{"nrhp_refnum":"79002160","name":"Pennsylvania Railroad Bridge","other_names":[],"category":"structure","location":{"address":"11th St.","address_restricted":false,"city":"Pittsburgh","county":"Allegheny County","state":"PA","lat":40.44946812300003,"lon":-79.99695033199998,"geom_source":"nps_gis"},"listed_date":"1979-08-13","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering","Transportation"],"significance_levels":["local"],"summary":{"what_it_is":"A double-decked, steel through truss railroad bridge carrying Conrail trackage across the Allegheny River at Eleventh Street in Pittsburgh, Allegheny County, Pennsylvania.","why_significant":"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.","narrative":"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.","period_of_significance":"1901-1904","architect_builder":"Pennsylvania Railroad engineers (design); American Bridge Company (builder)","architectural_style":null,"criteria":["C"],"status_note":"The document states the bridge has been in continual use since it was raised in 1918 and is in good condition, altered.","vacant_flag":false,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:30.219218-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/79002160.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/79002160/f7f01c03e7-800.webp","url_1600":"https://nationalhistoricalregister.com/media/79002160/f7f01c03e7-1600.webp","licence":"CC0","author":"Jim.henderson","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Ft_Wayne_RR_Bridge_Pittsb_jeh.jpg\" rel=\"noopener\">Jim.henderson</a>, <a href=\"http://creativecommons.org/publicdomain/zero/1.0/deed.en\" rel=\"license noopener\">CC0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Ft_Wayne_RR_Bridge_Pittsb_jeh.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71997806","wikipedia":"https://en.wikipedia.org/wiki/Fort_Wayne_Railroad_Bridge","wikidata":"https://www.wikidata.org/wiki/Q5472302"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/allegheny-county/pennsylvania-railroad-bridge-79002160/"}