The Gotthard Base Tunnel (GBT; German: Gotthard-Basistunnel, Italian: Galleria di base del San Gottardo, Romansh: Tunnel da basa dal Son Gottard) is a railway tunnel through the Alps in Switzerland. It opened on 1 June 2016, and full service began on 11 December 2016. With a route length of 57.09 km (35.5 mi), it is the world’s longest and deepest traffic tunnel and the first flat, low-level route through the Alps. It lies at the heart of the Gotthard axis and constitutes the third tunnel connecting the cantons of Uri and Ticino, after the Gotthard Tunnel and the Gotthard Road Tunnel.
The link consists of two single-track tunnels connecting Erstfeld (Uri) with Bodio (Ticino) and passing below Sedrun (Graubünden). It is part of the New Railway Link through the Alps (NRLA) project, which also includes the Ceneri Base Tunnel further south (scheduled to open late 2020) and the Lötschberg Base Tunnel on the other main north-south axis. It is referred to as a “base tunnel” since it bypasses most of the already existing Gotthard railway line, a winding mountain route opened in 1882 across the Saint-Gotthard Massif, which was operating at its capacity before the opening of the GBT. The new base tunnel establishes a direct route usable by high-speed rail and heavy freight trains.
The main purpose of the Gotthard Base Tunnel is to increase local transport capacity through the Alpine barrier, especially for freight, notably on the Rotterdam–Basel–Genoa corridor, and more specifically to shift freight volumes from trucks to freight trains. This not only significantly reduces the danger of fatal road crashes involving trucks, but also reduces the environmental damage caused by the ever-increasing amount of freight hauled by heavy trucks. The tunnel provides a faster connection between the canton of Ticino and the rest of Switzerland, as well as between northern and southern Europe, cutting the Basel/Zürich–Lugano–Milan journey time for passenger trains by one hour (and from Lucerne to Bellinzona by 45 minutes).
After 64 percent of Swiss voters accepted the NRLA project in a 1992 referendum, first preparatory and exploratory work began in 1996. The official start of construction began on 4 November 1999 at Amsteg. Drilling operations in the eastern tunnel were completed on 15 October 2010 in a breakthrough ceremony broadcast live on Swiss TV, and in the western tunnel on 23 March 2011. The tunnels’ constructor, AlpTransit Gotthard AG, originally planned to hand over the tunnel to Swiss Federal Railways (SBB CFF FFS) in operating condition in December 2016 but, on 4 February 2014, the handover date was changed to 5 June 2016 with the start of an 850-day opening countdown calendar on the AlpTransit homepage. As of 1998, the total projected cost of the project was CHF 6.323 billion; as of December 2015, the final cost is projected as CHF 9.560 billion. Nine people died during construction.
Since the 13th century, the 2,106 metre-high Gotthard Pass has been an important trade route from northern to southern Europe. Control of its access routes led to the birth of the Swiss Confederacy. The Gotthard Pass is located halfway between Lake Lucerne and Lake Maggiore. It is the shortest link between the navigable Rhine and the Po. The traverse of the pass took days.
Quite late, compared to other pass routes through the Alps on a north-south axis (e.g. Simplon, San Bernardino, Brenner), namely in 1822, the first Saint-Gotthard Pass road was established after centuries-long usage of a bridle path. From 1842 onwards, a daily course by the Gotthard Post, a stagecoach drawn by five horses with ten seats, still took about 23 hours from Como to Flüelen.
“The Gotthard Post” on the Tremola (1873 by Rudolf Koller)
In 1882, with the inauguration of the Gotthard Railway Tunnel, the travel time between Altdorf and Biasca was reduced dramatically to only hours, though often accompanied with overnight stays in huge Fin de siècle-hotels, for example in Biasca. These days, it still was an adventure and it was only afordable to the very rich anyhow.
In autumn of 1921, the final stagecoach traversed the pass.
Electrification of the railway line in 1922 significally reduced travel time even more. Refilling water boilers of steam locomotives was no longer necessary. There were also the technical advantages of electrical engines and future technical improvements.
It is said that the first car traversed the pass in 1895. The first reported surmounting of the pass in 1901 still took more than a day.
From 1924, car transport on trains through the railway tunnel began. The sections between Göschenen and Andermatt, the Schöllenen ravine, and especially the Tremola, had countless hairpin turns and serpentine curves from the peak of the pass to Airolo on the southern side of the pass, dropping 1,000 metres (3,300 ft) in altitude, posing a huge challenge for automobiles.
