Fifty-five hours. For this time, the Autobahn 7 is to be closed this weekend between Volkspark and Waltershof in the direction of Hanover. Nothing has been going on the southbound route since Friday evening and until Monday morning, traffic is being diverted via the A1 and the city center. In the coming week there will be another closure in the direction of Flensburg. The reason for this is construction work for the construction of the Altona cover – one of the largest and probably most spectacular motorway projects in Germany.
Two days before the major closure, WELT AM SONNTAG met project coordinator Karina Fischer at the construction site. Entry is the bridge at Kielkamp. After 2028, when the 2230 meter long cover is finished, what was separated when the A7 was built in the 1970s will be brought together here: the Luther Park, laid out around the Luther Church in Bahrenfeld. But from the bridge you still have a good view of the construction site and the work that is scheduled for this and the coming weekend.
To the south, the view falls on the bridges of Bahrenfelder Chaussee, Osdorfer Weg and Behringstrasse. When the A7 was last closed in the Altona area in March, some of the bridges were demolished, leaving only half of the original lanes.
“The bridge over the Bahrenfelder Chaussee was particularly stubborn and time-critical,” says Fischer. Because the bridge was originally intended to withstand the route of a tram line, it was filled with significantly more metal than the construction site planners had expected. After the scheduled 79 hours, the northern part of the bridge was demolished and most of the rubble was removed.
The first replacement for the bridge section is to be built this weekend. In contrast to the previous tunnel projects in Schnelsen and Stellingen, however, the bridges in Altona will not be largely replaced by makeshift bridges. Instead, the construction of the tunnel segments on which roads such as Osdorfer Weg or Bahrenfelder Chaussee will later run is being preferred.
For this purpose, the motorway builders have already set up the future tunnel walls in the middle and on the outside in the past few weeks. They started with drilling up to 30 meters deep into which the foundation pillars of the future tunnel walls were cast. The construction of the actual tunnel walls followed later. This weekend, the first of around 100 pre-cast reinforced concrete beams will be placed and anchored on them. In the coming week, the parts will then be placed on the other side.
This should actually happen on all three bridges, some of which have already been demolished. But the work on Behringstrasse has been delayed. In this area directly north of the Elbe tunnel, deviations from the calculated data were found during drilling, explains Fischer. “Now that needs to be looked into more closely. We are working while traffic is moving, so we cannot take any risks for the motorway.” That is why the foundation work cannot be continued at the moment and the prefabricated parts cannot be used during the closures.
Anyone who has been stuck in traffic on the A7 over the past few days could have already seen parts of the future tunnel ceilings: slightly curved concrete beams with steel rods sticking out at the top. Where there is enough space next to the motorway, the construction companies involved have temporarily stored the beams. “The rest is in the Braun car park at the Volksparkstadion,” explains Fischer. There is even a concrete production plant for the construction site. Because once the prefabricated parts have been laid, connected and boarded up, they are then poured into their final form with concrete.
In the fall, the new sections of the tunnel should finally be ready for traffic to roll over them. In November there will be another full closure of the A7. 79 hours for the demolition of the remaining halves of the bridge.
Fischer’s phone rings, a journalist. He wants to know why the A7 had to be closed on a weekend during the peak travel season during the summer holidays. A valid question. “I understand that,” Fischer replies. “We had to take into account other construction measures such as the A1 and also events such as the triathlon in Hamburg, because you can’t divert traffic through the city,” she explains.
And she makes it clear that it is difficult to completely avoid the holiday travel season, which lasts ten weeks across all federal states. “We mustn’t bring our construction site to a standstill.” But wouldn’t there have been a solution other than a complete closure in each direction? You have played through several scenarios, she replies routinely. “Believe me, with this solution there are the fewest restrictions overall.” Otherwise, the insertion of the tunnel sections would have taken weeks, for which lanes would have been lost again and again. “It’s like peeling off a plaster. It’s bad for a moment, but over quickly.”
Karina Fischer has been in charge of the tunnel projects in Hamburg for years. She remembers that she was involved with the cover Altona from the start. She was already involved in the first variant planning. Today Fischer’s employer is the Autobahn GmbH des Bundes. Here the federal government has bundled all of its motorway projects in new ways and has taken responsibility for tasks that it had previously outsourced to the federal states.
The people who worked on the A7 expansion project, for which DEGES took over the planning and construction, have largely remained the same, says Fischer. And there are many, she herself is just the coordinator who speaks to the outside world. When she was recently made “mistress” of the construction site by a medium, she was very irritated and annoyed.
Meanwhile, northbound traffic has come to a standstill next door. Drivers observe what is happening on the construction site from the traffic jam. Two young men wave from a convertible. This reminds Fischer of an anecdote that local residents told her. “When the autobahn was just being built, many people in Hamburg walked along it, waved and were happy when a car drove by.”
Today, the A7 is one of the busiest autobahns in Germany. In sections in Hamburg there are up to 154,000 vehicles a day. A congestion that should be mitigated with the expansion of the highway. Because the motorway will later be wider and cause more noise, noise protection must be improved.
This is also the reason why the cover – which is officially called the noise protection tunnel – is being built over the Altona section. The first call for a cap on the Autobahn came in the late 1980s. At that time, the CDU and the Greens in the Altona district assembly applied for a roof over the motorway. But little happened for decades – mainly because neither the federal government, as the responsible body for the motorway, nor Hamburg wanted to assume the costs for better noise protection. The turning point only came with the plans to expand the A7. Finally, in 2016, the Senate and Parliament decided to extend the 730 meter long cover planned by the federal government to 2230 meters.
In the future, the tunnel will start in the north just behind the Volkspark junction and end in the south about 300 meters before the Elbe tunnel. In April 2021, the then Federal Transport Minister Andreas Scheuer (CSU) and Hamburg’s Transport Senator Anjes Tjarks (Greens) accompanied the start of construction work.
At the start of construction, Tjarks emphasized the urban significance of the project: “The Altona motorway cover will enable Hamburg to repair the city on a historic scale: it will bring together entire districts and it will massively protect the health of the people who live there.”
The covering of the motorway section creates space for the construction of 3800 apartments, 3000 of them in Altona. However, they should not be created directly above the tunnel. It is planned to move allotment gardens to the concrete cover and to use the freed-up areas as building land. The completion of the first tunnel tube is planned for the end of 2025. From then on, all motorway traffic should disappear under the concrete cover. The construction costs for the project amount to 790 million euros. Hamburg will take on 291 million euros of this.
That it works can be seen further north: At the end of 2019, a first noise protection tunnel was completed on the A7 in Hamburg-Schnelsen. A second tunnel in Hamburg-Stellingen was officially put into operation in 2021.
