPS GIS) |
What listing means for this property
For a publicly owned building or structure, listing mainly matters when federal funds, permits or licences are involved: projects then go through Section 106 review so effects on the property are considered. Listing also strengthens applications for preservation grants and, for leased income-producing uses, can enable the federal rehabilitation tax credit.
General information, not legal or tax advice. Rules change; confirm with your State Historic Preservation Office or a qualified adviser.
Sources and further reading
- National Park Service, National Register of Historic Places database (snapshot May 2026), reference 79002160.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q5472302
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.