View source for IND Sixth Avenue Line

{{short description|New York City Subway line}}
{{about|the current New York City Subway line under Sixth Avenue through Midtown Manhattan|the former elevated line through Midtown Manhattan|IRT Sixth Avenue Line|the current New York City Subway line under Sixth Avenue through Lower Manhattan|IND Eighth Avenue Line|the current PATH tubes under Sixth Avenue through Lower Manhattan|Uptown Hudson Tubes}}
{{good article}}
{{Use American English|date=June 2023}}
{{Use mdy dates|date=December 2023}}
{{Infobox rail line
| color           = {{rcr|NYCS|sixth}}
| name            = IND Sixth Avenue Line
| image           = {{rint|nycs|B|size=50}} {{rint|nycs|D|size=50}} {{rint|nycs|F|size=50}} {{rint|nycs|Fd|size=50}}
{{rint|nycs|M| size=50}}
| image_width     = 200px
| caption         = The [[B (New York City Subway service)|B]], [[D (New York City Subway service)|D]], [[F (New York City Subway service)|F]], [[F (New York City Subway service)|&lt;F&gt;]], and [[M (New York City Subway service)|M]], which use the Sixth Avenue Line through [[Midtown Manhattan]], are colored orange.
| type            = [[Rapid transit]]
| system          = [[New York City Subway]]
| locale          = [[Manhattan]], [[New York City]]
| start           = South of [[59th Street–Columbus Circle (IND Eighth Avenue Line)|59th Street–Columbus Circle]]; [[57th Street (IND Sixth Avenue Line)|57th Street]]
| end             = North of [[Jay Street–MetroTech (IND Culver Line)|Jay Street–MetroTech]]; south of [[Grand Street (IND Sixth Avenue Line)|Grand Street]]
| stations        = 14
| daily_ridership = 400,687<ref name="ridership">{{NYCS const|riderref|weekday}}</ref>
| open            = 1936–1968
|owner       = [[Government of New York City|City of New York]]
|operator    = [[New York City Transit Authority]]
| character       = Underground
| stock           =
| tracks          = 2–4
| gauge           = {{track gauge|ussg}}
| electrification = [[Direct current traction|600V DC using a third rail]]
| map             = {{IND Sixth Avenue Line|inline=1}}
| map_state       = collapsed
}}

The '''IND Sixth Avenue Line''' is a [[rapid transit line]] of the [[B Division (New York City Subway)|B Division]] of the [[New York City Subway]] in the United States. It runs mainly under [[Sixth Avenue (Manhattan)|Sixth Avenue]] in [[Manhattan]], and continues south to [[Brooklyn]]. The [[B (New York City Subway service)|B]], [[D (New York City Subway service)|D]], [[F (New York City Subway service)|F]], and [[M (New York City Subway service)|M]] trains, which use the Sixth Avenue Line through [[Midtown Manhattan]], are colored {{NYCS const|color|orange}}. The B and D trains<!--{{NYCS trains|Sixth express|time=nolink}}--> use the express tracks, while the F, &lt;F&gt; and M trains<!--{{NYCS trains|Sixth local|time=nolink}}--> use the local tracks.

The Sixth Avenue Line, constructed in stages during the 1930s, was the last trunk line built by the [[Independent Subway System]] (IND) before it was incorporated into the modern-day New York City Subway. It was more difficult to build than other subway trunk lines in New York City because construction had to proceed around, over, and under existing tunnels and elevated structures. The Sixth Avenue Line replaced the [[Interborough Rapid Transit Company]] (IRT)'s [[IRT Sixth Avenue Line|Sixth Avenue elevated]], which closed in 1939. The first section of the line opened in 1936 from [[West Fourth Street–Washington Square (IND Lines)|West Fourth Street]] to [[East Broadway (IND Sixth Avenue Line)|East Broadway]] with service provided by [[IND Eighth Avenue Line|Eighth Avenue Line]] trains. This section was initially referred to as the Houston-Essex Street Route. The Sixth Avenue subway was completed in 1940, providing service north of West Fourth Street, connecting to the [[IND Queens Boulevard Line|Queens Boulevard Line]] and the Eighth Avenue Line.

Initially, the Sixth Avenue Line carried only local service, since there were no express tracks between [[34th Street–Herald Square (IND Sixth Avenue Line)|34th Street]] and West 4th Street. In 1967 and 1968, the [[Chrystie Street Connection]] was completed, connecting the line with former BMT lines in Brooklyn via the Manhattan Bridge and with the [[BMT Jamaica Line]] over the Williamsburg Bridge. Two new stations at 57th Street and Grand Street, as well as a pair of express tracks between 34th and West 4th Streets, were built to provide the necessary capacity for the new service to Brooklyn.

There are branches on both ends of the line. On the south end, the express tracks used by the {{NYCS trains|Manhattan Bridge north|time=nolink}} diverge to [[Grand Street (IND Sixth Avenue Line)|Grand Street]] and the [[Manhattan Bridge]]. The local tracks continue through the Rutgers Street Tunnel and to [[York Street (IND Sixth Avenue Line)|York Street]] in Brooklyn (used by the {{NYCS trains|Sixth Rutgers|time=nolink}}) or via the Chrystie Street Connection and the Williamsburg Bridge to the BMT Jamaica Line in Brooklyn (used by the {{NYCS trains|Chrystie Williamsburg|time=nolink}}). On the north end, north of [[47th–50th Streets–Rockefeller Center (IND Sixth Avenue Line)|47th–50th Streets–Rockefeller Center]], the express tracks diverge to [[Seventh Avenue (IND Lines)|Seventh Avenue–53rd Street]] and the IND Eighth Avenue Line, while a spur used by the {{NYCS trains|Sixth 63rd|time=nolink}} continues under Sixth Avenue to [[57th Street (IND Sixth Avenue Line)|57th Street]] and the [[63rd Street Lines]]; the local tracks, used by the {{NYCS trains|Sixth Queens|time=nolink}}, merge with the IND Queens Boulevard Line and continue to [[Queens]].

== Extent and service ==
The following services currently use part or all of the Sixth Avenue Line,<ref>{{NYCS const|serviceguide}}</ref> whose services' bullets are colored {{NYCS const|color|orange}}:
{|class="wikitable"
!rowspan=2|&nbsp;
!colspan=4|Time period
!rowspan=2|Section of line
|-
!Rush hours
!Middays<br>and<br>evenings
!Weekends
!Late nights
|-
|{{rint|newyork|B}}
|align=center colspan=2|express
|align=center colspan=2|no service
|full line from [[Seventh Avenue (IND Queens Boulevard Line)|Seventh Avenue]] to [[Grand Street (IND Sixth Avenue Line)|Grand Street]]
|-
|{{rint|newyork|D}}
|align=center colspan=4|express
|full line from [[Seventh Avenue (IND Queens Boulevard Line)|Seventh Avenue]] to [[Grand Street (IND Sixth Avenue Line)|Grand Street]]
|-
|{{rint|newyork|F}}
|align=center colspan=4|local
|full line from [[57th Street (IND Sixth Avenue Line)|57th Street]] to [[York Street (IND Sixth Avenue Line)|York Street]]
|-
|{{rint|newyork|Fd}}
|align=center|local
|align=center colspan=3|no service
|full line from [[57th Street (IND Sixth Avenue Line)|57th Street]] to [[York Street (IND Sixth Avenue Line)|York Street]]
|-
|{{rint|newyork|M}}
|align=center colspan=2|local
|align=center colspan=2|no service
|between [[47th–50th Streets–Rockefeller Center (IND Sixth Avenue Line)|47th–50th Streets–Rockefeller Center]] and [[Broadway–Lafayette Street (IND Sixth Avenue Line)|Broadway–Lafayette Street]]
|}

The majority of the Sixth Avenue Line has four tracks, two local and two express. At each end, these pairs of tracks split, giving the line two north and two south ends. One of the north ends is at [[57th Street (IND Sixth Avenue Line)|57th Street]], where two tracks lead south under [[Sixth Avenue (Manhattan)|Sixth Avenue]] from the [[63rd Street Lines|IND 63rd Street Line]] (used by the [[F (New York City Subway service)|F]] train at all times). The other is just south of [[59th Street–Columbus Circle (IND Eighth Avenue Line)|59th Street–Columbus Circle]], where a two-track line splits from the [[IND Eighth Avenue Line]] at a [[flying junction]] (with connections to the local and express tracks), immediately turns east under [[53rd Street (Manhattan)|53rd Street]], and crosses the [[IND Queens Boulevard Line]], which parallels it just to the north. At [[Seventh Avenue (IND Queens Boulevard Line)|Seventh Avenue]], the southbound track is above the northbound track (the same is true on the Queens Boulevard Line, though north is the opposite direction from the Sixth Avenue Line). These tracks are used by the [[B (New York City Subway service)|B]] and [[D (New York City Subway service)|D]] express trains.<ref name="tracks">{{NYCS const|trackref|trackbook3}}</ref>

The express tracks from Columbus Circle then turn south to go under Sixth Avenue, merging with the branch from 57th Street and the local tracks' split from the IND Queens Boulevard Line (used by the [[M (New York City Subway service)|M]] local train). The branch from 57th Street merges into both the local and express track pairs; there are no direct track connections between the local and express tracks.<ref name="tracks" /> South of this point, the Sixth Avenue Line consists of four tracks from west to east: the southbound express track, the southbound local track, the northbound express track, and the northbound local track. After passing through [[47th–50th Streets–Rockefeller Center (IND Sixth Avenue Line)|47th–50th Streets–Rockefeller Center]], the two southbound tracks cross each other; the tracks from Columbus Circle become the two center express tracks, and the tracks from the Queens Boulevard Line are the two outside local tracks.<ref name="tracks" /><ref name="p1248809011" />

South of [[42nd Street–Bryant Park (IND Sixth Avenue Line)|42nd Street–Bryant Park]] is a large [[interlocking]] with six crossovers and switches. The original express tracks ended just to the south at [[34th Street–Herald Square (IND Sixth Avenue Line)|34th Street–Herald Square]] and some services switched to the local tracks at the interlocking.<ref name="tracks" /> This was done because the [[Port Authority Trans-Hudson|PATH]]'s [[Uptown Hudson Tubes]] already existed under Sixth Avenue south of [[33rd Street (Manhattan)|33rd Street]], and so the Sixth Avenue Line local tracks were built on each side of PATH. The section between [[West Fourth Street–Washington Square (New York City Subway)|West Fourth Street–Washington Square]] and 34th Street–Herald Square, the only express section of this line, was originally built as a two-track subway with the provision to expand to four tracks later.<ref name="The New York Times 1940" /> The express tracks were added in the 1960s in conjunction with the [[Chrystie Street Connection]] project.<ref name="Levey 1961" /> As a result, they are placed under the local tracks and PATH using the deep-bore tunneling method.<ref name="tracks" /><ref name="Levey 1961" /> At West Fourth Street–Washington Square, the express tracks return to the same level as the local tracks, and the two pairs of tracks in each direction are connected with diamond crossovers. A flying junction just to the south connects the local tracks of the Sixth and Eighth Avenue Lines. The Sixth Avenue Line then turns east under [[Houston Street (Manhattan)|Houston Street]] with an express station at [[Broadway–Lafayette Street (IND Sixth Avenue Line)|Broadway–Lafayette Street]].<ref name="tracks" />

