It will take a while until the second S-Bahn main line is completed, i.e. another decade. At least something is moving underground now. On Wednesday, Deutsche Bahn (DB) began digging the first tunnel. It is rescue shaft 3 in Arnulfpark not far from Hackerbrücke. The rescue structure is 34 meters deep and 55 meters long.
Bärbel Fuchs from the Bavarian Railway Company (BEG) took over the tunnel sponsorship. She is supposed to bring the construction workers luck during the construction phase, so to speak, as an earthly representative of Saint Barbara, the patron saint of miners.
Pastor Florian Wagner presents tunnel sponsor Bärbel Fuchs with a figure of Saint Barbara.
(Photo: Sven Hoppe/dpa)
The symbolic tunnel stop underground.
(Photo: Sven Hoppe/dpa)
With the opening of the tunnel to the rescue shaft, a new phase has been reached, says overall project manager Kai Kruschinski-Wüst. The tunnel structures are the “heart” of the second main route. According to a railway spokesman, the large tubes through which the trains will later run will probably be dug with huge tunnel boring machines in 2026 and 2027.
The small tunnel at Arnulfpark is being built using a mining method using compressed air rather than tunneling machines. The tunnel cross-section is removed from the subsoil using an electrically operated hydraulic excavator and then secured with shotcrete and in-situ concrete shells.
Around 120 specialists from all over Europe are deployed, working in a shift system around the clock, seven days a week. Because the rescue shaft passes under eleven tracks in the apron of the main station, the DB monitors this sensitive area with around 2,000 measuring points. The DB is also temporarily lowering the groundwater level in the construction area with the help of 21 wells.
A total of around 4,500 cubic meters of earth will be excavated for the structure. This corresponds roughly to the volume of two and a half Olympic swimming pools. Rescue shaft 3, which the DB also calls the “Bärbel Tunnel”, is one of a total of nine tunnels on the second main line. In the future, this will consist of four traffic tunnels, two rescue tunnels, two rescue shafts and a connecting tunnel from Marienhof to the U3/U6 subway lines. There are also 16 cross connections.