North-South line

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The north-south line on C1 masts northeast of Mannheim

The north-south line , and Rhine landline or Südleitung called, was originally a total of about 600 km in length composite line system for three-phase high-voltage transmission , which the substation Brauweiler west of Cologne with the Vermuntwerk of Vorarlberg Illwerke and Schluchseewerk in southern Black Forest association.

The line was built by the Rheinisch-Westfälische Elektrizitätswerk between 1924 and 1929 and its entire length was put into operation on April 17, 1930. It made it possible for the first time to distribute the electrical power between the power grids in northern and southern Germany as needed and economically and, in particular, to use overcapacities at the Illwerke and Schluchseewerks for the high energy requirements of the Ruhr area . It thus formed the backbone of the emerging German high-voltage network, through which "a first major development phase in the establishment of parallel operation and in the integration of the largest networks into the integrated system was completed".

From 1979 the northern part of the original line was almost completely replaced by more powerful new buildings. The southern parts are still in operation and are mostly operated by Amprion (formerly RWE Transportnetz Strom ), individual sections by TransnetBW (formerly Energie -versorgung Schwaben or EnBW Transportnetze AG).


Development in the Rhineland

Foothills headquarters in 1914, the year it was opened

With the commissioning of the foothill control center, RWE under Hugo Stinnes developed from a regional power plant operator in the Rhineland and parts of Westphalia to a supra-regional energy supplier. After it was founded in 1898, it initially only supplied the city of Essen with electricity, but in 1905 it was acquired by the Rhenish Berggeist lignite mine near Brühl along with the associated power station, which was completed in 1899. When supplies at the Berggeist mine were running low, a supply contract was signed with the Roddergrube mine near Hürth in 1913, which guaranteed RWE to purchase the lignite there. Bernhard Goldenberg , Technical Director of RWE, planned to convert the lignite into electricity using a company's own power plant and therefore developed a thermal power plant based on Georg Klingenberg's concept that generates energy from the lignite in the Roddergrube. The 1,914 put into operation Vorgebirgszentrale (1920 in honor of the late 1917 Bernard Goldberg's in Gold Mine renamed) developed through constant extensions shortly after the First World War, the most powerful power plant in Europe. In the course of this, the power plant in the Berggeist mine was shut down.

In order to transfer the electricity generated in the golden mine to consumers in the surrounding area, RWE has already set up an extensive overhead line network. The experience gained with the 110 kV test route between Lauchhammer and Riesa , which was commissioned in 1912, was used to operate the company's own long-distance network with this voltage as well. Between 1914 and 1917, lines were built that connected the golden mine as the main switching point with the Erftwerk near Grevenbroich , the Reisholz power plant (built in 1908 by RWE) and some other facilities in the Ruhr area and in the Bergisches Land . Because of the expansions in the golden mine carried out at short intervals, it was stated in the RWE Annual Report 1912/13 that “it is correct in the future to build power stations with even greater capacities under favorable electricity generation conditions and to provide them with even larger supply areas by using higher transmission voltages than this has been common practice up to now. "Finally," neighboring plants [...] must come to an understanding [...] regarding the location of their power stations and the layout of their transmission networks if a lot of capital is not to be wasted unnecessarily. "

Shortly after the First World War , plans were therefore made to couple the RWE power plants and their transmission network with other energy sources in order to ensure constant availability of electrical energy. A plan from 1923 consisted of connecting hydropower plants in the Alps to the power plants in the Rhine with transmission lines. Under Arthur Koepchen , who had been technical director since 1917, RWE took over the majority in Elektrizitäts-Actiengesellschaft (EAG) formerly W. Lahmeyer & Co. from Frankfurt am Main in 1923 from the Swiss electrical bank . As a result, it came into the possession of shares in some energy supply companies in southern Germany that were affiliated with Lahmeyer AG:

Plans for an interconnected network

In March 1923 Arthur Koepchen, together with Ernst Henke and Bernhard Salomon, visited the facilities of Lechwerke and KAWAG, two subsidiaries of Lahmeyer AG. Since the Lechwerke hydropower plants produced excess electricity in the summer and the KAWAG steam power plant produced surplus in the winter that was not deductible in Württemberg, Koepchen had the vision of connecting both power plant locations with an extra high voltage line and thus absorbing the excess electricity and transporting it there where it was needed in the meantime.

The first plans drawn up in May 1923 provided for a 160 km long line between Heilbronn and Augsburg to connect the power plants of the subsidiaries with one another and, in Augsburg, a connection to the Bayernwerk , which would have its own nationwide 110 kV network when the Walchensee power plant went into operation put into operation. Koepchen's plan based on these considerations then provided for the extension of this line via Höchst to the Golden Mine, which would have increased the range of the Golden Mine in addition to transporting electricity from the southern German hydropower to the Rhineland. Because it was feared that competing companies could counteract the plans, the plan was initially kept secret and officially only recorded on the 160 km long Heilbronn – Augsburg connection. The negotiations with the Bavarian and Württemberg authorities therefore took place under the leadership of the EAG.

In autumn 1923, the WÜSAG subsidiary Oberschwäbische Elektrizitätswerke AG (OEW), together with the Swiss Bündner Kraftwerke AG, signed a contract with the state of Vorarlberg to build hydropower plants on the Ill above Bludenz and on the Lünersee . As Bündner Kraftwerke AG ran into financial difficulties, the RWE subsidiary Growag stepped in in November 1923. The contract guaranteed the shareholders of RWE a total of 600 million kWh of storable annual generation. Only a year later, on November 5, 1924, the Vorarlberger Illwerke GmbH (VIW) was founded by the RWE, the District Association of Upper Swabian Electricity Works , the People's State of Württemberg and the State of Vorarlberg , which built the Vermuntwerk by 1930 .