East of Broadway–Lafayette Street, the express tracks turn south and use the Chrystie Street Connection to [[Grand Street (IND Sixth Avenue Line)|Grand Street]] before crossing the north side of the [[Manhattan Bridge]] into Brooklyn. The express tracks used to continue on to the express tracks at [[Second Avenue (IND Sixth Avenue Line)|Second Avenue]] before the tracks were rerouted to the Chrystie Street Connection. The local tracks split at this point. One pair continues east to Second Avenue (used by the F train) while the other pair merges with the [[BMT Nassau Street Line]] at [[Essex Street (BMT Nassau Street Line)|Essex Street]] (used by the M train).<ref name="tracks" /> Since the IND typically installed express–local crossovers beyond the fronts of the station platforms, an anomaly in the track layout was created when the Chrystie Street Connection was built. A crossover exists west of Broadway–Lafayette Street only on the northbound side, allowing trains from the Manhattan Bridge to reach the Eighth Avenue local tracks at West Fourth Street but not vice versa.<ref name="tracks" /><ref name="MTA-DF-Swap">{{cite AV media|url=https://www.youtube.com/watch?v=vZf4uKhVlHU |archive-url=https://ghostarchive.org/varchive/youtube/20211212/vZf4uKhVlHU| archive-date=December 12, 2021 |url-status=live|title=Brooklyn D and F Train Swap Explained|date=November 13, 2020|publisher=[[Metropolitan Transportation Authority]]|access-date=February 28, 2021|via=YouTube}}{{cbignore}}</ref> As a result, unusual routings are required whenever a train on the Eighth Avenue Line needs to access the Manhattan Bridge.{{efn|For instance, during a 2020 service change when the D train was rerouted via the Eighth Avenue Line's local tracks north of West Fourth Street, it ran on the [[IND Culver Line]] (the F train's normal route in Brooklyn). The F train ran on the [[BMT West End Line]] (the D train's normal route in Brooklyn).<ref name="MTA-DF-Swap"/>}}

[[File:York tower Rutgers tunnel jeh.JPG|thumb|upright|York Street ventilation tower for Rutgers Street tunnel]]

Just before approaching Second Avenue, the local tracks split into four tracks again. The two center tracks, which are not used in revenue service, dead-end just east of the Second Avenue station. They were built as part of the [[Proposed expansion of the New York City Subway#1929–1939 plans|IND's proposed expansion in the 1930s]], and would have merged with the never-built [[IND Worth Street Line]] and then entered Brooklyn. The line would have run to [[Utica Avenue]] in Brooklyn if it had been completed.<ref>{{cite news|url=https://www.nytimes.com/packages/pdf/nyregion/20070408_SUBWAY_DOCS/19290916_subway_doc.pdf|title=100 Miles of Subway in New City Project; 52 of them in Queens|newspaper=The New York Times|date=September 16, 1929|page=1|access-date=June 11, 2014|issn=0362-4331|archive-date=June 27, 2022|archive-url=https://web.archive.org/web/20220627230221/https://www.nytimes.com/packages/pdf/nyregion/20070408_SUBWAY_DOCS/19290916_subway_doc.pdf|url-status=live}}</ref><ref name="Cite RNT"/>{{rp|11}} Other provisions for unbuilt lines exist at the mezzanine levels of the Second Avenue and [[East Broadway (IND Sixth Avenue Line)|East Broadway]] stations, where unfinished open spaces indicate where stations for the [[Second Avenue Subway]] and IND Worth Street Line, respectively, would have been built.<ref name="Cite RNT">{{Cite Routes Not Taken}}</ref>{{rp|13}}<ref name="Brennan">{{cite web|url=http://www.columbia.edu/~brennan/abandoned/indsecsys.html|title=Abandoned Stations : IND Second System unfinished stations|last=Brennan|first=Joseph|date=2002|access-date=August 30, 2016|work=columbia.edu|archive-date=March 2, 2016|archive-url=https://web.archive.org/web/20160302160433/http://www.columbia.edu/~brennan/abandoned/indsecsys.html|url-status=live}}</ref>

The local tracks in Manhattan turn south under [[Essex Street (Manhattan)|Essex Street]] and Rutgers Street before crossing under the [[East River]] via the Rutgers Street Tunnel. The tracks then become [[IND Culver Line]] in Brooklyn, stopping at the outer tracks of [[Jay Street–MetroTech (IND Culver Line)|Jay Street–MetroTech]].<ref name="tracks" />

== History ==

=== Planning ===
New York City mayor [[John Francis Hylan]]'s original plans for the [[Independent Subway System]] (IND), proposed in 1922, included building over {{convert|100|mi}} of new lines and taking over nearly {{convert|100|mi}} of existing lines. The lines were designed to compete with the existing underground, surface, and elevated lines operated by the [[Interborough Rapid Transit Company]] (IRT) and [[Brooklyn–Manhattan Transit Corporation]] (BMT).<ref>{{cite news|url=https://www.nytimes.com/1923/08/04/archives/two-subway-routes-adopted-by-city-estimate-board-accepts-wash.html|title=Two Subway Routes Adopted by City|date=August 4, 1923|newspaper=The New York Times|access-date=August 1, 2019|page=9|issn=0362-4331|archive-date=June 30, 2019|archive-url=https://web.archive.org/web/20190630012122/https://www.nytimes.com/1923/08/04/archives/two-subway-routes-adopted-by-city-estimate-board-accepts-wash.html|url-status=live}}</ref><ref>{{cite news|url=https://www.nytimes.com/1924/03/12/archives/plans-now-ready-to-start-subways-commission-notifies-city-it-can.html|title=Plans Now Ready to Start Subways|date=March 12, 1924|newspaper=The New York Times|access-date=August 1, 2019|page=1|issn=0362-4331|archive-date=June 28, 2019|archive-url=https://web.archive.org/web/20190628162149/https://www.nytimes.com/1924/03/12/archives/plans-now-ready-to-start-subways-commission-notifies-city-it-can.html|url-status=live}}</ref> The IND Sixth Avenue Line was designed to replace the elevated [[IRT Sixth Avenue Line]].<ref name="nytimes.com">{{cite news|url=https://www.nytimes.com/1930/01/11/archives/delaney-for-razing-elevated-line-now-work-in-6th-av-could-begin-in.html|title=Delaney For Razing Elevated Line Now; Work in 6th Av. Could Begin in Six Months if Condemnation Started at Once, He Says. Sees Cut In Subway Cost Eliminating Need for Underpinning Would Save $4,000,000 and Speed Construction, He Holds.|date=January 11, 1930|newspaper=The New York Times|issn=0362-4331|access-date=April 27, 2018|archive-date=April 28, 2018|archive-url=https://web.archive.org/web/20180428094447/https://www.nytimes.com/1930/01/11/archives/delaney-for-razing-elevated-line-now-work-in-6th-av-could-begin-in.html|url-status=live}}</ref> However, since the Sixth Avenue corridor was such an important subway link, the elevated remained open while construction on the Sixth Avenue subway proceeded.<ref>{{cite news|url=https://www.nytimes.com/1931/09/17/archives/ends-move-to-scrap-6th-avenue-elevated-transit-commission-explains.html|title=Ends Move To Scrap 6th Avenue Elevated; Transit Commission Explains No Interest Has Been Shown in Demolition Since January.|date=September 17, 1931|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=August 7, 2018|archive-url=https://web.archive.org/web/20180807220747/https://www.nytimes.com/1931/09/17/archives/ends-move-to-scrap-6th-avenue-elevated-transit-commission-explains.html|url-status=live}}</ref>

In 1924, the IND submitted its list of proposed subway routes to the [[New York City Board of Transportation]] (NYCBOT), which approved the program. The IND's program consisted of two lines underneath Sixth Avenue in Manhattan. The first line would be a {{Convert|0.74|mi|km|-long|adj=mid}} section in Lower Manhattan between Lispenard Street to the south and Eighth Street to the north, comprising part of the present-day Eighth Avenue Line. The second line would be a {{Convert|2.47|mi|km|-long|adj=mid}} section running between Carmine Street to the south and 53rd Street to the north, comprising much of the present-day Sixth Avenue Line. South of Carmine Street, the Sixth Avenue Line would curve east under [[Houston Street]], then south under [[Essex Street]] and Rutgers Street before continuing south into Brooklyn.<ref>{{Cite news|url=https://www.nytimes.com/1925/03/21/archives/new-subway-routes-in-hylan-program-to-cost-186046000-board-of.html|title=New Subway Routes in Hylan Program to Cost $186,046,000 – Board of Transportation Adopts 22.90 Miles of Additional Lines – Total Now $345,629,000 – But the Entire System Planned by Mayor Involves $700,000,000 – Description of Routes – Heaviest Expenditures Will Be Made on Tunnels – No Allowance for Equipment – New Subway Routes to Cost $186,046,000|date=March 21, 1925|newspaper=The New York Times|access-date=April 8, 2018|language=en-US|issn=0362-4331|archive-date=April 9, 2018|archive-url=https://web.archive.org/web/20180409045244/https://www.nytimes.com/1925/03/21/archives/new-subway-routes-in-hylan-program-to-cost-186046000-board-of.html|url-status=live}}</ref>

Work on the core section of the IND Sixth Avenue Line, located between Fourth and 53rd Streets, was not to begin for several years. The section of Sixth Avenue from Ninth to 33rd Streets was already occupied by the [[Hudson & Manhattan Railroad]] (H&M)'s Uptown Hudson Tubes. At first, the city intended to take over the portion of the Uptown Tubes under Sixth Avenue for IND use, then build a pair of new tubes for the H&M directly underneath it. The IND had committed to building the Sixth Avenue line, and the H&M's [[33rd Street station (PATH)|33rd Street]] terminal was located both above and below preexisting railroad tunnels, hence the IND's plan to convert part of the H&M tubes.<ref>{{cite news|url=https://www.nytimes.com/1924/11/20/archives/6th-av-subway-plan-hinges-on-tubes-use-city-must-reach-agreement.html|title=6th Av. Subway Plan Hinges On Tubes' Use; City Must Reach Agreement With Hudson & Manhattan to Carry Out Project.|date=November 20, 1924|newspaper=The New York Times|issn=0362-4331|access-date=April 26, 2018|archive-date=April 26, 2018|archive-url=https://web.archive.org/web/20180426153319/https://www.nytimes.com/1924/11/20/archives/6th-av-subway-plan-hinges-on-tubes-use-city-must-reach-agreement.html|url-status=live}}</ref> However, the H&M objected, and so negotiations between the city and IND and the H&M continued for several years.<ref>{{cite news|url=https://www.nytimes.com/1929/09/01/archives/final-contracts-to-finish-subway-awarded-by-city-include-20000000.html|title=Final Contracts To Finish Subway Awarded By City; Include $20,000,000 for Cars, Equipment and Substations for Manhattan Line. Operation Set For 1931 Board of Transportation Moves to Rid Sixth Avenue of Trolley Tracks. Seeks To Buy Franchise Line Willing to Exchange It for Bus Permit—Negotiations Pushed to Extend Tube.|date=August 1, 1929|newspaper=The New York Times|issn=0362-4331|access-date=April 26, 2018|archive-date=April 26, 2018|archive-url=https://web.archive.org/web/20180426153214/https://www.nytimes.com/1929/09/01/archives/final-contracts-to-finish-subway-awarded-by-city-include-20000000.html|url-status=live}}</ref>

