The Frankfurt City Tunnel is standard gauge railway in

Frankfurt Frankfurt, officially Frankfurt am Main (; Hessian: , "Frank ford on the Main"), is the most populous city in the German state of Hesse. Its 791,000 inhabitants as of 2022 make it the fifth-most populous city in Germany. Located on its na ...

and the core of the

Rhine-Main S-Bahn The Rhine-Main S-Bahn system is an integrated rapid transit and commuter train system for the Frankfurt/Rhine-Main region, which includes the cities Frankfurt am Main, Wiesbaden, Mainz, Offenbach am Main, Hanau and Darmstadt. The network compris ...

. The line runs underground for its entire length.

Central Station to Konstablerwache

The first section was put into operation on 28 May 1978 to Hauptwache. S-Bahn trains began operating on the

Taunus Railway The Taunus Railway (German: ''Taunus-Eisenbahn'') is a double-track electrified railway line, which connects Frankfurt and Wiesbaden, Germany. It is 41.2 km long and follows the course of the Main on its north side, running quite close to ...

(S1), the

Main-Lahn Railway The Main-Lahn railway (german: Main-Lahn-Bahn), also called the Limburg railway (''Limburger Bahn''), is a double-track, electrified main railway line in Germany. The long line extends from Frankfurt Central Station (''Hauptbahnhof'') to Eschhofen ...

(S2), the

Limes Railway The Limes Railway (german: Limesbahn) is a continuously electrified and single-track railway that runs on the southern edge of the Taunus in the German state of Hesse, connecting the towns of Niederhöchstadt and Bad Soden am Taunus. It is named ...

(S3), the

Kronberg Railway The Kronberg Railway (german: Kronberger Bahn) is now the northern part of Frankfurt S-Bahn line S4, which connects Langen, Frankfurt am Main and Kronberg im Taunusin Hesse, Germany. The route branches off the Homburg line in Rödelheim and con ...

(S4), the

Homburg Railway The Homburg Railway (german: Homburger Bahn ) is an 18 km line from Frankfurt am Main to Bad Homburg in the German state of Hesse. It was opened in 1860 as one of the first railway lines in Germany. It is now part of the Rhine-Main S-Bahn ...

(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 Central stations or central railway stations emerged in the second half of the nineteenth century as railway stations that had initially been built on the edge of city centres were enveloped by urban expansion and became an integral part of the ...

. The

Main Railway The Main Railway (German: ''Mainbahn'', pronounced 'mine barn') is a 37.5 km-long double-track rail electrification, electrified railway line, which runs on the south side of the river Main (river), Main from Mainz to Frankfurt (Main) Hauptbahnhof, ...

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 Alte Oper (Old Opera) is a concert hall in Frankfurt am Main, Hesse, Germany. It is located in the inner city, Innenstadt, within the banking district Bankenviertel. Today's Alte Oper was built in 1880 as the city's opera house, which was destro ...

and the

Deutsche Bank Twin Towers The Deutsche Bank Twin Towers, also known as Deutsche Bank Headquarters (German: ''Zwillingstürme der Deutschen Bank'' or ''Hauptverwaltung Deutsche Bank AG''), is a twin tower skyscraper complex in the Westend-Süd district of Frankfurt, Ge ...

. The tunnel bends to the east and after 250 metres it joins Tunnel C of the

Frankfurt U-Bahn The Frankfurt U-Bahn is a Stadtbahn system serving Frankfurt, Hesse, Germany. Together with the Rhine-Main S-Bahn and the Frankfurt Straßenbahn, it forms the backbone of the public transport system in Frankfurt. Its name derives from the Germa ...

, 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 A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A Pipeline transport, pipeline is not a tunnel, though some recent tunnels have used ...

tunnel, 600 metres to the east beneath the

Zeil The Zeil () is a street in the city centre of Frankfurt, Germany. The name, which dates back to the 14th century, is derived from the German word ''Zeile'' "row" and originally referred to a row of houses on the eastern end of the north side; th ...

Konstablerwache Konstablerwache is a central square in the centre of Frankfurt am Main and part of its pedestrian zone. It lies to the east of Hauptwache with both squares linked by the Zeil, the central shopping area of the city. History At the corner of the ...

. This section is also a joint tunnel with the U-Bahn; the S-Bahn lines run between the U-Bahn lines. The tunnel has a train frequency of roughly 28 trains per hour in each direction, that is one train every two minutes. During the rush hour the frequency is approximately one train every two minutes.

Tunnelling under the Main

The next major phase of construction followed in 1990 when the line was extended in a southeasterly direction. Ostendstraße station was built between the streets of Hanauer Landstrasse and Ostendstraße. 300 meters further south the route crosses the

Main Main may refer to: Geography * Main River (disambiguation) **Most commonly the Main (river) in Germany * Main, Iran, a village in Fars Province *"Spanish Main", the Caribbean coasts of mainland Spanish territories in the 16th and 17th centuries ...

. The tunnel was built by digging a trench in the river bottom and sinking the tunnel tubes into it, half the river at a time. After passing under the Main the tunnel divides: One branch runs in the direction of

Sachsenhausen Sachsenhausen () or Sachsenhausen-Oranienburg was a German Nazi concentration camp in Oranienburg, Germany, used from 1936 until April 1945, shortly before the defeat of Nazi Germany in May later that year. It mainly held political prisoners ...

where it runs under the Sachsenhausen old town to Frankfurt Lokalbahnhof and then climbs a ramp to the embankment of the South Main railway to

Frankfurt South station Frankfurt, officially Frankfurt am Main (; Hessian: , " Frank ford on the Main"), is the most populous city in the German state of Hesse. Its 791,000 inhabitants as of 2022 make it the fifth-most populous city in Germany. Located on its ...

. At the South station the S-Bahn connects with regional and main line services was built,

trams A tram (called a streetcar or trolley in North America) is a rail vehicle that travels on tramway tracks on public urban streets; some include segments on segregated right-of-way. The tramlines or networks operated as public transport are ...

and the U-Bahn. The second section, which was completed in 1992, branches off to the east on the Sachsenhausen side after the passage under the Main towards Mühlberg. Then the line comes to the surface prior for a few kilometres until the next station at Offenbach-Kaiserlei where the

Offenbach City Tunnel The Offenbach City Tunnel is a railway tunnel on the Frankfurt Schlachthof–Hanau line in Offenbach am Main in the German state of Hesse. It is used by all of the eastern branches of the Rhine-Main S-Bahn ( S1, S2, S8 and S9). It runs largely ...

begins. This underground section has three underground stations and ends at Offenbach Ost station, where the Rodgau line branches off.

Branch to Ostbahnhof

Between Konstablerwache and Ostendstraße stations the entrance for a tunnel branching towards Frankfurt East station was built for the proposed north Main branch of the S-Bahn to

Hanau Hanau () is a town in the Main-Kinzig-Kreis, in Hesse, Germany. It is located 25 km east of Frankfurt, Frankfurt am Main and is part of the Frankfurt Rhine-Main, Frankfurt Rhine-Main Metropolitan Region. Its Hanau Hauptbahnhof, station is a ...

References

External links

Construction work information of Deutsche Bahn
{{coord missing, Hesse Railway lines in Hesse Transport in Frankfurt Rhine-Main S-Bahn Railway tunnels in Germany Underground commuter rail Railway lines opened in 1978 1978 establishments in Germany