Technical specifications

Project description

  • Double-track railway tunnel KL=1,695 m
    closed construction method, L=1035 m, A =110-125 m²
    Cut and cover method L=400m
    top-down method L=210 m
  • 3 emergency exits
  • Open land section, L=5,898 m
  • Earthworks, drainage works, noise protection, accompanying paths, retention areas


  • 1 underpass structure
  • 1 stormwater bridge

Construction method

  • Closed construction method:
    combination of tunnel excavator and drill and blast
  • Cut and cover and top-down method
    with separate bored pile sheeting


  • Quaternary: Sand, gravel
  • Neogene: sandstone, silt / clay/ marl- rock, silt

General data

Koralmbahn (railway) Graz–Klagenfurt B 1581
Lot 3 – Hengsberg Tunnel,

ÖBB Infrastruktur Bau AG

Wayss & Freytag Ingenieurbau AG
as technical leader of a joint venture

Construction period
2007 to 2010

Construction costs
€ 76.8 million

Railway tunnel, double-track
2.730 m
Construction Method
Drill and blast method in combination with tunnel excavator
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