The IND and H&M finally came to an agreement in 1930. The city had decided to build the IND Sixth Avenue Line's local tracks around the pre-existing H&M tubes, and add express tracks for the IND underneath the H&M tubes at a later date.<ref name="nytimes.com"/> However, the city still planned to eventually take over the H&M tracks, convert them to express tracks for the IND line, then build a lower level for the H&M.<ref>{{cite news|url=https://www.nytimes.com/1935/08/08/archives/6th-av-tube-work-to-be-begun-oct-1-plans-speeded-on-12000000.html|title=6th Av. Tube Work to be Begun Oct. 1|date=August 8, 1935|newspaper=The New York Times|access-date=October 7, 2011|page=23|issn=0362-4331|archive-date=April 16, 2018|archive-url=https://web.archive.org/web/20180416134854/https://www.nytimes.com/1935/08/08/archives/6th-av-tube-work-to-be-begun-oct-1-plans-speeded-on-12000000.html|url-status=live}}</ref>

The IND started advertising bids for the section of the Sixth Avenue Line between 43rd and 53rd Streets in April 1931.<ref>{{cite news|url=https://www.nytimes.com/1931/04/21/archives/the-sixth-avenue-subway.html|title=The Sixth Avenue Subway.|date=April 21, 1931|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=April 28, 2018|archive-url=https://web.archive.org/web/20180428180947/https://www.nytimes.com/1931/04/21/archives/the-sixth-avenue-subway.html|url-status=live}}</ref> However, that May, construction was postponed because of fears that it would disrupt the [[Catskill Aqueduct]], one of the [[New York City water supply system]]'s crucial [[water main]]s to Brooklyn and Queens.<ref>{{cite news|url=https://www.nytimes.com/1931/05/06/archives/6th-avenue-subway-is-put-off-18-months-delaney-delays-start-because.html|title=6th Avenue Subway Is Put Off 18 Months; Delaney Delays Start Because of Peril to Water Main to Brooklyn and Queens. Awaits New Supply Tube Announcement Follows Conference With Dietz Over Danger of Damage From Blasting. Action Is A Surprise Bids for Work on New City Link Already Advertised—Many Obstacles to Project Arose. Work Ahead of Schedule. Many Obstacles Arose.|date=May 6, 1931|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=April 28, 2018|archive-url=https://web.archive.org/web/20180428181330/https://www.nytimes.com/1931/05/06/archives/6th-avenue-subway-is-put-off-18-months-delaney-delays-start-because.html|url-status=live}}</ref> The NYCBOT wanted to start work on the section between 33rd and 39th Streets first so that the engineering issues with the H&M tubes and water main could be resolved.<ref>{{cite news|url=https://www.nytimes.com/1931/05/08/archives/speed-plans-for-link-of-6th-av-subway-transportation-board.html|title=Speed Plan For Link Of 6th Av. Subway; Transportation Board Engineers Want Work Started First From 33d to 39th Street.|date=May 8, 1931|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=April 28, 2018|archive-url=https://web.archive.org/web/20180428182849/https://www.nytimes.com/1931/05/08/archives/speed-plans-for-link-of-6th-av-subway-transportation-board.html|url-status=live}}</ref> In January 1932, the city announced an agreement with the [[New York City Water Supply Board]]. The IND wanted to start construction on the Sixth Avenue line by June so that some of the projected train traffic on the Eighth Avenue line, which was slated to open that year, could be rerouted through Sixth Avenue instead.<ref>{{cite news|url=https://www.nytimes.com/1932/01/01/archives/plans-work-in-june-on-6th-av-subway-city-to-push-section-north-of.html|title=Plans Work In June on 6th Av. Subway; City to Push Section North of 29th St. to Permit Routing of Eighth Av. Line. Contracts To Be Let Soon Agreement With Water Supply Board Opens Way for Construction Held Up by Condult Hazards.|date=December 1, 1931|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=April 28, 2018|archive-url=https://web.archive.org/web/20180428182708/https://www.nytimes.com/1932/01/01/archives/plans-work-in-june-on-6th-av-subway-city-to-push-section-north-of.html|url-status=live}}</ref> In 1933, the [[New York City Board of Estimate]] requested a $25.5 million federal loan for the construction of the Sixth Avenue line.<ref>{{cite news|url=https://www.nytimes.com/1933/10/03/archives/25500000-loan-for-transit-asked-transportation-board-applies-for.html|title=$25,500,000 Loan For Transit Asked; Transportation Board Applies for Federal Funds to Finish Subway System. 22-Month Task Ahead Projects to Add 18 Miles to the City's Network Planned to Start Immediately.|date=October 3, 1933|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=April 28, 2018|archive-url=https://web.archive.org/web/20180428182838/https://www.nytimes.com/1933/10/03/archives/25500000-loan-for-transit-asked-transportation-board-applies-for.html|url-status=live}}</ref>

===Opening of southern section===
The first portion of the line to be constructed was then known as the Houston–Essex Street Line, which ran under Houston, Essex, and Rutgers Streets. The contract for the line was awarded to Corson Construction in January 1929, at which time the city began evicting 10,000 residents within the line's route.<ref>{{cite news|url=http://timesmachine.nytimes.com/timesmachine/1929/02/24/95882577.html|title=East Side Subway Will Evict 10,000; Work on New Line, Likely to Begin in May, Will Force Many Tenants to Move. 200 Buildings Will Fall Transportation Board Notifies Property Owners—Condemnation to Coat Over $11,000,000. Expect Work to Start in May. Residents Recall Other Days.|date=February 24, 1929|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=May 6, 2022|archive-url=https://web.archive.org/web/20220506014904/https://timesmachine.nytimes.com/timesmachine/1929/02/24/95882577.html|url-status=live}}</ref> Construction of this section officially started in May 1929.<ref>{{cite news|url=https://www.nytimes.com/1929/05/02/archives/east-side-subway-started-by-mayor-he-breaks-ground-for-crosstown.html|title=East Side Subway Started By Mayor; He Breaks Ground for Crosstown System at Second Av. and East Houston St. Miller Hails Project Sees Area Rejuvenated by Line and City's Plan to Raze Old Tenements.|date=May 2, 1929|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=April 28, 2018|archive-url=https://web.archive.org/web/20180428184807/https://www.nytimes.com/1929/05/02/archives/east-side-subway-started-by-mayor-he-breaks-ground-for-crosstown.html|url-status=live}}</ref> The contract for the [[Rutgers Street Tunnel]], connecting Manhattan and Brooklyn, was awarded in May 1930.<ref>{{cite news|url=https://www.nytimes.com/1930/05/22/archives/13000000-contracts-for-subways-let-one-for-11674060-is-for.html|title=$13,000,000 Contracts For Subways Let; One for $11,674,060 Is for Construction of East River Tunnel to Brooklyn.|date=May 22, 1930|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=April 28, 2018|archive-url=https://web.archive.org/web/20180428182722/https://www.nytimes.com/1930/05/22/archives/13000000-contracts-for-subways-let-one-for-11674060-is-for.html|url-status=live}}</ref> In May 1933, the city started widening Essex and Rutgers Streets to accommodate the future subway line underneath.<ref>{{cite news|url=https://www.nytimes.com/1933/05/08/archives/begins-street-widening-city-will-increase-essex-and-houston-from-50.html|title=Begins Street Widening.; City Will Increase Essex and Houston From 50 to 80 Feet.|date=May 8, 1933|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=April 28, 2018|archive-url=https://web.archive.org/web/20180428182752/https://www.nytimes.com/1933/05/08/archives/begins-street-widening-city-will-increase-essex-and-houston-from-50.html|url-status=live}}</ref>

The Houston and Essex Street Line began operations at noon on January 1, 1936, with two local tracks from a junction with the Eighth Avenue Line south of West Fourth Street–Washington Square east under Houston Street and south under Essex Street to a temporary terminal at [[East Broadway (IND Sixth Avenue Line)|East Broadway]]. [[E (New York City Subway service)|E]] trains, which ran from [[Jackson Heights, Queens]] to [[Hudson Terminal (IND Eighth Avenue Line)|Hudson Terminal]], were shifted to the new line to East Broadway.<ref name="East Broadway">{{cite news|url=https://www.nytimes.com/1936/01/02/archives/la-guardia-opens-new-subway-link-warmly-praises-delaney-as-he-puts.html|title=LaGuardia Opens New Subway Link|date=January 2, 1936|newspaper=The New York Times|access-date=October 7, 2011|page=1|issn=0362-4331|archive-date=December 11, 2021|archive-url=https://web.archive.org/web/20211211081448/https://www.nytimes.com/1936/01/02/archives/la-guardia-opens-new-subway-link-warmly-praises-delaney-as-he-puts.html|url-status=live}}</ref> Two express tracks were built on the portion under Houston Street until Essex Street-Avenue A; the tracks were intended to travel under the East River and connect with the never-built IND Worth Street Line in Williamsburg, Brooklyn.<ref name=Brennan/>

Just after midnight on April 9, 1936, trains began running under the East River via the Rutgers Street Tunnel, which connected the Houston-Essex Street Line with the north end of the Culver Line at a junction with the Eighth Avenue Line north of [[Jay Street–Borough Hall (IND Culver Line)|Jay Street–Borough Hall]]. E trains were sent through the connection to [[Church Avenue (IND Culver Line)|Church Avenue]]. Simultaneously, the [[IND Fulton Street Line|Fulton Street Line]] was opened to [[Rockaway Avenue (IND Fulton Street Line)|Rockaway Avenue]] and the [[A (New York City Subway service)|A]] and [[C (New York City Subway service)|C]] trains, which had used Smith Street, were rerouted to Fulton Street.<ref name="Rutgers">{{cite news|url=https://www.nytimes.com/1936/04/06/archives/two-subway-links-start-wednesday-city-will-begin-operating-fulton.html|title=Two Subway Links Start Wednesday|date=April 6, 1936|newspaper=The New York Times|access-date=October 7, 2011|page=23|issn=0362-4331|archive-date=June 14, 2018|archive-url=https://web.archive.org/web/20180614021430/https://www.nytimes.com/1936/04/06/archives/two-subway-links-start-wednesday-city-will-begin-operating-fulton.html|url-status=live}}</ref><ref>{{cite news|url=https://select.nytimes.com/gst/abstract.html?res=FA0D13FF385B1B7B93CBA9178FD85F428385F9|title=New Subway Link Opened by Mayor|date=April 9, 1936|newspaper=The New York Times|access-date=October 7, 2011|page=23|issn=0362-4331|archive-date=December 11, 2021|archive-url=https://web.archive.org/web/20211211110233/https://www.nytimes.com/1936/04/09/archives/new-subway-link-opened-by-mayor-he-tells-15000-in-brooklyn-it-will.html|url-status=live}}</ref>