The first plan for the interconnector was to operate it with a voltage of 220 kV, twice the transmission voltage of 110 kV that was previously considered the highest possible. While 220 kV has been used in the USA since 1921, it was not yet considered possible in Europe to operate supra-regional networks with voltages above 110 kV. Therefore, in 1923, RWE first built a 40 km long test line from Ronsdorf to Genna . In addition to the experimental setup, in the long term it was to serve as the first section of the planned RWE high-voltage network, which, in addition to the hydropower plants, should also connect the power plants of the Braunschweigische Kohlen-Bergwerke AG. Since the operation of this line had initially encountered numerous problems, the network planning was still considered to be technically and economically too risky. In order to save weight and material costs, a copper hollow cable with a diameter of 42 mm was used, which had been developed in cooperation with AEG , Siemens-Schuckertwerke and Felten & Guilleaume .

A study trip to the Southern California Edison Company and Pacific Gas and Electric Company , which already operated several 220 kV lines, finally convinced Koepchen and Henke of the feasibility of their project. There were even concerns as to whether even a 220 kV line would soon reach its capacity limit due to the large gain in energy and the expectation of further high growth rates. During the planning, it was therefore decided to dimension the interconnector, which was first presented in plans in 1924 in its later form, for an even higher voltage of 380 kV. Koepchen assumed a power consumption of over 400 MW per circuit for a hollow rope with a diameter of 42 mm.

Construction of the interconnector

The construction of the high-voltage connection, initially known as the southern line , began in 1924 when the RWE transmission network already had 500 km of 110 kV lines that stretched from the Dutch border to Koblenz . Since the Reichspost and the Reichsbahn feared that the operational low-voltage systems would be influenced, it was not operated with a grounded zero point, but with Petersen compensation . For the construction of the line, numerous contracts and collaborations had to be entered into with the Hessian, Baden, Württemberg and Bavarian authorities, as there was no uniform expropriation law for the route construction. Thus there were lengthy negotiations about the individual mast locations. EAG was in the lead in the negotiations, as it had contacts with authorities and enough construction experience.

The fact that the line should run through the Rhine-Main area provoked a conflict with the Free State of Prussia and the state-owned Prussian Electricity AG , which wanted to supply the local electricity market from the Borken power station . At that time, the individual energy supply companies still operated largely unconnected as island networks and therefore tried to prevent large consumers from being enticed away or endangering their respective supply areas. Prussia therefore refused the expropriations and permits necessary for the further construction from the Kelsterbach substation and the Main crossing until the supply contract was concluded. The conflict was provisionally settled in 1927 in the so-called Second Electric Peace , in which the boundaries of the delivery areas were laid down.

The route planners were also faced with problems on the section between Herbertingen and Hoheneck substation . The originally planned direct route was forbidden in order not to impair traffic at what was then Böblingen Airport . Instead, the route creates a wide arc around the neighboring cities of Böblingen and Sindelfingen . There was a legal dispute in this connection .

From the end of 1928, RWE took a 50% stake in the founding of the Schluchseewerk , whose first plant, the Häuser power plant , went into operation in its first expansion stage in 1931, and 77% in the Albbruck-Dogern power plant. Originally, the power plants connected to the Tiengen substation were to be connected to Herbertingen via a 110 kV line. However, the connection was also implemented for a voltage of 380 kV.


The first section of the north-south line between Neuenahr and Rheinau went into operation in 1926 for a test with 110 kV. After the first construction phase of the Brauweiler substation, the largest outdoor switchgear in the world, went into operation on October 28, 1928, the entire section from Brauweiler via Neuenahr and Rheinau to Hoheneck was already under voltage with 110 kV.

On October 12, 1929, the main control line in Brauweiler with the subsequent 220 kV system was ready for operation, so the line from Brauweiler to Kelsterbach, then to Rheinau and finally to Hoheneck could be converted to 220 kV operating voltage.

In January 1930 the northern line from Brauweiler via Wesel to Ibbenbüren went into operation, as did the Koepchenwerk , which was integrated into a pipeline system designed as a ring via Osnabrück to Paderborn and back to Brauweiler. With the commissioning of the Herbertingen, Tiengen and Bludenz stations on April 17, 1930, the combined operation between alpine hydropower and Rhenish coal power was able to commence, thus giving the start of a globally unique network system.

In World War II

After the National Socialists established a dictatorship under the sole leadership of the NSDAP when Adolf Hitler came to power in 1933 , the Energy Industry Act passed in December 1935 under Reich Economics Minister Hjalmar Schacht was a product of the harmonization of political and economic life . The entire electricity industry was placed under the supervision of the Reich Ministry of Economics , which meant that the planning, operation and financing of the energy supply network could now be designed solely according to the political ideas of the Nazi regime. Military aspects in particular were decisive in ensuring that the decentralized energy supply was retained - with a central energy supply with only a few large power plants, these would represent militarily vulnerable targets.

In the course of the Energy Industry Act , the main control center in Brauweiler was declared a district load distributor, which was directly subordinate to the Reichsstelle für die Elektrizitätswirtschaft (also called Reichslastverteiler ), a central office for regulating the entire German network beyond the energy suppliers. Depending on the amount of electricity available, shutdowns were carried out on instructions by the Reichslastverteiler and the planning office of the Reich Minister for Armaments and War Production . Despite the bombing of industrial plants in World War II, the RWE network remained largely in operation until 1944, while the golden mine, for example, was largely destroyed in October 1944. As the central busbar for the energy supply of the heavily industrialized regions in western and southern Germany, the RWE transmission network quickly became the focus of the allied combat units.

At the beginning of 1945, at this point in time the fighting was shifting further and further west, the US Army occupied the main control room in Brauweiler. Parts of the network in the area on the left bank of the Rhine were destroyed, which interrupted the connection with the power plants in southern Germany. On March 5, 1945, after being occupied by the US military, the main control center reported the interruption of supply on the north-south line:

“We have just been occupied by Allied troops. […] The pipelines on the left bank of the Rhine are mostly on the ground. We no longer have any connection with the south. We are also separating from the area on the right bank of the Rhine. "

As early as the beginning of July 1945, a few weeks after the end of the war, network operations on the north-south line could be resumed. The rapid reconstruction also corresponded to the wish of the British military government in its zone of occupation , in which parts of the RWE network were located, to bring the power grid back into operation. By 1948, the last war-related damage and temporary work in the network had been removed. In the same year, RWE and eight other West German energy supply companies founded the Verband Deutsche Verbundgesellschaft (DVG) in Heidelberg .

