Gotthard Base Tunnel

Passenger trains will be able to travel as fast as 250 km/h (155.3 mph) through the new tunnels, reducing travel times for trans-alpine train trips by 50 minutes – and by one hour once the adjacent Zimmerberg and Ceneri Base Tunnels are completed.
AlpTransit Gotthard AG is responsible for construction. It is a wholly-owned subsidiary the Swiss Federal Railways (SBB-CFF-FFS).
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).