{"nrhp_refnum":"88000792","name":"Lindbergh Viaduct","other_names":[],"category":"structure","location":{"address":"US 422/Mineral Spring Rd. over Mineral Spring Creek","address_restricted":false,"city":"Reading","county":"Berks County","state":"PA","lat":40.33132649400005,"lon":-75.89972319599997,"geom_source":"nps_gis"},"listed_date":"1988-06-22","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering"],"significance_levels":["state"],"summary":{"what_it_is":"A reinforced concrete open-spandrel arch highway bridge carrying US 422 over Mineral Spring Creek in City Park, Reading, Berks County, Pennsylvania. Built in 1927 by Whittaker & Diehl, with the designer listed as unknown.","why_significant":"The nomination describes it as an unusual example of an open-spandrel concrete arch bridge, notable for its configuration and ornamentation. Its thirteen arches are skewed rather than straight, with three wide ribs per arch, and its ornamental piers are capped by matching light posts. The form notes it is one of fifteen open-spandrel arch bridges in the nomination and one of two skewed examples, representing the additional engineering needed for a skewed design. It is significant under engineering.","narrative":"Lindbergh Viaduct is a concrete open-spandrel arch bridge in City Park in Reading, Berks County, carrying US 422 over Mineral Spring Creek. Built in 1927 by the contractor Whittaker & Diehl, it is 866 feet long and carried on thirteen arches, five of them measuring 83 feet and the rest 42 feet. Those spans were short for a concrete bridge of its period. Its significance rests on its engineering: the arches are skewed rather than set square to the crossing, and each rests on three wide ribs. The ornamental piers are capped with light posts whose detailing varies to suit the skew. The nomination counts it as one of fifteen open-spandrel arch bridges in the group, and one of only two that are skewed, which made the design more demanding than a straight bridge. Sidewalks and parapets have since been replaced, and the structure is recorded as altered.","period_of_significance":"1927","architect_builder":"Whittaker & Diehl (builder/contractor); designer/engineer unknown","architectural_style":null,"criteria":["C"],"status_note":"Sidewalks and parapets have been replaced; the form marks the structure as altered.","vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:37.288493-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/88000792.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/88000792/b74d9cfc4f-800.webp","url_1600":"https://nationalhistoricalregister.com/media/88000792/b74d9cfc4f-1600.webp","licence":"Public domain","author":"Smallbones","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Lindbergh_Bridge_Reading_PA.jpg\" rel=\"noopener\">Smallbones</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Lindbergh_Bridge_Reading_PA.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71992358","wikipedia":"https://en.wikipedia.org/wiki/Lindbergh_Viaduct","wikidata":"https://www.wikidata.org/wiki/Q6552177"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/berks-county/lindbergh-viaduct-88000792/"}