| Official Name: | de|Zimmerbergtunnel | ||||
| Zimmerberg Tunnel | |||||
| Other Name: | de|Horgerbergtunnel[1] | ||||
| Line: | Thalwil–Arth-Goldau railway | ||||
| Location: | Zürich, Switzerland | ||||
| Coordinates: | 47.2503°N 8.5853°W | ||||
| Status: | Active | ||||
| System: | Swiss Federal Railways (SBB CFF FFS) | ||||
| Crosses: | Zimmerberg | ||||
| Start: | Horgen Oberdorf | ||||
| End: | Sihlbrugg | ||||
| Construction: | September 1894 – August 1896 | ||||
| Owner: | SBB CFF FFS | ||||
| Operator: | SBB CFF FFS | ||||
| Traffic: | Train | ||||
| Character: | Passenger and freight | ||||
| Notrack: | Single | ||||
| El: | 15 kV/16.7 Hz AC | ||||
| Grade: | 13‰[2] | ||||
| Map: |
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The Zimmerberg Tunnel is a 1984m (6,509feet)-long railway tunnel under the Zimmerberg mountain in the Canton of Zurich, Switzerland which opened in 1897.[3] [4]
Construction began in September 1894 from the Horgen portal. Breakthrough was achieved on 15 March 1896, and construction finished in August 1896. The tunnel was opened to traffic on 1 June 1897 along with the rest of the Thalwil–Zug railway line.[5] [6] [7] On 5 February 1923, electrification of the railway line, including the tunnel, was completed.
Together with the Albis Tunnel, the tunnel forms the railway passage through the Zimmerberg and Albis on the Thalwil–Arth-Goldau railway line which is an important feeder to the Gotthard railway.
The segment leading through the two tunnels constitutes a single-track section on the Thalwil–Arth-Goldau railway.[8] The proposed phase II of the Zimmerberg Base Tunnel aims to resolve the bottleneck formed by the single-track sections and to allow for faster traffic on the Thalwil–Arth-Goldau railway.[9]