rather than streets, so trains were signed for Coney Island, Canarsie and Jamaica rather than Stillwell Avenue, Rockaway Parkway and 168th Street. Stations also tended to use local names, but this gradually changed, especially as lines were upgraded, so that stations like Bath Junction on the Sea Beach Line became New Utrecht Avenue and Manhattan Terrace on the Brighton Line became Avenue J. The BMT introduced numbers for all its services in 1924 but these were mostly for map purposes, since none of equipment displayed line numbers until the D-type Triplex cars were introduced as prototypes in 1925, and then in production in 1927, and these only on the front of the trains (but after 1953 on R16 equipment also on the sides ). In 1931 these numbers were also used on 20 IND R1 cars when they were tested by the City on BMT lines, and also on 140 of these cars from 1949 to 1955 while in BMT service as well. IRT The IRT was the contractor with the City of New York to operate the first subway line; by that time it was already leasing all the elevated railways in Manhattan. Unlike the BMT, the IRT had multiple long mainlines (eventually six of them) from which several branch lines extended into the Bronx, Queens and Brooklyn. The IRT therefore named their services for these mainlines rather than their branches. The branch lines were mentioned on the destination signs instead, so that typical signage read Lexington Avenue Express to Woodlawn — Jerome and Utica Avenue — Brooklyn, meaning Woodlawn on the Jerome Avenue Line and Utica Avenue on the Brooklyn Line. Where a service ended in downtown Manhattan, it simply carried the destination name, for example South Ferry or Chatham Square. The IRT subways used a logical numbering system, but the numbers were not used publicly until the R12 cars were introduced in 1948, under City management. Due to the lack of new IRT construction, this system has largely stayed intact to this day, with the only major changes being at the Brooklyn end. IND The IND adopted the IRT system whole but reversed the terminal and line name on the destination signs: Queens - 179th St. for 179th Street terminal on the Queens Boulevard Line. The IND also adopted a similar logical labeling system, but used them publicly on trains and maps. Single letters were used to