===Construction and opening of Midtown section===
In April 1935, engineers started planning in earnest for the Midtown section of the Sixth Avenue Line.<ref>{{cite news|url=https://www.nytimes.com/1935/04/01/archives/plans-to-be-drawn-for-6th-av-subway-80-engineers-and-draftsmen-to.html|title=Plans To Be Drawn For 6th Av. Subway; 80 Engineers and Draftsmen to Begin Work at Once on Detailed Specifications.|date=March 1, 1935|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=April 28, 2018|archive-url=https://web.archive.org/web/20180428182704/https://www.nytimes.com/1935/04/01/archives/plans-to-be-drawn-for-6th-av-subway-80-engineers-and-draftsmen-to.html|url-status=live}}</ref> The first contract, for the section between 40th and 47th Streets, was awarded to Rosoff-Brader Construction in October 1935.<ref>{{cite news |date=October 31, 1935 |title=Subway Award Goes To Rosoff Company; Sixth Av. Contract Is Let Under Specified Use of Excavated Rock Despite Lower Bid. |newspaper=The New York Times |url=https://www.nytimes.com/1935/10/31/archives/subway-award-goes-to-rosoff-company-sixth-av-contract-is-let-under.html |access-date=April 28, 2018 |issn=0362-4331 |archive-date=April 28, 2018 |archive-url=https://web.archive.org/web/20180428182901/https://www.nytimes.com/1935/10/31/archives/subway-award-goes-to-rosoff-company-sixth-av-contract-is-let-under.html |url-status=live }}</ref><ref name="p128702539">{{cite news |date=October 31, 1995 |title=$6,040,000 Contract For City Subway Awarded |page=10 |work=Wall Street Journal |issn=0099-9660 |id={{ProQuest|128702539}}}}</ref> Mayor [[Fiorello H. La Guardia]] broke ground for the Sixth Avenue subway at [[Bryant Park]] on March 23, 1936.<ref>{{Cite news |date=March 22, 1936 |title=Mayor to Start Work on Sixth Av. Subway; La Guardia to Use Pneumatic Drill at Ceremony at Noon Tomorrow in Bryant Park. |language=en-US |work=The New York Times |url=https://www.nytimes.com/1936/03/22/archives/mayor-to-start-work-on-sixth-av-subway-la-guardia-to-use-pneumatic.html |access-date=July 10, 2022 |issn=0362-4331 |archive-date=July 10, 2022 |archive-url=https://web.archive.org/web/20220710164944/https://www.nytimes.com/1936/03/22/archives/mayor-to-start-work-on-sixth-av-subway-la-guardia-to-use-pneumatic.html |url-status=live }}</ref><ref name="p1222069808">{{cite news |date=March 24, 1936 |title=Mayor Starts Construction of 6th Av. Subway: Demands Razing of 'El' as He Breaks Ground at Bryant Park Entrance Appeals for Unification Warns Rate War Is Likely to Follow Failure of Plan |page=9 |work=New York Herald Tribune |id={{ProQuest|1222069808}}}}</ref> The Carleton Company was hired in September 1936 to construct the section from 27th to 33rd Streets,<ref>{{Cite news|date=September 23, 1936|title=Subway Job Awarded; Carleton Company Is Favored for Sixth Avenue Link.|language=en-US|work=The New York Times|url=https://www.nytimes.com/1936/09/23/archives/subway-job-awarded-carleton-company-is-favored-for-sixth-avenue.html|access-date=July 11, 2022|issn=0362-4331|archive-date=July 11, 2022|archive-url=https://web.archive.org/web/20220711062057/https://www.nytimes.com/1936/09/23/archives/subway-job-awarded-carleton-company-is-favored-for-sixth-avenue.html|url-status=live}}</ref> and Rosoff-Brader was hired that October to build the segment from 33rd to 40th Streets.<ref>{{Cite news|date=October 28, 1936|title=Wins 6th Av. Subway Job; Rosoff Concern Gets Contract for 40th-33d St. Section.|language=en-US|work=The New York Times|url=https://www.nytimes.com/1936/10/28/archives/wins-6th-av-subway-job-rosoff-concern-gets-contract-for-40th33d-st.html|access-date=July 11, 2022|issn=0362-4331|archive-date=July 11, 2022|archive-url=https://web.archive.org/web/20220711062057/https://www.nytimes.com/1936/10/28/archives/wins-6th-av-subway-job-rosoff-concern-gets-contract-for-40th33d-st.html|url-status=live}}</ref> The next month, the George A. Flynn Corporation received a contract for the construction of the section between 47th and 53rd Streets.<ref>{{Cite news|date=November 18, 1936|title=Subway Contract Let; 6th Av. Line From 47th to 53d St. to Cost $4,616,476.|language=en-US|work=The New York Times|url=https://www.nytimes.com/1936/11/18/archives/subway-contract-let-6th-av-line-from-47th-to-53d-st-to-cost-4616476.html|access-date=July 10, 2022|issn=0362-4331|archive-date=July 11, 2022|archive-url=https://web.archive.org/web/20220711030808/https://www.nytimes.com/1936/11/18/archives/subway-contract-let-6th-av-line-from-47th-to-53d-st-to-cost-4616476.html|url-status=live}}</ref> The Arthur A. Johnson Corp. and Necaro Co. received the contract to build the segment between 18th and 27th Streets in January 1937.<ref>{{Cite news|date=January 23, 1937|title=New 6th Av. Subway Contract Let|language=en-US|work=The New York Times|url=https://www.nytimes.com/1937/01/23/archives/new-6th-av-subway-contract-let.html|access-date=July 11, 2022|issn=0362-4331|archive-date=July 11, 2022|archive-url=https://web.archive.org/web/20220711062043/https://www.nytimes.com/1937/01/23/archives/new-6th-av-subway-contract-let.html|url-status=live}}</ref> The final contract, between 9th and 18th Streets, was awarded to Spencer White & Prentis in June 1937.<ref name=p1240440213>{{cite news |id={{ProQuest|1240440213}} |title=6th Ave. Subway Contract Let |date=June 6, 1937 |page=19 |work=New York Herald Tribune}}</ref>

[[File:Central Substa 53 jeh.JPG|thumb|53rd Street powerhouse]]
The construction of the Sixth Avenue Line was very difficult because of the various utilities and tunnels above, below, and beside the line. At the time, it was considered the costliest subway line in the city.<ref name="Harrington 1935">{{cite news|url=https://www.nytimes.com/1935/05/05/archives/city-plans-its-costliest-subway-in-a-short-two-miles-under-sixth.html|title=City Plans Its Costliest Subway; In a Short Two Miles Under Sixth Avenue the Engineers Will Encounter Many Intricate Problems|last=Harrington|first=John W.|date=May 5, 1935|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=July 11, 2022|archive-url=https://web.archive.org/web/20220711174824/https://www.nytimes.com/1935/05/05/archives/city-plans-its-costliest-subway-in-a-short-two-miles-under-sixth.html|url-status=live}}</ref> The line was built as a four-track tunnel north of 33rd Street, but there were only two tracks south of that street. The work largely involved [[cut-and-cover]] excavations, although portions of the subway had to be tunneled through solid rock.<ref name="p1223317978">{{cite news |date=November 7, 1937 |title=The Tube Takes Shape in 6th Av.: Most of the Excavation Is Done, And, Considering, Done Quietly: Despite the Intricacies of Underground Utility Facilities and Overhead Elevated Line, There Are Fewer Inconveniences and Complaints on Tliis Project Than Construction Usually Brings |page=A3 |work=New York Herald Tribune |id={{ProQuest|1223317978}}}}</ref> Builders had to use very small charges of dynamite so that they would not disrupt the H&M tunnels alongside the route, the street and elevated line above, and the water main below.<ref>{{cite news|url=https://www.nytimes.com/1935/08/14/archives/transit-body-pushes-6th-av-subway-plan-commission-approves-changes.html|title=Transit Body Pushes 6th Av. Subway Plan; Commission Approves Changes in Hudson Tubes to Permit Start of Building.|date=August 14, 1935|newspaper=The New York Times|issn=0362-4331|access-date=April 28, 2018|archive-date=April 28, 2018|archive-url=https://web.archive.org/web/20180428182855/https://www.nytimes.com/1935/08/14/archives/transit-body-pushes-6th-av-subway-plan-commission-approves-changes.html|url-status=live}}</ref> The Sixth Avenue Elevated had to be underpinned during construction, adding another $4 to $5 million to construction costs. The Catskill Aqueduct was located around {{convert|200|ft|m}} below the avenue's surface, and workers on the new subway had to be careful to not cause any cracks in the aqueduct.<ref name="The New York Times 1940" /><ref name="Harrington 1935"/> As part of the construction of the IND line, the H&M's 14th Street and 23rd Street stations had to be rebuilt to provide space for the IND's 14th Street and 23rd Street stations, which would be located at a similar elevation. The 19th Street station was not affected because the IND tracks were located below the H&M tracks at that point.<ref name="The New York Times 1940"/> However, the 33rd Street station had to be relocated to the south of its existing location, above the new IND line. The IND platforms were to be located at the same elevation as the present H&M station, and there was no room to build a new subway station either above or below the level of the existing H&M station.<ref name="Harrington 1935"/>

