Krolsky Tunnel Ends, Mansky Tunnel to CommenceContractor OAO Bamtonnelstroy has announced the Lovat RME375SE series 21400 TBM has broken through on the Krolsky rail tunnel, the first rail tunnel built by a TBM in Russia. Excavation of this challenging tunnel, constructed for the Russian federal railways, was completed on 30th May, 2008 at the eastern portal. The 9.5 m-diameter mixed face TBM bored the 2,254 m tunnel through varied and difficult geological conditions. Equipped with 394 mm disc cutters, the TBM drove through blocky grounds, slate, and granite ranging up to 250 MPa, as well as water saturated loose soils. Several fissures and fracture zones were encountered. The fractured nature of the rock resulted in high permeability, with water inflow rates of 30 to 300 cu m/hour. Click here. Visit www.lovat.com German company tacs provided the electronic target. The video target determines the coordinates of the laser hit point by means of high precision video cameras and special recognition software. Visit www.tacsgmbh.deThe TBM will now be refurbished, with upgrades supplied by Lovat for the nearby Mansky tunnel, a 2,500 m drive through similar geological conditions. 28/08.