{"nrhp_refnum":"88000840","name":"Layton Bridge","other_names":[],"category":"structure","location":{"address":"LR 26191 over Youghiogheny River","address_restricted":false,"city":"Layton","county":"Fayette County","state":"PA","lat":40.08936573600005,"lon":-79.73011382099997,"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 pin-connected Pratt through truss highway bridge over the Youghiogheny River at Layton, Fayette County, Pennsylvania, built in 1899.","why_significant":"The nomination argues the bridge is an unusually configured Pratt through truss, with the road deck framed into the verticals high above the bottom chord rather than just above it, a feature visible only in elevation. It is described as the only example of this type among the fourteen Pratt through trusses included in the nomination. The area of significance is engineering.","narrative":"Built in 1899 by the Pencoyd Iron Works, a firm operated by the A. and P. Roberts Company of Philadelphia, this steel bridge crosses the Youghiogheny River at Layton in Fayette County. It is a pin-connected Pratt through truss with two main spans of 181 feet each and fifteen secondary spans of 32 feet, with approaches of 16 feet, giving an overall length of 811 feet. The bridge is 25 feet wide and carries a single lane of vehicular traffic. Its significance lies in an unusual design: the road deck passes midway through the truss, with the floorbeams joined to the verticals well above the bottom chord, instead of sitting just above it as in the standard arrangement. This configuration is visible only in side elevation. Among the fourteen Pratt through trusses in the nomination, it is the only example of this type. The bridge is also noted for its engineering interest, and the surrounding area is a wooded, undeveloped setting.","period_of_significance":null,"architect_builder":"A. & P. Roberts Company (Pencoyd Iron Works, Pencoyd, PA)","architectural_style":"Pratt through truss","criteria":["C"],"status_note":"Document lists present use as vehicular and notes a 1974 deck repair.","vacant_flag":false,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:35.725497-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/88000840.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/88000840/7eeed74250-800.webp","url_1600":"https://nationalhistoricalregister.com/media/88000840/7eeed74250-1600.webp","licence":"Public domain","author":"PennDOT","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Layton_Bridge.jpg\" rel=\"noopener\">PennDOT</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Layton_Bridge.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71992922","wikipedia":"https://en.wikipedia.org/wiki/Layton_Bridge","wikidata":"https://www.wikidata.org/wiki/Q6505710"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/fayette-county/layton-bridge-88000840/"}