Breakthrough 1155m Børtveit
With a breakthrough for the tunnel at Børtveit Kraftverk at Stord 21 July 2017, yet another managed long-distance drilling has been carried out with great results. The tunnel with a diameter of Ø740 mm over a length of 1155 m will replace the existing pressure shaft to the Børtveit power plant, which is made with pipe gate in the day. After the drilling has now been carried out at the bottom of the drained hopper, the work with the lining of the tunnel over full length must be started immediately. The work with lining is also performed by Norhard. The tunnel must be lined with Ø660 mm steel pipes which are successively welded and pushed in from the lowest end of the tunnel.