REGION Stockholm, the state-owned company developing Stockholm’s metro, has awarded Implenia an SKr 1bn ($US 101.8m) contract to build a connecting tunnel to the expanded Högdalen metro depot to provide access to from the Green and Yellow lines.
The project includes a 2km tunnel through rock and a 500m-long underground stabling area for trains. The tunnel is being built in a densely populated urban area and close to other metro routes using blasting technology. Implenia will also equip the tunnel with electrical and telecommunications systems, control systems, ventilation equipment and fire-suppression sprinklers.

The Högdalen depot is being equipped with new storage, cleaning and graffiti removal facilities, and will be able to accommodate 50 trains, twice as many than at present. To provide space for the new facilities, the depot compound is being extended 30m to the south.
“We are very proud of being chosen for this large, complex and multidisciplinary infrastructure project, fully in line with our strategy, and thank our client Region Stockholm for their trust in Implenia,” says Mr Christian Späth, head of the civil engineering division at Implenia. “We are looking forward to fruitful collaboration on the project and are glad to bring in our longstanding tunnelling expertise as well as our skills in project management and sustainability.”