Later developments

Operation with 300 kV

It became apparent that the transmission capacity of the 220 kV lines through the numerous large power plants built in the Rhenish district in the 1950s - such as the Frimmersdorf , Fortuna , Weisweiler power plants and a renewed expansion of the golden mine - was no longer sufficient, which is why the DVG tests at the 380 kV level, which was first introduced in Sweden in 1952, on a test site near Mannheim. Rather provisionally, the 253 km long section from Brauweiler to Rheinau was increased to 300 kV voltage in October 1952, for which switches and transformers for this voltage level were installed in Brauweiler and Rheinau and the insulator chains were expanded by two to three links on the masts.

Conversion of a circuit to 380 kV

In 1957, the voltage level of 380 kV in the German high-voltage network was introduced on a circuit of the new Rommerskirchen – Hoheneck line , the route of which was largely laid parallel to the north-south line. In 1964, in the Hoheneck – Herbertingen – Tiengen section, a circuit on the north-south line was converted to 380 kV, this happened together with the conversion of the second circuit on the Rommerskirchen-Hoheneck line. In particular, the electricity generated in the Swiss hydropower plants should be exchanged with an even greater capacity with that from the West German coal-fired power plants, especially since the Swiss side was also pushing ahead with the expansion to 380 kV. From 1965 the Tiengen substation was connected to the Swiss substation in Beznau via a 380 kV line.

Laying of cables at Frankfurt Airport

Low single-level masts at Frankfurt Airport, September 2017 (the north-south line has been dismantled here since 2008)

South of the Kelsterbach substation, the north-south line with two other lines (Kelsterbach – Schönbrunn, Kelsterbach – Dettingen ) ran directly west past Frankfurt Airport . Since the airport was built under the National Socialists in the mid-1930s and opened in 1936 only a few years after the lines had been built, it was necessary to change the course of the line in order not to endanger air traffic.

The first construction preparations for this were carried out immediately after the end of the war in 1946, partly because of the presence of the US Air Force at the Rhein-Main Air Base in the southern area of ​​the airport. However, due to the shortage of materials in the immediate post-war period, no steel could be obtained for the construction of new masts.

With the construction of the Aschaffenburg – Kelsterbach line in 1949, the situation changed. This line, which was built due to the separation of the power grid of the Soviet occupation zone and the later GDR as a connection between the Reichssammelschiene network in Bavaria and the West German network, ran around 5 km further west of the three existing lines to the substation in the area of ​​the airport Kelsterbach.

The laying of the remaining lines was not carried out until 1956, when air traffic increased as a result of the regained air sovereignty of the Federal Republic of Germany, which had been sovereign since May 1955, and the northern runway was extended. In addition to the Kelsterbach – Aschaffenburg line, RWE had an approximately 190 m wide strip in the pine forest cleared in order to move the overhead lines there. When a vegetation fire broke out in the line in 1977, a biotope in the form of a heathland was created on the burned areas.

The construction of the Runway West 1981–1984 made it necessary to lay the overhead lines again, this time only in the southern area. Since then, the lines have been running on low single-level masts .


Southern sections of the north-south line to Pfungstadt. These parts are still in use today.

Bludenz – Herbertingen

After leaving the substation in Bludenz - Bürs , the line first leads in a northerly direction, then in a north-westerly direction through the Walgau to Rankweil , from there down into the Rhine Valley and back to the north. In parts it runs very close to the Swiss border until it leads up the Pfänder at Wolfurt , where it turns first to the northeast and then again to the northwest. At Hohenweiler it crosses the border with Germany, leads on a very short stretch with 10 masts through Bavaria and reaches Baden-Württemberg . It leads through Upper Swabia , past Ravensburg and meets the line coming from Tiengen near Hohentengen- Eichen . At the same time it leads to the Herbertingen substation .

Since a circuit of the TransnetBW line has been operated with 380 kV since 1998 in Baden-Württemberg, there is a line branch on the BAB 96 to the Obermooweiler substation, from which a circuit leads to the Grünkraut substation located directly on the route . The second TransnetBW district leads from Grünkraut on the north-south line to Herbertingen. Most of the original masts from 1929 are still in place in Austria; the masts on Bavarian territory in the area and between the BAB 96 and Ravensburg were replaced by modern barrel masts between 2008 and 2009 .

Tiengen – Herbertingen

The section beginning in Tiengen leaves the substation parallel to numerous other overhead lines to the north and turns after a short distance to the northeast. Along the border with the Swiss canton of Schaffhausen , it runs parallel to a 220 kV line to Beuren / Stockach , which turns south near Honstetten , to the east. Between Pfullendorf and Ostrach , the direction changes to the north, where it meets the line from Bludenz and runs parallel to it to the Herbertingen substation.

Herbertingen – Hoheneck

After Herbertingen, the line leads north through the Danube Valley , past Riedlingen and reaches the Swabian Alb near Zwiefaltendorf . Via Hayingen , Gomadingen and St. Johann , it rises from the Alb down to the Neckar Valley at the Glems pumped storage plant . At Rommelsbach , there has been a line branch for 380 kV to the Metzingen substation since 2008 . It crosses the Neckar near Pliezhausen and runs through the Schönbuch between Walddorfhäslach and Dettenhausen . It then runs right through Holzgerlingen and Ehningen and meets the 380 kV Pulverdingen - Oberjettingen line west of Böblingen , to which it initially follows northwards, then from Renningen to the northeast. To the west of Leonberg it separates from it again and leads to the northeast. At Eglosheim it turns east and reaches the Hoheneck substation north of Ludwigsburg . The separate introduction of the two circuits into the 220 kV switchgear has already been relocated to the C1 masts used north of Hoheneck.


