Work has already finished on one of the first BBI construction sites. Berlin Airports completed the first section of the western rail link as planned on 30 April 2007 with the construction companies Bilfinger Berger and Max Bögl. The 90-metre long and 23.80-metre wide reinforced concrete section of the tunnel represents the western entrance to the 3.4-kilometre long train tunnel, including the BBI terminal station. The tunnel floor is laid 10.5 metres deep. It took ten months to construct and cost a total of EUR 3.7 million. It was extremely important for the rest of the construction process that the tunnel section be completed on schedule, as numerous supply and waste disposal lines for the BBI must be laid along the tunnel. The future Selchow bypass, the L75, will be laid over this tunnel.
Dr. Rainer Schwarz, CEO of Berlin Airports, appeared satisfied with the timely completion of the tunnel: "We are delighted that the tunnel has been completed on schedule. We can now start laying the supply and waste disposal lines for the BBI."