2 Sept 2015. Swedish highways administration Trafikverket has awarded to Implenia of Switzerland the first of six major drill+blast tunnelling lots for construction of the 21km Stockholm Bypass. Some 18km of the three lane alignment will be run underground at depths of up to 70m and a maximum rock overburden of 100m. A further 14km of access ramps and 4km of access tunnels make for a mega-project that comprises 54km of underground construction.