Parallel to the 220 kV Hoheneck – Neckarwestheim line , the line crosses the Neckar again directly north of Hoheneck and meets the 380 kV Neckarwestheim– Mühlhausen line , which is a hybrid line with the Neckarwestheim – Stuttgart line operated by Deutsche Bahn . These three lines run in parallel until shortly before Neckarwestheim, where the line coming from GKN joins, whose circuits lead to the north. From here, the north-south line has not been laid on the original masts since the 1980s, as a four-circuit line was built here, which has two 380 kV circuits from Neckarwestheim and Mühlhausen to Großgartach . This line crosses the Neckar in the southwest of Heilbronn for the third time, before the two 380 kV circuits lead to the Großgartach substation near Leingarten and the north-south line has its original masts again. From here it leads in a north-westerly to westerly direction and was relocated to low Danube and one-level masts at Kirchardt as part of the construction of a temporary motorway airport on the A 6 , and its course was slightly changed. It leads past Sinsheim and Meckesheim before the original route to Nussloch near Schatthausen was dismantled and the remaining circuit was relocated to the 220 kV Neurott - Hüffenhardt line to make room for a residential area. Past Leimen and parallel to the 110 kV RheinauSchönbrunn line , it reaches the Mannheim-Rheinau substation .

Rheinau – Pfungstadt

Behind the Rheinau substation, five overhead lines run parallel to the north-south line, including the 380-kV Rommerskirchen – Hoheneck line bundled to the north, with the Neckar being crossed a fourth time. To the east of Mannheim - Wallstadt , the line is divided and the north-south line leads to Weinheim to the northeast, across the state border with Hesse , then to the north parallel to Bergstrasse and the Flörsheim-Stuttgart traction power line . At Hähnlein , the two lines meet the 380 kV Bürstadt – Urberach line , to which they run parallel to Pfungstadt .

Today the north-south line ends in the Pfungstadt substation. This system was only built after the construction of the north-south line in the line route as a 220/110 kV substation and expanded by a 380 kV system from 2015 to 2016.

Pfungstadt – Kelsterbach

Until the section from Pfungstadt to Kelsterbach was dismantled in 2007, the north-south line north of the Pfungstadt substation began again. Initially it ran parallel to the 110 kV Darmstadt – Heppenheim line and had been laid on modern barrel masts near Weiterstadt in the A 5 area since the 1970s , as the line originally ran very close to the autobahn and the eight-lane line that took place from 1972 to 1978 Expansion stood in the way. At Mörfelden it encountered three 110 and 220 kV lines coming from Urberach and led to the northwest, on single-level masts around the end of the West runway at Frankfurt Airport and then in a wide aisle to the north, then along the A 3 to the east to the Kelsterbach substation . During the expansion of the airport, the lines were laid out on the approach lanes in 1956 and 1984.

Kelsterbach – Koblenz

The entire section from Kelsterbach to Koblenz no longer exists on original masts. It led to the west, crossed the Main at Okriftel and led behind Marxheim over the Taunus , along the Idsteiner Senke, at Hünstelden through the Goldener Grund to Rhineland-Palatinate , at Geilnau over the Lahn valley , through the southern Westerwald and between Urbar and Koblenz- Wallersheim across the Rhine . This Rhine crossing was laid on C1 masts with additional traverses for two earth ropes . Directly behind the Rhine crossing it led to the Koblenz substation.

The Marxheim – Koblenz section was replaced by a two-circuit 380 kV line around 1980, and this happened on the Kelsterbach – Marxheim section in 2009. In the course of the construction of the northwest runway, the Kelsterbach substation was reduced in size, relocated and from 220 kV to 380 kV converted.

Koblenz – Brauweiler

From Koblenz, the north-south line ran continuously parallel to the 380 kV Rommerskirchen – Hoheneck line, for the construction of which the existing line was used in the 1950s. At Weißenthurm it was taken to the local substation in the 1970s. It runs a few kilometers from the lower Middle Rhine Valley , crosses the Brohl at Burgbrohl - and the Ahr Valley at Heppingen . In the vicinity of the state border with North Rhine-Westphalia , it switched from C1 to C2 masts, then went north near Meckenheim , along the western outskirts of Bonn and again to the north-west near Bornheim , where it went to the transformer station in Sechtem , which will later be on the line was integrated. Behind it, it now leads past Brühl and Hürth and meets the lines at Frechen that come from the Golden Mine and also lead to Brauweiler . Together with these, it runs north to the Brauweiler substation .

The Koblenz – Weißenthurm section was dismantled without replacement in 2009; between Weißenthurm and Grafschaft it was replaced in 2010, and from Grafschaft to Sechtem in 2013 by a 380 kV line. Since 2017, work has been underway between Sechtem and Brühl for a four-circuit 380 kV line to replace the old north-south line. It will later be extended to Brauweiler, with the result that the last section north of the Rhine-Main area, which was laid on original masts, will also disappear.

Overview of the line sections

North-South line (DA-CH)
Original line route with substations

Since the entire length of the north-south line is owned by RWE or, since 2009, Amprion , the line sections are numbered internally by the company, the so-called construction control number (sheet). Since it was planned as a 380 kV line, it was assigned numbers starting with the number 4. It counts from north (Brauweiler) to south (Bludenz), starting at 4501. The branch to Tiengen is numbered 4510.

It is noteworthy that there were no substations of the line in Neuenahr, Heppenheim and Fürfeld, here the construction control number changed in the route.

Route Construction control
Mast type Installation Remarks
Brauweiler point Neuenahr 4501 C2 1928 Replaced by 380 kV between Sechtem and Neuenahr from 2012 to 2013,
currently (2018) replaced by 380 kV between Brühl and Sechtem
Point Neuenahr – Koblenz 4502 C1 1926 Completely replaced by 380 kV from 2009 to 2010
Koblenz – Kelsterbach 4503 C1 1926
Replaced by 380 kV between Koblenz and Marxheim from 1979–1980 and between Marxheim and Kelsterbach in 2009
Kelsterbach point Heppenheim 4504 C1 1926 Dismantled without replacement between Kelsterbach and Pfungstadt 2007–2008
Point Heppenheim-Rheinau 4505 C1 1926
Rheinau point Fürfeld 4506 C1 1928 The second 220 kV circuit was dismantled
at the end of 2003, and the line at Wiesloch was relocated to a TransnetBW route
Point Fürfeld – Hoheneck 4507 C1 1928 The second 220 kV circuit was dismantled at the end of 2003,
and the line between Leingarten and Neckarwestheim was
relocated to a TransnetBW route
Hoheneck – Herbertingen 4508 C3 1930
Herbertingen – Bürs 4509 C3 1930 Shared use of 380 kV circuits of the TransnetBW between Herbertingen
and Neuravensburg
Herbertingen – Tiengen 4510 C3 1930

Used masts

The entire line was originally installed on overhead line pylons with a three-level arrangement. Most of the line south of Pfungstadt is still on original masts.

