Construction of the Eutingen–Horb section (1874) Württemberg completed the section from Eutingen to connect to the
Upper Neckar Railway (
Obere Neckarbahn) in Horb on 1 June 1874. However, the aim was not to connect Horb via the
Gäu and
Böblingen to Stuttgart. Rather, the Royal Württemberg State Railways established the
Nagold Valley Railway, a connection between
Pforzheim and Horb, the completion of which made Horb a railway junction in 1874. However, the Royal Württemberg State Railways initially did not attempt to build a much shorter direct connection from Stuttgart to Horb because the gradients seemed too difficult to overcome.
Construction of the Stuttgart–Eutingen section (1879) On 22 March 1873, the state of Württemberg legislated the creation of a railway between Stuttgart, via
Herrenberg and Eutingen, to Freudenstadt, closing the gap between Stuttgart and Eutingen. In the discussions prior to the passage of this law, the term
Gäubahn was used for the first time to label the section Stuttgart–Freudenstadt, and the term would later become the name for the entire line between Stuttgart and Singen. In November of the same year, construction on the technically challenging railway began in Stuttgart, led by the Württemberg engineer Georg Morlok. The route on the hillside was complicated, it required inclines of up to 1:52,
bank engines in front and behind trains to Stuttgart-West, a large number of tunnels and deep cuts, the 430 metre-long and 39 metre-high Vogelsang embankment and the 42 metre-high Ziegelklingen embankment. A total of 1,600,000 cubic metres of earth were moved. The section to Vaihingen was the most expensive of the entire route, which cost a total of 31 million marks. Much of the labour recruited by Morlok came from Italy. Construction went well: During the winter 1877/78, the line had already reached Herrenberg. On 20 August 1879, after a trial run from Stuttgart to Freudenstadt, the Royal Württemberg State Railways officially opened this section on 2 September 1879, in the presence of Georg Morlok, the president of Württemberg
Hermann von Mittnacht, the mayor of Stuttgart Gottlob Friedrich von Hack, and many other dignitaries. The construction of this section shortened the distance between Stuttgart via Horb and Tuttlingen to Immendingen by 35 kilometers, and cut the trip time by 1 to 2 hours.
From regional to long-distance railway (1879–1919) The Stuttgart–Horb–Tuttlingen–Immendingen line was primarily of regional significance at this time. The terminus of all long-distance travel was Immendingen. By the end of the 19th century trip times were becoming quite a bit shorter, to the point where the trip between Tuttlingen and Stuttgart had been cut down to only 3 hours in 1897, 4 to 5 hours less than in the 1870s. Starting in 1900, 3 daily express long-distance trains traversed the line. Around the turn of the century, the Royal Württemberg State Railways mostly used the steam locomotives of the class
Württemberg AD for their express service, which were in turn replaced by the class
Württemberg C during World War I. The class
Württemberg T 5 was used for regional service. Possibly the most famous passenger on this line,
Vladimir Lenin, the leader of the
Russian Revolution, travelled from Zürich via Stuttgart to
Petrograd in a special train on 9 April 1917. The Royal Württemberg State Railways started to lay a second track alongside the originally single-track railway on short sections of the line in the 1880s and 1890s. In 1886, the first section to be made into a twin-track line was the 4.4-kilometer-long piece between Horb am Neckar and Eutingen im Gäu. In 1895, the 8.6-kilometer-long section between Stuttgart Hauptbahnhof and Stuttgart West received a second track and this was as extended as far as Böblingen from 22 November 1905. The 1.2-kilometer connecting curve between Stuttgart North (
Nordbahnhof) and the Stuttgart–Horb railway was opened on 1 November 1895. An initially planned connection line between Zuffenhausen and Stuttgart West was not realised. Traffic between Stuttgart and Böblingen increased from 16 trains (1890/91) to 32 trains in the winter of 1902/03. In the period between World War I and
World War II, the transport infrastructure in Germany received numerous improvements. On 22 October 1922, the new main station in Stuttgart (
Stuttgart Hauptbahnhof) was officially opened. This removed the chokepoint at the terminus of the line and enabled the expansion of the capacity of rail traffic.
