Katschberg Tunnel Breaks Through in AustriaThe 5,414 m Katschberg tunnel on the A10 Tauern motorway connects Salzburg with Carinthia. It is a single bored tunnel and for obvious safety reasons, such a long tunnel requires that a second tube be built. The first blast of the EUR96.5 million second Katschberg tunnel took place on 20th May, 2005. And after slightly more than ten months, breakthrough of the top heading was celebrated on 12th April, 2006. The total length of the tunnel is 5,898 m, whereof 5.4 km is bored using the drill and blast method. The cross section is approx. 90 sq m. Two attacks have been started, using one jumbo at each drive to excavate the top heading first and the benches in a second sequence. The machines are three-boom jumbos, i.e. an Atlas Copco XL3 C drill rig at the north drive and an Atlas Copco 353 SB at the south end. The explosives have been charged in the blast holes using two Normet NC carriers. Crews work seven days a week in three shifts per day. In December 2005, progress had already reached 2,750 m at the north drive and 1,350 m at the south, with only 1,300 m to go to hole through the top heading. The good geology (paragneiss in the north, black slate, green slate and phyllite in the south) enabled crews to achieve a daily advance of 15 metres. Visit www.atlascopco.com or www.boomer-rig.com and www.normet.fiSwellex bolts of Atlas Copco and SN-bolts of Alwag (250 kN, lengths of 4 m, 6 m and 8 m) reinforce the tunnel together with lattice girders (diameters of 70/20/30) also supplied by Alwag. Two Meyco Potenza concrete sprayers are used. Normet NC carrier at the Katschberg tunnel The shotcrete is not reinforced with fibres. Visit www.swellex.com, www.alwag.at and www.meyco-equipment.ch/e/machines_potenza.htmTwo Liebherr L 564T wheel loaders, six GHH MK-A30.1 dump trucks and two Liebherr R 932T excavators will muck away 420,000 cubic metres of rock. Visit www.liebherr.com and www.ghh-fahrzeuge.deThe safety equipment in both tunnels will comply with the most modern standards by means of a semi-transverse ventilation system (with ventilation slots every 100 metres), cross passages every 170-288 m, bright lighting and wall coating, radio coverage, etc. The E&M equipment will be installed from the summer of 2007.The new tunnel is scheduled to open at the end of 2007 but will remain a two-way link while the first tunnel is rehabilitated. This will cost EUR16.3 million. Opening of the two tubes to one-way traffic is programmed for the summer of 2008. Click at/21. Visit www.alpine.at, www.bemo.net and www.jaegerbau.com. To read more (in German), visit www.asfinag.at/strassenbau/ 24/06.