Right : The »IS-20-119« after its capture by advancing German troops Russian IS20 1-4-2 Passenger Steam Locomotive Named after Iosif Stalin himself, the IS20 was the most powerful series-built steam passenger locomotive in the pre-war Soviet Union. Apart of the running gear identical with the huge FD20 freight steam engine , 638 of these 133-ton engines were built at the Kolomna and Lugansk Locomotive Works between 1932 and 1941. Due to the poor railway state during the war, the IS20 was mainly deployed to rear sections services.