The H&M's 33rd Street terminal closed on December 26, 1937, and service on the H&M was cut back to 28th Street to allow for construction on the subway to take place.<ref>{{Cite news|url=https://www.nytimes.com/1937/12/26/archives/hudson-tube-terminus-at-33d-st-closes-today.html|title=Hudson Tube Terminus At 33d St. Closes Today|date=December 26, 1937|newspaper=The New York Times|access-date=April 26, 2018|language=en-US|issn=0362-4331|archive-date=April 26, 2018|archive-url=https://web.archive.org/web/20180426161746/https://www.nytimes.com/1937/12/26/archives/hudson-tube-terminus-at-33d-st-closes-today.html|url-status=live}}</ref> The 33rd Street terminal was moved south to 32nd Street and reopened on September 24, 1939. The city had to pay $800,000 to build the new 33rd Street station and reimbursed H&M another $300,000 to the H&M for the loss of revenue.<ref>{{Cite news|url=https://www.nytimes.com/1939/09/24/archives/hudson-tube-opens-terminal-today-remodeled-33d-st-station-cost-city.html|title=Hudson Tube Opens Terminal Today – Remodeled 33d St. Station Cost City $800,000 as Part of 6th Ave. Subway Expense – Closed for Two Years – Two Train Platforms and 3 Sets of Tracks Among New Transit Equipment|date=September 24, 1939|newspaper=The New York Times|access-date=April 15, 2018|language=en-US|issn=0362-4331|archive-date=April 16, 2018|archive-url=https://web.archive.org/web/20180416073451/https://www.nytimes.com/1939/09/24/archives/hudson-tube-opens-terminal-today-remodeled-33d-st-station-cost-city.html|url-status=live}}</ref> The 28th Street station was closed at this time because the southern entrances to the 33rd Street terminal were located only two blocks away, rendering the 28th Street stop unnecessary. It was demolished to make room for the IND tracks below.<ref>{{Cite news|url=https://www.nytimes.com/1939/09/12/archives/tube-terminal-to-reopen-station-at-33d-st-and-6th-ave-to-renew.html|title=Tube Terminal to Reopen – Station at 33d St. and 6th Ave. to Renew Service Sept. 24|date=September 12, 1939|newspaper=The New York Times|access-date=April 15, 2018|language=en-US|issn=0362-4331|archive-date=April 16, 2018|archive-url=https://web.archive.org/web/20180416013332/https://www.nytimes.com/1939/09/12/archives/tube-terminal-to-reopen-station-at-33d-st-and-6th-ave-to-renew.html|url-status=live}}</ref> The IRT's Sixth Avenue elevated ultimately closed in December 1938, just before the Sixth Avenue subway was completed.<ref>{{Cite news|url=https://www.nytimes.com/1938/12/05/archives/gay-crowds-on-last-ride-as-sixth-ave-elevated-ends-60year-existence.html|title=Gay Crowds On Last Ride As Sixth Ave. Elevated Ends 60-Year Existence; 350 Police On Duty But the Noisy Revelers Strip Cars in Hunt for Souvenirs Suit May Delay Razing Little Threat Seen to Plan, However-Jobless Workers to Press Their Protest Makes Only One Stop Entrances Are Boarded Up Final Trains Run On Elevated Line Police Guard Structure|date=December 5, 1938|newspaper=The New York Times|access-date=April 26, 2018|language=en-US|issn=0362-4331|archive-date=April 26, 2018|archive-url=https://web.archive.org/web/20180426161929/https://www.nytimes.com/1938/12/05/archives/gay-crowds-on-last-ride-as-sixth-ave-elevated-ends-60year-existence.html|url-status=live}}</ref>

In addition to threading around the H&M tunnel, the line had to pass over the [[BMT Canarsie Line]] along 14th Street, over the tunnels leading to Penn Station, under the four-track [[BMT Broadway Line]] at Herald Square, over the [[IRT Flushing Line]] at 41st Street, and under the [[42nd Street Shuttle]]. Even though the line had to pass around multiple transit lines, the grades were kept to a minimum.<ref name="The New York Times 1940" /> The line included four-track stations at West Fourth, 34th, 42nd, and 47th–50th Streets. There were four sets of crossovers between 34th and 42nd Streets, and the southbound express track crossed over the southbound local track at a grade-separated flyover between 42nd and 47th–50th Streets.<ref name=p1248809011>{{cite news |id={{ProQuest|1248809011}} |title=Work to Begin On Last 6th Av. Tube Link Soon: With 9th–18th St. Contract Let, $57,000,000 Project Will Be Ready in 1941 No Federal Aid for City Man-Made, Natural Hazards Pose Many Problems |last=Vogel | first=W. P. Jr. |date=July 11, 1937 |page=A3 |work=New York Herald Tribune}}</ref> Bellmouth tunnels north of 47th–50th Streets were built to allow for a future extension under Central Park and along Morningside Avenue to 145th Street.<ref name=p1248809011/><ref name=nyt-1940-08-12/> This extension was part of the Board of Transportation's long-range program, and was estimated to cost $34.914 million as of August 1940. Construction was expected to start some time after 1946.<ref name=nyt-1940-08-12>{{Cite news|url=https://www.nytimes.com/1940/08/12/archives/transit-projects-seek-771256499-board-asks-this-as-capital-outlay.html|title=Transit Projects Seek $771,256,499 – Board Asks This as Capital Outlay for 6 Years, Including $154,330,244 for 1941 – Outlines Vast Program – Ambitious Plans to Make Most of Unification Face Knife of Planning Commission – $10,607,000 Engineering Cost – Wants Transfer Links|date=August 12, 1940|newspaper=The New York Times|access-date=April 15, 2018|language=en-US|issn=0362-4331|archive-date=April 16, 2018|archive-url=https://web.archive.org/web/20180416013321/https://www.nytimes.com/1940/08/12/archives/transit-projects-seek-771256499-board-asks-this-as-capital-outlay.html|url-status=live}}</ref>

[[File:Sixth Avenue Subway Will Be Opened to the Public at 12-01 A.M. Sunday, Dec. 15, 1940.jpg|thumb|Sixth Avenue Subway Will Be Opened to the Public at 12:01 A.M. Sunday, December 15, 1940.]]
[[File:IND after 6th Ave.png|thumb|IND services immediately after the main part of the line opened]]
On December 15, 1940, local subway service began on Sixth Avenue from the West Fourth Street subway station to the 47th–50th Streets station with track connections to the IND 53rd Street Line. The construction of the Sixth Avenue Line cost $59.5 million.<ref name="The New York Times 1940">{{cite news|url=https://www.nytimes.com/1940/12/15/archives/new-subway-line-on-6th-ave-opens-at-midnight-fete-mayor-and-2000.html|title=New Subway Line on 6th Ave. Opens at Midnight Fete|date=December 15, 1940|newspaper=The New York Times|access-date=October 7, 2011|page=1|issn=0362-4331|archive-date=December 13, 2021|archive-url=https://web.archive.org/web/20211213213358/https://www.nytimes.com/1940/12/15/archives/new-subway-line-on-6th-ave-opens-at-midnight-fete-mayor-and-2000.html|url-status=live}}</ref> The opening of the Sixth Avenue Line relieved train traffic on the Eighth Avenue Line, which was used by all services except for the [[G (New York City Subway service)|G]] Brooklyn–Queens Crosstown service. The additional capacity allowed for the reintroduction of the [[AA (New York City Subway service)|AA]] for off-peak service between [[168th Street (IND Eighth Avenue Line)|168th Street]] and [[Hudson Terminal (IND Eighth Avenue Line)|Hudson Terminal]] via the [[IND Eighth Avenue Line|Eighth Avenue Line]], and the creation of the rush-hour BB between 168th Street and [[34th Street-Herald Square (IND Sixth Avenue Line station)|34th Street-Herald Square]] via Sixth Avenue. In addition, the [[D (New York City Subway service)|D]] train, which ran between [[Norwood–205th Street (IND Concourse Line)|Norwood–205th Street]] and Hudson Terminal via Sixth Avenue, was introduced to provide service between Sixth Avenue and the Concourse Line. The F train, running between [[Parsons Boulevard (IND Queens Boulevard Line)|Parsons Boulevard]] and [[Church Avenue (IND Culver Line)|Church Avenue]] via Sixth Avenue, was created to provide express service between Sixth Avenue and Queens. Finally, the E train was cut back from Church Avenue to Broadway–Lafayette Street, running to Queens via the Eighth Avenue Line.<ref>{{Cite news|url=https://www.nytimes.com/1940/12/15/archives/the-new-subway-routes.html|title=The New Subway Routes|date=December 15, 1940|newspaper=The New York Times|access-date=April 15, 2018|language=en-US|issn=0362-4331|archive-date=April 16, 2018|archive-url=https://web.archive.org/web/20180416013306/https://www.nytimes.com/1940/12/15/archives/the-new-subway-routes.html|url-status=live}}</ref><ref>{{Cite news|url=https://www.nytimes.com/1940/12/05/archives/6th-ave-tube-adds-two-new-services-provides-express-facilities-to.html|title=6th Ave. Tube Adds Two New Services – Provides Express Facilities to Queens and Local Trains to Washington Heights – Subway Opens on Dec. 15 – Changes in Routings on Other Lines to Bring Faster Time and Less Congestion|date=December 5, 1940|newspaper=The New York Times|access-date=April 15, 2018|language=en-US|issn=0362-4331|archive-date=June 17, 2018|archive-url=https://web.archive.org/web/20180617194705/https://www.nytimes.com/1940/12/05/archives/6th-ave-tube-adds-two-new-services-provides-express-facilities-to.html|url-status=live}}</ref><ref>{{Cite news|url=https://www.nytimes.com/1939/12/02/archives/new-subway-to-add-2-needed-services-opening-of-6th-ave-line-to.html|title=New Subway to Add 2 Need Services – Opening of 6th Ave. Line to Provide Uptown Local Route and More Queens Expresses|date=December 2, 1939|newspaper=The New York Times|access-date=April 15, 2018|language=en-US|issn=0362-4331|archive-date=April 16, 2018|archive-url=https://web.archive.org/web/20180416013308/https://www.nytimes.com/1939/12/02/archives/new-subway-to-add-2-needed-services-opening-of-6th-ave-line-to.html|url-status=live}}</ref>

=== Sixth Avenue express tracks and the Chrystie Street Connection ===
On April 19, 1961, ground was broken for a $22 million project to build two express tracks between the [[West Fourth Street (IND Sixth Avenue Line)|West Fourth Street]] and [[34th Street–Herald Square (IND Sixth Avenue Line)|34th Street–Herald Square]] stations.<ref name="Levey 1961">{{Cite news|url=https://www.nytimes.com/1961/04/19/archives/construction-of-new-ind-tunnel-for-6th-ave-line-begins-today.html|title=Construction of New IND Tunnel For 6th Ave. Line Begins Today; Express Tracks Deep Under Street to Run From 4th to 34th St. – 1964 Finish Set for $22,000,000 Job|last=Levey|first=Stanley|date=April 19, 1961|newspaper=The New York Times|access-date=April 28, 2018|language=en-US|issn=0362-4331|archive-date=April 29, 2018|archive-url=https://web.archive.org/web/20180429024442/https://www.nytimes.com/1961/04/19/archives/construction-of-new-ind-tunnel-for-6th-ave-line-begins-today.html|url-status=live}}</ref> The express tracks were built {{convert|80|ft|m}} beneath the surface. The construction was done in two portions. The first section was between West 9th and 19th Streets, and the second section was between West 19th and 31st Streets.<ref name="New York City Transit Authority 1965">{{Cite book|title=Annual Report 1964–1965|publisher=New York City Transit Authority|year=1965}}</ref> The express tracks were part of an $80 million subway improvement program that began with the reconstruction of the [[DeKalb Avenue (BMT Fourth Avenue Line)|DeKalb Avenue]] station in Brooklyn. The second phase of construction was the [[Chrystie Street Connection]], which would connect the BMT lines coming over the [[Manhattan Bridge]] and the [[Williamsburg Bridge]] with the IND Houston Street Line.<ref name="The New York Times 1961">{{cite news|url=http://timesmachine.nytimes.com/timesmachine/1961/04/19/101458878.html?pageNumber=41|title=Construction of New IND Tunnel For 6th Ave. Line Begins Today; Express Tracks Deep Under Street to Run From 4th to 34th St. – 1964 Finish Set for $22,000,000 Job|date=April 19, 1961|newspaper=The New York Times|access-date=July 8, 2016|issn=0362-4331}}</ref><ref name="New York City Transit Authority 1961" /> There was also to be a new two-track spur line between West 52nd and 58th Streets with a terminal at [[57th Street (IND Sixth Avenue Line)|57th Street]] to allow trains to short turn.<ref>{{Cite news|url=https://query.nytimes.com/gst/abstract.html?res=9905E6DE1531E73BBC4F51DFB4678388679EDE|title=IND Contract Awarded|date=December 27, 1963|newspaper=The New York Times|access-date=September 18, 2017|language=en-US|issn=0362-4331}}</ref> The two projects would allow 45 additional trains per hour, carrying a combined 90,000 passengers, to enter Manhattan during rush hours.<ref name="The New York Times 1961" /><ref name="New York City Transit Authority 1961">{{Cite web|url=http://www.thejoekorner.com/brochures/index-6av-exp-tracks.html|title=Ground Breaking Program For Additional Subway Tracks|date=April 19, 1961|publisher=New York City Transit Authority|via=thejoekorner.com|access-date=January 25, 2016|archive-date=November 21, 2018|archive-url=https://web.archive.org/web/20181121185629/http://www.thejoekorner.com/brochures/index-6av-exp-tracks.html|url-status=live}}</ref>

