Breakthrough of the northern fault zone on 29 April 2026

Since 14 February 2025, the tunnel boring machine (TBM) has been driving through the northern half of the second Gotthard tunnel. On 29 April 2026, it reached the cavern of the northern fault zone, around four kilometres from the tunnel portal in Göschenen.

Upon reaching tunnel metre 4,000, the last piece of rock broke away and the TBM “Alessandra” stood in the northern cavern of the “Mesozoikum” fault zone. According to mining tradition, the passage was first crossed by a miner carrying a statue of Saint Barbara.

The breakthrough was also marked in an official ceremony: in front of numerous miners and project participants, FEDRO Director Jürg Röthlisberger underlined the great importance of the Gotthard for Switzerland in his speech. He described it as probably Switzerland’s most emotional section of road and as an important link between north and south. This was echoed by Daniel Spörri, Chairman of the Construction Commission of the “secondo tubo” work group, who praised the entire construction team for their outstanding performance.

The northern fault zone “Mesozoikum” is around 320 metres long and consists mainly of loose rock. Mechanical excavation with the tunnel boring machine would not have been possible in this section. For that reason, the zone was accessed in 2024 via a separate access tunnel and then excavated conventionally by drilling and blasting. Steel arches, anchors and shotcrete were used, among other things, to secure the section. This work was completed in September 2025. As a result, the known risks for the main tunnelling work on the northern side were significantly reduced.