Heavy plate for the tunnel boring machine Gotthard

With the new Gotthard rail tunnel in Switzerland, one of the most elaborate construction projects of our time comes into being. The prospective longest transport tunnel in the world with its length of 57 km should optimize the rail connection Basel-Milan. For the construction of the new Gotthard rail tunnel, the commissioned construction companies ordered four of the world's most powerful tunnel boring machines. More freight trains and passenger trains can commute between Basel and Milan because of the new tunnel which is to be parallel to the Gotthard road tunnel. Due to the more even route of lines the trains are able to travel much faster than before with speeds up to 250 km/h. The completion of this extraordinary construction project is aspired for 2016.

For the building of the tunnel four Gripper tunnel boring machines are applied. Each one of these 3,050 t heavy machines has a maximum drill diameter of up to 9.58 m and is powered with 3,500 kW (Torque 8500 kNm). After finishing the section Bodio-Faido in October 2006 two Gripper tunnel boring machines had to be generally overhauled and their drill heads had to be extended before they could continue their work in the next section (Faido-Sedrun). For the construction of these tunnel boring machines Dillinger Hütte delivered overall 2,088 t of heavy plate steel S355J2G3 with a thickness range of 30 to 200 mm.