However, the section between 9th and 19th Streets soon experienced various delays: although it had started in April 1961,<ref name="Levey 1961" /> work was halted by a water main break in 1962,<ref>{{Cite news|url=https://www.nytimes.com/1962/12/08/archives/break-in-main-cuts-6th-avenue-subway-main-break-cuts-6th-ave-subway.html|title=Break in Main Cuts 6th Avenue Subway; Main Break Cuts 6th Ave. Subway|last=Katz|first=Ralph|date=December 8, 1962|newspaper=The New York Times|access-date=April 28, 2018|language=en-US|issn=0362-4331|archive-date=April 29, 2018|archive-url=https://web.archive.org/web/20180429041903/https://www.nytimes.com/1962/12/08/archives/break-in-main-cuts-6th-avenue-subway-main-break-cuts-6th-ave-subway.html|url-status=live}}</ref> and by July 1963, the work was only 20 percent complete.<ref name="AnnualReport19632" /> Construction on the section between West 19th and 31st Streets was further along: it had started in the middle of 1961, and was 60 percent complete in July 1963.<ref name="AnnualReport19632">{{Cite book|title=Annual Report 1962–1963|publisher=New York City Transit Authority|year=1963}}</ref> The first section was 88 percent complete on June 30, 1965, and the second section was 99 percent complete on that date. Between West 55th and 58th Street, a third of the structural work was done by this date.<ref name="New York City Transit Authority 1965" /> No stations were constructed along the new express tracks, but provisions were incorporated into the design of the tunnel to permit the addition of future lower level stations at 14th Street and 23rd Street without disturbances to train operation.<ref name="AnnualReport19632" />

On November 26, 1967, the first part of the Chrystie Street Connection opened and Sixth Avenue Line express tracks opened from 34th Street–Herald Square to [[West Fourth Street–Washington Square (IND Sixth Avenue Line)|West Fourth Street–Washington Square]]. With the opening of the connection to the Manhattan Bridge, BB service was renamed B and it was extended via the new express tracks and the connection to the [[BMT West End Line]] in Brooklyn. D service was routed via the connection and onto the [[BMT Brighton Line]] instead of via the Culver Line. It only ran express during rush hours. F service was extended from Broadway–Lafayette Street during rush hours, and from 34th Street during other times to Coney Island via the Culver Line.<ref name="Cite RNT" />{{Rp|216–217}}<ref name="NYTimes-ChrystieStChanges-1967">{{cite news|url=https://timesmachine.nytimes.com/timesmachine/1967/11/16/90418352.pdf|title=Subway Changes to Speed Service: Major Alterations in Maps, Routes and Signs Will Take Effect Nov. 26|last1=Perlmutter|first1=Emanuel|date=November 16, 1967|newspaper=The New York Times|issn=0362-4331|access-date=July 7, 2015|archive-date=October 30, 2021|archive-url=https://web.archive.org/web/20211030145628/https://timesmachine.nytimes.com/timesmachine/1967/11/16/90418352.html?pdf_redirect=true&site=false|url-status=live}}</ref><ref name="NYTimes-ChrystieSt-Bewilder-1967">{{cite news|url=https://query.nytimes.com/gst/abstract.html?res=9C0CE0DD1738E23ABC4F51DFB767838C679EDE|title=BMT-IND Changes Bewilder Many – Transit Authority Swamped With Calls From Riders as New System Starts|last1=Perlmutter|first1=Emanuel|date=November 27, 1967|newspaper=The New York Times|issn=0362-4331|access-date=August 23, 2015|archive-date=December 11, 2021|archive-url=https://web.archive.org/web/20211211164816/https://www.nytimes.com/1967/11/27/archives/bmtind-changes-bewilder-many-transit-authority-swamped-with-calls.html|url-status=live}}</ref> On July 1, 1968, the 57th Street station and the portion of the Chrystie Street Connection connecting the line with the Williamsburg Bridge opened.<ref name="Hofmann 1968" /><ref name="The New York Times 1968">{{Cite news|url=https://query.nytimes.com/gst/abstract.html?res=9C06E4D61230E034BC4F51DFB0668383679EDE|title=Luncheon in Subway Opens Station|last=Perlmutter|first=Emanuel|date=June 27, 1968|newspaper=The New York Times|access-date=September 18, 2017|language=en-US|issn=0362-4331}}</ref> Service on the KK was inaugurated, running from 57th Street to [[168th Street (BMT Jamaica Line)|168th Street]] on the [[BMT Jamaica Line]]. B service was extended during non-rush hours from West Fourth Street to 57th Street. D trains began running express via the Sixth Avenue Line at all times.<ref name="Hofmann 1968">{{Cite news|url=https://query.nytimes.com/gst/abstract.html?res=9E07E6DD1131E034BC4953DFB1668383679EDE&legacy=true|title=Skip-Stop Subway Begins Run Today – KK Line Links 3 Boroughs – Other Routes Changed|last=Hofmann|first=Paul|date=July 1, 1968|newspaper=The New York Times|issn=0362-4331|access-date=November 27, 2016|archive-date=November 28, 2016|archive-url=https://web.archive.org/web/20161128051204/http://query.nytimes.com/gst/abstract.html?res=9E07E6DD1131E034BC4953DFB1668383679EDE&legacy=true|url-status=live}}</ref>

=== Later improvements ===
The [[Program for Action]], a series of subway and commuter rail expansions proposed by the MTA to then-Governor [[Nelson Rockefeller]], included a spur of the line to the underserved [[Alphabet City]] neighborhood on the Lower East Side. The spur would run under [[Houston Street]], [[Avenue C (Manhattan)|Avenue C]], and [[14th Street (Manhattan)|14th Street]].<ref name="int-arch">{{cite web | title=Full text of "Metropolitan transportation, a program for action. Report to Nelson A. Rockefeller, Governor of New York." | website=Internet Archive | date=November 7, 1967 | url=https://archive.org/stream/metropolitantran00newy/metropolitantran00newy_djvu.txt | access-date=February 3, 2022}}</ref><ref name="LLC1971">{{cite news|last1=Cohen|first1=Richard|title=Second Avenue Subway: Bumpy Road Ahead|url=https://books.google.com/books?id=CuMCAAAAMBAJ&pg=PA39|work=[[New York (magazine)|New York]]|publisher=[[New York Media, LLC]]|date=February 8, 1971|access-date=February 3, 2022|pages=37–40}}</ref> The branch's construction was delayed in 1971 after voters blocked a bond issue, then canceled along with most of the Program's new projects after the 1975–76 [[New York City fiscal crisis]] and extreme MTA fare revenue fluctuations.<ref name="Danielson Doig 1982">{{cite book | last1=Danielson | first1=M.N. | last2=Doig | first2=J.W. | title=New York: The Politics of Urban Regional Development | publisher=University of California Press | series=Lane Studies in Regional Government | year=1982 | isbn=978-0-520-90689-1 | url=https://archive.org/details/newyorkpoliticso0000dani | access-date=February 3, 2022| url-access=registration }}</ref>{{rp|pages=238–243}}<ref>{{cite web|url=http://wagner.nyu.edu/files/news/rescue.pdf|title=From Rescue to Renaissance: The Achievements of the MTA Capital Program 1982 – 2004|first1=Mark|last1=Seaman|first2=Allison L. C.|last2=de Cerreño|first3=Seth|last3=English-Young|website=[[New York University|nyu.edu]]|publisher=[[Rudin Center for Transportation Policy & Management]]|access-date=February 3, 2022|archive-date=March 10, 2022|archive-url=https://web.archive.org/web/20220310021858/https://wagner.nyu.edu/files/news/rescue.pdf|url-status=live}}</ref>

The tracks at 57th Street were originally built for a proposed extension under [[Central Park]] to [[Harlem]].<ref name="The New York Times 1940" /> The stub-end tracks were eventually connected to the [[63rd Street Lines|IND 63rd Street Line]] when the latter opened in October 1989. The 63rd Street line only extended to the [[21st Street–Queensbridge (IND 63rd Street Line)|21st Street–Queensbridge]] station in Queens, and did not connect to any other lines in that borough. The [[Q (New York City Subway service)|Q]] train served the 63rd Street extension on weekdays and the {{NYCS|B}} train stopped there on the weekends; both services used the Sixth Avenue Line.<ref>{{cite news|url=https://www.nytimes.com/1989/10/29/nyregion/the-subway-to-nowhere-now-goes-somewhere.html|title=The 'Subway to Nowhere' Now Goes Somewhere|last=Lorch|first=Donatella|date=October 29, 1989|newspaper=The New York Times|access-date=September 26, 2009|issn=0362-4331|archive-date=March 19, 2011|archive-url=https://web.archive.org/web/20110319210859/http://www.nytimes.com/1989/10/29/nyregion/the-subway-to-nowhere-now-goes-somewhere.html|url-status=live}}</ref> The Q train, a part-time express within Brooklyn via the BMT Brighton Line, ran along the Sixth Avenue Line between 1988 and 2001, when the [[Manhattan Bridge south tracks]] were closed for reconstruction.<ref>{{Cite news|url=https://www.nytimes.com/1988/12/12/nyregion/all-aboard-somewhere-for-subway-changes.html|title=All Aboard. . .Somewhere. . .for Subway Changes!|last=Lyall|first=Sarah|date=December 12, 1988|newspaper=The New York Times|access-date=December 24, 2017|language=en-US|issn=0362-4331|archive-date=March 6, 2016|archive-url=https://web.archive.org/web/20160306113048/http://www.nytimes.com/1988/12/12/nyregion/all-aboard-somewhere-for-subway-changes.html|url-status=live}}</ref><ref>{{cite news|url=https://www.nytimes.com/2001/07/21/nyregion/manhattan-bridge-service-changes.html|title=Manhattan Bridge Service Changes|date=July 21, 2001|newspaper=The New York Times|issn=0362-4331|access-date=April 30, 2018|archive-date=July 3, 2018|archive-url=https://web.archive.org/web/20180703191041/https://www.nytimes.com/2001/07/21/nyregion/manhattan-bridge-service-changes.html|url-status=live}}</ref>

