Independent Subway System
Overview
Status	Incorporated into theNew York City Subway
Owner	City of New York
Service
Operator(s)	New York City Transit Authority
Depot(s)	Concourse Yard,Jamaica Yard,Pitkin Yard,207th Street Yard
Rolling stock	R46,R68,R68A,R160,R179,R211
History
Opened	1932; 93 years ago (1932)
Closed	1940; 85 years ago (1940) (acquisition by theNYC Board of Transportation)
Technical
Track gauge	4 ft 8+1⁄2 in (1,435 mm)standard gauge
Route map

TheIndependent Subway System (IND; formerly theISS^[a]) was arapid transit rail system inNew York City that is now part of theNew York City Subway.^[2] It was first constructed as theEighth Avenue Line inManhattan in 1932.^[3] It was originally also known as theIndependent City-Owned Subway System (ICOSS) or theIndependent City-Owned Rapid Transit Railroad (ICORTR).^[1]

One of three subway networks that became part of the modern New York City Subway, the IND was intended to be fully owned and operated by the municipal government, in contrast to the privately operated or jointly fundedInterborough Rapid Transit Company (IRT) andBrooklyn–Manhattan Transit Corporation (BMT) companies. It was merged with these two networks when the subway system wasunified in 1940.^[1]

The original IND services are the modern subway'sA,C,E,F, andG services, as well as the portions of theB andD services that are not in Brooklyn. In addition, the BMT'sM andR use trackage that was originally built for the IND, while theQ uses theIND Second Avenue Line, which was built after the unification of the three systems. TheRockaway Park Shuttle supplements theA service. For operational purposes, the IND and BMT lines and services are referred to jointly as theB Division.^[1]

Until 1940, it was known as the Independent City-Owned Subway System (ICOS), Independent Subway System (ISS), or Independent City-Owned Rapid Transit Railroad. It became known as the IND after unification of the subway lines in 1940; the nameIND was assigned to match the three-letter initialisms that the IRT and BMT used.^[1]

The first IND line was theEighth Avenue Line inManhattan, opened on September 10, 1932; for a while the whole system was colloquially known as theEighth Avenue Subway. The original IND system was entirely underground in the four boroughs that it served, with the exception of a short section of theIND Culver Line containing two stations spanning theGowanus Canal in theGowanus section of Brooklyn.^[1]

In the early 1920s, MayorJohn Hylan proposed a complex series of city-owned and operated rapid transit lines to compete with the BMT and IRT, especially their elevated lines.^[4][5] The New York City Transit Commission was formed in 1921 to develop a plan to reduce overcrowding on the subways. The original plans included:^[1]

• Two major trunk lines in midtown Manhattan, with one running underEighth Avenue and one underSixth Avenue, which already had an elevated line
• A crosstown subway under 53rd Street (connecting with the Eighth and Sixth Avenue subways) running under theEast River to Queens Plaza (Long Island City), meeting with aBrooklyn–Queens crosstown line, and continuing underQueens Boulevard and Hillside Avenue to179th Street, where bus service would converge
• A subway under theGrand Concourse inthe Bronx, diverging from the Eighth Avenue Line in Manhattan at 145th Street andSaint Nicholas Avenue

These lines were completely built as planned. All but a short portion of the Culver Line (over theGowanus Canal) are underground.^[1]

On March 14, 1925, the groundbreaking of the Eighth Avenue subway took place at 123rd Street and St. Nicholas Avenue.^[1]

On July 8, 1931, the first train ofR1s left Coney Island at 11:35am and ran via theBMT Sea Beach Line toTimes Square. The trip took 42 minutes.^[1]

On September 10, 1932, theEighth Avenue Line opened from207th Street toChambers Street, inaugurating the IND. In February 1933 theCranberry Street Tunnel opened, along with the Eighth Avenue Line fromChambers Street toJay Street–Borough Hall. On the northern end of the construction, in the Bronx, the connectingConcourse Line opened on July 1, 1933 from205th Street to145th Street.^[3] On the IND's opening day, it had a relatively small subway car fleet of 300 cars, while the IRT had 2,281 subway and 1,694 elevated cars, and the BMT had 2,472 cars.^[1]

