A joint venture between Swiss tunnelling specialist Implenia and Norwegian contractor Stangeland Maskin has won a role on the €2.6bn Boknafjord tunnel, work on which is due to begin this month.

The pair will work on one of three main packages. Implenia will excavate a 9km stretch of the twin tunnel, while Stangeland Maskin will construct a section of connecting road, and will also handle drainage and the transportation of spoil.

The contract is worth €375m, with Implenia’s share being €300m.

When complete in around 2030 the Boknafjord will be the world’s longest and deepest subsea tunnel, with a length of 27km and a depth of up to 392m. It will cross Boknafjord between the municipalities of Randaberg and Bokn in Rogaland County.

Erwin Scherer, global head of tunnelling with Implenia, commented: “The E03 Boknafjord tunnel is a large and complex infrastructure project … where we can contribute our many years of experience and proven expertise in tunnel construction and related civil engineering disciplines.”

Implenia said in a press release that the joint venture was selected because it offered “the best overall package and intelligent solutions”. It added that it had already worked successfully with Stangeland Maskin on the Eiganes Tunnel in Norway and was working as a joint venture on the E39 Lyngdal project.

Last month, Swedish contractor Skanska was chosen to build the northern part of the scheme. For that deal, worth €470m, Skanska will construct 18.5 km of tunnel and 2km of road above ground.