Citytunnel Frankfurt

Frankfurt City Tunnel
S3 train to Bad Soden at Hauptbahnhof low level, ET 420
Overview
Locale	Frankfurt, Hesse, Germany
Line number	3681
Technical
Route number	645.2, 645.5, 645.6
Route map  Operating points and lines  To Mainz, Wiesbaden, Bad Homburg, Friedberg Hauptbahnhof ramp 50.0 Frankfurt (Main) Hbf underground 50.8 Taunusanlage U-Bahn from Praunheim/Hausen 51.6 Hauptwache 52.2 Konstablerwache U-Bahn to Ostbahnhof/Enkheim ~52.6 to North Main S-Bahn (planned) 53.0 Ostendstraße Main 53.8 Frankfurt Schlachthof junction 54.4 Lokalbahnhof End of Frankfurt City Tunnel (4,728 m) South Main line to Frankfurt South Line to Hanau 54.4 Mühlberg End of Frankfurt-Mühlberg Tunnel (1,633 m) Oberrad(planned) South Main line to Offenbach Offenbach City Tunnel South Main S-Bahn

The Frankfurt City Tunnel is standard gauge railway in Frankfurt and the core of the Rhine-Main S-Bahn. The line runs underground for its entire length.

The first section was put into operation on 28 May 1978 to Hauptwache. S-Bahn trains began operating on the Taunus Railway (S1), the Main-Lahn Railway (S2), the Limes Railway (S3), the Kronberg Railway (S4), the Homburg Railway (S5) and the Main-Weser Railway (S6) after climbing a ramp under the former postal station in the tunnel and reached the surface about 500 metres east of the central station. The Main Railway service (S14, now S8), was introduced shortly later.

The line runs northeast for about 700 metres from the central station to Taunusanlage station, built on the site of the old city walls near the Alte Oper and the Deutsche Bank Twin Towers. The tunnel bends to the east and after 250 metres it joins Tunnel C of the Frankfurt U-Bahn, which was built together with the City Tunnel under the Freßgass (the pedestrianised streets of Kalbächer Gasse and Große Bockenheimer Straße, named after its eateries) to Hauptwache. In 1983, the city tunnel was extended, largely in a cut and cover tunnel, 600 metres to the east beneath the Zeil to Konstablerwache. This section is also a joint tunnel with the U-Bahn; the S-Bahn lines run between the U-Bahn lines.