COP 3038 Rock Drills Shape Norwegian HydroBirkeland Entreprenørforretning is in joint venture with Spilde Entreprenør to build the first phase of the 41.8 GWh Kløvtveit project in Hordaland, Norway. Birkeland has been the first Norwegian contractor to order a drill rig equipped with the Atlas Copco COP 3038 super fast hydraulic drills to drive tunnels for client BKK. Visit www.spilde.no and www.bkk.noIts new Atlas Copco Rocket Boomer L2C30 is currently completing the first tunnel to tap water from the mountaintop lake Kløvtveitvatnet in the Gulan province on the shores of the Austgul fjord. The joint venture has completed the power station, and most of the penstock pipeline running down the slopes of the fjord valley from near the tunnel portal. Access to the tunnel portal has been achieved by constructing a 25% grade, rockfill road with hairpin bends from the power station level to the required elevation. Birkeland is driving the last 85 metres of the 17% grade tunnel approaching the lake tap. The tunnel section is being increased vertically to enable the L2C30 to be positioned correctly to drill a steeply inclined round for a short, 2.5 m-diameter shaft to be excavated. With the final blast, this will break through to the bed of the Kløvtveitvatnet, thus providing the water source for the power plant. The 670 m-long 20 sq m tunnel is formed in two straight runs forming a 'dog leg' in changeable ground conditions in hard gneiss. Birkeland has achieved 30-55 m per week progress using 59 6-m blast holes across the face. Atlas Copco Secoroc Magnum SR bits of 48 mm diameter are used for most of the holes. Blasting uses normal ANFO mix with Dynomit primers and Nonel LP detonation. After blasting the face is scaled with an Atlas Copco 2004 hydraulic breaker mounted on a Caterpillar M316 wheel excavator. Three 30-tonne trucks (one Volvo and two Mercedes) are loaded at the tunnel face with a Cat 980G wheel loader. Visit www.boomer-rig.com, www.atlascopco.com/secoroc, www.cat.com, www.forcit.fi and www.dynonobel.comNo permanent tunnel support is required as the tunnel will be filled with concrete around a 1 m-diameter pipeline. The pipeline will be installed to connect up with that on the valley surface to link with the power station before the final breakthrough into the Kløvtveitvatnet. Work will be completed on this part of the project by January or February 2006 after which snow may make access difficult.Birkeland has also won the contract for the second phase of the project, which involves two more tunnels to create water passages from the Transdalsvatnet to the Kløvtveitvatnet and from the dammed Austgulsvatnet to the eastern branch of the Kløvtveitvatnet. Birkeland will excavate a third tunnel under the Miåneset headland. These later three tunnels will be commenced in 2006, with the whole project due for completion in 2007. 47/05.