Cars transport on trains in the 1930s
From 1953 onwards, the pass road was sequentially improved and expanded at several sections along the Gotthard route, finally ending in 1977 with the opening of an expressway fully circumventing the Tremola.
The old pass road, the Tremola
Time was further dramatically reduced with the opening of the Gotthard Road Tunnel and the finalization of the northern part of A2 motorway through the Urner Reusstal, with many additional tunnels (then leading from Basel to the Gotthard Road Tunnel), in 1980. With the completion in 1986 of the A2 motorway in the Valle Leventina, the huge valley leading from Airolo down to Bellinzona, and the surmounting of the Monte Ceneri between Bellinzona and Lugano in 1983, finally a continuous motorway was established from the northern border of Switzerland in Basel to the southern border in Chiasso, or the shortest motorway route from North-German Hamburg as far as South-Italian Sicilly, bringing down the competitiveness of the railway line.
Today, both the rail and the road routes are among the most important passages through the Alps on the north-south axis.
After the opening of the auto tunnel, in 1980, traffic increased more than tenfold. The existing tunnel was at its capacity by 2013. A second tunnel will be built next to the first, as per a national referendum. Construction is to start in 2020 and finish in 2027.
Relative location and size of Gotthard Tunnel (1882) and Gotthard Base Tunnel (2016) both yellow. Red: open-air rail
As early as 1947, engineer Eduard Gruner imagined a two-story base tunnel from Amsteg to Biasca, both rail and road, with a stop at Sedrun, to provide a faster and flatter passage through the Swiss Alps. Similarly to Gruner’s idea, the GBT cuts through the Gotthard Massif some 600 m (2,000 ft) below the older tunnel. On the current track, the Gotthard Railway, only trains up to 1,300 t (1,400 short tons; 1,300 long tons) when using two locomotives or up to 1,500 t (1,700 short tons; 1,500 long tons) with an additional bank engine at the end of the train are able to pass through the narrow mountain valleys and through spiral tunnels climbing up to the portals of the old tunnel at a height of 1,151 m (3,776 ft) above sea level. When the GBT is in full service, standard freight trains of up to 3,600 t (4,000 short tons; 3,500 long tons) will be able to pass this natural barrier.
Because of ever-increasing international truck traffic, Swiss voters chose a shift in transportation policy in February 1994 (Traffic Transfer Act, enacted in October 1999). A second law, the Alpine Protection Act of 1994, required a shift of as much tonnage as possible from truck transport to train transport.
The goal of both the laws is to transport trucks, trailers and freight containers through Switzerland, from Basel to Chiasso, and beyond by rail to relieve the overused roads, and that of the Gotthard in particular, by using intermodal freight transport and rolling highways (where the entire truck is transported). The GBT substantially contributes to the requirements of both laws and enables a direct flat route from the ports of the North Sea (notably Rotterdam) to those of the Mediterranean Sea (notably Genoa), via the Rhine corridor.
Passenger trains can travel up to 250 km/h (155 mph) through the GBT, currently reducing travel times for trans-Alpine train journeys by about 40 minutes, and by one hour once the adjacent Zimmerberg and Ceneri Base Tunnels are completed. This is viewed as a revolution, especially in the isolated region of Ticino, which is separated from the rest of the country by the Alps and the Gotthard. The two stations of Bellinzona and Lugano (respectively named “Gate of Ticino” and “Terrace of Ticino”) were entirely renovated for the opening of the GBT, among other improvements.
As of 2016, the Gotthard Base Tunnel is the longest railway tunnel in the world. It is the third Swiss tunnel to bear this title, after the Gotthard Tunnel (15 km, 1882) and the Simplon Tunnel (19.8 km, 1905). It is the third tunnel built under the Gotthard, after the Gotthard Tunnel and the Gotthard Road Tunnel.
The Gotthard Base Tunnel is, with a length of 57.09 kilometres (35.47 mi) and a total of 151.84 km (94.3 mi) of tunnels, shafts and passages, the longest railway tunnel in the world,[note 1] with a geodetic distance of 55.782 kilometres (34.661 mi) between the two portals. It is also the first flat route through the Alps or any other major mountain range, with a maximum height of 549 metres (1,801 ft) above sea level, corresponding to that of Berne. It is the deepest railway tunnel in the world, with a maximum depth of 2,450 metres (8,040 ft), comparable to that of the deepest mines on Earth. Without ventilation, the temperature inside the mountain reaches 46 °C (115 °F).