Deutsche Reichsbahn altered the route taken by the line in the centre of Stuttgart to Eckartshaldenweg, avoiding Stuttgart North station, in autumn 1922. In the 1920s, the
Free People's State of Württemberg, as Württemberg was known during the
Weimar Republic, undertook to expand the single-track lines constructed in the 19th century. The goal was to enable rail traffic from
Berlin to Switzerland and Italy to utilise not just the railways in the neighbouring territories of Baden and
Bavaria, but also the tracks owned by Württemberg. In addition, the
Reichswehr had an interest in a high-capacity rail connection between Berlin and the southwestern border, which, particularly after the return of
Alsace-Lorraine to France in 1918, was not as close to the French border as the
Rhine Valley Railway from
Mannheim to
Basel, and would not be as easy to disrupt in the event of war. The occupation of the city of
Offenburg by French troops in 1923 reinforced the desire for an effective and efficient alternative route. As part of the expansion of the line, the Reichsbahn also expanded Horb am Neckar station, and replaced the old Eutingen station building with a large new building. The expansions during the 1920s and 1930s resulted in great improvements in the service schedule on the Gäubahn. Express trains travelled from Berlin via
Erfurt,
Würzburg, Stuttgart, Zürich, and
Milan all the way to
Rome. The last peacetime schedule in 1939 showed 3 express trains from Berlin to
Italy, even though not all of the trains continued from Milan to Rome. In addition there was express service between Berlin and
Lucerne as well as between Stuttgart and Konstanz. Travel time between Stuttgart and Singen was cut to 2 hours and 41 minutes in 1933, and the regional and local service schedules also saw marked improvements. As was true prior to the railway expansion, and since World War I, the Württemberg class C steam locomotives were used in express service. After the construction of the connecting curve from
Tuttlingen to Hattingen, the
Prussian P 10 which assumed the lead on these trains. The Württemberg class C was reassigned to manage the regional and local service traffic. The class Württemberg T 5 was also still seen, but was replaced by 1933 by the
DRG Class 24. The
Prussian P 8 had already been used since 1920 between Horb and Immendingen. For freight service, the
Prussian G 12 as well as the
Württemberg K were used. Starting in 1924, the Reichsbahn began to assign the
Prussian G 10 to short-distance freight service, and between 1936 and 1938, the
DRG Class 86 saw use in the same capacity. During World War II, passenger service was reduced in favour of the rather more significant freight traffic.
Axis partner Italy received coal shipments from
Upper Silesia using freight trains on the line. It lost much of its military freight significance in the North-South corridor with the German attack on the
Soviet Union, and many of the newer locomotives, especially the
Prussian P 10, were relocated by the Reichsbahn to eastern Europe, while passenger trains on the line again saw the use of the Württemberg C locomotive.
War damage, dismantlement and diesel operation (1945–1962) Until February 1945, the Gäubahn did not suffer much damage during World War II, with the exception of aerial bombardment in 1944/45, which caused severe damage to the stations in Herrenberg and Horb am Neckar. This damage only disrupted traffic in the short term. More significant was the damage caused by German troops in April 1945, when several bridges were blown up between Stuttgart and Böblingen, stopping train traffic altogether shortly before the end of the war. Also in April 1945, American and French troops occupied southwestern Germany, which meant that the section of the line between
Bondorf and Stuttgart fell into the
American zone of occupation, while the section between
Ergenzingen and Horb was assigned to the French zone. It was not until 13 August 1946 that the railway was opened again for through traffic.
France insisted on its right to reparations, unlike the
United States of America, and in 1946 dismantled the second track between Horb and Tuttlingen, which had only been laid a few years before. Ever since, the Gäubahn is twin-tracked only between Stuttgart and Horb, as well as between Hattingen and Singen. The border between the American and French zones was responsible for the lack of through-traffic between Stuttgart and Singen, which did not resume until 1948. Compared to the heyday of the line at the end of the 1930s, the service schedule was severely reduced, and did not reach the same level as before the war until the end of the 1950s. The service to and from Berlin, for which the line had been expanded in the time between the wars, was not resumed by the
Deutsche Bundesbahn, and the traffic corridor Berlin–Erfurt–Würzburg–Stuttgart–Zürich had lost its significance due to the separation of
East Germany and
West Germany. Starting in the 1950s, the Bundesbahn extended some of the express trains between Zürich and Stuttgart to
Hamburg. Also, express service was reinstated between Stuttgart and Italy, largely due to the influx of guest workers from Italy into
Baden-Württemberg at the end of the decade. These trains primarily saw the use of the
Prussian P 10 and the
Prussian P 8. Between 1958 and the middle of the 1970s, diesel locomotives of the class
DB Class V 100 and
DB Class V 200 replaced the steam locomotives on the Gäubahn, with the DB Class V 200.1 being used for freight service.
