At one point, the tunnel passes 12m below the Stromsas traffic tunnel. The reddish Drammen granite is said to be relatively easy to drill. Around 165,000m2 of contact grouting has been undertaken to minimise water ingress and the destructive effects of freeze-thaw cycles. So, far drilling and blasting has resulted in around 100,000m3 of spoil which is being used for land reclamation purposes in the River Drammenselva, and at Holmen Docks, Drammen.
There are 90 operators and 50 office workers on the site with work undertaken in two shifts of 10-12 hours. Reports confirmed that as a result of strict hygiene requirements, no one has tested positive for Covid-19.
Epiroc is supplying significant machinery to the project, including Boomer drill rigs XE3C and E2C, and the Scooptram ST18 loader, which is being used to clear blasted rock from three escape tunnels totalling 1,400m in length. Three workshops have been created within the tunnel for maintaining and servicing equipment.
The work started in autumn 2019 and is expected to complete in 2024.
