 "S-Bahn" is short for "Schnellbahn", which can be translated as "rapid railway".The Vienna S-Bahn consists of a multitude of branch lines extending beyond the city boundary, most of which converge at a central route segment called the "Stammstrecke" ("trunk line").While many of the individual lines run at half-hourly or hourly intervals, they are able to offer combined frequencies of only a few minutes or less along the "Stammstrecke".