BMT Third Avenue Line

The Fifth Avenue Line, also called the Fifth Avenue Elevated or Fifth Avenue-Bay Ridge Line, was an elevated rail line in Brooklyn, New York City, United States. It ran above Hudson Avenue, Flatbush Avenue, Fifth Avenue, 38th Street, and Third Avenue from Downtown Brooklyn south to Bay Ridge. The portion on Third Avenue was called the Third Avenue Elevated to distinguish service from the West End Elevated.

The Union Elevated Railroad Company, leased by the Brooklyn Elevated Railroad, built the Hudson Avenue Elevated, a branch of the Brooklyn Elevated's Lexington Avenue Elevated. This line split from the Brooklyn Elevated at a junction at Hudson and Park Avenues (where exit 29 of the Brooklyn–Queens Expressway is now located), and traveled south above Hudson Avenue to the Long Island Rail Road's Flatbush Avenue terminal. Trains began operating between Fulton Ferry (the terminal of the Brooklyn Elevated) and Flatbush Avenue on November 5, 1888.

The line crossed the Myrtle Avenue Elevated at grade two blocks south of its merge with the Brooklyn Elevated. On its second day of operation, November 6, a Hudson Avenue train crashed into a Myrtle Avenue train. Service was suspended immediately, and did not resume until June 22, 1889, when an extension south to Third Street was completed, and a new connection into Myrtle Avenue opened, taking trains between Third Street and Sands Street at the end of the Myrtle Avenue Elevated, and replacing the four track crossings with one. The unused two blocks north of Myrtle Avenue were placed back in service on December 9, 1889, when Myrtle Avenue trains began to use it to reach Fulton Ferry via the old Brooklyn Elevated.

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