{"nrhp_refnum":"74001732","name":"Experimental Mine, U.S. Bureau Of Mines","other_names":[],"category":"site","location":{"address":"S of Bruceton off Cochran Mill Rd.","address_restricted":false,"city":"Bruceton","county":"Allegheny County","state":"PA","lat":40.30491357600005,"lon":-79.98108602599996,"geom_source":"nps_gis"},"listed_date":"1974-10-18","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering","Education"],"significance_levels":["national"],"summary":{"what_it_is":"The Experimental Mine is a coal mine operated by the U.S. Bureau of Mines near Bruceton in Allegheny County, Pennsylvania, built as a large-scale testing laboratory. It was started in the summer of 1910 by driving entries into the outcrop of the Pittsburgh coal bed.","why_significant":"The nomination argues the mine is significant because it was established after a series of coal-mine explosion disasters in 1906 and 1907 to study the causes of such explosions. Its research on coal-dust explosibility, ventilation, stoppings, roof control and mine safety is described as basic to recommended procedures for the coal industry.","narrative":"Begun in the summer of 1910 by driving entries into the outcrop of the Pittsburgh coal bed, the Experimental Mine near Bruceton in Allegheny County was established by the U.S. Bureau of Mines to investigate the causes of coal-mine explosions. The tract was leased from the Pittsburgh Coal Company, which sold it to the Bureau in 1924. The mine follows a conventional room-and-pillar layout, with main entries about 1,300 feet long, reinforced concrete stoppings, and gunited roof and ribs in the explosion-testing zone. The site was chosen so that violent explosions are deflected upward by the steep north bank of the valley, limiting damage to nearby dwellings. Research there has covered coal-dust explosibility, firedamp diffusion, ventilation, extinguishment apparatus, explosives, stopping strength, coal pillar compressibility and roof pressures. Demonstrations and training for miners and officials have drawn thousands of observers over the decades.","period_of_significance":"1910-1924","architect_builder":null,"architectural_style":null,"criteria":[],"status_note":"In use as a Bureau of Mines testing facility; the form also notes it was purchased from the Pittsburgh Coal Company in 1924.","vacant_flag":false,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:11:30.374567-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/74001732.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/74001732/6cee44a59e-800.webp","url_1600":"https://nationalhistoricalregister.com/media/74001732/6cee44a59e-1600.webp","licence":"Public domain","author":"United States Department of the Interior / United States Bureau of Mines (1910); specific persons unknown","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:ExperimentalMinePA.jpg\" rel=\"noopener\">United States Department of the Interior / United States Bureau of Mines (1910); specific persons unknown</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:ExperimentalMinePA.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71994805","wikipedia":"https://en.wikipedia.org/wiki/Experimental_Mine,_U.S._Bureau_of_Mines","wikidata":"https://www.wikidata.org/wiki/Q5421121"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/allegheny-county/experimental-mine-u-s-bureau-of-mines-74001732/"}