The new IND Eighth Avenue Line was built using 1,000,000 cubic yards (27,000,000 cu ft) ofconcrete and 150,000 short tons (140,000,000 kg) ofsteel. Theroadbed of the new subway was expected to last 30 years.^[1] At the time of the line's opening, other portions of the Independent Subway System were under construction, including five underwater tunnels:^[1]

• Cranberry Street Tunnel, 8,487 feet (2,587 m) long
• Rutgers Street Tunnel, 5,479 feet (1,670 m) long
• 53rd Street Tunnel, 5,589 feet (1,704 m) long
• Concourse Tunnel, 5,397 feet (1,645 m) long
• Greenpoint Tube, 4,790 feet (1,460 m) long

There was somevandalism on the IND Eighth Avenue Line's opening day, as some of the uptown stations were broken into by people who cloggedturnstile slots withgum and other objects. Two months after the IND opened for business, three exits from the96th Street and103rd Street stations – at 95th and 97th Streets and at 105th Street, respectively – were closed due to theft.^[1]

The Queens Boulevard Line, also referred to as theLong Island City−Jamaica Line,Fifty-third Street−Jamaica Line, andQueens Boulevard−Jamaica Line prior to opening,^[6][7][8] was an original line of the city-owned Independent Subway System (IND), planned to stretch between theIND Eighth Avenue Line in Manhattan and 178th Street and Hillside Avenue in Jamaica, Queens.^[6][8][9]

The first section of the line, west fromRoosevelt Avenue to50th Street, opened on August 19, 1933.^[10]E trains ran local toHudson Terminal (today's World Trade Center) in Manhattan, while theGG (predecessor to currentG service) ran as a shuttle service between Queens Plaza andNassau Avenue on theIND Crosstown Line, which opened on the same day.^{[11][12][13][14][15][16]}

TheCranberry Street Tunnel, extending the Eighth Avenue express tracks east under Fulton Street toJay Street–Borough Hall in Brooklyn, was opened for the morning rush hour on February 1, 1933.^[17] Until June 24, 1933,High Street was skipped.^[1]

The first short section of the IND Culver Line opened on March 20, 1933, taking Eighth Avenue ExpressA trains (and for about a month from July to AugustC trains) south from Jay Street toBergen Street.^[18][19] The rest of the line opened on October 7, 1933 to the "temporary" terminal at Church Avenue,^[18][20] three blocks away from the Culver elevated at Ditmas Avenue.^[21][22] In 1936, the A was rerouted to theIND Fulton Street Line andE trains from theQueens Boulevard Line replaced them.^[18]

The first part of theIND Sixth Avenue Line, or what was then known as theHouston–Essex Street Line, began operations at noon on January 1, 1936 with two local tracks from a junction with theWashington Heights, Eighth Avenue and Church Street Line (Eighth Avenue Line) south ofWest Fourth Street–Washington Square east underHouston Street and south underEssex Street to a temporary terminal atEast Broadway.E trains, which ran fromJackson Heights, Queens toHudson Terminal, were shifted to the new line to East Broadway.^[23] 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-builtIND Worth Street Line in Williamsburg, Brooklyn.^{[24][25][26][27]}

Just after midnight on April 9, 1936, trains began running under theEast River via the Rutgers Street Tunnel, which connected the Houston-Essex Street Line with the north end of theJay–Smith–Ninth Street Line at a junction with the Eighth Avenue Line north ofJay Street–Borough Hall.E trains were sent through the connection toChurch Avenue. Simultaneously, theFulton Street Line was opened toRockaway Avenue and theA andC trains, which had used Smith Street, were rerouted to Fulton Street.^[28][29]

During construction, streetcar service along Sixth Avenue was terminated. The city had the choice of either restoring it upon the completion of construction or abandoning it immediately. As the city wanted to tear down theIRT Sixth Avenue Line right away and save on the costs of shoring it up while construction proceeded underneath it, the IRT Sixth Avenue Line was purchased for$12.5 million and terminated by the city on December 5, 1938.