For the section from Hoheneck via the Rheinau, Kelsterbach and Koblenz substations to Bad Neuenahr, the C1 mast was used, for the other sections, masts of types C2 and C3, depending on the expected ice load . The change from C2 / C3 to C1 masts takes place today in the Hoheneck substation, previously on the open road on the border between Rhineland-Palatinate and North Rhine-Westphalia west of the Grafschafter district of Oeverich. Individual C3 masts were used north of Hoheneck because of their higher load capacity when crossing highways or rivers.

C1 mast: a guy mast at the front ,
supporting masts behind

C1 mast

The C1 mast is designed for two three-phase circuits with a voltage of 220 kV in a three-level arrangement as a barrel mast , with the two lower cross members braced together and with a relatively small distance from one another in the case of support masts . The first sections of the lines went into operation in 1926 on the sections with this type of mast.

In contrast to this, the original C1 masts for the Rhine crossing near Koblenz had an additional upper traverse for two earth cables .

Today C1 masts can still be found on large parts of the section from Pfungstadt via Mannheim-Rheinau to Hoheneck. At Wiesloch and in the Leingarten - Neckarwestheim section , the north-south line has now been laid on shared routes with other lines, and the original masts have been dismantled on these sections. At Grombach , the course of the line was subsequently changed due to the establishment of a temporary motorway airport on the nearby A 6 and low single-level and Danube masts were used. Individual masts were also replaced by new constructions.

C3 mast, on the right a newer design

C2 and C3 mast

These barrel masts with three separate cross members can be used for three-phase lines with one or two circuits up to 380 kV. They have the same construction, the C3 type is designed for four times the ice load thanks to the use of reinforced components. The picture on the left shows C3 masts of the two branches south of Herbertingen, the mast in the picture on the right is more recent. It belongs to the Tiengen branch, which was later moved to Herbertingen separately.

Most of the C3 masts south of Hoheneck are still in operation (as of 2018), while the C2 masts on the northern section are being gradually dismantled.

The switching line from the Goldenberg power plant to Brauweiler, which was built in 1928 and partially runs parallel to the north-south line, is also laid on such masts. Today, however, it is only operated with 110 kV.


The seven transformer stations originally built along the line - the Tiengen transformer station was not completed until later - were all implemented by Siemens-Schuckertwerke according to a uniform circuit diagram . A total of 14 power transformers with 60 kVA each were installed. Due to fluctuations in the load, a constant voltage could not be achieved on the 220 kV line, which is why reactors with 6,000 kVA each and phase shifting transformers were installed in all substations .

The technical application of the new voltage level for the first time in Germany resulted in a number of new findings in the field of network operation.


The Brauweiler substation went into operation on October 28, 1928 in an initial expansion stage at the 110 kV level, followed a year later by the 220 kV system and the start of operation of the control room for the main control line in Brauweiler, which was moved from the golden mine . At the time of full commissioning, it was the largest such system in the world and represented the central hub for feeding the electricity from the Rhenish lignite power plants into the national network. 40 switch panels were on the 110 kV level and 13 switch panels on the 220 kV -Level set up. In addition to the logistics center, the system management network of Amprion GmbH is located here as the successor to the main control center in Brauweiler.


The Koblenz substation on the northern outskirts in the Wallersheim district established the connection to the southern RWE network area on the left bank of the Rhine. There was a connection to the two power plants in Trier and the Saar power plant in Mettlach via a 220/110 kV line . The line crossed the Rhine immediately to the east of the substation .


The Kelsterbach substation, southwest of Frankfurt am Main, served not only to connect RWE's own network in southern Hesse but also to network with other energy providers. About two-circuit 110-kV lines were in each case the main power stations at maximum , the HEAG in Darmstadt and the power plant Dettingen in the power of Prussia Elektra in Hanau and the Bayernwerk about Aschaffenburg . Another connection to the Prussian Elektra network was via a direct line to the Wölfersheim power station .


The Rheinau substation on the eastern outskirts of Mannheim was used for the network operation with the Badenwerk as well as the feed-in of electricity from the nearby large Mannheim power station . The Neckar AG hydropower plants were connected via a 110 kV line along the Neckar between Mannheim and Ludwigsburg .


The electricity from the large Württemberg power plant in Heilbronn , some Neckar AG power plants and the Pleidelsheim hydropower plant owned by Kraftwerk Altwürttemberg AG was fed in via the Hoheneck substation . It also served as a central hub for the energy supply for the Stuttgart region.


The Herbertingen substation primarily served to feed in the electricity from the Rhine power plant Albbruck-Dogern , the Aare power plant in Beznau and the Schluchseewerk in the southern Black Forest , which feed via the Tiengen substation into a 220 kV line that is routed separately to the Herbertingen substation. A coupling line led from Herbertingen to the Lechwerke network in Memmingen .


The Bürs substation, southwest of Bludenz, was the southern starting point of the interconnected line and the end point of the lines from the hydropower plants of Vorarlberger Illwerke . While the Vermuntwerk was already completed when the substation went into operation, the Rodundwerk , located downstream, followed in 1943.

Mined sections

Marxheim – Koblenz

The section between Marxheim and the Koblenz substation was completely dismantled in the years 1979-80 and replaced by a 78-kilometer 380-kV line - this is one of the few 380-kV lines in Germany. which is installed almost entirely on barrel masts. The construction of this line was connected with the construction of the Mülheim-Kärlich nuclear power plant, which was taking place at the same time , and in the course of which a new 380 kV substation was built in Weißenthurm .

