The first two phases of turning the 3,000 t TBM Martina through 180 degrees have been completed at the Sparvo tunnel on the A1 motorway Variante di Valico, Italy.
Contractor Toto SpA Costruzioni Generali is employing an innovative moving system based on air cushion technology, designed and built by Palmieri Group. The Palmieri system of pneumatic sliding steel cradles on 80 air cushions is facilitating rotation of the 15.6 m-diameter TBM on a special low-friction sliding surface laid by Toto. The TBM will then be moved to the launch position for the second tunnel drive, towed by two trucks and stabilized by other motor vehicles as a drift checking system. With traditional techniques the operation would have taken some months, whereas the Palmieri moving system has reduced this to just a few days, maximizing TBM availability and minimizing overall excavation time. Excavation of Sparvo tunnel is expected to be completed by June, 2013. Click here for the video of first shifting phase on 27th September. For more click here and it/21. Visit www.totospa.it and www.palmierigroup.com. 42/12.