On December 15, 1940, local subway service began on Sixth Avenue from the West Fourth Street subway station to the 47-50th Street subway station with track connections to the IND 53rd Street Line.^[30] The Sixth Avenue Line's construction cost $59,500,000. The following routes were added with the opening of service:

• TheAA Washington Heights Local was brought back for non-rush-hour service between168th Street andHudson Terminal via theEighth Avenue Line.
• TheBB Washington Heights Local was added for rush-hour only service between168th Street andHudson Terminal via the Sixth Avenue Line.
• TheD Bronx Concourse Express was added for service betweenNorwood–205th Street andHudson Terminal via the Sixth Avenue Line.
• E (Queens–Manhattan Express) service was cut back fromChurch Avenue toBroadway–Lafayette Street.
• F (Queens–Manhattan Express) was added for service betweenParsons Boulevard andChurch Avenue via the Sixth Avenue Line.

Sixth Avenue express service would not begin until 1967, after theChrystie Street Connection opened.^[1]

TheFulton Street Line was opened from Jay Street toRockaway Avenue on April 9, 1936, including the stub terminal atCourt Street. A shuttle was operated between Court Street and Hoyt–Schermerhorn Streets.^[28][31]

On December 31, 1936, the Queens Boulevard Line was extended from Roosevelt Avenue toKew Gardens–Union Turnpike.^{[32][33][34][10]}

The Queens Boulevard Line was extended to Hillside Avenue and 178th Street, with a terminal station at 169th Street on April 24, 1937.^{[11][33][35][36]} That day, express service began on the Queens Boulevard Line during rush hours, withE trains running express west of 71st–Continental Avenues, andGG trains taking over the local during rush hours.^[37][38] The initial headway for express service was between three and five minutes.^[39]

The entire Crosstown Line was completed and connected to theIND Culver Line on July 1, 1937, whereupon theGG was extended in both directions toSmith–Ninth Streets andForest Hills–71st Avenue.^[1][40]

From April 30, 1939 to October 28, 1940, the Queens Boulevard Line served the1939 New York World's Fair via theWorld's Fair Railroad. The World's Fair line ran via a connection through theJamaica Yard and throughFlushing Meadows–Corona Park along the current right-of-way of theVan Wyck Expressway.^[12][33][41] Despite calls from public officials such as Queens Borough President George Harvey to make the line a permanent connection toFlushing and northern Queens, the line was demolished in 1941.^[12]

Mayor John Hylan proposed some never-built lines in 1922 even before the first leg of the IND was completed. These lines included:^[1]

