Lovat Selected for RAV Line by SNC-Lavalin and SELILovat has been selected by the SNC-Lavalin - SELI JV to supply a soft rock Earth Pressure Balance TBM, that will be used to bore 2.1 km twin tunnels (view alignment maps here), from False Creek South station to beyond Robson station in Vancouver. Lovat will design, custom manufacture, and test a new 6.1 m-diameter TBM for delivery to site by 15th March, 2006. Tunnelling is programmed to commence on 1st May, 2006. The TBM will be designed for conditions of up to 4 bar EPB pressure and an advance rate of 15 cm/min. The tunnels will pass beneath False Creek where a 4-metre tidal range will cause twice daily fluctuations in EPB pressures of up to 0.5 bar. After passing under the ocean under False Creek bay (with expected water pressure of up to 3 bar), the tunnels will thread their way under and between high rise condominiums and office towers, negotiating multiple 200 m-radius curves to avoid building foundations. The geology along the alignment will consist of sandstone (containing volcanic dykes) and glacial till (which contains very large granitic boulders). To cope with the varied geotechnical conditions, a ground conditioning system comprising of foam and polymer will be used. Additionally, a bentonite ground loss replacement system will be used for fine control of EPB pressure.The cutting head of the TBM will be open-type, with 17" disc cutters powered by a 1,200 kW VFD (Variable Frequency Drive). The tunnel will be lined with prefabricated concrete segments. The segment moulds will be supplied by Same. The excavated material will be mucked away by a Schöma train. Visit www.lovat.com, www.schoema-locos.de and contact s.a.m.e@samesnc.comThe contract to bore the tunnels, cross passages between them every 250 m, shafts and three stations at Robson, Yaletown (Davie) and False Creek South (Second Avenue) is worth about EUR130 million. The tunnels form part of the Richmond-Airport-Vancouver (RAV) line, a light rail connection between Vancouver International Airport and Richmond city centre with downtown Vancouver due to enter in service in 2010 for the winter Olympic Games. Click ca/24. Visit www.snc-lavalin.com, www.selitunnel.com and www.ravprapidtransit.com 40/05.