Electrification The Bundesbahn electrified the section between Stuttgart and Böblingen in 1963, with the goal of reducing travel time in local service trains in the Stuttgart area. The section Böblingen–Horb was converted to electric operation in 1974, followed by Böblingen–Horb section in 1977. The 150 metre-long Kaufwald tunnel was converted into a cutting in nine months in the run-up to electrification in 1958/1959 with single-track operation. The cutting required the removal of 170,000 cubic metres of overburden. After the section between Böblingen und Stuttgart was electrified in 1963, initially it was locomotives of the
DRG class E 17,
DB Class 141,
DRG Class E 44, and
DRB Class ET 55, which saw service. These were then replaced with
DRG Class ET 25,
DB Class ET 27, and DRG Class ET 65 by 1969. After 1974, and the electrification of the Böblingen–Horb section, the Bundesbahn used the
DB Class E 10 for regional service on the line and used the same locomotive for express service after 1977. For freight service, the Bundesbahn initially relied on the
DB Class E 50 and
DRG Class E 93, switching to the
DB Class 151 in the 1980s, then the
DB Class E 40 starting in 1988; since 1993, it has been the
DB Class 143 responsible for freight service.
Integration into the S-Bahn network In 1985, the section between Stuttgart and Böblingen was incorporated into the network of the
Stuttgart S-Bahn. Since then, S-Bahn services run from Stuttgart Hbf on the
Verbindungsbahn (connection line), which is entirely underground in the centre of the city, and which meets up with the Stuttgart–Horb railway at
Stuttgart Österfeld station. The Verbindungsbahn cuts down the trip distance of the S-Bahn by 5.5 kilometers, and puts the
University of Stuttgart into the rail network, while regional and long-distance trains still use the old line, but Stuttgart West station lost its passenger service in 1985. In the run-up to the integration into the S-Bahn network, Goldberg station was opened in 1982. It is named after a residential area in Sindelfingen, but it is actually in Böblingen. On 5 December 1992, the Deutsche Bundesbahn extended the S1 line of the Stuttgart S-Bahn from Böblingen to Herrenberg, thus significantly improving local transport between the Korngäu region and the state capital. For this purpose, Hulb station was put into operation on 8 December 1990 in Böblingen, opening up the extensive industrial area there.
New long-distance and local service (since 1990) By 1991, the number of express trains on the line increased to eight daily trains, with five of those continuing on past Zürich to the cities of Milan,
Genoa, and
Lecce or
Naples. On the other hand, traffic to the north was largely eliminated; for example, just a single express trains traveled on to
Nuremberg at the time. The trip between Stuttgart and Singen now took exactly two hours, and was made by locomotives of the DB Class 110 and DB Class 181. Starting in 1993, the Deutsche Bundesbahn, and, from 1994, the privatised
Deutsche Bahn AG, attempted to shorten express trip times even further. To achieve this goal, the Gäubahn saw test runs of the Italian
Pendolino, as well as the Swedish
X 2000. Between 1993 and 1995, two trains of the
EuroCity service type replaced some of the traditional express trains on the line. For a short time, TEE-RABe trains of the
Swiss Federal Railways were in use, which cut the trip time between Stuttgart and Singen to 1 hour and 50 minutes. On 1 March 1998, two tilting trains of the type
ETR 470, owned by the Swiss firm
Cisalpino AG, replaced some express service trains, since German tilting technology trains were not available for service yet. This replacement did not initially result in shorter trip times. In 1999, the DB AG radically altered long-distance traffic on the Gäubahn, and stopped, with one exception, using locomotive-powered trains altogether. For the first time, trains of the type
DB AG Class 415 with tilting technology were used on the line, and these trains, together with the Cisalpino, made up the bulk of long-distance trains. This resulted in a trip time of 1 hour and 44 minutes between Stuttgart and Singen. The Cisalpini were responsible for the traffic between Stuttgart and Milan, while the ICE trains carried the load between Stuttgart and Zürich; the through traffic between Stuttgart via Genoa to Naples was eliminated. In 2005, the last locomotive-powered express train, the so-called
IC Insubria, was also removed. One year later, in December 2006, the Cisalpino service was stopped, eliminating direct connections to Italy, and making the ICE the only long-distance carrier on the Gäubahn. From December 2006,
ICE T sets composed of five-car sets (class 415), were replaced by seven-car sets (class 411) for ICE services. After problems with vehicle availability and delays, ICE operations on the Stuttgart–Zürich route were discontinued on 21 March 2010 and replaced by intercity trains with Swiss Federal Railways carriages. Long-distance traffic was then operated solely with rolling stock from the Swiss Federal Railways until 2017. In spring 2012, at a European timetable conference, Deutsche Bahn spoke out in favour of ending long-distance traffic between Stuttgart and Zürich, but failed again due to resistance from the Swiss Federal Railways. == Operations ==