Gotthard Base Tunnel

The new Gotthard Base Tunnel together with the Zimmerberg Base Tunnel form the northern part of the Gotthard axis of the Alptransit project
(yellow: major tunnels, red: existing main tracks, numbers: year of completion).

The Gotthard Base Tunnel (GBT) is a railway tunnel under construction in Switzerland. With a planned length of 57 km (35.4 mi) and a total of 151.84 km (94.3 mi) of tunnels, shafts and passages planned, it will be the longest tunnel (of all railway and road tunnels) in the world upon completion, ahead of the current record holder, the Seikan Tunnel (connecting the Japanese islands of Honshū and Hokkaidō). The project is designed to feature two separate tunnels containing one track each. The tunnel is part of the Swiss AlpTransit project, also known as New Railway Link through the Alps (NRLA) which also includes the Lötschberg Base Tunnel between the cantons of Berne and Valais. Like the Lötschberg tunnel, it is intended to bypass winding mountain routes and establish a direct route suitable for high speed rail and heavy freight trains. On completion it is expected to decrease the current 3.5 hours travel time from Zürich to Milan by one hour. It will also reduce the time between Zürich and Lugano to 1 hour 40 minutes. The two portals will be near the villages of Erstfeld, Canton Uri and Bodio, Canton Ticino.

Completion had been projected for 2015 but, due to delays, it was expected in early 2007 that the tunnel would not be completed before 2018.^[1] However, with a break-through in one of the tunnels achieved on 15 June 2009, an opening date for the tunnels during 2017 seems likely since work currently is progressing at a faster-than-expected pace.^[2]

Nearby are two more St. Gotthard Tunnels: the 1881 Gotthard Rail Tunnel and the 1980 Gotthard Road Tunnel.

Background

Intermodal train on the current Gotthardbahn in the Biaschina Gorge; truck on viaduct heading towards Gotthard road tunnel.

The route over Gotthard Pass or one of its tunnels is one of the most important passages through the Alps on the north-south axis in Europe. Traffic has increased more than tenfold since 1980 and the existing road and rail tunnels are at their limits. In order to provide a faster and flatter passage through the Swiss Alps, the Swiss voters have decided to build this tunnel cutting through the Gotthard massif at nearly ground level, 600 m (1,969 ft) below the existing railway tunnel. On the current track, the Gotthardbahn, only trains up to 1,400 t (1,543 ST; 1,378 LT) ^[3] when using two locomotives or up to 1,700 t (1,874 ST; 1,673 LT) 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 1,100 m (3,609 ft) above sea level. Once the new tunnel is completed, standard freight trains of up to 4,000 t (4,409 ST; 3,937 LT) will be able to pass this natural barrier as easily as if the Alps did not exist. Because of the ever increasing international truck traffic, the Swiss voted on 20 February 1994 for a shift in transportation policy (Traffic Transfer Act, enacted on 8 October 1999). The goal of both the laws (and the goal of the Gotthard Base Tunnel, which is one of the means by which the law will achieve its objective), is to transport trucks, trailers and freight containers from southern Germany to northern Italy and vice versa by train to relieve the already overused roads (intermodal freight transport and so called rolling highway where the entire truck is being transported), and to meet the political requirement of shifting as much tonnage as possible from truck transport to train transport, as required by the 'Alpine Protection Act' of 1994.^[4]

Passenger trains, on the other hand, will be able to travel as fast as 250 km/h (155.3 mph) (although it is questionable how easy it will be for high-speed trains to achieve this speed if they are sharing the tunnels with slower freight traffic) through the new tunnels, reducing travel times for trans-alpine train trips by 50 minutes—and by one hour once the adjacent Zimmerberg and Ceneri Base Tunnels are completed.

Scheme of the Gotthard Base Tunnel, centrepiece of the New Railway Link through the Alps NRLA (green: excavation in progress).

Construction

AlpTransit Gotthard AG is responsible for construction. It is a wholly owned subsidiary of the Swiss Federal Railways (SBB-CFF-FFS). To cut construction time in half, four access tunnels were built so that the construction of the tunnel can start at four (now five) different sites simultaneously (Erstfeld, Amsteg, Sedrun, Faido and Bodio).

A tunnel system with two single track tunnels is being built. The two rail tunnels are joined approximately every 325 m (1,066 ft) by connecting galleries. Trains can change tunnels in the two multifunction stations (MFS) at Sedrun and Faido. These stations will house ventilation equipment and technical infrastructure, and will serve as emergency stops and evacuation routes upon tunnel completion.

Construction site near Bodio.

Wye junction at multifunction station Faido.

