Czechoslovak State Railways

Czechoslovak State Railways (Československé státní dráhy in Czech or Československé štátne dráhy in Slovak, often abbreviated to ČSD) was the state-owned railway company of Czechoslovakia.

The company was founded in 1918 after the end of the First World War and dissolution of Austria-Hungary. It took over the rolling stock and infrastructure of the Imperial Royal Austrian State Railways.

In 1930 Czechoslovakia had 13600 km of railways: the fifth-largest network in Europe. Of these 81% were state (ČSD)-owned, and the trend was to nationalize the remaining private railways. Most of the infrastructure was concentrated in the industrial regions of the Czech lands. 87% of the railroads were single-track. 135,000 people were employed on the railways: about 1% of the population.

When Nazi Germany dissolved Czechoslovakia in 1939, the Protectorate of Bohemia and Moravia formed the "Bohemian-Moravian Railway" company (in Czech Českomoravské dráhy-ČMD, in German Böhmisch-Mährische Bahn-BMB) under the control of Deutsche Reichsbahn (DR). In the Slovak State the "Slovak Railways" company (in Slovak Slovenské železnice-SŽ) was formed.

In 1945 ČSD was re-established.

After the dissolution of Czechoslovakia at the end of 1992, the company was divided into the state-owned České dráhy (Czech Railways) and Železnice Slovenskej republiky (Railways of the Slovak Republic). The fixed infrastructure was transferred to the successor countries according to location; the remainder was divided by 2:1 ratio.

Electrification

 * Electrification of the railways started gradually during the 1920s. In Prague the trains used a direct current system at 1.5 kV.
 * To power the line from Prague to Chop (Чоп, Čop, Ukraine State), a direct current system using 3 kV was built after 1945.
 * To the north of this line, trains use direct current with voltage 3 kV, to the south they use alternating current with voltage 25 kV at 50 Hz. These two systems continue today.