Breakthrough of the Campanas Tunnel on the Navarre Canal The Campanas tunnel, on section 4 of the Navarre canal between Tiebas and Añorbe (9.03 km), broke through on 27th February, 2006. Tunnelling commenced on 26th July, 2005 (click here). The 4,020 m-long tunnel has been driven by a 6.19 m-diameter telescopic double shield TBM supplied by Wirth. Visit www.wirth-europe.comThe tunnel has a circular section, of 5.4 m of internal diameter, and has been designed for a nominal flow of 45 cu m/s. In total, 120,000 cubic metres of rock has been excavated and 1,340,000 kg of steel has been used for the support of the tunnel.Section 4 forms part of a contract package together with sections 5 and 18. With the tunnel, the canal will cross underground highway AP-15, road N-121 and the Pamplona-Castejon railway. The section also includes the Ucar-Olcoz tunnel (230 m) and the Tirapu tunnel (300 m) to mitigate impact on the environment. Click here to read more on the project and the TBM. Click es/72. 10/06.