Pennsylvania Railroad locomotive classification
PRR Class Builders Model Build date Total produced Wheel arrangement Service Power output
AS6 S-1 1947-1951 40 B-B Switcher 600 hp ( 450 kW )
AS10 S-2 1948-1954 90 B-B Switcher 1,000 hp ( 750 kW )
AS10a T-6 1958 6 B-B Switcher 1,000 hp ( 750 kW )
AF15 FA-1 1948-1950 8 B-B Freight 1,500 hp ( 1,120 kW )
AF15 FB-1 1948-1950 8 B-B Freight 1,500 hp ( 1,120 kW )
AF16 FA-2 1951 24 B-B Freight 1,600 hp ( 1,190 kW )
AF16 FA-2 1951 12 B-B Freight 1,600 hp ( 1,190 kW )
AFP20 PA-1 1947 10 A1A-A1A Pass 2,000 hp ( 1,490 kW )
AFP20 PB-2 1947 5 A1A-A1A Pass 2,000 hp ( 1,490 kW )
ARS10 RS-1 1948-1952 27 B-B Freight 1,000 hp ( 750 kW )
ARS15 RS-2 1948 6 B-B Freight 1,500 hp ( 1,120 kW )
ARS16 RS-3 1951-1955 115 B-B Freight 1,600 hp ( 1,190 kW )
ARS16a RSD-4 1952-1953 6 C-C Freight 1,600 hp ( 1,190 kW )
ARS18 RS-11 1956-1957 32 B-B Freight 1,800 hp ( 1,340 kW )
ARS18a RSD-12 1957-1958 25 C-C Freight 1,800 hp ( 1,340 kW )
ARS20 RS-11 1956-1957 6 B-B Freight 2,000 hp ( 1,490 kW )
ARS24 RSD-15 1956 6 C-C Freight 2,400 hp ( 1,790 kW )
ARS24s RSD-7 1955-1956 5 C-C Pass 2,400 hp ( 1,790 kW )
ARS24 RS-27 1962 15 C-C Freight 2,400 hp ( 1,790 kW )
AF24 C-424 1962 1 C-C Freight 2,400 hp ( 1,790 kW )
Diesel classification [ 1 ] -- Alco
See also : List of ALCO diesel locomotives
Locomotive classification on the Pennsylvania Railroad took several forms. Early on, steam locomotives were given single-letter classes. As the 26 letters were quickly assigned, that scheme was abandoned for a more complex system. This was used for all of the PRR's steam locomotives, and - with the exception of the final type bought (the E44) - all electric locomotives also used this scheme.