Düsseldorf-Derendorf–Dortmund Süd railway

The RhE had already opened the last part of its Ruhr line on 19 November 1874. This route meant that the Dortmund RhE station could not be built near the joint Dortmund station of the BME and CME station, which had originally been opened by the Cologne-Minden Railway Company (Cöln-Mindener Eisenbahn-Gesellschaft, CME) in 1847 and is now called Dortmund Hauptbahnhof. Therefore, it built its station next to the Dortmund KWE station, which was built at the same time by the Royal Westphalian Railway Company (Königlich-Westfälische Eisenbahn, KWE), southeast of central Dortmund on a then undeveloped area between the streets of Märkischen Straße and Voßkuhle. This joint station later became Dortmund South Station (Bahnhof Dortmund Süd).

The RhE built a new line from its station in Dortmund to the south in order to serve the local mines. On 12 November 1875, the first freight train ran to Hörde RhE station (later Hörde-Hacheney). On 28 December 1878, the line was extended to Löttringhausen, which was connected two years to the Dortmund-Löttringhausen–Bochum-Langendreer railway (known as the Rheinischer Esel, Rhenish Ass).

Also on 19 November 1874, the RhE opened the Troisdorf–Mülheim-Speldorf railway, connecting its Ruhr line with its East Rhine Railway. As with many of its other lines, the RhE chose a very direct route, which bypassed central Düsseldorf.

Ruhr Viaduct in Herdecke

The route was very difficult between Vohwinkel and Hagen, particularly in the densely populated Wuppertal area, because the easiest route through the centre of the valleys of the Wupper and Ennepe was already occupied by the trunk section of the BME. Therefore, the railway was built on a slope, requiring complex engineering structures such as viaducts and tunnels, which still influence much the city in the northern districts of Wuppertal. The most famous structure is the imposing Ruhr Viaduct in Herdecke.

Several other lines branched off this railway: in Wuppertal-Barmen the line to Hatzfeld and the line to Hattingen branched off, in Gevelsberg the Elbsche Valley Railway branched off to Witten and in Dortmund-Löttringhausen the former line to Langendreer branched off to Witten Ost. In Neu-Dornap/Vohwinkel, the line crossed the Wuppertal-Vohwinkel–Essen-Überruhr railway (the so-called Prince William Railway), in Hagen-Haspe the line connected with the Ennepe Valley Railway and in Hagen-Vorhalle it crossed the BME trunk line.

Economically, it could not compete in the following years with the more centrally located main line of the BME despite good gradients–the steep Erkrath-Hochdahl incline on the competing BME line could not initially be climbed by the locomotives under their own power and trains had to be hauled by a cable system. After the nationalisation of the line in 1880 the Wuppertal Northern Railway therefore was used only for a modest regional passenger services and as relief line to the main route and as a detour when required.

For this purpose various connection lines were built between the Wuppertal Northern Railway and the adjacent lines:

• On 1 June 1890, the Royal Railway Division at Elberfeld opened the line between Oberbarmen and Wichlinghausen (line (VzG) number 2710), connecting with the Wuppertal-Wichlinghausen–Hattingen railway opened six years earlier.
• On 1 November 1894, a direct connection from Haspe RhE (now Hagen-Heubing) to Hagen Hauptbahnhof (line 2804) was opened.
• On 1 April 1896, a connection was opened from Varresbeck and Lüntenbeck to Vohwinkel (line 2722) initially for freight; a month later the first passenger train ran on it
• On 2 January 1912, passenger traffic was discontinued between Herdecke and Hagen-Eckesey (formerly Hagen RhE) and a new connection (line 2821) was opened between Herdecke and Hagen-Vorhalle Yo junction (on the BME trunk line) to Hagen Hbf.
• In 1913, a branch line (line 2712) was opened from Schwelm-Loh (formerly Schwelm RhE) to the old Wuppertal-Langerfeld freight yard.
• On 2 June 1957, the route to Dortmund South station was finally closed and instead a connecting curve was opened with the Dortmund–Soest railway to provide direct access to Dortmund Hauptbahnhof.

On 27 September 1991, most passenger traffic on the Wuppertal Northern Railway—which had most recently operated with class 515 battery-powered railbuses—was closed. After that there were only a few special trips. On 17 December 1999, the last freight train ran on the line.

In Wuppertal-Barmen the line crosses the urban area on the Steinweg Viaduct

Class 515 battery-powered railbuses at Wuppertal-Lüntenbeck running towards Vohwinkel in 1989