Planning for the 63rd Street Line's $645 million connection from the 21st Street–Queensbridge station to the IND Queens Boulevard Line in Queens began in December 1990, and construction began on September 22, 1994.<ref>{{Cite web|url=https://www.fhwa.dot.gov/Environment/air_quality/cmaq/research/advancing_mobility/03cmaq08.cfm|title=New York City Transit 63rd Street-Queens Boulevard Connection-New York City – Advancing Mobility – Research – CMAQ – Air Quality – Environment – FHWA|website=[[Federal Highway Administration|Federal Highway Administration (FHWA)]]|publisher=Federal Highway Administration|access-date=July 3, 2016|archive-date=August 8, 2016|archive-url=https://web.archive.org/web/20160808044438/http://www.fhwa.dot.gov/Environment/air_quality/cmaq/research/advancing_mobility/03cmaq08.cfm|url-status=live}}</ref><ref>{{Cite web|url=http://www.mta.info/nyct/facts/ffhist.htm|title=About NYC Transit – History|date=October 19, 2002|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=September 18, 2016|url-status=bot: unknown|archive-url=https://web.archive.org/web/20021019203759/http://www.mta.info/nyct/facts/ffhist.htm|archive-date=October 19, 2002}}</ref><ref name="CivilEng-FinalConnection-Jul2000">{{cite journal|last2=Shanbhag|first2=Radmas|date=July 2000|title=The Final Connection|journal=[[American Society of Civil Engineers|Civil Engineering]]|volume=86|issue=7|pages=56–61|last1=Silano|first1=Louis G.}}</ref> The Connector came into regular use on December 16, 2001. A new Sixth Avenue local service, the V, was introduced operating local via Sixth Avenue and terminating in the center tracks of the Sixth Avenue Line's Second Avenue station. The V ran local on the Queens Boulevard Line, and it only operated during weekdays. At this time, the F, which ran express along the Queens Boulevard Line, was rerouted to operate via the 57th Street station and the 63rd Street line north of the 47th–50th Streets–Rockefeller Center station, rather than via the 53rd Street tunnel. Both the 63rd Street and the 53rd Street lines merge into the Queens Boulevard Line in Queens.<ref>{{Cite web|url=http://www.thejoekorner.com/brochures/index-v-train.html|title=The Opening of the New 63rd Street Connector|date=November 2001|publisher=New York City Transit|via=thejoekorner.com|access-date=January 24, 2016|archive-date=December 8, 2015|archive-url=https://web.archive.org/web/20151208123440/http://www.thejoekorner.com/brochures/index-v-train.html|url-status=live}}</ref><ref>{{Cite news|url=https://www.nytimes.com/2001/12/17/nyregion/v-train-begins-service-today-giving-queens-commuters-another-option.html|title=V Train Begins Service Today, Giving Queens Commuters Another Option|last=Kershaw|first=Sarah|date=December 17, 2001|newspaper=The New York Times|issn=0362-4331|access-date=October 14, 2016|archive-date=March 25, 2010|archive-url=https://web.archive.org/web/20100325003759/http://www.nytimes.com/2001/12/17/nyregion/v-train-begins-service-today-giving-queens-commuters-another-option.html|url-status=live}}</ref> On June 28, 2010, the V was replaced by the M, which began using the Chrystie Street Connection to the Williamsburg Bridge. Regular M trains make all former V stops except for Second Avenue.<ref>{{cite web|url=http://web.mta.info/nyct/service/ServiceReduction/part1.htm|title=NYC Transit 2010 Service Reduction Proposals|date=January 27, 2010|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 30, 2016|archive-date=April 6, 2022|archive-url=https://web.archive.org/web/20220406185727/http://web.mta.info/nyct/service/ServiceReduction/part1.htm|url-status=live}}</ref><ref>{{cite news|url=https://www.nytimes.com/2010/03/20/nyregion/20train.html|title=Under a New Subway Plan, the V Stands for Vanished|last=Grynbaum|first=Michael M.|date=March 19, 2010|newspaper=The New York Times|access-date=March 20, 2010|issn=0362-4331|archive-date=September 4, 2020|archive-url=https://web.archive.org/web/20200904022108/https://www.nytimes.com/2010/03/20/nyregion/20train.html|url-status=live}}</ref><ref>{{Cite web|url=http://web.mta.info/news/pdf/NYCT_Summary_of_Revisions.pdf|title=Modifications to 2010 NYC Transit Service Reductions|date=March 19, 2010|website=mta.info|publisher=New York City Transit|pages=4–5|access-date=August 30, 2016|archive-date=June 6, 2014|archive-url=https://web.archive.org/web/20140606235349/http://web.mta.info/news/pdf/NYCT_Summary_of_Revisions.pdf|url-status=live}}</ref>

In 2004, full Manhattan Bridge service was restored. This resulted in full B and D express service being restored from 34th Street–Herald Square to the Manhattan Bridge, where the services continued to Brooklyn. However, the terminals of the B and D were reversed from prior to the Manhattan Bridge service suspensions. B service operates weekdays only via the Brighton Line express tracks to Brighton Beach, replacing the [[Q (New York City Subway service)|&lt;Q&gt;]] express on the Brighton Line. D service operates 24/7 along the West End Line because residents of [[Bensonhurst, Brooklyn|Bensonhurst]], a neighborhood located near the West End Line, wanted full-time direct subway service to Manhattan.<ref>{{Cite news|url=https://www.nytimes.com/2004/02/20/nyregion/a-subway-map-remade-in-hopes-of-matching-routes-and-riders.html|title=A Subway Map Remade, in Hopes of Matching Routes and Riders|last=Luo|first=Michael|date=February 20, 2004|newspaper=The New York Times|access-date=June 20, 2018|issn=0362-4331|archive-date=October 18, 2022|archive-url=https://web.archive.org/web/20221018171028/https://www.nytimes.com/2004/02/20/nyregion/a-subway-map-remade-in-hopes-of-matching-routes-and-riders.html|url-status=live}}</ref>

The 2015–2019 [[Metropolitan Transportation Authority]] Capital Plan called for the Sixth Avenue Line's [[23rd Street (IND Sixth Avenue Line)|23rd Street]] and [[57th Street (IND Sixth Avenue Line)|57th Street]] stations, along with 31 others, to undergo a complete overhaul as part of the [[Enhanced Station Initiative]]. Updates would include cellular service, Wi-Fi, USB charging stations, interactive service advisories and maps, improved signage, and improved station lighting.<ref>{{cite web|url=http://gothamist.com/2016/01/08/subway_facelift_shutdown.php|title=MTA Will Completely Close 30 Subway Stations For Months-Long "Revamp"|last=Whitford|first=Emma|date=January 8, 2016|website=gothamist.com|publisher=Gothamist|archive-url=https://web.archive.org/web/20160801200338/http://gothamist.com/2016/01/08/subway_facelift_shutdown.php|archive-date=August 1, 2016|url-status=dead|access-date=July 18, 2016}}</ref><ref>{{Cite web|url=https://www.governor.ny.gov/sites/governor.ny.gov/files/atoms/files/MTAStations.pdf|title=Map of stations part of the Enhanced Station Initiative|website=governor.ny.gov|publisher=State of New York|access-date=July 18, 2016|archive-date=November 2, 2019|archive-url=https://web.archive.org/web/20191102093442/https://www.governor.ny.gov/sites/governor.ny.gov/files/atoms/files/MTAStations.pdf|url-status=live}}</ref> The renovations at both stations were supposed to last from July to December 2018. The renovations were conducted under a $124.9 million contract that also included the renovation of the [[28th Street (IRT Lexington Avenue Line)|28th Street]] station on the [[IRT Lexington Avenue Line]].<ref>{{Cite web|url=http://www.mta.info/press-release/nyc-transit/repairs-and-improvements-coming-three-manhattan-6fm-subway-stations|title=Repairs and Improvements Coming to Three Manhattan 6FM Subway Stations|date=June 15, 2018|website=mta.info|publisher=Metropolitan Transportation Authority|language=en|access-date=June 18, 2018|archive-date=September 4, 2019|archive-url=https://web.archive.org/web/20190904162831/http://www.mta.info/press-release/nyc-transit/repairs-and-improvements-coming-three-manhattan-6fm-subway-stations|url-status=dead}}</ref> 23rd Street reopened ahead of schedule on November 29, 2018,<ref>{{cite web|url=http://web.mta.info/nyct/service/StationInfo_23st/index.htm|title=Service Restored Trains stop at 23 St|date=November 29, 2018|website=mta.info|publisher=Metropolitan Transportation Authority|archive-url=https://web.archive.org/web/20181005103814/http://web.mta.info/nyct/service/StationInfo_23st/index.htm|archive-date=October 5, 2018|url-status=dead|access-date=November 29, 2018}}</ref> while 57th Street reopened on December 19, 2018.<ref>{{Cite web|url=http://travel.mtanyct.info/serviceadvisory/routeStatusResult.aspx?tag=F&date=12/19/2018&time=&method=getstatus4|title=Planned Service Changes for: Wednesday, December 19, 2018|website=mta.info|publisher=Metropolitan Transportation Authority|language=en|archive-url=https://web.archive.org/web/20181220005800/http://travel.mtanyct.info/serviceadvisory/routeStatusResult.aspx?tag=F&date=12%2F19%2F2018&time=&method=getstatus4|archive-date=December 20, 2018|url-status=dead|access-date=January 20, 2019}}</ref>

As part of the 2015–2019 Capital Program, the 34th Street and West Fourth Street interlockings on the IND Sixth Avenue Line were upgraded at a cost of $356.5 million. The interlocking upgrades would support [[communications-based train control]] (CBTC) installation on the [[Signaling of the New York City Subway#Automation|Queens Boulevard, Culver, and Eighth Avenue lines]].<ref name="MTA-Transit-Jan2019">{{Cite web|url=http://web.mta.info/mta/news/books/pdf/190122_1030_transit-bus.pdf|title=Transit & Bus Committee Meeting|date=January 22, 2019|publisher=Metropolitan Transportation Authority|pages=176–177|access-date=January 19, 2019|archive-url=https://web.archive.org/web/20190120093550/http://web.mta.info/mta/news/books/pdf/190122_1030_transit-bus.pdf|archive-date=January 20, 2019|url-status=dead}}</ref>

