Zürich Hauptbahnhof
The Hirschengraben Tunnel is a railway tunnel in the Swiss city of Zürich. The tunnel runs from the western approaches to Zürich Hauptbahnhof railway station, east under the station, the river Limmat and city centre before turning south and surfacing at Zürich Stadelhofen station. It includes a set of underground platforms at Zürich Hauptbahnhof, and carries twin standard gauge () tracks electrified at 15 kV AC 16,7 Hz using overhead catenary.