Polish railways regained pre-war locomotives from Hungary, Czechoslovakia and Yugoslavia (in 1947), yet units from the eastern parts of Poland were taken over by USSR and rebuilt to operate on a wide gauge. Two years after the war's end, the first passenger cars are built in Cegielski (Poznań) and PaFaWag (Wrocław), while freight cars were being built in Chrzanów and Zielona Góra. At the same time, Warsaw railway lines were rebuilt together with the tunnel under the country's capital. As a part of the Ministry of Communication, the Bureau for Railway Electrification was founded. The first projects were to rebuild all lines that had been electrified before the war, and then the Warsaw–Żyrardów–Skierniewice–Koluszki and the Warszawa–Sochaczew lines would be electrified. The electrification was planned to bring 3000V AC into Polish railways.