== Station listing ==
{{NYCS service legend
| alltimes         = show
| allexceptrush    =
| allexceptnights  = show
| nightsonly       = show
| nightsweekends   =
| weekdaysonly     = show
| rushonly         =
| rushpeak         = show
| weekendsevenings = show
}}
{| class="wikitable"
|-
!Neighborhood<br />(approximate)
!{{Access icon}}
!Station
!Tracks
!Services
!Opened
!Transfers and notes
|-
| align=center colspan=7 | '''[[Manhattan]]'''
|-
!colspan=7 style="background-color: silver;"|Branch from the [[63rd Street Lines|IND 63rd Street Line]] ({{NYCS 63rd IND|time=show}})
|-
|rowspan=11|[[Midtown Manhattan]]
|
|{{stl|NYCS|57th Street|Sixth}}
|2
|{{NYCS 63rd IND|time=show}}
|July 1, 1968<ref name="The New York Times 1968" />
|
|-
|colspan=6|&nbsp;
|-
!colspan=6 style="background-color: silver;"|Express Tracks split from the [[IND Eighth Avenue Line]] ({{NYCS Sixth 53rd|time=show}})
|-
|
|{{stl|NYCS|Seventh Avenue|Sixth}}
|express
|{{NYCS Sixth 53rd|time=show}}
|August 19, 1933<ref name="NYTimes-INDQBLCrstwnOpen-1933">* {{cite news|url=https://timesmachine.nytimes.com/timesmachine/1933/08/18/99841892.pdf|title=Two Subway Units Open at Midnight – Links in City-Owned System in Queens and Brooklyn to Have 15 Stations|date=August 18, 1933|newspaper=The New York Times|issn=0362-4331|access-date=November 7, 2015|archive-date=December 10, 2021|archive-url=https://web.archive.org/web/20211210175107/https://timesmachine.nytimes.com/timesmachine/1933/08/18/99841892.html?pdf_redirect=true&site=false|url-status=live}}
* {{cite news|url=http://fultonhistory.com/Newspaper%2014/Jamaica%20NY%20Long%20Island%20Daily%20Press/Jamaica%20NY%20Long%20Island%20Daily%20Press%201933/Jamaica%20NY%20Long%20Island%20Daily%20Press%201933%20-%204319.pdf|title=New Queens Subway Service Will Be Launched Tonight; Tunnel From Manhattan Open to Jackson Heights; Service Will Eventually Be Extended Through To Jamaica|date=August 18, 1933|newspaper=Long Island Daily Press|access-date=July 27, 2016|agency=[[Fultonhistory.com]]|page=20|archive-date=May 30, 2020|archive-url=https://web.archive.org/web/20200530192302/https://fultonhistory.com/Newspaper%2014/Jamaica%20NY%20Long%20Island%20Daily%20Press/Jamaica%20NY%20Long%20Island%20Daily%20Press%201933/Jamaica%20NY%20Long%20Island%20Daily%20Press%201933%20-%204319.pdf|url-status=live}}
* {{cite news|url=http://fultonhistory.com/newspaper%2011/New%20York%20Evening%20Post/New%20York%20NY%20Evening%20Post%201933%20Grayscale/New%20York%20NY%20Evening%20Post%201933%20Grayscale%20-%203621.pdf|title=New Queens Tube To Open Saturday: Brooklyn-Long Island City Link of City Line Also to Be Put in Operation|date=August 17, 1933|newspaper=[[New York Post|New York Evening Post]]|access-date=July 27, 2016|agency=[[Fultonhistory.com]]|page=18|archive-date=May 30, 2020|archive-url=https://web.archive.org/web/20200530192306/https://fultonhistory.com/newspaper%2011/New%20York%20Evening%20Post/New%20York%20NY%20Evening%20Post%201933%20Grayscale/New%20York%20NY%20Evening%20Post%201933%20Grayscale%20-%203621.pdf|url-status=live}}</ref>
|[[IND Queens Boulevard Line]] ({{NYCS Queens 53rd west|time=show}})
|-
|colspan=6|&nbsp;
|-
!colspan=6 style="background-color: silver;"|Local Tracks split from the [[IND Queens Boulevard Line]] ({{NYCS Sixth Queens|time=show}})
|-
!colspan=6 style="background-color: silver;"|Branch line merges ({{NYCS 63rd IND|time=show}})
|-
!colspan=6 style="background-color: silver;"|Main line ({{NYCS Sixth|time=show}})
|-
| {{Access icon}}
|{{stl|NYCS|47th–50th Streets–Rockefeller Center}}
|all
|{{NYCS Sixth|time=show}}
|December 15, 1940<ref name="The New York Times 1940" />
|
|-
|[[File:Aiga elevator.svg|20px|alt=Elevator access to mezzanine only]]
|{{stl|NYCS|42nd Street–Bryant Park}}
|all
|{{NYCS Sixth|time=show}}
|December 15, 1940<ref name="The New York Times 1940" />
|[[IRT Flushing Line]] ({{NYCS Flushing south|time=show}}) at {{stl|NYCS|Fifth Avenue}}<br />[[IRT Broadway–Seventh Avenue Line]] ({{NYCS Broadway-Seventh|time=show}}) at {{stl|NYCS|Times Square–42nd Street|Broadway-Seventh}}, daytime only<br>[[BMT Broadway Line]] ({{NYCS Broadway|time=show}}) at {{stl|NYCS|Times Square–42nd Street|Broadway}}, daytime only<br>[[42nd Street Shuttle]] ({{NYCS 42nd|time=show}}) at {{stl|NYCS|Times Square}}, daytime only<br>[[IND Eighth Avenue Line]] ({{NYCS Eighth south|time=show}}) at {{stl|NYCS|42nd Street–Port Authority Bus Terminal}}, daytime only
|-
| {{Access icon}}
|{{stl|NYCS|34th Street–Herald Square|Sixth}}
|all
|{{NYCS Sixth|time=show}}
|December 15, 1940<ref name="The New York Times 1940" />
|[[BMT Broadway Line]] ({{NYCS Broadway|time=show}})<br>[[Pennsylvania Station (New York City)|Penn Station]]: [[Amtrak]], [[Long Island Rail Road]], and [[New Jersey Transit Rail Operations|New Jersey Transit]]<br>[[M34 (New York City bus)|M34/M34A Select Bus Service]]<br>Connection to [[Port Authority Trans-Hudson|PATH]] at {{stl|PATH|33rd Street}}
|-
|[[Chelsea, Manhattan|Chelsea]]
|
|{{stl|NYCS|23rd Street|Sixth}}
|local
|{{NYCS Sixth local|time=show}}
|December 15, 1940<ref name="The New York Times 1940" />
| [[M23 SBS (New York City bus)|M23 Select Bus Service]]<br>Connection to [[Port Authority Trans-Hudson|PATH]] at {{stl|PATH|23rd Street}}
|-
|rowspan=2|[[Greenwich Village]]
| {{Access icon}}&nbsp;↑
|{{stl|NYCS|14th Street|Sixth}}
|local
|{{NYCS Sixth local|time=show}}
|December 15, 1940<ref name="The New York Times 1940" />
|[[BMT Canarsie Line]] ({{NYCS Canarsie|time=show}})<br>[[IRT Broadway–Seventh Avenue Line]] ({{NYCS Broadway-Seventh south|time=show}})<br>Connection to [[Port Authority Trans-Hudson|PATH]] at {{stl|PATH|14th Street}}<br>[[M14 (New York City bus)|M14A/M14D Select Bus Service]]<br>Station is [[Americans with Disabilities Act of 1990|ADA-accessible]] in the northbound direction only.
|-
|{{Access icon}}
|{{stl|NYCS|West Fourth Street–Washington Square}}
|all
|{{NYCS Sixth|time=show}}
|December 15, 1940<ref name="The New York Times 1940" />
|[[IND Eighth Avenue Line]] ({{NYCS Eighth south|time=show}})
|-
!colspan=7 style="background-color: silver;"|Local crossovers to/from the [[IND Eighth Avenue Line]] (no regular service)
|-
|rowspan=1|[[NoHo]]
|{{Access icon}}
|{{stl|NYCS|Broadway–Lafayette Street}}
|all
|{{NYCS Sixth|time=show}}
|January 1, 1936<ref name="East Broadway"/>
|[[IRT Lexington Avenue Line]] ({{NYCS Lexington local|time=show}}) at {{stl|NYCS|Bleecker Street}}
|-
!colspan=7 style="background-color: silver;"|Express tracks turn under Chrystie Street ({{NYCS Chrystie Manhattan|time=show}})
|-
!colspan=7 style="background-color: silver;"|Local tracks split to the [[BMT Nassau Street Line]] ({{NYCS Chrystie Williamsburg|time=show}}) and also continue under Houston Street ({{NYCS Sixth south|time=show}})
|-
|colspan=7|&nbsp;
|-
!colspan=7 style="background-color: silver;"|Branch under [[Chrystie Street Connection|Chrystie Street]] ({{NYCS Chrystie Manhattan|time=show}})
|-
|rowspan=1|[[Chinatown, Manhattan|Chinatown]]
|
|{{stl|NYCS|Grand Street|Sixth}}
|express
|{{NYCS Chrystie Manhattan|time=show}}
|November 27, 1967<ref name="NYTimes-ChrystieSt-Bewilder-1967" />
|
|-
!colspan=7 style="background-color: silver;"|To north tracks of [[Manhattan Bridge subway tracks|Manhattan Bridge]]
|-
|colspan=7|&nbsp;
|-
!colspan=7 style="background-color: silver;"|Branch under [[Houston Street (Manhattan)|Houston Street]] ({{NYCS Sixth south|time=show}})
|-
|rowspan=1|[[East Village, Manhattan|East Village]]
|
|{{stl|NYCS|Second Avenue}}
|local<br />layup tracks
|{{NYCS Sixth south|time=show}}
|January 1, 1936<ref name="East Broadway"/>
|[[M15 SBS (New York City bus)|M15 Select Bus Service]]
|-
|rowspan=2|[[Lower East Side]]
|
|{{stl|NYCS|Delancey Street}}
|local
|{{NYCS Sixth Rutgers|time=show}}
|January 1, 1936<ref name="East Broadway"/>
|[[BMT Nassau Street Line]] ({{NYCS Williamsburg|time=show}}) at {{stl|NYCS|Essex Street}}
|-
|
|{{stl|NYCS|East Broadway}}
|local
|{{NYCS Sixth Rutgers|time=show}}
|January 1, 1936<ref name="East Broadway"/>
|
|-
| align=center colspan=7 | '''[[Brooklyn]]'''
|-
!colspan=7 style="background-color: silver;"|[[Rutgers Street Tunnel]] under the [[East River]]
|-
|rowspan=1|[[DUMBO, Brooklyn|DUMBO]]
|
|{{stl|NYCS|York Street}}
|local
|{{NYCS Sixth Rutgers|time=show}}
|April 9, 1936<ref name=Rutgers/>
|
|-
!colspan=7 style="background-color: silver;"|Continues as the [[IND Culver Line]] ({{NYCS Sixth Rutgers|time=show}})
|}

==Notes==
{{notelist}}

== References ==
{{Reflist}}

== External links ==
{{attached KML|display=inline,title}}
* [https://www.nycsubway.org/wiki/IND_6th_Avenue_Line nycsubway.org – IND 6th Ave./63rd St. Line]
* {{Structurae|id=20032022|title=Rutgers Street Tunnel}}

{{NYCS lines navbox}}
{{NYCS navbox}}
{{Crossings navbox
|structure        = Crossings
|place            = [[East River]]
|bridge           = Rutgers Street Tunnel
|bridge signs     = {{NYCS Sixth Rutgers|time=bullets}}
|upstream         = [[Williamsburg Bridge]]
|upstream signs   = {{NYCS Williamsburg|time=bullets}}
|downstream       = [[Manhattan Bridge]]
|downstream signs = {{NYCS Manhattan Bridge|time=bullets}}
}}

[[Category:New York City Subway lines|6th Avenue Line]]
[[Category:Independent Subway System|6th Avenue]]
[[Category:Railway lines opened in 1936|6th Avenue]]
[[Category:1936 establishments in New York City]]