12 was the BMT's designation for trains that used the BMT Lexington Avenue Line. This number was used on service listings on company maps, but was never displayed on train equipment, nor were trains referred to as "12 trains" in the manner of the current system, but were called Lexington Avenue Line trains. Between 1925 and 1931, all rush hour service was extended to 111th or 168th Street. In addition, some afternoon rush hour trains were added between Sands Street (on the Brooklyn side of the Brooklyn Bridge) and 111th Street.