October 15, 2010: Breakthrough of the 57-km long eastern tube. An important milestone at the Gotthard Base Tunnel. Image Source: Herrenknecht.com 27 February 2013 By Michele Petrello Etter October 15, 2010: Breakthrough of the 57-km long eastern tube. An important milestone at the Gotthard Base Tunnel. Image Source: Herrenknecht.com