Rowa Tunnelling Logistics Back-up for Niagara Falls TunnelA 10,421 m-long tunnel underneath the City of Niagara Falls will feed more water to the existing Sir Adam Beck hydroelectric plant in Ontario, Canada. In addition to the tunnel itself, the tunnel's inlet and outlet as well as all auxiliary work are to be designed and built.Strabag contracted Rowa Tunnelling Logistics to develop, manufacture and supply a back-up system compatible with the 14.4 m-diameter gripper TBM to be supplied by Robbins. Click here. This 105 m-long back-up system consists of four elements on four levels. The first element is equipped with a stepper installation, while the remaining three are towed on running gears.In addition to the usual infrastructural components, two rock bolt drilling machines for anchor lengths of four to six metres are installed on the back-up system. Also, two newly developed longitudinally displaceable all-round spraying robots with a spraying area of 360° have been installed. The removal of the excavated material will take place by means of a conveyor belt installation, starting with the machine conveyor over the back-up conveyor and the tunnel conveyor up to the waste tip.Rowa's order includes various components, such as spraying robots, rail supports, mobile and stationary working platforms, a suspended crane, rails, metallic constructions, a stepper installation, infrastructure elements for Robbins, a workshop container, a monorail suspension crane, rock bolt drilling equipment, mortar installation, dedusting of theTBM, coarse grain elimination, equipment for the workforce, compressed air equipment, industrial and cooling water outfit, back-up conveyor belt, continuous conveyor, transloading crane, ventilation and airduct storage, electric systems, auxiliary rails, a transloading crane for auxiliary rails, and a traverse crane. The delivery and operational dates are planned around summer time.The tunnel starts with a -7.82% drop over a length of about 1,500 m, continues with a practically horizontal stretch over a length of about 7,400 m and ends with an ascending gradient of +7.25% over the last 1,500 m. The alignment will also follow an horizontal curve radius of over 1,000 m. Starting in 2009, the energy production of the plant will increase by 1,600 to 13,400 GW hours. Click ca/13. Visit www.rowa-ag.ch, www.robbinstbm.com and www.opg.com 11/06.