Network The S-Bahn routes all feed into one of three core lines: a central, elevated east–west line (the ), a central, mostly underground north–south line (the ), and a circular line (the ). Outside the , suburban routes radiate in all directions. Lines S1, S2, S25, and S26 are north–south lines that use the north–south tunnel as their midsection. They were equally distributed into Oranienburg, Bernau, and Hennigsdorf in the north, and Teltow Stadt, Lichtenrade, and Wannsee. Lines S3, S5, S7, S9, and S75 are east–west lines using the cross-city railway. The western termini are located at Potsdam and Spandau, although the S5 only runs as far as Westkreuz and the S75 to . The eastern termini are Erkner, Strausberg Nord, Ahrensfelde, and Wartenberg. The S9 uses a connector curve () at to switch from the to the south-eastern leg of the . Another curve, the to the north-eastern , was originally served by the S86 line, but it was demolished in preparation of the rebuilding of station and was not rebuilt afterwards. Both connector curves were heavily used in the time of the
Berlin Wall, as trains coming from the north-eastern routes couldn't use the West Berlin north–south route and the Southern leg of the pre- and post-
Wall was in West Berlin. Lines S41 and S42 continuously circle around the , the former clockwise, the latter anti-clockwise. Lines S45, S46, and S47 link destinations in the southeast with the southern section of the via the tangential link from the to the via
Köllnische Heide. Lines S8 and S85 are north–south lines using the eastern section of the between and
Treptower Park via
Ostkreuz, using the in the South. Formerly, there existed four curves at and allowing to go to a northern ring () and to a southern ring () using central tracks of . and are common terms, but never scheduled routes as separate rings. One curve of at left over for internal use, the other one is mentioned connector at .
Routes Generally speaking, the first digit of a route number denotes the main route or a group of routes. Thus, S25 is a branch of S2, while S41, S42, S45, S46, and S47 are all routes that share some of the same route. So S41, S42, S45, S46, and S47 are together S4. However, the S4 does not exist as an independent entity. Since 9 January 1984, all the West Berlin S-Bahn routes are labelled with an "S" followed by a number. This system had been in use with other West German S-Bahn systems (such as Hamburg) for years. On 2 June 1991 this was extended to the East Berlin lines as well. Internally, the Berlin S-Bahn uses (literally groups of trains) which normally run every twenty minutes (S41/S42 are an exception to this as their run every 10 minutes). Some lines, e.g. the S85, are made up of only one , while others, like S5, are actually multiple combined. Some do not run the entire line and terminate at intermediate stops. are called by a (radio designator), which is derived from the
German spelling alphabet. Some are not used in regular service, such as Heinrich, Baikal, Jaguar, Gustav, or Saale (being used for special soccer service trains, usually running for fans under the line S3 between and ). Stations in brackets are serviced at certain times only (Monday through Friday during offpeak in the case of and during peak in the case of and ). only runs Monday through Friday. Also, not every train reaches the nominal terminus of a line. For example, every other train on runs only to
Frohnau, five stops before
Oranienburg, and the last stop on towards
Erkner which is reached by every train is
Friedrichshagen. Similarly, some northbound trains terminate at
Gesundbrunnen, and most trains run only to
Strausberg or even
Mahlsdorf, rendering
Strausberg Nord the least served stop on the whole network.
Route changes in 2009 On 31 August 2009 a few semi-permanent changes to the line routes were applied. Because of renovations to station, including dismantling the tracks connecting the and the – • (formerly ↔
Spandau) could not turn west at this station any more. The line thus followed the and then branches northwards past , like and , and terminated at
Pankow. • To compensate for the diminished throughput on the , the (formerly
Erkner ↔ ) was extended westwards to
Spandau.
Route changes in 2012 Because of the progress achieved in the renovation in 2012, the – • was shortened to operate only between and Erkner. • was extended to Spandau. • operated every 10 minutes between and .
Route changes in 2017 On 21 August 2017, with the completion of the renovation, and on 10 December 2017, with the completion of the connection between the and at , the following changes were made: • was introduced, operating from to , to replace lost S85 service on 10 December 2017. • was extended from back to on 21 August 2017, and was further extended to Spandau on 10 December 2017, replacing the S5. • was shortened from Spandau to on 10 December 2017. • was shortened from back to on 5 October 2017, and was further truncated to Ostkreuz on 10 December 2017. • was diverted from to Pankow, replacing the S9 on 10 December 2017. • was diverted from Pankow to Spandau on 10 December 2017 replacing the previous S5 service.
Service hours The S-Bahn generally operates between 4am and 1am Monday to Friday, between 5am and 1am on Saturdays and between 6:30am and 1am on Sundays during normal daytime service. However, there is a comprehensive night-time service on most lines between 1am and 5am on Saturdays and 01:00 and 06:30 on Sundays, which means that most stations enjoy a continuous service between Friday morning and Sunday evening. One exception to this is the section of the between and which sees no service in these hours. Most other lines operate without route changes, but some are curtailed or extended during nighttime. Particularly, the , , , , , , , are unchanged, and the and have no nighttime service. Westbound lines , , , and northbound terminate at stations , , , and
Treptower Park, respectively. == History ==