Work on the Osterberg high-speed rail tunnel has got underway near Kalzendorf in Sachsen/Anhalt, Germany.

Drill and blast excavation of the twin, 2,072m long tunnels is being undertaken by a joint venture of Porr, Interegger, Ostu/Stettin and Jaeger Bau.

Tunnelling, which commenced in January from the east portal and was formally launched in February, is programmed to finish in late 2010. By the end of March the bores had advanced 489m and 391m, respectively.

The Osterberg project is to be completed in early 2012 for a budget of Euro120M (US$160M) set by DB Nettz, the new build arm of the national rail authority Deutsche Bahn (DB). It will form part of the Leipzig/Halle to Erfurt section of the North-South high speed rail link between Berlin and Munich, which will see trains travelling at up to 300km/h from 2017, reducing the travel time to four hours, it is planned.

There are three tunnels on the 123km long route between Leipzig/Halle to Erfurt – Osterberg, Finne (6.9km) and Bibra (6.4km) – all of which are in Sachsen-Anhalt. DB aims to have this section of the high-speed line commissioned by 2015.

Drill and blast excavation of Bibra tunnel started in October last year and the twin tubes are being advanced from both portals. The alignment through red sandstone is well above groundwater level. By the end of March they had both advanced approximately 817m from the west portal and 870m from the other end. The contractor is a JV of Marti Tunnelbau, Marti and Johann Bunte

Excavation of Finne tunnel began almost a year ago with the first of two 10.82m diameter Herrenknecht Mixshields (T&TI, September 2008, p7). Geology comprises weathered sandstone and lay-silt in a fault zone, and high groundwater for part of the alignment, though drier red sandstone elsewhere will enable some NATM construction.

Advancing from the south portal, the west and east tunnel drives had progressed 3,734m (over half way) and 1,146m, respectively, by the end of March with the TBMs S-419 and S-420. A Wayss & Freytag-led JV with Max Bogl and two units of Porr is building the tunnels.

Also in February, Porr celebrated along with JV partner Max Bogl the early completion of the 5.8km long TBM drive on Lot3-4 (Munster-Wiesing) of the Lower Inn Valley rail line, in Austria. Excavation with the 13m diameter Herrenknecht Mixshield lasted 19 months, which was six months shorter than programmed.