Implenia has received an order from the Austrian Federal Railways to build the Semmering base tunnel for CHF 770 million. Implenia has a 50% stake in the consortium, or CHF 385 million. With a total length of 27.3 km (14.73 miles) the Semmering base tunnel is part of Austria's new southern railway, which is meant to be the central axis for trans-European routes from the Baltic coast to the Adriatic.

Implenia's order includes the work on the 13 kilometre long middle section (Lot 2.1). This section includes 26 cross passages, an emergency stop station and two 400-metre ventilation shafts to supply the entire construction site. Construction works will last some ten years starting from January 2014.