Editing IND Culver Line (section)

====Culver Viaduct====
[[File:NYCS IND Culver GowanusCanalBridge.jpg|thumb|200px|The Culver Viaduct spans the [[Gowanus Canal]].]]
The northern section of the Culver Line is a four-track line, entirely underground except for [[Smith–Ninth Streets (IND Culver Line)|Smith–Ninth Streets]] and [[Fourth Avenue (IND Culver Line)|Fourth Avenue]] stations.<ref name="tracks" /> The two stations sit on a massive one-mile long<ref name="MTA-CulverRehabPresentCB6-2007" /> steel and concrete [[viaduct]] which spans the [[Gowanus Canal]] between 9th and 10th Streets. This structure is now referred to as the '''Culver Viaduct''' or '''Culver Line Viaduct''',<ref name="MTA-FLineReview-2009" /><ref name="MTA-GLineReview-2013" /> the only portion of the original IND subway to be elevated, and the only section other than the now-demolished [[IND World's Fair Line|World's Fair Railroad]] to be outdoors.<ref name="gay" /><ref>{{Cite web |url=http://forgotten-ny.com/2004/06/crazy-train-some-of-the-more-unusual-subway-stations/ |title=Crazy Train: NYC's Weirdest Subway Stations |date=June 20, 2004 |access-date=August 23, 2015 |archive-date=September 7, 2015 |archive-url=https://web.archive.org/web/20150907185802/http://forgotten-ny.com/2004/06/crazy-train-some-of-the-more-unusual-subway-stations/ |url-status=live}}</ref> The viaduct was constructed due to the depth of the canal (15 feet at its deepest point),<ref name="gay" /><ref name="NYTimes-INDCulver-Gowanus-1927" /><ref>{{cite web |title=Gowanus Canal Superfund Site: Kings County, New York |url=http://www3.epa.gov/region02/superfund/npl/gowanus/pdf/gowanus_prap.pdf |publisher=[[United States Environmental Protection Agency]] |access-date=November 7, 2015 |date=December 2012 |archive-date=November 23, 2015 |archive-url=https://web.archive.org/web/20151123211941/http://www3.epa.gov/region02/superfund/npl/gowanus/pdf/gowanus_prap.pdf |url-status=live}}</ref> due to the topography of the Park Slope neighborhood,<ref name="gay" /><ref name="NYTimes-INDCulver-Gowanus-1927" /> and to avoid local stores in the area.<ref name="BklynStandard-INDFultonCulver-Nov1927" /> Otherwise, a tunnel carrying the line would have to have been built below both the canal and the [[BMT Fourth Avenue Line]] (necessitating stations deep below the ground); or Ninth Street would be raised above grade level to pass over the canal and BMT subway.<ref name="NYTimes-INDCulver-Gowanus-1927" />

Both underground options were considered expensive and impractical, and the viaduct was estimated to save $12 million in construction costs when it was selected in 1927.<ref name="NYTimes-INDCulver-Gowanus-1927" /> During planning, the viaduct's height was later increased from {{convert|60|ft|m}}<ref name="NYTimes-INDCulver-Gowanus-1927" /> to around {{convert|90|ft|m}}, due to now-defunct navigation regulations for tall-mast shipping.<ref name="BklynStandard-INDFultonCulver-Nov1927">{{cite news|title=Subway Dirt Will Start to Fly Here Soon: Board Indicates Private Property to Be Taken in Cranberry Street.|url=http://fultonhistory.com/highlighter/highlight-for-xml?altUrl=http%3A%2F%2Ffultonhistory.com%2FNewspaper%252014%2FBrooklyn%2520NY%2520Standard%2520Union%2FBrooklyn%2520NY%2520Standard%2520Union%25201927%2FBrooklyn%2520NY%2520Standard%2520Union%25201927%2520-%25206908.pdf&highlightsFile=http%3A%2F%2Fwww.fultonhistory.com%2Fhighlighter%2Fhits%2F5f6e489edcc6e30d125ab8598d3f4e05#page=1|access-date=June 30, 2016|work=[[Brooklyn Standard Union]]|agency=[[Fultonhistory.com]]|date=November 10, 1927|page=2}}</ref><ref name="gay" /><ref>{{cite news |title=Gowanus Bridge Discussed; Concerns Along Canal Object to Fixed Span at Army Hearing |url=https://timesmachine.nytimes.com/timesmachine/1927/09/23/118646473.pdf |newspaper=[[The New York Times]] |access-date=November 7, 2015 |date=September 23, 1927 |archive-date=October 6, 2022 |archive-url=https://web.archive.org/web/20221006132645/https://timesmachine.nytimes.com/timesmachine/1927/09/23/118646473.html?pdf_redirect=true&site=false |url-status=live}}</ref> Because of this, Smith–Ninth Streets was built at an elevation of {{convert|87.5|ft|m}}, the highest subway station above ground level in the world.<ref name="MTA-FLineReview-2009" /><ref>{{Cite web |url=http://www.mta.info/news/stories/?story=177 |title=Rebuilding the Culver Viaduct |access-date=August 23, 2015 |archive-date=September 25, 2012 |archive-url=https://web.archive.org/web/20120925005121/http://www.mta.info/news/stories/?story=177 |url-status=live}}</ref><ref>Brooklyn!!, Summer 2013 issue, p.7, caption on photo from station reopening celebration, www.brooklyn-usa.org</ref> Fourth Avenue, meanwhile, is actually at a lower elevation and altitude than the Seventh Avenue underground station.

For most of its history, G service has terminated at Smith–Ninth Streets, relaying using the express tracks and switches at Fourth Avenue.<ref name="tracks" /> This occasionally caused delays to F service, and prevented express service from being operated.<ref name="MTA-FLineReview-2009" /><ref name="MTA-GLineReview-2013" /><ref name="MTA-CulverRehabPresentCB6-2007">{{cite web |title=Culver Line Rehabilitation: Presentation to Community Board 6 Transportation Committee – November 15, 2007 |url=http://cdn-sas.secondavenuesagas.com/wp-content/uploads/Culver%20Presentation.pdf |website=secondavenusagas.com |publisher=[[Metropolitan Transportation Authority]] |access-date=September 7, 2015 |archive-url=https://web.archive.org/web/20150907045743/http://cdn-sas.secondavenuesagas.com/wp-content/uploads/Culver%20Presentation.pdf |archive-date=September 7, 2015 |date=November 15, 2007 |url-status=dead}}</ref> In 2009, the G's terminus was moved to Church Avenue in order to complete renovations on the viaduct.<ref name="MTA-FLineReview-2009" /><ref name="MTA-GLineReview-2013" /> In July 2012, the G extension was made permanent.<ref name="MTA-GLineReview-2013" /><ref>{{Cite news|url=http://www.brooklynpaper.com/stories/35/29/dtg_gtrainsaved_2012_07_27_bk.html|title=G wiz! MTA plans to save the G train extension!|last=O'Neill|first=Natalie|date=July 19, 2012|newspaper=[[The Brooklyn Paper]]|access-date=July 21, 2012|archive-date=September 17, 2012|archive-url=https://web.archive.org/web/20120917053417/http://brooklynpaper.com/stories/35/29/dtg_gtrainsaved_2012_07_27_bk.html|url-status=live}}</ref>