• A West Side trunk line in Manhattan between 14th Street and the city limits atYonkers. The line would be 4 tracks between 14th Street and 162nd Street, 3 tracks to Dyckman Street, and 2 tracks to the terminal. There would be a two-track spur from 162nd Street to 190th Street via Amsterdam Avenue. From 14th Street, the line would split; two tracks would connect to the BMT Canarsie Line and two tracks would continue south to a loop at Battery Park and an East River tunnel toAtlantic Avenue and Hicks Street, Brooklyn. Supposedly, there was also a plan of a line toRed Hook.
• A trunk line, 4 tracks, onFirst Avenue from the Harlem River to 10th Street. From 10th Street, the line would split. Two tracks would run viaThird Avenue and theBowery to a new Lafayette Avenue subway in Brooklyn. The other two would run to a loop near City Hall. From the Harlem River, the line would run to161st Street, and split into two 3-track routes: one to Fordham Road & Southern Blvd and the other to Webster Ave. & Fordham Road, where it would join the current IRT White Plains Road line and continue to 241st Street. Since this portion of the IRT El was already built to BMT clearances, and Hylan's system would consider using BMT clearances as well, all that would have to be done along this section is shave back the platforms.
• A line from125th Street (near today'sHenry Hudson Parkway) crosstown, to and across theEast River, toAstoria, Queens, likely connecting to theBMT Astoria Line.
• A new subway line, with between two and four tracks at various areas, from approximately theHunters Point Avenue station on today'sIRT Flushing Line in Queens, heading in a southeasterly direction to Lafayette Avenue, Brooklyn. At Lafayette Avenue, the line would split. Two tracks would turn into a four-track line along Lafayette Avenue. The other two tracks would run to Flatbush and Franklin Avenues.
• A 4-track subway line from Brooklyn'sBorough Hall via the Lafayette Avenue subway toBedford Avenue. From there it was three tracks toBroadway toCypress Hills, Brooklyn where the line would continue on the present-dayBMT Jamaica Line. (The line would have ended at168th Street, where the BMT Jamaica Line once ended.) The subway would have run directly under the line along Broadway giving it direct competition for passengers, and (in Hylan's opinion) draining revenues from the BMT. Two tracks of the Lafayette Avenue subway would connect with the proposed First Avenue line.
• A new branch off theIRT Eastern Parkway Line in Brooklyn ontoUtica Avenue, running under Utica toFlatlands Avenue.
• A 4-track subway under Flatbush Avenue in Brooklyn toNostrand Avenue, to Emmons Avenue in Sheepshead Bay, turning west onto Emmons Avenue to Surf Avenue inConey Island. A branch of this line would head out toFloyd Bennett Field under Flatbush Avenue.
• Extension of theBMT Canarsie Line to the BMT Jamaica Line somewhere beyond 121st Street in Queens.
• A new line running from Prospect Avenue via Fort Hamilton Parkway, to 10th Avenue, terminating at 90th Street.BMT Culver Line trains would use this line.
• Extension of theBMT Fourth Avenue Line in Brooklyn, south toBay Ridge – 95th Street. (This was the only other line that was complete.)
• Extension of the BMT Fourth Avenue Line east to the Fort Hamilton Parkway Line and theBMT West End Line.
• A two-track line from the BMT Fourth Avenue Line at 67th Street to Staten Island via theStaten Island Tunnel.
• Extension of theIRT New Lots Line from New Lots Avenue to Lefferts Boulevard.
• Extension of the IRT Flushing Line to Bell Boulevard inBayside viaMain Street,Kissena Boulevard, andNorthern Boulevard.
• A branch off the IRT Flushing Line to Jamaica fromRoosevelt Avenue.^[1]

A major expansion of the IND was first planned in 1929.^[42] It would have added over 100 miles of new routes in Manhattan, Brooklyn, Queens, and the Bronx, merging with, intersecting or extending the existing IND rights-of way. It was claimed that this expansion, combined with the operating IRT, BMT, and IND lines, would provide subway service within a half mile of anyone's doorstep within these four boroughs.^[42] Pricing – excluding acquisition and equipment costs – was estimated atUS$438 million. The entire first phase had only cost US$338 million,including acquisition and equipment costs.^[42]

Not long after these plans were unveiled, theWall Street Crash of 1929 occurred and theGreat Depression was ushered in, and the plans essentially became history overnight.^[42] Various forms of the expansion resurfaced in 1939,^[1] 1940,^[43] 1951,^[44]1968,^[45][46] and 1998^[47] but were never realized. This was the time when the IND had planned widespread elevated construction.^[1]

TheSecond Avenue Subway, one of the main parts of the plan, is open between 63rd and 96th Streets as of January 1, 2017.

