Electrification of the "Südbahn"

Electrification of the "Südbahn"

The origins of the " Schäwbische Eisenbahn" go back more than 170 years. Between 1846 and 1850, the " Südbahn" was built and from 1905 to 1913, it was expanded to a double track. It was the first railway line to connect the towns on Lake Constance with the Upper Swabian centers of Ravensburg, Biberach and Ulm.

Today, the Suedbahn is thus one of the oldest railroad lines in Baden-Württemberg and at the same time one of the few double-track main lines in Germany that are not yet fully electrified. This will change with the inclusion of the project as a "priority requirement" in the current Federal Transport Infrastructure Plan and its inclusion there as an access route for the "New Railway Link through the Alps" (NEAT) in Switzerland.

The official project start in March 2018 was preceded by a planning phase lasting several years and an initiative of local cities, municipalities, districts, chambers of commerce and regional associations, which culminated in the foundation of the Interessenverband (IV) Südbahn in 2006 and has been a major driving force behind the project in cooperation with DB Netz AG and the state of Baden-Württemberg.

Construction began in September 2018, and since then the bulk of the electrification measures for the southern runway have naturally concerned the construction of the overhead contact lines (OLA) for the main lines, along with overtaking and station tracks. Their total length with catenary systems amounts to over 250 kilometers and requires the installation of more than 4,000 catenary masts.

This work is being carried out within partial and total closures of the four construction sections along the line. In addition, the construction project also requires extensive construction measures "next to" the line. These include the renewal of road and footpath overpass structures due to insufficient clearance heights in Fronreute, Laupheim, Biberach, Aulendorf and Ulm. Likewise, 400 m of retaining walls must be newly built south of Ulm, as the clearance gauge is no longer sufficient for the higher line speeds. This also requires adjustments to the control and safety technology (LST). The clearance gauge of the railroad overpass over the river Argen is also too tight for overhead line operation. Particularly challenging here is not so much the 76 m length of the bridge as its status as an architectural monument worthy of protection.

Furthermore, in addition to a renewal of the level crossings in Ulm-Einsingen and Bad Schussenried, contact protection measures have to be retrofitted at numerous overpasses, which are necessary for future electrical operation. An important aspect resulting from the planning phase are passive noise protection measures in the residential areas directly adjacent to the line in accordance with the Federal Immission Control Ordinance (BlmSchV), as well as planning measures for environmental compatibility, water, nature and species protection, together with the handling of flora-fauna habitat areas near the line. The power supply for the future electrified line will be ensured by the construction of a new electrical converter plant near Niederbiegen and in the north by the connection to a switching station in Ulm main station and in the south in Lindau-Aeschach.

Commissioning of the electrified southern runway is scheduled for December 2021. DB Netz AG is thus realizing the long-awaited modernization of the connection between Upper Swabia and the Lake Constance region to the national and international rail network. The electrified operation to rail will contribute significantly to an environmentally friendly, sustainable and above all future-proof mobility in Southern Germany. As one of seven nationwide "lighthouse projects" for the German rail network, significant, concrete improvements in rail traffic are expected in the future. For example, after the electrified southern runway goes into operation, connections at the Ulm and Lindau clocking points can be improved and travel times reduced by eliminating the need for the previous locomotive change in Ulm.

The work in the construction phases - status September 2020: construction phases 1 and 2

Two construction sections between Ulm-Aulendorf (approx. 60 kilometers)

In the entire section from Ulm to Aulendorf, the main overhead line system including underground cable construction was largely completed by September 2020. South of Ulm, 400 m of retaining walls, the Ulm-Donautal, Biberach and Laupheim overpasses and the raising of the pedestrian walkway in the area of Biberach station were also completed. The retrofitting of 16 road bridges with contact protection is under construction.

The permanent way work required to increase the line speed was bundled with the upcoming work of the permanent way program and completed with the Ulm-Einsingen level crossing. The reconstruction of the Bad Schussenried I and II level crossings will be completed in the near future. The first construction stage of the conversion of the signal boxes Aulendorf and Bad Schussenried to ESTW technology was successfully completed.

The work in the construction phases - status September 2020: construction phase 3

Aulendorf-Friedrichshafen section (approx. 40 kilometers)

In the Aulendorf-Ravensburg section, the main construction measures of new overhead line construction, underground cable construction, superstructure (track lowering) and the new construction of the Aulendorf-Rugetsweiler road bridge have mostly been completed.

In the Ravensburg-Friedrichshafen section, during the period of full closure from 14.09. to 19.12.20, work will be carried out in particular on new overhead line construction, underground cable laying, superstructure (track lowering) and retrofitting existing overpasses.

The work in the construction phases - status September 2020: construction phases 4

Friedrichshafen-Lindau section (approx. 23 kilometers)

Work on the new construction of the railroad overpass over the Argen and the overhead line systems including cable construction in this section has been completed.

The great public interest that accompanied the construction of the new railroad overpass over the Argen was met with daily updates via webcam on the project website. The access numbers amounted to over 10,000 visitors / month.

Facts and figures

• Construction time of the original line from 1846 to 1850
• Double-track expansion from 1905 to 1913
• Route length from Ulm main station via Friedrichshafen (city) to Lindau-Aeschach: 120 kilometers
• Total length of the tracks to be electrified (including station tracks): 253 kilometers.
• Around 4,000 catenary masts will be installed.
• New overpasses in Ulm-Donautal, Laupheim, Biberach and Aulendorf. Demolition of the bridge in Fronreute.
• Contact protection and earthing equipment is retrofitted at 31 overpasses.

Further information: Project website "Südbahn"