Southern Pacific Railroad's AC-2 class of steam locomotives was the second in the AC series of cab forward locomotives built for Southern Pacific (SP). This class consisted of locomotives that were rebuilt from Baldwin-built SP MC-4 class locomotives by 1930. The rebuild from MC-4 class gained the locomotives about in tractive effort, but also increased the locomotives' weight by about . The locomotives were deemed successful and remained in active service until after World War II. References Baldwin locomotives Mallet locomotives AC-02 2-8-8-2 locomotives Simple articulated locomotives Steam locomotives of the United States Scrapped locomotives Standard gauge locomotives of the United States Freight locomotives Cab forward steam locomotives