TheCourt Street station on the IND Fulton Street Line was closed on June 1, 1946 due to low ridership.^[48][49][50] After World War II ended, workers and materials became available for public use again. The badly needed extension to the more efficient terminal at Broadway −East New York (the currentBroadway Junction station) opened on December 30, 1946.^[12][51] The extension of the Fulton Street Line, the completion of which had been delayed due to war priorities, was finished by funds obtained by MayorWilliam O'Dwyer and was placed in operation on November 28, 1948, running along Pennsylvania Avenue and Pitkin Avenue toEuclid Avenue near the Queens border. Forty additionalR10 cars were placed into service for the extension. The cost of the extension was about $46,500,000. It included the construction of the newPitkin Avenue Storage Yard, which could accommodate 585 subway cars on 40 storage tracks.^{[12][38][52][53][54]}

The existing169th Street station provided an unsatisfactory terminal setup for a four track line, and this required the turning ofF trains at Parsons Boulevard, and no storage facilities were provided at the station. Therefore, the line was going to be extended to 184th Place with a station at179th Street with two island platforms, sufficient entrances and exits, and storage for four ten-car trains. The facilities would allow for the operation of express and local service to the station.^[55][56] Construction on the extension started in 1946, and was projected to be completed in 1949.^[56] The extension was completed later than expected and opened on December 11, 1950.^[57] This extension was delayed due to theGreat Depression andWorld War II. BothE andF trains were extended to the new station.^[57][58]

During the 1950s, the IND was extended over two pieces of elevated line that were disconnected from the original BMT system: theBMT Culver Line in 1954, and theLiberty Avenue extension of theBMT Fulton Street Line in 1956.^[1] On October 30, 1954 theCulver Ramp opened, connecting the IND Culver Line to the BMT Culver Line atDitmas Avenue. IND trains begin operating over the BMT Culver Line toConey Island–Stillwell Avenue.^[1] On April 29, 1956, the Liberty Avenue Elevated, the easternmost section of the formerBMT Fulton Street Line, was connected to the IND Fulton Street Line. IND service was extended fromEuclid Avenue out toLefferts Boulevard via a new station atGrant Avenue.^[1]

On June 28, 1956, service on theIND Rockaway Line began betweenEuclid Avenue andRockaway Park at 6:38 PM and between Euclid Avenue andWavecrest at 6:48 PM.^{[59][60][61][62][63][64]} A new station atFar Rockaway–Mott Avenue opened on January 16, 1958, completing the Rockaway Line.^[65]

In November 1967, the first part of the Chrystie Street Connection opened and Sixth Avenue Line express tracks opened from34th Street–Herald Square toWest Fourth Street–Washington Square. With the opening of the connection to the Manhattan Bridge,BB service was renamedB and was extended via the new express tracks and the connection to the West End Line in Brooklyn. In non-rush hours,B service terminated northbound at either West 4th Street (middays and Saturdays) or as theTT shuttle at 36th Street in Brooklyn (nights and Sundays).D service was routed via the connection and onto the 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.^[12][66][67]

In July 1968, the57th Street station opened and the portion of the Chrystie Street Connection connecting the line with the Williamsburg Bridge was opened for regular service (although it had been previously used in passenger service for occasional post-Chrystie Street weekendD maintenance reroutes). Service on theKK was inaugurated, running from 57th Street to168th Street on theBMT Jamaica Line.B service began running during non-rush hours (local on 6th Avenue) to 57th Street.D trains began running express via the Sixth Avenue Line at all times.^[68]

In December 1988 theIND Archer Avenue Line opened fromJamaica Center–Parsons/Archer toJamaica–Van Wyck.^[69][70]

A month shy of twenty years after construction began, theIND 63rd Street Line went into service on October 29, 1989, after an expenditure of $898 million,^[71] extending service from 57th Street with new stations at Lexington Avenue, Roosevelt Island, and 21st Street at 41st Avenue in Queens. The IND line was served byQ trains on weekdays,B trains on weekends andF trains at night (signed Q northbound from 2nd Avenue and southbound as far as 57th Street), as well as the extended JFK Express. The 1,500-foot connector to the Queens Boulevard Line had not yet started construction.^[72] The BMT connection between the new Lexington Avenue station and 57th Street-7th Avenue was not in use at that time; it was built for the future connection to the Second Avenue Subway for BMT Broadway service from theUpper East Side toLower Manhattan.