Like the two other tunnels passing below the Gotthard, the Gotthard Base Tunnel connects two Alpine valleys across the Saint-Gotthard Massif: the Urner Reusstal in the canton of Uri, in which flows the river Reuss, and the Valle Leventina, the largest valley in the canton of Ticino, in which the river Ticino flows. Unlike most other tunnels, the Gotthard Base Tunnel passes under several distinct mountain massifs, two of them being major subranges of the Alps, the Glarus Alps and the Saint-Gotthard Massif, with the valley of the Anterior Rhine, the Surselva in the canton of Graubünden, between them.
The tunnel passes under these two ranges more than 2 kilometres (1.2 mi) below the Chrüzlistock (2,709 m (8,888 ft)) and the Piz Vatgira (2,983 m (9,787 ft), near the Lukmanier Pass). While the cantons of Uri and Ticino are part of the German- and Italian-speaking areas of Switzerland respectively, the Surselva is mainly Romansh-speaking.
The north and south portals on the same spring day. Note the prevalence of coniferous trees at the north portal and the absence of them at the south portal.
The Alps strongly influence the European climate – and that of Switzerland in particular – and there can be substantially different weather conditions at each end of the GBT, described by the Ticinese architect Mario Botta: “The light changes at the Gotthard: that of the Mediterranean Sea is not the same as that of the continent, that of the central lands, that of Europe far away from the sea.” On average, the temperature is 2 to 3 °C (4–5 °F) higher on the south side than the north side, but on some days, temperature differences are well over 10 °C (18 °F).[note 2]
The north portal lies in the north of the municipality of Erstfeld at an elevation of 460 metres (1,510 ft), east of the Reuss. There, the tunnel penetrates the western slopes of the Bälmeten and Chli Windgällen (although only marginally) before passing below the valley of the Chärstelenbach, a creek in the Maderanertal. From there, the tunnel runs parallel to the small valley of Etzli, below the Witenalpstock. The main crest of the Glarus Alps, which is the watershed between the Reuss and the Anterior Rhine, is crossed below the Chrüzlistock, the crest having an elevation of about 2,700 metres (8,900 ft) at this point.
From the crest and border, the tunnel runs parallel to the small valley of the river Strem (Val Strem) before passing below Sedrun and the Anterior Rhine. From the bottom of the valley, the tunnel proceeds towards the valley of the Rein da Nalps (Val Nalps) and passes east of Lai da Nalps, before crossing the Gannaretsch range below the western summit of Piz Vatgira (2,981 metres (9,780 ft)). This is the deepest point of the tunnel, with a rock layer of 2,450 metres (8,040 ft) above it. The tunnel then passes below the valley of the Rein da Medel (Val Medel) and west of Lai da Sontga Maria. After a few kilometres the tunnel crosses the watershed between the Anterior Rhine and the Ticino, just north of Pizzo dell’Uomo (2,525 metres (8,284 ft)). This point corresponds to the main chain of the Alps, and is the main drainage divide between the Rhine and the Po. For a few kilometres, the tunnel passes below two western tributaries of the Brenno in the Valle Santa Maria before crossing the last range, west of the Passo Predèlp (about 2,500 metres (8,200 ft)) and east of Faido. It then follows the eastern slopes of the large Valle Leventina, the valley of the Ticino, for about 18 kilometres (11 mi) to the south portal at Bodio, at an elevation of 312 metres (1,024 ft), just 3 kilometres (1.9 mi) before Biasca, where the Brenno converges with the Ticino.
The closest railway stations to the portals are Altdorf and Biasca. The first regularly served railway stations on the base line (as of 2016/17) are those of Arth-Goldau (Schwyz), a railway node with links to Lucerne and Zürich, and Bellinzona (the “Gate of Ticino”), with links to Locarno, Luino and Lugano (via the Monte Ceneri Rail Tunnel). The journey from Arth-Goldau to Bellinzona takes not more than an hour. The station of Altdorf is planned to be served by 2021. There also have been talks of using that of Biasca. The travel between Altdorf and Biasca would last less than 25 minutes.