The Radolfzell–Mengen railway (also called in German the Hegau-Ablachtal-Bahn — Hegau–Ablach Valley Railway) is a branch line in the German state of Baden-Württemberg. It runs from Radolfzell via Stockach to Mengen, with a total length of 56.78 km (35.28 mi). The line is standard gauge (1,435 mm) and was originally built as a mainline connection from Ulm via Lake Constance (Bodensee) to Switzerland.
Route
The line begins at Radolfzell station on the Lake Constance shoreline, runs north through Stahringen and Stockach, then follows the Ablach river valley through Meßkirch and Krauchenwies to its terminus at Mengen. At Stahringen, the Stahringen–Friedrichshafen railway branches off toward Lindau. The line reaches a maximum elevation of 621 m at Schwackenreute.
History
The railway was conceived in the mid-19th century as part of an international route between Vienna and Paris, and between Berlin and Milan. Construction was authorized by trilateral treaties between the Grand Duchy of Baden, the Kingdom of Prussia, and the Kingdom of Württemberg.
The line opened in sections:
- 20 July 1867: Radolfzell–Stahringen–Stockach
- 3 February 1870: Stockach–Schwackenreute–Meßkirch
- 6 September 1873: Meßkirch–Krauchenwies–Mengen (along with the branch from Krauchenwies to Sigmaringen)
A fast pair of trains between Radolfzell and Ulm was introduced in 1873 but abandoned in 1875 due to low demand. The line was downgraded to a branch line in 1879.
Decline and closures
Regular passenger services were abandoned in stages:
- 1954: Krauchenwies–Mengen passenger services closed
- 1960: All traffic on Krauchenwies–Mengen ended; the section was dismantled
- 1969: Meßkirch–Krauchenwies passenger services closed
- 1972: Stockach–Meßkirch passenger services closed
- 1982: Radolfzell–Stockach passenger services closed
The Krauchenwies–Mengen section was rebuilt and returned to freight service in 1986.
Reactivation
In 1996, the southern section between Radolfzell and Stockach was reactivated for passenger services, operated under the brand name Seehäsle. Services were initially operated by Mittelthurgaubahn (later SBB GmbH) using GTW 2/6 diesel multiple units. Since 2006, operations have been run by Hohenzollerische Landesbahn (HzL) using Regio-Shuttle diesel multiple units, with services running every half-hour at peak times on weekdays.
The northern section from Stockach to Mengen is used primarily for freight trains and excursion services. Since 2021, trains have operated between Stockach and Mengen on Sundays and public holidays under the brand name Biberbahn.
Ownership
The line has multiple owners: DB InfraGO owns the sections from 0.0–8.0 km and 55.9–56.7 km; the district of Konstanz owns the section from 8.0–17.8 km; and Ablachtalbahn GmbH owns the section from 17.8–55.9 km.
