The tunnel drive for Stockholm’s new power tunnel has been completed.
TBM Elektra, operated by the Hochtief-Implenia joint venture, broke through on May 3 after excavating the Anneberg-Skanstull. The Herrenknecht open gripper machine bored through hard rock 50-100m below the Swedish capital.
The 13.5km tunnel connects substations at Anneberg and Skanstull and is the second of four phases in Svenska Kraftnät’s (Swedish National Grid) City Link project. The project also includes six ventilation shafts, elevator systems, the construction of technical buildings for electrical equipment at Anneberg and the shafts across the city.
Along the full length of the 5m-diameter tunnel the TBM worked through extremely hard rock and a large volume of injected grout material was required. The tunnelling team also had to work under densely populated areas of Stockholm and in the immediate vicinity of the Strömmen passage (part of the Baltic Sea) as well as several historic and sensitive buildings such as the University of Stockholm, museums and galleries.
Implenia’s head division civil engineering, Erwin Scherer, said he was very proud of the experienced team, which applied their comprehensive tunnelling experience and showed great commitment to the project.
“I thank everyone for their excellent work and our client Svenska Kraftnät for their collaboration and trust,” he said.
