During World War II the railroad remained operational during most of the German occupation albeit only on part of the line. In 1947 the company was nationalized by the Soviet installed communist government and in 1951 placed under the administration of the Polish State Railways and renamed to Warszawska Kolej Dojazdowa (Warsaw Commuter Rail), however the line retained a narrower loading gauge and its specific electrification system while the national rail network uses 3 kV DC. During the 1960s the line was gradually trimmed at its and ends and in Warsaw moved to newly built tracks in the cutting of western part of the Warsaw Cross-City Line. In 1972 the almost half-a-century-old English Electric railcars were replaced by new PKP class EN94 EMUs produced by Pafawag in Wrocław designed specially for the line.