The bomb that exploded near the Donnersbergerbrücke on Wednesday was about two to three meters deep. Deutsche Bahn (DB) itself is currently not commenting on the circumstances why it was not discovered beforehand. It is also still unclear how the accident will affect the progress of construction.
At this point, construction is currently underway at the entrance to the western portal of the second trunk line tunnel. There the second main S-Bahn line, initially coming from Laim station, disappears underground, only to come back to the surface after seven kilometers between Ostbahnhof and Leuchtenbergring.
The railway calls the tunnel the “core” of the route, which, including the above-ground sections, will be ten kilometers long. And the effort is enormous, since large parts of the route as well as the future main train station and Marienhof stations are around 40 meters deep, while the newly planned Ostbahnhof station is only 16 meters below the ground.
The starting pit for the tunnel boring machine is currently being built at the site of the explosion. From there, the machine digs into the ground. For the starting excavation, a box-shaped so-called bored pile wall is first erected to stabilize the excavation.
In the west, the construction work is much further than in the east of the city
At this point, the bores go down to a depth of 20 meters, at the end the holes are filled with concrete, which gradually creates a stable wall. This prevents the ground from collapsing or groundwater from penetrating. From there on, the tunneling machine digs into the depths relatively quickly.
The new trunk line begins east of Laim station with two bridges. These enable the two new tracks to be extended from the existing trunk line to the new route. This initially runs on the north side of the existing tracks, then crosses the freight tracks from the Laim marshalling yard to the Südring and then passes under the Friedenheimer Bridge. In the tunnel, the new trunk line then crosses under the old one and changes to its southern side, the first underground station is the main train station.
At the other end of the main route, northeast of Haidenauplatz, the construction process is similar. Because there is still no building permit due to the rescheduling, nothing can be said about the start of construction. In the west, however, the progress is already clearly visible, especially at Laim train station, where, for example, the new tied arch bridge was installed in the summer.
The so-called environmental composite tube for pedestrians, cyclists and local public transport at Laim station is already taking shape. The railway plans to start digging the new tube next year.
Construction dust and construction noise in the heart of the city: At Marienhof, too, people have been busy digging for a long time.
(Photo: Robert Haas)
The construction work on Marienhof and the main train station is also clearly progressing. According to the railway, it is currently not yet possible to say when the actual work on tunneling will begin in the west. One thing is certain: a total of six tunnel boring machines will be used because, in addition to the two tubes for the trains, a rescue tunnel is also being dug. The machines then meet in the middle at Marienplatz, where they are to be dismantled and transported away in individual parts.
Work has been going on for more than four years on the second trunk line, and it is eagerly awaited in order to relieve traffic in Munich and stabilize the suburban train system, which is prone to disruption.
First of all, everything should be ready in 2026, then the railway corrected the schedule to 2028 due to numerous rescheduling, for example at the Ostbahnhof and the Hauptbahnhof. When asked whether the new schedule can really be adhered to, Deutsche Bahn does not yet give a clear answer. Deutsche Bahn has not yet denied reports that the project has been delayed further.