Gotthard Base Tunnel

To cut construction time in half, four access tunnels were built so that the construction the tunnel could start at four (a fifth was added later) different sites simultaneously (Erstfeld, Amsteg, Sedrun, Faido and Bodio).
The tunnels are joined approximately every 325 m (1,066 ft) by connecting galleries.
Trains can change tunnels in the two multifunction stations (MFS) at Sedrun and Faido. These stations will house ventilation equipment and technical infrastructure and will serve as emergency stops and evacuation routes upon tunnel completion.