{"nrhp_refnum":"06000024","name":"Substation 42","other_names":[],"category":"structure","location":{"address":"154 E. 57th St.","address_restricted":false,"city":"New York","county":"Manhattan","state":"NY","lat":40.76041647900007,"lon":-73.96864284099996,"geom_source":"nps_gis"},"listed_date":"2006-02-09","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Transportation","Architecture","Engineering","Community Planning and Development"],"significance_levels":["local"],"summary":{"what_it_is":"Substation 42 is a single-story, double-height masonry electrical substation at 154 East 57th Street in Midtown Manhattan, completed in 1917 as part of IRT Contract 3 under the Dual Contracts.","why_significant":"It is significant for transportation and community planning and development because it powered an IRT subway extension during the Dual Contracts period. It also meets the criterion for engineering and architectural design as one of the best remaining examples of a typical Dual Contracts substation. It was the last fully operational substation in the subway system using original manual rotary converters, which ran until 1995.","narrative":"Substation 42 is a brick-and-concrete electrical station at 154 East 57th Street in Midtown Manhattan, built in 1917 under IRT Contract 3. It converted high-voltage alternating current into the low-voltage direct current that ran through the subway's third rails. The single-story, double-height building has a striated brown brick facade on a pink granite plinth, a stone-coped parapet with Art Deco-style geometric panels, a large window bank, and two portals. Inside, exposed steel trusses carry a concrete ceiling, and an overhead bridge crane spans the main room. It is simpler than the earlier, highly stylized substations, but it is among the best surviving examples of a Dual Contracts substation. It was the last substation in the system to run original manual rotary converters, which operated until 1995. It supplied power to the Lexington Avenue IRT line and a BMT line, and now sits among modern office towers and retail space. Its listing recognizes its role in transportation, engineering and the city's expansion.","period_of_significance":"1917","architect_builder":null,"architectural_style":"Late 19th and Early 20th Century American Movements","criteria":["A","C"],"status_note":"The building is in good condition and substantially intact, though the equipment has been removed and modern electrical equipment has replaced the rotary converters.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:51:53.030614-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_NY/06000024.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/06000024/80fd78193b-800.webp","url_1600":"https://nationalhistoricalregister.com/media/06000024/80fd78193b-1600.webp","licence":"CC BY-SA 3.0","author":"Americasroof at English Wikipedia","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:57substation.jpg\" rel=\"noopener\">Americasroof at English Wikipedia</a>, <a href=\"https://creativecommons.org/licenses/by-sa/3.0\" rel=\"license noopener\">CC BY-SA 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:57substation.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/75313883","wikipedia":null,"wikidata":"https://www.wikidata.org/wiki/Q6134975"},"indexable":true,"url":"https://nationalhistoricalregister.com/new-york/manhattan/substation-42-06000024/"}