Swiss Federal Railways has awarded Implenia a CHF 145M (£96.7M) contract to build the new Bözberg railway tunnel in Switzerland.
The 4m corridor is being added to the Gotthard route in order to encourage a further shift of transalpine freight transport from road to rail.
The largest sub-project within this scheme is the replacement of the existing Bözberg tunnel in Canton Aargau with a new twin-track tunnel.
The northern portal of the new tunnel is located near Effingen, while the southern portal is near Schinznach-Dorf. Installation sites are being set up at both locations.
The main drilling work will be done by a tunnel boring machine starting at the Schinznach-Dorf site. A loading station will be set up on the Schinznach-Brugg-Wildegg transport route to take away the spoil.
Construction is scheduled to start in spring 2016, and the tunnel is due to become operational in 2020.