Planning for the connection to theIND Queens Boulevard Line began in December 1990, with the final design contract awarded in December 1992. Construction began on September 22, 1994.^{[73][74][75][76][77]} The remaining section from 21st Street to the Queens Boulevard Line cost $645 million. In December 2000, the 63rd Street Connector was opened for construction reroutes.^[78] The Connector came into regular use in December 2001 with the rerouting ofF service at all times to 63rd Street. The construction project extended the lower level LIRR tunnel and involved a number of other elements, including the integration of ventilation plants, lowering a sewer siphon 50 feet, rehabilitation of elements of the existing line, mitigating ground water, diverting trains which continued to run through the project area and widening of the entry point to the Queens Boulevard Line to six tracks. This new tunnel connection allowed rerouting the Queens Boulevard LineF trains via the 63rd Street Tunnel, which opened up capacity through the 53rd Street tunnel to Manhattan which allowed a new local service, theV train, to provide additional Queens Boulevard service to Manhattan, along Sixth Avenue. This service was discontinued in 2010 and replaced with an extension of theM train.^[71]

• Concourse Line (B and ​D trains): under theGrand Concourse from 205th Street south to 161st Street, then west under theHarlem River into Manhattan and south to the Eighth Avenue Line (parallel to theIRT Jerome Avenue Line)
• Eighth Avenue Line (A, ​C, and ​E trains): from 207th Street, south roughly underBroadway; underSaint Nicholas Avenue,Eighth Avenue, Greenwich Avenue,Sixth Avenue (with a junction with the Sixth Avenue Line/Houston Street Line), Church Street, andFulton Street; under theEast River via theCranberry Street Tunnel into Brooklyn, to the Fulton Street Line (parallel to theIRT Ninth Avenue Line)
• Sixth Avenue Line (B, ​D, ​F, <F>, and ​M trains): from a split from the Eighth Avenue Line at 53rd Street, two blocks east to Sixth Avenue, then south under Sixth Avenue to a junction with the Eighth Avenue Line north of Houston Street, then east under Houston Street and south under Essex Street and Rutgers Street to the Rutgers Street Tunnel to Brooklyn – parallel to the IRTSixth Avenue Elevated
• Queens Boulevard Line (E and ​M trains): from the 53rd Street Tunnel from Queens, west under 53rd Street past a junction with the Sixth Avenue Line to merge with the Eighth Avenue Line – partly parallel to the IRTSixth Avenue Elevated connection to the IRTNinth Avenue Elevated along 53rd Street^[1]

• 53rd Street Tunnel (E and ​M trains) – along the Queens Boulevard Line
• Rutgers Street Tunnel (F and <F>​ trains) – connecting the Sixth Avenue Line to the Culver Line
• Cranberry Street Tunnel (A and ​C trains) – connecting the Eighth Avenue Line to the Fulton Street Line^[1]

• Queens Boulevard Line (E, ​F, <F>, ​M, and ​R trains): from 169th Street, west under Hillside Avenue, Queens Boulevard, Broadway, Northern Boulevard and 44th Drive to the 53rd Street Tunnel to Manhattan
• Crosstown Line (G train): from the Queens Boulevard Line at Queens Plaza, south under Jackson Avenue, Manhattan Avenue, Union Avenue, Marcy Avenue and Lafayette Avenue, coming into the middle of the Fulton Street Line and connecting south into the Culver Line
• Culver Line (originally the Smith Street Line) (F, <F>, and ​G trains): from the Rutgers Street Tunnel, south under Jay Street and Smith Street, coming to the surface and turning east over theGowanus Canal at Ninth Street, then back underground, under Ninth Street, Prospect Park West, Prospect Avenue, Fort Hamilton Parkway and McDonald Avenue, ending at Church Avenue (later extended south along the BMT Culver Line)
• Fulton Street Line (A and ​C trains): fromCourt Street (now the New York Transit Museum) and the Cranberry Street Tunnel east under Fulton Street to Rockaway Avenue (later extended east along the BMTLiberty Avenue Elevated) – parallel to the BMTFulton Street Elevated^[1]

The following extensions and connections were built after unification in 1940:

• Queens Boulevard Line (E, ​F, and <F> trains): extended east to 179th Street
• Culver Line (F and <F>​ trains): extended south along the ex-BMT Culver Line
• 60th Street Tunnel Connection (R train): connecting the BMT's60th Street Tunnel to the Queens Boulevard Line
• Fulton Street Line (A train): extended east to and over the BMTLiberty Avenue Elevated
• Rockaway Line (A train): south from the Fulton Street Line east ofRockaway Boulevard^[1]
• Chrystie Street Connection, connecting the Houston Street Line (Sixth Avenue Line) to the BMT lines over theWilliamsburg Bridge (M train) andManhattan Bridge (B and ​D trains)
• Archer Avenue Line (E train): from the Queens Boulevard Line at Van Wyck Boulevard south and east to Jamaica Center
• 63rd Street Line (F and <F> train): connecting the Sixth Avenue Line and the Queens Boulevard Line through the63rd Street Tunnel, and connecting to theBMT 63rd Street Line

The following extension is partially open:

• IND Second Avenue Line (Q train): from96th Street to72nd Street, then connecting with the BMT 63rd Street Line^[79]

Many IND lines were designed to be parallel to existing IRT and BMT subway lines in order to compete with them.

• TheIND Concourse Line is within one to three short blocks of theIRT Jerome Avenue Line for most of its length. It was also planned to replace the then-NYW&B-ownedline as well as theIRT White Plains Road Line.
• TheIND Eighth Avenue Line is within 0.25 miles (0.40 km) of theIRT Broadway–Seventh Avenue Line and theIRT Lenox Avenue Line for most of its length. It was designed to replace theIRT Ninth Avenue Line.
• TheIND Sixth Avenue Line was designed to replace theIRT Sixth Avenue Line.
• TheIND Fulton Street Line is within 0.5 miles (0.80 km) of theIRT Eastern Parkway Line and theIRT New Lots Line for most of its length in Brooklyn. It was designed to replace theBMT Fulton Street Line.
• TheIND Crosstown Line was designed to replaceBMT streetcars.
• TheSecond Avenue Subway is designed to be within 0.25 miles (0.40 km) of theIRT Lexington Avenue Line, and to replace theIRT Second Avenue Line and theIRT Third Avenue Line.

Additionally, some never-built lines were designed to replace old elevated lines.

• TheIRT Dyre Avenue Line andIRT Pelham Line were to be recaptured by the IND Second Avenue Line.
• The IND Utica Avenue Line and theIND Archer Avenue Line were both designed to replace parts of theBMT Jamaica Line. The latter would also be planned to replace theAtlantic Branch of the Long Island Rail Road.^[1]

As originally designed, the IND train identification scheme was based on three things: the Manhattan trunk line served (8th Avenue or 6th Avenue), the northern branch line served (Washington Heights, Grand Concourse/Bronx, or Queens Boulevard), and the service level (Express or Local). The 8th Avenue routes were A, C, and E. The 6th Avenue routes were B, D, and F. The A and B served Washington Heights. The C and D served the Grand Concourse. The E and F served Queens Boulevard via the 53rd Street Tunnel.^[80]

A single letter indicated an express service, while a double letter indicated local service. G was used for Brooklyn-Queens "Crosstown" service. H was used for any service on the extended Fulton Street (Brooklyn) line that did not originate in Manhattan.^[80]

The first designations were as follows:

Virtually all possibilities were used at one time or another, either in regular service or as brief special routes.^[1] The "G" single-letter service was used forG service toWorld's Fair Station in 1939.

The final pre-Chrystie Street Connection service is shown here; for more details, see the individual service pages. Terminals shown are the furthest the service reached.^[80]

After the Chrystie Street Connection opened, the original IND Service Letter scheme was gradually abandoned. All lines, whether local or express, now use a single letter, and only the 8th Avenue/6th Avenue distinction (A, C, E vs. B, D, F) has been maintained.^[1] Following consolidation under city ownership, the numbered routes of the formerBMT system were also gradually relabeled to letters for consistency with the IND system.

