Written by: TrainSim-James
In the 1840s, there was a need for a new railway in Germany to shorten the journey between Offenburg and Singen, the initial plans that were drawn up depicted a railway that would cut through the scenic Black Forest to reduce the journey distance by about 90 km. However despite the benefits of this line, it was deemed that the complex and expensive construction of the route and all the structures required would not be possible to build.
The main struggle for builders was the incredible height difference throughout the Black Forest, and how to avoid a gradient steeper than 2% at any point which locomotives would not be able to cope with. Luckily some 20 years after the plans were abolished, a civil engineer called Robert Gerwig came up with the idea of using multiple hair-pin loops and numerous curving tunnels to avoid the steep gradients.
By 1863 the construction of a railway line through the Black Forest had begun and would take about 10 years to complete. There were several options proposed for the actual route and the winner was the Sommeraulinie via Hornberg and Triberg as this line, albeit more challenging, was the only option located solely in Baden.
Some of the railway proved to be relatively easy to construct, the section between Offenberg and Hausach was able to utilise the Kinzig Valley, a tributary of the Rhine, and only needed to work on the river itself once near Gengenbach. Other areas proved to be more challenging, the section between Engen and Donaueschingen was situated in the watershed of the Rhine and the Danube and had to tunnel through the local limestone to avoid it, a 240m section of the Danube also had to be re-routed to make room for the line.
The most difficult section of the Black Forest Railway to construct was between Hornberg and Sankt Georgen, as this was where Robert Gerwig’s solution was put into fruition. Several major hair-pin loops were built to keep the railway within its gradient boundaries as it climbed along the valley. The loops extended the length of this section from 21 to 38 km, a lengthy but necessary solution. This section was the last to be built of the railway, and the whole 149 km route was completed by 1873.
Despite only being partially constructed, services began running along completed sections of the line in 1866 from Offenberg to Hausach and between Engen and Singen, there were also connections to Konstanz via the Baden Mainline. The line started with 5 scheduled passenger services a day that would run from Offenberg to Konstanz. Operations increased as the line was completed, the population grew and locomotives got faster, the only hindrance on services was the First World War which left only one passenger service on the line.
After WWI the Black Forest Railway picked itself back up again and was eventually in need of expansion, thankfully the provision of upgrading the line was realised during construction and by 1921 the track between Offenberg – Hauscah and Villingen – Singen was doubled. Services were interrupted in 1923 when French Soldiers occupied Offenberg and Appenweier from February until December, limiting the line to one express per day and causing complicated re-routes to take place.
To further modernise the Black Forest Railway, the Hornberg viaduct was removed in 1924 in place for a brand new arched bridge across the Reichenbach Valley with the aim to increase capacity along the line, a few years alter one of the many tunnels saw its final days when it was excavated into a cutting. This viaduct received collateral war damage in 1945 and closed the railway for just over 2 months before it was repaired.
In the mid-1950s railbuses started to appear on the line as did the DB Class V 200 which worked as the replacement of steam locomotives along the Black Forest. To make the line more flexible in its operation and an economical attraction, it was decided to electrify the Black Forest Railway in the early 1970s. Electrification proved to be interesting, the extensive number of tunnels meant much of the track bed had to be lowered in a number of locations, and several smaller stations were taken out of use around this time too.
In 1989, Deutsche Bundesbahn began their new InterRegio services, one of which departed Konstanz and headed for Kassel via the Black Forest Railway, this massively increases the connectivity between the towns of the Black Forest and the major cities of Germany. Other services of this type eventually went to the likes of Berlin, Lübeck and Hamburg.
Under Deutsche Bahn operation many service changes have occurred, some of the line saw operations from the Ortenau S-Bahn begin, along with Swiss services that connect the two countries together. DB also saw the end of the InterRegio services in place for Interregio-Express and Intercity operations. DB Regio makes up a lot of the services along the line which use modern TRAXX locomotives and double decker passenger stock that provide unbeatable capacity and outstanding views of the Black Forest.
Over its operational life the Black Forest Railway has been essential in the growth of the smaller towns situated in the southern Black Forest, with longer distance services ever increasing the reach across not only Germany but also into the likes of Switzerland and beyond. Thanks to the beautiful nature of the Black Forest, the line has also made itself a popular tourist attraction for railfans and landscape lovers alike.