District heating network expansion on schedule

Essen. The first construction section in the expansion of the district heating network in Essen, operated by STEAG, is totally on schedule. With the successful crossing below Schützenbahn street, an important step towards completion of the works on time has been taken. “Now, there’s nothing to stop the ‘Am Heimbusch’ housing estate being connected to the district heating network by the end of September,” says Dr. Peter Schäfer, Managing Director of STEAG Fernwärme Essen GmbH & Co. KG and also Chairman of the Board of the municipal utility Stadtwerke Essen.

STEAG is gradually expanding its district heating network within and along the nine Essen districts of Frillendorf, Kray, Südostviertel, Huttrop, Bergerhausen, Rüttenscheid, Stadtwald, Margarethenhöhe and Bredeney. For this purpose, a new underground main district heating line will be laid over a distance of six kilometers. Residents in these districts will then be able to use the reliable, convenient and climate-friendly district heating system and by doing so support the transition to sustainable heating in their local area. The partners STEAG and Stadtwerke Essen have taken a major step towards this goal with the construction phase now nearing successful completion.

Successful non-intrusive crossing at Schützenbahn
The crossing of the busy Schützenbahn street and the streetcar tracks that also run on it involved a large amount of engineering effort. “Using a drill head, we first drilled three parallel tunnels under the road, around 51 meters long,” says STEAG’s project manager Georg Röttgers. In doing so, the drill head not only prepared the way forwards, but also pulled reinforced concrete tubes with a total diameter of 128 centimeters each from the rear.

Two of the three tunnel tubes created in this way will in future be used to supply district heating. The corresponding district heating pipes have already been laid in the concrete tubes and have been or will soon be connected to the upstream and downstream district heating pipes. “We have constructed the third tube as a vacant conduit in consultation with the Stadtwerke Essen municipal utility. In future, it will be able to accommodate Stadtwerke lines without having to set up another major construction site to cross under the road,” explains Georg Röttgers.

Rapid progress on Elisenstrasse
The work in the Elisenstrasse area has been similarly rapid and successful. Since the end of March, the road has only been accessible as a one-way street in the direction of Burggrafenstrasse. Since then, no less than 1.3 kilometers of district heating pipes have been laid there. “This means that connection to the new main supply line, the eastern line, in the Burggrafenstrasse area is imminent,” says the project manager. The supply of the housing estate with climate-friendly district heating can therefore take place in the foreseeable future. “At the same time, completion of this section of the route is an important milestone for the future supply of district heating to the Aldi Campus.”

The challenge of a double track crossing
At the same time, there are currently slight delays at two points along the eastern line. “In the area of both Susannastrasse and Richard-Wagner-Strasse and the tunnel on Burggrafenstrasse there is currently still a need for coordination with Deutsche Bahn, because we have to cross railroad tracks at both points,” Georg Röttgers explains. The reason for the additional planning requirement is, among other things, the result of the preliminary geological investigations in the Susannastrasse area.

“Here it has been shown that the originally planned tunneling below the tracks is not possible because subsoil conditions do not permit an underpass at this point,” says Georg Röttgers. For that reason the company had to change plans and is now preparing an above-ground crossing of the railroad tracks there in cooperation with Deutsche Bahn. Due to these unforeseeable circumstances, it can be assumed that the construction work at this location will not be completed until 2021.

In the area of Burggrafenstrasse, too, applications have now been submitted to Deutsche Bahn for pipe driving under the three existing railroad tracks as an alternative to laying the district heating pipes in the existing tunnel. This will avoid obstructions to traffic in the tunnel area. The applications are currently still being examined by Deutsche Bahn, and so the actual construction work can only take place next year.

District heating partners give a positive assessment of the first construction phase
Notwithstanding these new challenges that only emerged during the course of the project, the project partners STEAG and Stadtwerke Essen have given a thoroughly positive interim assessment of the work carried out to date on this technically highly demanding major project. “The eastern line is not only an important project for our two companies. It is also a central element in the efforts of the city of Essen to take a major step forward in the energy transition at a local level,” says Michael Straus, Managing Director of STEAG Fernwärme GmbH. “The fact that we can make an important contribution to achieving this goal with the eastern line fills us, as an Essen-based company, with pride.”

At the same time, STEAG is well aware that the construction work on this major project over the past 18 months has undoubtedly been fraught with inconvenience for the citizens of Essen. “We would like to express our sincere thanks for the patience and understanding that people in the city have shown in the face of the many construction sites,” says Michael Straus. “We have succeeded in proving that this patience and understanding was justified by speedy, clean and – except for unforeseen circumstances – on-schedule work.

Felled trees are replaced
This also includes the commitment that wherever trees have had to give way to the construction measures, replacement plantings are provided. “We are in constant communication with the city of Essen and the municipal park service Grün & Gruga,” Michael Straus explains and assures that the company will also fulfil its commitments in this respect.

Photo caption: "On site, Tobias Grau (Stadtwerke Essen), Michael Straus and Georg Röttgers (both STEAG) get a picture of the status of the project (from left to right)."