The Prag Tunnel is a railway tunnel in the German city of

Stuttgart Stuttgart (; Swabian: ; ) is the capital and largest city of the German state of Baden-Württemberg. It is located on the Neckar river in a fertile valley known as the ''Stuttgarter Kessel'' (Stuttgart Cauldron) and lies an hour from the ...

under the Prag, a ridge between the Stuttgart basin and

Feuerbach Ludwig Andreas von Feuerbach (; 28 July 1804 – 13 September 1872) was a German anthropologist and philosopher, best known for his book ''The Essence of Christianity'', which provided a critique of Christianity that strongly influenced gener ...

. The two 680 metre-long bores of the tunnel connect

Stuttgart North station Stuttgart Nord station (german: Nordbahnhof) is in the German state of Baden-Württemberg. It consists of a passenger railway station on the Stuttgart S-Bahn and a goods yard. History Owing to the increasing volume of traffic, the Royal Württem ...

with Feuerbach station. Trains from Stuttgart run through the tunnel towards

Karlsruhe Karlsruhe ( , , ; South Franconian: ''Kallsruh'') is the third-largest city of the German state (''Land'') of Baden-Württemberg after its capital of Stuttgart and Mannheim, and the 22nd-largest city in the nation, with 308,436 inhabitants. ...

Mannheim Mannheim (; Palatine German: or ), officially the University City of Mannheim (german: Universitätsstadt Mannheim), is the second-largest city in the German state of Baden-Württemberg after the state capital of Stuttgart, and Germany's 2 ...

and

Heilbronn Heilbronn () is a List of cities and towns in Germany, city in northern Baden-Württemberg, Germany, surrounded by Heilbronn (district), Heilbronn District. With over 126,000 residents, it is the sixth-largest city in the state. From the late Mid ...

on the

Franconia Railway The Franconia Railway (german: Frankenbahn) is a railway line in the north of the German state of Baden-Württemberg and the Bavarian province of Lower Franconia that links Stuttgart and Würzburg. Its name comes from the fact that the majority o ...

and the

Mannheim–Stuttgart high-speed railway The Mannheim–Stuttgart high-speed railway is a 99 km long railway line in Germany, connecting the cities of Mannheim and Stuttgart. The line was officially opened on 9 May 1991, and InterCityExpress service began on 2 June. The Hanover ...

and towards

Ludwigsburg Ludwigsburg (; Swabian: ''Ludisburg'') is a city in Baden-Württemberg, Germany, about north of Stuttgart city centre, near the river Neckar. It is the largest and primary city of the Ludwigsburg district with about 88,000 inhabitants. It is ...

and

Leonberg Leonberg (; swg, Leaberg) is a town in the German federal state of Baden-Württemberg about to the west of Stuttgart, the state capital. About 45,000 people live in Leonberg, making it the third-largest borough in the rural district (''Landkr ...

on the

Stuttgart S-Bahn The Stuttgart S-Bahn is a suburban railway system (S-Bahn) serving the Stuttgart Region, an urban agglomeration of around 2.7 million people, consisting of the city of Stuttgart and the adjacent districts of Esslingen, Böblingen, Ludwi ...

. The tunnel runs in layers of Gipskeuper rock, containing

anhydrite Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the ...

, which swell strongly when in contact with water. The track centres in the two tubes are 3.70 and 4.00 m apart.

History

The first tube of the Prag tunnel was built as part of the first railway in Württemberg, the

Württemberg Central Railway The Central Railway (german: Zentralbahn or ''Centralbahn'') was the first phase of the Württemberg railways. It was built between 1844 and 1846 by the Royal Württemberg State Railways (''Königlich Württembergischen Staats-Eisenbahnen'') and ...

between Esslingen, Stuttgart and

. The first sod was turned on 26 June 1844 and marked the start of the construction of the Central Railway. Five shafts were sunk to enable the construction of the tunnel running through the Keuper layers; these were later filled in again. During a tunnel collapse 20 workers lost their lives. The 828.65 metre-long tunnel finally broke through after two years of construction and operations began on the Central Line on 15 October 1846. The tunnel was designed from the start for two-track operations, but it initially only had a single track. The second track was built between 1858 and 1861. Between 1911 and 1914, the tube that is now used by the S-Bahn was shortened to 680 m in order to build the freight rail link between the Gäu Railway (''Gäubahn'') and Stuttgart North Station.

Second tube

In 1907, it was decided to carry out extensive restructuring on the Stuttgart railway facilities, including upgrading the Stuttgart-Ludwigsburg line to four-tracks. From October 1908 a second, 680-metre long tunnel was built just to the northeast of the first, which accommodated two additional tracks. The tunnel broke through on 22 June 1909, but shortly afterwards it sank over a length of 20 to 30 metres and the ground above the tunnel sunk by up to four metres. After repairing the damage, it took until August 1910 to put the new tunnel into operations. Subsequently, the old tunnel, which had probably become unstable due to the construction of the new tunnel was initially blocked and it was then renovated. On this occasion, the tunnel was shortened by additional excavations on the Stuttgart side to give it a length of 680 metres as well. The renovation was completed on 21 August 1912 and, on 21–22 November 1912, the old bore was put back into service. Since then it has been used by suburban services (now part of the S-Bahn), while the new bore has been used by long-distance trains. Since 1981, a

Stuttgart Stadtbahn The Stuttgart Stadtbahn is a light rail system in Stuttgart, Germany. The Stadtbahn began service on 28 September 1985. It is operated by the Stuttgarter Straßenbahnen AG (SSB), which also operates the bus systems in that city. The Stuttga ...

(light rail) overpass has been located near the northern portals of both tubes. In this structure provision was made for the construction of a then planned additional freight track west of the S-Bahn tracks. This would have involved a third bore for the Prag Tunnel.

Future use / Stuttgart 21

After the commissioning of the

Stuttgart 21 Stuttgart 21 is a railway and urban development project in Stuttgart, Germany. It is a part of the Stuttgart–Augsburg new and upgraded railway and the Main Line for Europe (Paris—Vienna) within the framework of the Trans-European Networks. ...

project, the bore of the Prag Tunnel that is now used for long-distance and regional train will no longer be used for this traffic. These trains will in future be routed directly through the Feuerbach Tunnel from Feuerbach station to

Stuttgart Central Station Stuttgart Hauptbahnhof (; en, Stuttgart central station) is the primary railway station in the city of Stuttgart, the state capital of Baden-Württemberg, in southwestern Germany. It is the largest regional and long-distance railway station in ...

(''Hauptbahnhof''). Both of the old bores are to remain. The bore serving the S-Bahn network are to continue to be used by the S-Bahn. The long distance bore is also to be maintained and will be available in future to supply two additional tracks under the so-called ''P option'' of the Stuttgart 21 project. In the course of the development of the Stuttgart 21 project the North Cross (''Nordkreuz'') option was developed including a third two-track tunnel to be built for the S-Bahn tracks towards Stuttgart Nord station (deep level) and Stuttgart Central Station (deep level). (17-page document as ''version 09/99'')

Notes

References

* {{coord, 48.80976, N, 9.176095, E, region:DE-BW_type:railwaystation, format=dms, display=title Railway lines in Baden-Württemberg Transport in Stuttgart