Logo Bedretto Lab and logo ETH Zurich

History of the tunnel

In the early 70ties, the only way to travel from the Canton of Valais to Uri lead over the mountains. In wintertime, this was not an option either. In 1971, the federal council opened the passage politically by making the funds available to construct the Furka Railway Base tunnel connecting Oberwald (VS) with Realp (UR). As part of the construction of the Furka Tunnel (between 1971 and 1982) an annex tunnel was excavated: The Bedretto tunnel. It was used to remove excavating material and as a supply channel. After finalizing the Furka tunnel, the Bedretto tunnel was abandoned and neither used for rescue nor for maintenance purposes.

The Bedretto tunnel was excavated conventionally by drill and blast. The rock coverage, reaching from the tunnel until the surface, varies between 1,000 m and 1,500 m. The total length of the tunnel is 5,220 m with a width and height of 2.70 m. Therefore, the tunnel is rather narrow and has a horse shoe profile. The tunnel is a bare rock tunnel and was only consolidated in increased deformation zones with steel sets and wood lagging. However, these enforcements could not prevent the tunnel from collapsing at three sections, preventing any passage. In combination, these circumstances explain the abandonment of the tunnel.

Only in 2015, the tunnel was made accessible again. To this aim, all the debris was removed and critical parts anew secured. The reason was the installation of a new ventilation system at the Furka tunnel. In case of a major fire, fresh air is supplied in case of fire events which gave the Bedretto tunnel a new purpose: Providing fresh air from Ticino for the large new ventilation installations installed in small annex tunnels.

The Swiss Energy Strategy aims for 7% geothermal energy by 2050. With this objective in mind the Matterhorn Gotthard Bahn made the tunnel available to ETH to develop an underground laboratory.

The “Bedretto Underground Laboratory for Geosciences and Geoenergies” is under development since 2017 and is located about 2km from the south entrance. It is located in a 100 m long niche, initially a cross-junction for the tunnel railway. The “Bedretto Underground Laboratory for Geosciences and Geoenergies” is specifically developed to host large scale geothermal experimentation in conditions close to reality.

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.

May 2019 - Inauguration

The "Bedretto Underground Laboratory for Geoenergies" is inaugurated!

2018 - Scientific laboratory

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 Matterhorn-Gottard-Bahn and work begins on preparing the laboratory.

May 2017 - Energy Strategy 2020

The people approve the new Federal Energy Act, which corresponds to the first package of the Energy Strategy 2050. The latter provides that geothermal energy will cover 7% of demand in 2050. Scientific research is needed to increase this percentage!

2015 - New function

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.

2015 - Repair work

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.

2013 - Abandonment

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.


1982 - Opening of 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.

1981 - Fall of the diaphragm

The fall of the diaphragm of the Furka tunnel occurred on April 30, 1981. Only a year later the tunnel was opened to traffic.


1976 - Geological conditions

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.

1973 - Start of work

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!


The year of the avalanche

During the 1950s there is a desire and a need for a new and safe connection through the Alps. This need also emerges from the numerous avalanches that fell spontaneously in a short time in 1951.

Tunnel Facts

Length: 5220 m which makes it one of the longest bare rock tunnel in Switzerland

Width: 2.70m

Height: 2.70m