2-8-4 was a passenger derivative of the Class FD 1’E1’-h2 (2-10-2) freight locomotive and had many parts in common with the Class FD. The Soviet 2-8-4 was the most numerous single Berkshire class built in the world. Kolomna Locomotive Works built the first four locomotives. In 1935, production was transferred to the enlarged and modernised former which was renamed Voroshilovgrad Locomotive Works. A lotal of 649 locomotives of the two variants, Class IS20 and Class IS21 (later Class FDp), were built between 1932 and 1942. After Germany attacked the Soviet Union on 22 June 1941, the Russians evacuated all semi-completed class
2-8-8-2 still used on steel mill lines and other railroads until 1983. Other equivalent classifications are: UIC classification: 1DD1 (also known as German classification and Italian classification) French classification: 140+041 Turkish classification: 45+45 Swiss classification: 4/5+4/5 The first 2-8-8-2 was built in 1909 by Baldwin, who sold two to the Southern Pacific Railroad (classified MC-1), and then three each to the Union Pacific Railroad and UP-owned Oregon Railroad and Navigation Company. Baldwin conceived the type as an expansion of the 2-6-6-2 permitting a greater tractive effort. The next order for the type was from the Southern Pacific; these differed in being