Initially, the line was operated with a 220 kV and a 380 kV circuit - the second 380 kV circuit was not put into operation until 1990 and continues from Marxheim to the then newly built 380/110 kV transformer station in Bischofsheim . The former second 220 kV circuit, coming from Kelsterbach, was led to a power transformer installed in 1983 in the former 110 kV substation in Marxheim.

In the area of ​​the municipality of Hünstelden , the 380 kV circuit is looped into the Limburg substation via a 380 kV line laid on Danube masts . This line was built in 2009 and replaces a 220 kV line from the Koepchenwerk via Limburg to Kelsterbach that was built in the 1930s . The circuit, initially still operated with 220 kV, is currently (2018) being converted to 380 kV.

Shortly before the line reaches the Koblenz substation, it crosses the Rhine with two spans. In this area, it also carries two circuits of the 110 kV level. The substation itself was expanded to include a 380 kV switchgear in 2010, until then the 380 kV circuit ran past the system to Weißenthurm .


A last remnant of the old overhead line: overhead line mast converted into a cell phone mast near Weiterstadt

In the mid-1960s, the 220/110 kV Pfungstadt substation was built along the route and connected to both the north-south line and the parallel 380/220 kV line from Biblis to Urberach. From October 1989 to December 1990 a further 380 kV line was built between Griesheim and Marxheim with a transformer station in Bischofsheim , in view of the nationwide conversion of the transmission network in the Rhine-Main area from 220 to 380 kV . Although designed for four circuits, it was initially only occupied with one 380 kV circuit and one voltage-free circuit.

Since the Kelsterbach substation was located directly in the construction site of the planned northwest runway at Frankfurt Airport , the system had to be relocated. For this reason, a space-saving, gas-insulating indoor switchgear for 380 kV was used when the substation was built, so the 220 kV voltage level was omitted. Since the lines leading to the substation would not have been able to be laid as overhead lines for reasons of aviation safety due to flight operations , it was decided to reduce the existing overhead lines in order to have to lay relatively less expensive underground cables . The overhead line section of the north-south line from Pfungstadt to Kelsterbach should therefore be omitted without replacement, the section from Kelsterbach to Marxheim should be replaced by a 380 kV feed.

As a first preparatory measure, a third circuit was set up in 2005 along the 380 kV lines from Pfungstadt via Griesheim and Bischofsheim to Marxheim, which was dimensioned for 380 kV, but initially only operated with 220 kV. The overhead line between Pfungstadt and Kelsterbach was dismantled in 2008 - the 220 kV branch to the line to Urberach still exists, but is out of service. A mast stump of the dismantled overhead line was left standing and has served as a transmission mast for mobile communications ever since. The old, around 10-hectare open-air facility in Kelsterbach was demolished and the new indoor facility was rebuilt on an area of ​​around 1 ha away from the old location.

In 2009, the line section from Kelsterbach to Marxheim was replaced by a two-circuit 380 kV line on barrel and Danube masts , the circuits of which branch out in Marxheim from the direction of Bischofsheim or Kriftel and in front of the substation with a nearly 1 km long gas-insulated pipeline be guided. The 220 kV transformer in Marxheim, which went into operation in 1983, was no longer necessary when the new Kelsterbach substation went into operation due to the restructuring of the network.

The northwest runway was built from 2009 to 2011 and was put into operation on October 20, 2011.

Koblenz – Sechtem

Due to the restructuring measures in the German power grid and the new north-south routes of extra-high voltage lines required in the course of the energy transition, the line section from Wallersheim to Brauweiler has been and will be gradually converted into a 380 kV line. The original masts are replaced by other designs. At the beginning of 2009 the dismantling of the C1 masts between Koblenz-Wallersheim and Weißenthurm began. Due to the existing high voltage lines, no replacement line was built; today, a 110 kV line runs in the former route corridor as a replacement for neighboring 110 kV routes.

A year later, renovation work began between Weißenthurm and the state border with North Rhine-Westphalia . Since February 2011, the original line has been completely dismantled along with an old 110 kV line in this section and a 33 km long, combined 380/110 kV line has been in operation.

In May 2012, the roughly 30-kilometer section from the state border to Sechtem followed. Here too, in addition to the north-south line, an old 110 kV line was dismantled and the systems transferred to 92 new masts. The old masts were then dismantled. When it was completed in November 2013, the new line was able to go into operation with 380 kV as it is now connected to the 380 kV substation in Sechtem. In its final stage, this extra-high voltage line will run to the substation in Wesel , where a connection to the Dutch power grid is currently being built. The line connection then also serves to transport wind energy generated in northern Germany to the metropolitan areas in the south.

In March 2017, preparatory work began on the last section between Sechtem and Brauweiler and on to Rommerskirchen. While the old line route between Sechtem and Brühl has been replaced by a four-circuit 380 kV line together with another 220 kV line since 2018, construction between Hürth and Brauweiler is not yet possible due to a necessary change in the plan. The planned completion date is 2019. Then the last C2 masts will be dismantled.

Modifications in the existing street

Also along the remaining sections, most of which have been relocated to the original masts from the 1920s, some modifications were carried out in numerous places. In some cases, masts had to be relocated or rebuilt because they stood in the way of roads or building areas, but changes were also made in the route space. In some longer sections, the barrel masts from the 1930s were replaced by modern steel lattice masts.

Section between Bludenz and Herbertingen

New masts at the Grünkraut substation

Since 1998 a circuit of the north-south line in the area between Herbertingen and the BAB 96 near Neuravensburg has been operated with a nominal voltage of 380 kV, the connections Herbertingen-Grünkraut and Grünkraut-Obermooweiler. In contrast to the 220 kV circuit from Herbertingen to Bludenz, these circuits are operated by the Baden-Württemberg transmission network operator TransnetBW (or until March 2012 EnBW Transportnetze AG ). In the course of this, the Herbertingen, Grünkraut and Obermooweiler substations were expanded to include gas-insulated 380 kV indoor switchgear.

