Part of the Carola Bridge in Dresden collapses into the Elbe during the night. An important traffic artery is impassable. The city narrowly escapes a catastrophe. How could this happen?
Dresden narrowly escaped a catastrophe when the Carola Bridge partially collapsed. A section of the bridge, about 100 meters long, over which tram tracks and a footpath and cycle path ran, collapsed into the Elbe in the middle of the night. Another section is in danger of collapsing. Fortunately, no one was injured or killed. The police see no evidence of external influence and assume that it was an accident. But what caused the disaster?
Only minutes between last tram and collapse
The bridge is considered one of the most important traffic arteries in the city, and spans the Elbe in the city center. The collapse could have ended even worse: the last tram crossed the Carola Bridge just 18 minutes before the partial collapse. The tram crossed the bridge at 2:50 a.m. and the bridge collapsed at 3:08 a.m., the transport company said.
When Holger Kalbe, responsible for the safety of all bridges in Dresden, appears before the press in the morning, he appears visibly shaken. “Believe me, this is a morning you never want to experience,” said the head of the bridge and civil engineering department at the city of Dresden.
“The ground shook”
The first information about the bridge collapse came to the police during the night from their own colleagues: “We received the first report today shortly after 3 a.m. It was our own colleagues who were carrying out security measures at the Jewish synagogue 50 meters away,” reported police spokesman Thomas Geithner. “They described it as a large, heavy noise. The ground was shaking.”
Relief over a mild outcome
Saxony’s Prime Minister Michael Kretschmer (CDU) and Dresden’s Mayor Dirk Hilbert (FDP) are relieved that no one was injured. “It was a minor incident,” said Kretschmer. It is unthinkable that if it had happened during the day, there would have been trams and cars on the bridge. “We can only be grateful that no one was hurt in this terrible event,” said Dresden’s mayor Hilbert.
Corrosion as a cause?
The Carola Bridge is a prestressed concrete bridge built in 1971. Two of its bridge sections, parts A and B, have already been renovated in recent years. Part C, which was due to be renovated next year, has now collapsed. “This is a risk that we have been dealing with for many years,” said department head Kalbe. “It was not foreseeable that the condition of section C was so bad that it collapsed.”
The investigation into the exact cause of the accident is still ongoing, but Holger Kalbe has at least made one assumption: corrosion could be responsible – a result of poor maintenance in the past. “We had massive chloride ingress here during the GDR era,” said Kalbe. At the point where the bridge section collapsed, there was a mast belonging to the public transport company. It is conceivable “that massive chlorides penetrated that spot and led to corrosion of the reinforcement inside the bridge.”
Bridge construction specialist: A disaster that nobody predicted
Bridge construction expert Steffen Marx described the collapse as a disaster. “It is a disaster in particular because no one predicted it,” said Marx, who is a professor at the Institute of Concrete Structures at the TU Dresden, on site. “The structure must now be classified as being in complete danger of collapse.”
As one of the first large prestressed concrete bridges in the GDR, the Carola Bridge has all the shortcomings that such a structure from the early days of prestressed concrete bridges had. “One particularly tragic shortcoming is that the bridge has no redundancies, which means that if anything happens, it will collapse,” explained Marx.
District heating supply affected
The collapse also affected the district heating supply in Dresden. Two pipes burst and the escaping water completely flooded parts of the Terrassenufer. Only gradually can parts of the city be reconnected to the network.
And the emergency services are looking at the weather forecast with concern: the Elbe could flood. This is a problem because of the debris in the river. According to the German Weather Service, extremely heavy rainfall is expected in central Czech Republic and the Isar Mountains, among other places. This will have an impact on the Elbe and other rivers – the water is expected to rise.
Collapse site cordoned off
The police cordoned off a large area around the collapse site. Car traffic and trams were diverted. People were told to stay away as much as possible. Nevertheless, hundreds of onlookers gathered on the Elbe to catch a glimpse of the collapsed bridge.
The remaining parts of the bridge cannot be used until further notice. The remaining two bridge sections will not be released in the short term, said Kalbe. The collapsed part of the bridge was connected to the other bridge sections at one point. There was damage there too. The entire structure must now be checked.
Current traffic test on the bridge
The collapsed bridge section of the Carola Bridge in Dresden was to be repaired next year. In addition, a traffic trial on the bridge was to be carried out until the end of the year, with the aim of making the bridge safer for cyclists and pedestrians. The trial and the plan were controversially discussed. The Dresden AfD criticized the wrong prioritization in transport policy: the money for the traffic trial would have been better invested in static safety measures.
Police: No grounds for criminal proceedings
The police are currently assuming that the partial collapse was an accident. “There is zero evidence of any criminal behavior. There is no investigation,” said police spokesman Geithner. The aim now is to determine the exact cause. If it turns out that mistakes were made, then criminal proceedings would be initiated, said Geithner. “But these indications are lacking at the moment.”