In order to fully fulfill its supply mandate, SachsenEnergie must temporarily lay a second main supply line for district heating over the Augustus Bridge for the winter of 2024/2025. This is the result of the district heating experts’ forecasts and calculations. Immediately after the partial collapse of the Carola Bridge and the destruction of one of the main supply lines for Dresden’s district heating system, various variants for a second main connection between the two sides of the Elbe were planned and presented to the city.
“We can’t waste any time. The Augustus Bridge is the only Elbe crossing over which we can lay the temporary district heating pipes by mid-November. It is the fastest and safest solution. Only on this bridge can we connect the pipes directly into the distribution network. We have no other chance than this to secure comprehensive heat supplies in the northeast of the city in time for the start of winter. As a municipal utility, this is our mission, which does not allow any risk. Because no one knows today when the first frost will come and how cold the winter will be,”
explains Dr. Rutger Kretschmer, head of the power and heat business area, explains the situation clearly.
Hospitals and residential units must be able to be fully supplied at all times
The calculations come to the conclusion that without a temporary main line across the Elbe, when the outside temperature is around 0 °C, full heat can no longer be delivered to every customer. “Especially for the hospitals on the Neustädter Elbe side and another 36,000 sensitive residential units, this is unreasonable over a longer period of time,” emphasizes Dr. Kretschmer. Construction work on the temporary line began immediately after the city gave its approval a few days ago.
SachsenEnergie is laying two black pipes – for the supply and return of the district heating – with an outer diameter of 56 cm (inside diameter 40 cm), 1.60 m wide along the entire western footpath of the Augustus Bridge. At the blockhouse on the Neustadt side and in front of the Italian village on Theaterplatz, they will disappear into the ground and be connected to the distribution network. “The pipes are covered with plastic and have an outside temperature of 25 °C. They pose no danger to the surrounding area,” explains David Falkenberg, who is leading the construction of the temporary district heating pipes over the August Bridge.
There is no alternative to relocation to the Augustus Bridge
As an alternative to the Augustus Bridge, SachsenEnergie has also examined three variants of a temporary pipe bridge on the existing pillars of the Carola Bridge, freely hanging or on new pillars. All three variants had to be rejected because they took too long or there were too many risks with regard to the stability of the pillars or cables. A second culvert was also considered, but is not an option as a short-term solution due to the long construction period. “We can only achieve our goal of ensuring that there are no supply bottlenecks in winter and that no one has to freeze by laying the temporary cables on the Augustus Bridge,” sums up Dr. Kretschmer.
At the same time, the pipes at Carolaplatz are being repaired
As a first step towards restoring full heat supply, SachsenEnergie has been replacing the irreparably damaged pipes at Carolaplatz since September 23rd. This increases the hydraulic capacity again and more district heating can flow through the pipes in the same time at the same pressure. The new lines are scheduled to go into operation in mid-November.
“We now have two large district heating construction sites at the same time, where every day counts. Both measures have the highest priority and therefore require all of our strength,”
emphasizes Falkenberg. Due to this unplanned major task, there may be delays in other SachsenEnergie construction projects.
At Carolaplatz, SachsenEnergie is laying 300 m of new district heating pipes with a diameter of 50 cm directly at the Neustädter bridgehead. This will close the district heating connection between the two Königsufern, increase the hydraulic capacity and allow the district heating to flow more quickly into Dresden Neustadt.
Background of the construction work
Due to the partial collapse of the Carola Bridge, one of two main supply lines with district heating between the two sides of the Elbe was irreparably damaged. Since then, the district heating produced in the power plants on the old town side has been transported to the other side of the Elbe through the district heating culvert under the Elbe (near Marienbrücke) and then distributed into the district heating network. In addition, the large connection lines at Carolaplatz were completely destroyed by the collapse of the bridge. This means that after the district heating has flowed through the culvert, it is currently transported further to the north-east of Dresden through thinner pipes.
(Source: SachsenEnergie)