Originally, the changeover to 380 kV was not accompanied by a route modification or roping, as the line was designed for this voltage level when it was built in 1929. After corona discharges caused noise along the line route, which in sections leads through built-up areas, the conductors previously designed as two-way bundles were replaced by three-way bundles in these sections in 2000. Resident resistance arose against an originally planned, continuous replacement of the conductor cables, which was decided by the Ravensburg District Office on April 29, 2004, so that a court settlement was issued by the Tübingen Regional Council to the transmission network operator EnBW Transportnetze GmbH on April 28 , 2004 April 2008 approved the construction of a new line in sections.

By the end of August 2009, new masts were built in the section between the Grünkraut substation and the line branch near Neuravensburg, which, similar to the old line, can handle two circuits for 380 kV, but with conductor cables designed as four-bundles. Two masts at the Grünkraut substation and the masts on both sides of the BAB 96 had already been replaced by new buildings when the branch was built in 1998.

Connection of the line section to Tiengen

The wide spacing of the trusses with intermediate reinforcements in the fuselage suggests that this was originally a junction mast.

Even if no written evidence can be found for this, there is much to suggest that the Tiengen branch originally stood on a junction south of the village of Wolfartsweiler at 47 ° 59 ′ 42.7 ″  N , 9 ° 26 ′ 50.5 ″  E on the Bludenzer Zweig was firmly attached and was only run separately to the Herbertingen substation in 1943, when the intermediate level of the Schluchseewerk went into operation.

Rommelsbach - Herbertingen

Between Reutlingen - Rommelsbach and Herbertingen , the operator Amprion is planning to convert the north-south line for 61 km to full 380 kV operation (two circuits instead of just one) and the 220 average 43 m high original masts in this section with 181 new constructions in the form of an average 55 m high barrel type D mast . The conductor cables will also be replaced, instead of two bundles of four, bundles of four will be used, increasing the transmission capacity from 1000 to 1800 MVA per circuit. The new line connection is scheduled to go into operation in 2019.

In 2008, a junction mast for a 380 kV circuit in the Wendlingen substation was built near Rommelsbach , which leads to the route of the 380 kV line between Metzingen and Wendlingen. This enabled the 220 kV line from Wendlingen to Tiengen ( Black Forest line ) to be decommissioned and dismantled.

However, four of the original masts from 1928 are to be preserved: A 700 m long section of the line near Eningen under Achalm will remain as an industrial monument, the new line will run south of the current route.

Restructuring between Hoheneck and Mannheim-Rheinau

In the section between the Ludwigsburg-Hoheneck and Mannheim-Rheinau substations, the two lowest conductor ropes were dismantled between November 10 and December 16, 2003 in order to enable better use of the space under the line, which is now only operated with one circuit. For structural reasons, a fourth, now voltage-free conductor was left on the mast as the anchor phase . The cross struts were also implemented on a mast near Leingarten.

In the mid-1980s, a 380/220 kV line was built in the line between Neckarwestheim and Leingarten, which also carries the 220 kV circuits of the north-south line and replaces a single-circuit, parallel 220 kV line . The latter was the continuation of the line running parallel to the north-south line from Hoheneck via Neckarwestheim to Großgartach. This enabled Block II of the Neckarwestheim nuclear power plant to be connected to the 380 kV network. Even after the second 220 kV circuit was decommissioned and two conductor cables were dismantled, both 220 kV circuits, one of which is out of service, are still laid on the combination pylons.

To the west of the Bad Rappenau junction, the line crosses the A6 on very low single-level masts and passes the village of Grombach on newer Danube masts , before switching to the original C1 masts to the west of Grombach. This conversion was necessary because a makeshift motorway airport was set up south of Grombach . In the village of Grombach itself, new masts with two trusses were erected around 2009, which are only designed for one circuit. In the summer of 2009 a section of the line between Leimen and Schatthausen was relocated to the route of the 220 kV high voltage line Neurott-Hüffenhardt to make way for a new building area in Nussloch .


Pfungstadt - Weinheim

Amprion plans to build a new 380 kV connection between the Urberach, Pfungstadt and Weinheim substations by 2022, with TransnetBW continuing to Daxlanden near Karlsruhe . This will largely be built in the route space of the north-south line in the area from Pfungstadt to Rheinau, so that the original masts, including the last fully roped C1 masts, will then be dismantled.

Importance as a cultural monument

In the course of the planned renewal of individual masts in the section between Hoheneck and Herbertingen, the regional council of Stuttgart stated about the north-south line: “It is considered a pioneering achievement in the field of electricity supply and the energy industry and represents an important step on the way to today's European electricity network. “The masts in particular are“ rare, as other overhead lines significant in terms of technology history have already been dismantled ”.


  • Theo Horstmann, Klaus Kleinekorte (ed.): Electricity for Europe. 75 years of the main control room in Brauweiler 1928–2003, 284 pages, Klartext-Verlag Essen, ISBN 3-89861-255-4

Web links

Commons : Picture gallery of the north-south line  - album with pictures, videos and audio files
Commons : North-South Line  - collection of images, videos and audio files

