When the new "H" system was implemented on August 1, 1918, the Public Service Commission was unprepared for the heavy traffic using the 42nd Street Shuttle. The shuttle was closed for rebuilding at the end of August 3, and a paper transfer was added between Rector Street on the IRT Broadway–Seventh Avenue Line and Wall Street on the IRT Lexington Avenue Line (the only one of the two lines to go to Brooklyn at that time). Shuttle service resumed on September 28, 1918, but the transfer remained, and was expanded to allow transfers from Wall Street on the Brooklyn Branch of the Broadway–Seventh Avenue Line, its temporary end. After the Brooklyn Branch was completed on April 15, 1919, the transfer was no longer needed.