Grafenort – Engelberg Tunnel
| Overview | |
|---|---|
| Line | Luzern–Stans–Engelberg-Bahn |
| Location | Engelberg, Switzerland |
| Status | Active |
| Operation | |
| Constructed | 2001–2010 |
| Opened | 12 February 2010 |
| Owner | Zentralbahn |
| Operator | Zentralbahn |
| Traffic | Rail |
| Character | Passenger and freight |
| Technical | |
| Length | 4,043 m (13,264 ft) |
| No. of tracks | 1 |
| Track gauge | 1,000 mm (3 ft 3+3⁄8 in) metre gauge |
| Electrified | Overhead catenary 11 kV AC 16 2/3 Hz |
| Grade | 10.5% |
The Grafenort – Engelberg Tunnel is a railway tunnel on the Luzern–Stans–Engelberg-Bahn line, which forms one portion of the Zentralbahn in Switzerland. It replaced the steepest section of the line, an inclined length of 1,600 meters that had a peak gradient of 25%, allowing for a faster transit since its completion.
Following a number of preparatory surveys and assessments, construction of the tunnel commenced during March 2000. Work was delayed by two years due to a particularly severe flood that started in August 2005; it had been recognised beforehand that water ingress was a particular threat, thus the project included the construction of a concrete inner vault. The completed tunnel was officially opened during February 2010.