The Rennsteig Tunnel
The Rennsteig Tunnel, with two tubes each approx. 7,900 m in length and the longest road tunnel in Germany, was built by Wayss & Freytag Ingenieurbau AG in a joint venture between 1998 and 2003. This tunnel is the heart of the new A71 motorway connecting Erfurt to Schweinfurt and is situated at the ridge crossing of the Thuringian Forest between Geraberg and Suhl.
The two conventionally driven tunnel tubes were connected to each other every 300 m for safety reasons, whereas every second emergency tunnel is situated within a breakdown area and is fit for traffic. The tunnel lining consists of an outer shotcrete shell that is reinforced with lattice arches and reinforcing steel, a sealing of 2 mm thick plastic sheeting as well as a 30 to 40 cm thick reinforced concrete inner lining. In the area with a tectonic disturbance in the Kehl Valley, the conventional tunnel drive was carried out under the protection of a pipe umbrella over a length of 160 m.
Further details:
- 7,916 m length of the West tunnel
- 7,878 m length of the East tunnel
- 1.35 Mio. m³ excavation
- 80 m² standard cross-section
- 120 m² tunnel cross-section in breakdown areas
- 135,000 m³ shotcrete
- 290,000 m³ concrete of inner lining
- 8,000 t reinforcing steel