firm of Heins & LaFarge was hired to design the underground stations. Belmont incorporated the Interborough Rapid Transit Company (IRT) in April 1902 to operate the subway. The 116th Street station was constructed as part of the IRT's West Side Line (now the Broadway–Seventh Avenue Line) from 104th Street to 125th Street, for which construction began on June 18, 1900. The section of the West Side Line around this station was originally planned as a two-track line, but in early 1901, was changed to a three-track structure to permit train storage in the center track. Construction on the section between 104th Street and 125th Street had already begun prior to the design change, requiring that a portion of the work be undone. A third track was added directly north of 96th Street, immediately east of the originally planned two tracks. By late 1903, the subway was nearly complete, but the IRT Powerhouse and the system's electrical substations were still under construction, delaying the system's opening. The 116th Street station opened on October 27, 1904, as one of the original 28 stations of the New York City Subway from City Hall to 145th Street on the West Side Branch. The opening of the first subway line, and particularly the 116th Street station, helped contribute to the development of Morningside Heights and Harlem. Service changes and station renovations 20th century After the first subway line was completed in 1908, the station was served by West Side local and express trains. Express trains began at South Ferry in Manhattan or Atlantic Avenue in Brooklyn, and ended at 242nd Street in the Bronx. Local trains ran from City Hall to 242nd Street during rush hours, continuing south from City Hall to South Ferry at other times. In 1918, the Broadway–Seventh Avenue Line opened south of Times Square–42nd Street, thereby dividing the original line into an "H"-shaped system. The original subway north of Times Square thus became part of the Broadway–Seventh Avenue Line. Local trains were sent to South Ferry, while express trains used the new Clark Street Tunnel to Brooklyn. To address overcrowding, in 1909, the New York Public Service Commission proposed lengthening platforms at stations along the original IRT subway. As part of a modification to the IRT's construction contracts, made on January 18, 1910, the company was to lengthen station platforms to accommodate ten-car express and six-car local trains. In addition to