History of the tunnel
Excavation & abandonment
In the early 1970s, the only way to travel from the Canton of Valais to Uri was over the mountains, a route that was not possible during winter.
In 1971, the Federal Council opened the passage politically by making funds available for the construction of the Furka Railway Base Tunnel, connecting Oberwald (VS) with Realp (UR). As part of the construction works carried out between 1971 and 1982, an annex tunnel called the Bedretto tunnel was excavated. It served both as a route to remove excavated material and as a supply tunnel. After the completion of the Furka Tunnel, the Bedretto tunnel was abandoned and was no longer used for rescue or maintenance purposes.
The Bedretto tunnel was excavated using conventional drill-and-blast techniques. The rock overburden between the tunnel and the surface varies between 1,000 m and 1,500 m. The tunnel has a total length of 5,220 m and measures 2.70 m in both width and height, giving it a narrow horseshoe-shaped profile. It is a bare-rock tunnel, stabilized only in zones of increased deformation using steel sets and timber lagging. Nevertheless, these reinforcements could not prevent collapses at three sections, which made the tunnel impassable. Combined, these conditions explain why the tunnel was ultimately abandoned.
Tunnel Facts
Length: 5,220 m which makes it one of the longest bare rock tunnels in Switzerland
Width: 2.70 m
Height: 2.70 m
The entrance to the gallery during construction work for the laboratory (ETH Zurich, 2018).
The tunnel during during construction work for the laboratory (ETH Zurich, 2018).
The tunnel during during construction work for the laboratory (ETH Zurich, 2018).
The laboratory during its construction (ETH Zurich, 2018).
The Geothermal Testbed in 2023.
The new side tunnel, which houses the Earthquake Physics Testbed.
A new purpose
Only in 2015 was the tunnel reopened. To make it accessible again, debris was cleared and critical sections were newly secured. The trigger for this work was the installation of a new ventilation system in the Furka Tunnel. In case of a major fire, the system supplies fresh air, giving the Bedretto tunnel a new purpose: providing fresh air from Ticino to the large ventilation installations located in small annex tunnels.
Around the same time, a consortium of scientists began searching for a suitable tunnel to conduct research on deep geothermal energy. The Swiss Energy Strategy aims for geothermal energy to cover 7% of the country’s supply by 2050. The Bedretto tunnel offered ideal conditions for this type of research, and ultimately the Matterhorn Gotthard Bahn made the facility available to ETH Zurich to develop an underground laboratory dedicated to deep geothermal investigations. The “Bedretto Underground Laboratory for Geosciences and Geoenergies” opened in 2018 and initially focused on deep geothermal research; since then, it has broadened its research portfolio.
Historical Milestones
Pilot boreholes were drilled to allow a representative characterization of the Bedretto reservoir, to be used as monitoring boreholes for the stimulation and circulation experiments in later phases and to provide sufficient flexibility in hosting the stimulation boreholes.
In May 2019, we celebrated the inauguration of the BedrettoLab.
The tunnel of Bedretto is identified by the ETH Zurich as ideal for experiments in the field of geothermal energy. An agreement for the use of the tunnel is signed with the the Matterhorn Gotthard Bahn who owns the tunnel, and work begins on preparing the laboratory.
The people approved the new Federal Energy Act, which corresponds to the first package of the Energy Strategy 2050. This strategy foresees geothermal energy covering 7% of national demand by 2050. Scientific research is needed to increase this share.
The Bedretto tunnel is in operation again. A control centre for the new ventilation system has been installed at its intersection to the Furka tunnel.
After 33 years of non-use, the Bedretto tunnel is repaired, so that it can be walked again. Three large geological fractures are made safe.
The Bedretto tunnel is still unused, but efforts are being made at cantonal level in Ticino to build the rail link with the Furka tunnel.
The Furka base tunnel was opened in April 1982. The transport of cars through the tunnel began in September 1982. The Bedretto Window remains unused and no maintenance is planned in the following years.
The fall of the diaphragm of the Furka tunnel occurred on April 30, 1981. Only a year later the tunnel was opened to traffic.
The Federal Assembly approves an additional credit of CHF 80.4 million in addition to the CHF 76 million approved in 1971. The additional credit was mainly due to geological conditions.
The construction of the Furka railway tunnel begins and the tunnel of Bedretto is being built with the goal of speeding up construction work. The possibility of also connecting Ticino to the Furka tunnel has been abandoned.
Different connection hypotheses between the cantons of Valais, Ticino, Uri and Bern are evaluated. The discussion at federal level is on.
In the 1950s, the growing demand for a new and safe Alpine crossing became increasingly apparent. This demand was further driven by the series of spontaneous avalanches that struck within a short timeframe in 1951.