Switzerland
Gotthard Base Tunnel: High-accuracy at final breakthrough
The tunnel-boring machine, affectionately dubbed „Sissi“, in honour of the 19th century Austrian empress, by the international team of tunnellers engaged on the project, completed the final breakthrough in the eastern bore, with the ultra-high accuracy of just 8 cm transverse and 1 cm vertical deviation, on October 15, 2010.
Milestone in tunnel engineering
An identical TBM, nicknamed „Heidi“, an equally gigantic machine with a cutter head of 9.43 m diameter and a weight of 3400 t, is following in the western bore at a lag of 2.5 km, with the breakthrough there thus anticipated in April. This...
