Herrenknecht triumph at GotthardThe breakthrough of the eastern tube at the Gotthard Base Tunnel on 15.10.2010 not only completed a final link in the world's longest rail tunnel, but also signed up a triumph for the four Herrenknecht gripper TBMs that, to date, have completed 85 km of the total 114 km of running tunnels. Breakthrough in the western tube is expected in spring, 2011.The diameters of the TAT Consortium machines driving the south section were changed enroute by Herrenknecht engineers, from 8.83 m for the Bodio-Faido section to 9.43 m for the Faido-Sedrun section. The two Herrenknecht TBMs driving the north section Amsteg-Sedrun and Erstfeld-Amsteg for Strabag were 9.58 m-diameter. One of the latter, known as Gabi 2, set a world record in its class of 56 m advance in 24 h in late-summer, 2009. Two vault lining units supplied by MSD, a Herrenknecht branch company based in Dresden, are also at work in the tunnels, lining up to 600 m/month.For a summary of this magnificent project, and its highs and lows, read the Herrenknecht press release. For over 150 tunnelbuilder reports of Herrenknecht TBM accomplishments, click here and write Herrenknecht in the bottom left box. 42/10.