{"nrhp_refnum":"79003143","name":"West End-North Side Bridge","other_names":[],"category":"structure","location":{"address":"Western Ave. and Carson St.","address_restricted":false,"city":"Pittsburgh","county":"Allegheny County","state":"PA","lat":40.44800653400006,"lon":-80.02621685899999,"geom_source":"nps_gis"},"listed_date":"1979-08-24","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering"],"significance_levels":["local"],"summary":{"what_it_is":"A steel tied-arch highway bridge carrying a major north-south connection across the Ohio River about one mile downstream from the confluence of the Allegheny and Monongahela Rivers in Pittsburgh, Allegheny County, Pennsylvania. The county approved its design in 1930 and the structural steel was fabricated and erected by the American Bridge Company.","why_significant":"The nomination argues the bridge is an engineering achievement. It is described as the second tied-arch bridge and the greatest application of prestressed hanger principles in a bridge, with the arch thrust resisted by the truss bottom cord rather than by masonry masses. Its design is also described as one of the most beautiful and graceful bridges in Pittsburgh.","narrative":"Spanning the Ohio River about a mile below the confluence of the Allegheny and Monongahela Rivers in Pittsburgh, the West End-North Side Bridge carries a major north-south highway connection. Allegheny County's Bureau of Bridges approved the design in September 1930, and the Pennsylvania Public Service Commission approved construction in August 1931. The American Bridge Company fabricated and erected the structural steel, and the bridge cost $3,675,000. Its main span is a 778-foot tied arch, where the arch thrust is taken by the bottom chord of the truss rather than by masonry, a method compared to the string of a bow. Seven pony truss spans extend the total length to 1,891 feet, 3 inches. Improvements in 1948 and 1955 added new decking and barriers. The nomination regards the bridge as an engineering achievement, citing it as the second tied-arch bridge built and the greatest use of prestressed hangers in a bridge, while noting its graceful appearance.","period_of_significance":"1930-1932","architect_builder":"American Bridge Company (steel fabrication and erection)","architectural_style":null,"criteria":["C"],"status_note":null,"vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:30.768064-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/79003143.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/79003143/d2fec64b47-800.webp","url_1600":"https://nationalhistoricalregister.com/media/79003143/d2fec64b47-1600.webp","licence":"CC BY 2.0","author":"Andrewwinn","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Bridges_over_the_Ohio_River.jpg\" rel=\"noopener\">Andrewwinn</a>, <a href=\"https://creativecommons.org/licenses/by/2.0\" rel=\"license noopener\">CC BY 2.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Bridges_over_the_Ohio_River.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71997802","wikipedia":"https://en.wikipedia.org/wiki/West_End_Bridge","wikidata":"https://www.wikidata.org/wiki/Q7985069"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/allegheny-county/west-end-north-side-bridge-79003143/"}