Eiksund Tunnel Sets New RecordThe 7,765 m-long Eiksund tunnel in Norway has set a new world record when the deepest point excavated so far (-266 m below sea level) was reached on 31st May, 2006 thus beating the previous record held by the Hitra tunnel, also in Norway (-264 m). However, the Eiksund tunnel will go as deep as -287 m. The tunnel features two types of cross sections: 63 sq m (Norwegian profile T8.5) on 4,700 metres and a broader cross section of 87 sq m (Norwegian profile T11.5) on 3,000 metres. The tunnel alignment is located in an area of Precambrian gneiss and is dominated by two rockgroups: granitic gneiss in the northeast and mica gneiss in the south. The transition between the two rock types happens gradually within the area of the Eiksund tunnel.Mesta, the contractor, is using the drill and blast method on two attacks with one jumbo on each drive. The jumbos have been supplied by AMV. They are both AMV 21SGBC-CC fully computerised jumbos, capable of a coverage area of 11 m x 17 m and equipped with three booms and basket, 5.5 m feeders and Montabert HC 109 drifters. Drill bit diameter is 48 mm and for long hole drilling, injection and survey, they are using 64 mm bits. The drill bits are Sandvik CAPP bits. Visit www.mesta.no, www.amv-as.no, www.rocktools.sandvik.com and www.montabert.fr. The explosives used at the site are SSE emulsions (Slurrit) from Dyno Nobel. Visit www.dynonobel.com For rock removal, one loader is used at each attack, with 4-8 Volvo 330 dump trucks at each attack. Visit www.volvo.comFor support, point anchored bolts and sprayed concrete with fibres are installed. The supplier of bolts is Orsta. The steel fibres are Bekaert's Dramix supplied by Rescon Mapei. Visit www.orsta.com, www.ct-bolt.com/default.asp?page=18&article=24, www.bekaert.com and www.resconmapei.comIn addition to working platforms and shotcrete robots from AMV, crews are also using, at both tunnel ends, AMV's latest in injection equipment, the AMV 200 computerised grouting system, three injection lines with pressure level up to 200 bar (one at each drive). The required pressure at the Eiksund tunnel is 110 bar.The maximum water ingress is 300 litres/min per 1,000 m of tunnel and at the moment, tunnellers are facing 120 litres/min per 1,000 m of tunnel. The best week was 68 metres excavated at one attack.To date, progress totals 5,700 metres (4,100 m at the attack at Sorheim, Orsta and 1,600 m at the attack at Eika, Eiksund). Breakthrough is expected at the end of this year unless if some difficulties are encountered near the deepest point. Electrical and mechanical installations will start in January 2007. Entry in service is scheduled for July 2007. Click no/21. Visit http://sveinskeide.net/eiksundtunnelen/start.htm 26/06.