ÖBB-Infrastruktur commenced construction in 2014. From the Fröschnitzgraben access shaft south of Steinhaus am Semmering the tunnel driving is taking place in two directions.
The approximately four kilometre-long section towards Mürzzuschlag is being created with excavators and blasting; the approximately nine kilometre-long section towards Gloggnitz with two tunnel boring machines. The excavated material is taken to the nearby landfill site at Longsgraben.
For the Fröschnitzgraben access shaft, two shafts more than 400 metres deep and around ten metres in diameter were built. At their foot is a cavern - a gigantic underground construction site. The construction of the tunnel tubes will start here in 2017. Later on, the cavern will become an underground emergency stop.