Stadtbahn, Vienna, transport lines erected by the Imperial Railways to connect the main rail tracks with parts of Vienna that were further away from the railway system (also for military reasons, hence steam-driven) 1892-1901: Wiental (Wien valley) line and Donaukanal (Danube Canal) line, Guertel line, Vororte (suburban) line; partly as underground, partly as elevated railways; architectural design (one of the main works of Vienna Secessionism) by O. Wagner.
Passenger transport was suspended in World War I, the Wiental, Donaukanal and Guertel lines were taken over by the Municipality of Vienna in 1924/25 and electrified. The Wiental-Donaukanal line was converted into the underground line U 4 from 1976-1981, subsequently the Guertel line was transformed into U 6 and extended up to Philadelphiabruecke bridge and up to Siebenhirten in 1995. The Vororte line has been line S 45 of the Wiener Schnellbahn since 1987.
Literature#A. Horn, Wiener Stadtbahn, 1988.