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 terminal was located both above and below preexisting railroad tunnels, hence the IND's plan to convert part of the H&M tubes. However, the H&M objected, and so negotiations between the city and IND and the H&M continued for several years.