2-8-4 passenger trains. Later, when the line was upgraded with heavier rails, they were transferred to the Moscow-Kursk-Kharkov-Sinelnikovo line. When more class IS locomotives began to roll out from the Voroshilovgrad production lines, they were used on the upgraded Moscow-Smolensk-Minsk, Moscow to Valuiki and Mitchurinsk to Rostov-on-Don mainlines. Only one such locomotive was preserved, no. IS21-578, plinthed outside the main railway station in Kiev in Ukraine. Locomotives of a 2-8-4 wheel arrangement were used mainly for hauling fast express freight trains on heavy freight service. They often replaced older 2-8-2 Mikados where more power was required. In turn, they were often
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