Overviews on OpenStreetMap

Individual evidence

  1. RWE refers to the line section in the book Electricity for Europe - 75 years of the RWE main control line in Brauweiler 1928–2003 consistently as the "southern line"
  2. Norbert Gilson: The error as the basis of success. The RWE and the implementation of the economic calculation of the Verbundwirtschaft up to the 1930s, in: Helmut Maier (Ed.): Electricity Industry Between Environment, Technology and Politics: Aspects from 100 Years of RWE History 1898–1998, Freiberg 1999, p. 75 .
  3. ^ Hürth - Goldenberg-Werk. Retrieved September 17, 2018 .
  4. T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler from 1928 to 2003 . Klartext-Verlag, Essen 2003, ISBN 978-3-898-61255-5 , p. 16.
  5. Ulrich Pleitgen: In thoughts from Arthur Koepchen (1878-1954) , accessed on November 4, 2016
  6. Udo Leuschner : Kurzschluss, Münster 2007, p. 268; ders .: Basic knowledge RWE set up the first "interconnector", accessed on February 8, 2014.
  7. Norbert Gilson: The error as the basis of success. The RWE and the implementation of the economic calculation of the Verbundwirtschaft up to the 1930s, in: Helmut Maier (Ed.): Electricity Industry Between Environment, Technology and Politics: Aspects from 100 Years of RWE History 1898–1998, Freiberg 1999, p. 82 .
  8. ^ AG Atomindustrie Berlin, Chemical Industry Working Group, Cologne, p. 18: RWE - A giant with charisma. (PDF) Retrieved June 2, 2019 .
  9. Baden-Württemberg State Archives
  10. Norbert Gilson: The error as the basis of success. The RWE and the implementation of the economic calculation of the network economy up to the 1930s, in: Helmut Maier (Ed.): Electricity economy between environment, technology and politics: Aspects from 100 years of RWE history 1898-1998, Freiberg 1999, p. 78 .
  11. a b VDE Chronicle of Electrical Engineering: Power generation, power transmission and power distribution. (No longer available online.) Archived from the original on December 13, 2016 ; accessed on February 23, 2017 .
  12. ^ RWE AG: Chronicle 1921-1930. Retrieved June 16, 2015 .
  13. ^ Historical lexicon of Bavaria: United Industry Enterprises AG (VIAG). Retrieved September 30, 2016 .
  14. T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, ISBN 978-3-898-61255-5 , p. 59f
  15. United States Strategic Bombing Survey: Reports: European War, Issues 205-208 1945, p. 4.
  16. ^ A b T. Horstmann, K. Kleinekorte: Electricity for Europe - 75 years of RWE main control center in Brauweiler 1928–2003 . Klartext-Verlag, Essen 2003, ISBN 978-3-898-61255-5 , p. 62f
  17. T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, ISBN 978-3-898-61255-5 , p. 66
  18. a b Construction and operation of three high-voltage overhead lines in the area of ​​the Rhine-Main Airport on December 6, 1955 . In: The Hessian Minister for Labor, Economy and Transport (Ed.): State Gazette for the State of Hesse. 1956 No. 2 , p. 38 , item 38 ( online at the information system of the Hessian state parliament [PDF; 2.2 MB ]). mentions on p. 38 an expropriation procedure in favor of the operation of a 220/300 kV high-voltage overhead line from Kelsterbach to Rheinau .
  19. T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, ISBN 978-3-898-61255-5 , p. 88
  20. Chronicle of Frankfurt am Main Airport: From the estate of Traffic Director Rudolf Lange of Flughafen Frankfurt AG, page 167. Retrieved on April 2, 2017 .
  21. Aerial photos from 1953 , Geoportal Hessen
  22. Vogel und Umwelt, special issue birds and overhead lines . Retrieved September 17, 2018 .
  23. a b Bodnegger Mitteilungen, page 6: Conversion of the 380 kV line Herbertingen-Obermooweiler in the area of ​​the communities Grünkraut and Bodnegg, Lkrs. Ravensburg. Retrieved July 13, 2020 .
  24. Year 1928 ( Memento of May 8, 2016 in the Internet Archive ) Chronicle of Electrical Engineering, accessed on May 8, 2016
  25. Dipl.-Ing. H. Kirchhoff: company form and merchandising power: . Springer-Verlag, Berlin 1933, p. 131.
  26. The printed matter 9/1631 of 11 October 1979 , the power transmission line Koblenz-Marxheim lists on page 4 as currently under construction located.
  27. The Koblenz – Bischofsheim circuit was signposted in front of the Bischofsheim substation in 2015 as 220 kV Marxheim Ost , but in 2017 with ANK , i.e. H. a line that is currently dead
  28. a b Kraftwerke Mainz-Wiesbaden AG, page 14
  29. Explanatory report on high-voltage lines. (No longer available online.) Archived from the original on September 23, 2015 ; accessed on June 11, 2015 .
  30. This picture from April 12th, 2008 shows C1 masts without a rope in Weiterstadt
  31. ^ Energie Mittelrhein from February 6, 2009: Oldest German high-voltage line is being dismantled. Retrieved June 3, 2014 .
  32. ^ Amprion: Wesel-Koblenz. (No longer available online.) Archived from the original on June 2, 2015 ; accessed on June 11, 2015 .
  33. Amprion: project description. Retrieved July 3, 2015 .
  34. ^ Newspaper for local economy of November 27, 2013: line from Weißenthurm to Sechtem in operation. Retrieved June 11, 2015 .
  35. Amprion: Line construction largely confirmed - plan supplement required. March 14, 2018. Retrieved August 19, 2018 .
  36. ^ Amprion: Preparations for the construction of the overhead line between Rommerskirchen and Bornheim-Sechtem. (No longer available online.) March 3, 2017, archived from the original on March 20, 2017 ; Retrieved March 19, 2017 .
  37. Evidence for this: The design of the presumed branch mast, the alignment of a guy mast in the Tiengen branch shortly before it, which does not fit the current route, but points in the direction of this conspicuous mast, as well as the newer design of the masts of the Tiengen branch in the parallel section to Herbertingen.
  38. ^ Alb-Bote: New line, old route. Retrieved July 12, 2015 .
  39. ^ Amprion: Extra high voltage line Reutlingen-Herbertingen. (No longer available online.) Archived from the original on March 4, 2016 ; Retrieved July 12, 2015 .
  40. Reutlinger General-Anzeiger from June 1, 2016: Exciting information dates for the planned power line. Retrieved November 27, 2015 .
  41. ^ Picture from 1986 with a 380/220 kV line under construction and a parallel, old 220 kV line
  42. ^ Amprion: Project description Urberach-Weinheim. Retrieved September 15, 2016 .
  43. TransnetBW: 380 kV network reinforcement Weinheim – Karlsruhe. Retrieved September 15, 2016 .
  44. Stuttgarter Zeitung: Some electricity pylons remain as evidence of the times. May 7, 2018. Retrieved September 17, 2018 .