Robbins TBM Will Challenge New Heights in the AndesAssembly of a Robbins 5 m-diameter main beam TBM was completed in September 2006 for the Olmos trans-Andean project in Peru. Odebrecht awarded the complete contract for the TBM, back-up, spare parts, cutters, and operations personnel to Robbins in spring 2006. The TBM is scheduled to begin boring in the first quarter of 2007. The TBM will excavate a 13.8 km section of the 20.1 km trans-Andean tunnel, over 1,000 m above sea level. The Andes rise more than 1,800 m directly above the tunnel. The high cover creates several challenges, including very high ambient air temperatures of up to 52°C in the tunnel. A total of 6,222 metres (4,301 metres of tunnel and 1,921 metres of access adit) has been bored in the past. The total length remaining to be bored totals 15,009 metres. Visit www.robbinstbm.com Two interacting air-cooling systems will help combat the high temperatures in the tunnel. Air chiller systems mounted on the back-up deck and free-standing air chillers will cool the tunnel to 32°C or below. The TBM is capable of installing ground support including roof bolts, wire mesh, ring beams, and shotcrete for boring through the challenging quartz porphyry and andesite geology (UCS of up to 225 Mpa or 33,000 psi). A probe drill mounted on the machine will be used in areas where there are anticipated fault zones and the types of ground support installed will depend upon the geology encountered. The back-up will feature a two-TBM-stroke, double-track system for rail muck cars. Tunnel lining will involve installation of cast in situ tunnel lining in areas of bad ground after the TBM is removed from the tunnel. The Olmos project will transfer water from high altitudes in the Andes to a reservoir at Limon Dam in Peru for hydroelectricity and irrigation. The tunnel will transfer over 2 billion cubic metres of water annually from the Huancabamba River, a tributary of the Amazon, to the Olmos Valley on the Pacific Ocean watershed. The water will be used to irrigate 1,502 sq km of farmland and to generate 600 MW of electricity at a proposed hydroelectric station. The Peruvian national government and the Lambayeque regional government signed in July 2004 a 20-year build-operate concession to Concesionaria Trasvase Olmos, a subsidiary of Norberto Odebrecht of Brazil. Preliminary works commenced in February 2006. Click pe/17. Read E-News Weekly 22/2003. Visit www.peot.gob.pe/polmos.html 44/06. The TBM's probe drill will be used in conjunction with various ground support systems to bore through challenging geology