The IND was built with longer platforms than those of the IRT or BMT. Initial plans called for stations to be built with 660 feet (201 m) long platforms to accommodate trains of eleven 60-foot (18.3 m) cars. These lengths were shortened, as stations on theIND Eighth Avenue Line between72nd Street and163rd Street – Amsterdam Avenue have lengths of exactly 600 feet (183 m). There were two exceptions:96th Street was 615 feet (187 m) on both levels, as that was the standard length of platforms built for the IND after the 1940s.^[1]

The81st Street–Museum of Natural History station had an uptown platform that was 630 feet (192 m) long, and a downtown platform that was 615 feet (187 m). Platforms of exactly 600 feet (183 m) length can be found on someIND Queens Boulevard Line stations betweenElmhurst Avenue and67th Avenue.^[1]

Some of theIND Sixth Avenue Line stations have much greater platform lengths. In34th Street–Herald Square, the uptown platform was originally 745 feet (227 m), long enough to hold a 12-car train of 60-foot (18.3 m) cars. The downtown platform was originally 685 feet (209 m). Both platforms of the23rd Street station are 670 feet (204 m). The47th–50th Streets–Rockefeller Center station has platforms that are 665 feet (203 m).^[1]

In theIND Second System, planned stations would have been 700 to 720 feet (213 to 219 m) long and tile work would have been more "modern".^[1]

The Independent Subway System operated solely with one family of subway cars - commonly referred to as theR1–9 fleet - comprising theR1s,R4s,R6s,R7/As andR9 cars. After the equipment was retired in the 1970s, twenty cars were sent to various museums. Eleven of these cars are preserved by theNew York Transit Museum and Railway Preservation Corp. The other nine are on private property or preserved at other museums.

• Brooklyn–Manhattan Transit Corporation (BMT)
• Brooklyn Rapid Transit Company (BRT)
• Interborough Rapid Transit Company (IRT)

Books:

• Cudahy, Brian J. (1988).Under the Sidewalks of New York (revised ed.). Lexington, Mass: The Stephen Greene Press.
• Cunningham, Joseph; DeHart, Leonard (1977).A History of the New York City Subway System: The Independent System and City Ownership.
• Dahl, Gerhard M. (1924).Transit Truths. Brooklyn, NY: Brooklyn-Manhattan Transit Corporation.
• Fischler, Stan (1997).The Subway: A Trip Through Time on New York's Rapid Transit. Flushing, NY: H & M Productions, Inc.
• George, Herbert (1993).Change at Ozone Park. Flanders, NJ: RAE Publishing Inc.
• Kahn, Alan Paul; May, Jack (1977).The Tracks of New York, Number 3. New York: Electric Railroaders' Association, Inc.
• Kramer, Frederick A. (1990).Building the Independent Subway. New York: Quadrant Press, Inc.
• Kramer, Frederick A. (1991).Subway to the World's Fair. Westfield, NJ: Bells and Whistles.
• Snyder, Robert W. (1997).Transit Talk. Brooklyn, NY, New Brunswick, NJ and London: New York Transit Museum and Rutgers University Press.

Periodicals:

• Electric Railroaders' Association:Headlights Magazine: August 1956, February 1968, February 1973, August 1974, July/September 1977, May/June 1988

Newspapers:

• The New York Times (before 1977), most notably: 1929: September 16, 22; 1932: September 4, 8, 9, 10; 1940: June 1, 2, 12, 13; 1967: November 22, 26, 28
• Unpublished document from New York City Transit Authority – precursor to "Facts and Figures", 1977

• Media related toIndependent Subway System (category) at Wikimedia Commons

• Independent Subway System
• Defunct public transport operators in the United States
• History of the New York City Subway
• Railway companies disestablished in 1940
• Railway companies established in 1932
• Transportation in Queens, New York
• Transportation in the Bronx
• Transportation in Manhattan
• Transportation in Brooklyn
• History of transportation in New York City
• American companies established in 1932
• 1932 establishments in New York City
• 1940 disestablishments in New York (state)

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