The TBM from Bodio has arrived at MFS Faido on September 6, 2006.

Scale model of the TBM S-210.

In the eastern bore near Amsteg.

Access to the site where the Sedrun station is being excavated is quite difficult. The station is only reachable by a level access tunnel of 1 km (0.6 mi) from the valley floor near Sedrun, where at the end two shafts lead 800 m (2,625 ft) straight down to the base tunnel level. A project to construct a functioning railway station called Porta Alpina at this site was put on indefinite hold in September 2007.

As of 31 May 2009 (2009 -05-31)^[update], final break-through for all tunnels is expected in Spring 2011.^[5] In December 2009, the expected date of the first final break-through had been moved forward to November 2010.^[6] On the 9 April, the date of the first final break-through was moved forward yet again, and is currently expected on 15 October 2010.^[7]

Allocation of work

The contracts are being let in sections as follows:

• Erstfeld (section from Erstfeld to Amsteg) 7.7 km (4.8 mi) – two TBMs started boring the two tubes. The break-through of the east tube between Erstfeld and Amsteg took place on 15 June 2009 and was transmitted live by Swiss Television (SF TV).^[8] The portal area is being surface-mined, and drilling and blasting for the two branchoffs (see above under Construction) is nearly complete; this work is expected to be complete by the time the rest of the tunnel excavation is finished.
• Amsteg (section from Amsteg to north of Sedrun) 11.4 km (7.1 mi) – work being carried out by ARGE AGN (Strabag and Züblin Murer)^[9] On 9 December 2009, the Amsteg section was officially handed over to the tunnel's owner. Railway track will now start to be installed.^[6] Civil engineering construction, concreting and lining work all complete.^[10]
• Sedrun (section immediately north and south of Sedrun) 6.8 km (4.2 mi) – working being carried out by Transco (Bilfinger Berger, Implenia, Frutiger and Pizzarotti)^[11] The last break-through of the Gotthard Project, Sedrun to Faido, is expected to occur during autumn 2010.^[12] Civil engineering construction, concreting and lining work all complete on Sedrun North.^[13]
• Faido (section from south of Sedrun to Faido) 14.6 km (9.1 mi) – work being carried out by Consorzio TAT (Alpine Mayreder Bau, CSC Impresa costruzioni, Hochtief and Implenia and Impregilo)^[14]
• Bodio (section from Faido to Bodio) 16.6 km (10.3 mi) – work being carried out by Consorzio TAT (Alpine Mayreder Bau, CSC Impresa costruzioni, Hochtief, Implenia and Impregilo)^[14] Civil engineering construction, concreting and lining work all complete.^[15]

Facts and figures

• Length: 56.978 km (35.404 mi) (western tunnel) 57.091 km (35.475 mi) (eastern tunnel)
• Total length of all tunnels and shafts: 151.84 km (94.35 mi)
• Diameter of each of the single-track tubes: 8.8-9.5 m
• Distance between cross passage tunnels: ca. 325 m
• Maximum overburden: ca. 2500 m
• Start of construction: 1993 (sounding drills), 1996 (preparations), 2003 (mechanical excavation)
• End of construction: 2016–2017
• Commissioning: End of 2017
• Total cost: CHF 9.74 billion ^[16] (as at June 2010) (US$9.0 billion)
• Trains per day: 200–250
• Volume of excavated rock: 26,500,000 t (29,211,250 ST; 26,081,473 LT) (13,300,000 m³/17,395,743 cu yd or the equiv. of 5 Giza pyramids)
• Number of tunnel boring machines (TBM): 4 (2 southbound from Amsteg to Sedrun, 2 northbound from Bodio to Faido and Sedrun, section from Erstfeld to Amsteg will also be built with TBM, maybe the same used for Amsteg-Sedrun)
  • Total length: 440 m (1,440 ft) (incl. back-up equipment)
  • Total weight: 3,000 t (3,307 ST; 2,953 LT)
  • Power: 5 megawatts
  • Max. excavation daily: 25–30 m (82–98 ft) (in excellent rock conditions)
  • Total excavation length by TBM: about 45 km (28 mi)
  • Manufacturer: Herrenknecht, Schwanau, Germany

See also

References

External links

• Alptransit Gotthard AG – Official project site
• Study on the optional Use of Jet Fans in the Gotthard Base Tunnel near the Portals to support the Emergency Ventilation
• (German) Brochure for the Porta Alpina project
• Overall project writeup by SpiegelOnline, plus a proposed tourist elevator (December 2006)
• (French) TSR "Gotthard: From Dream to Nightmare" "Temps Present", 24 May 2007
• (German) AGN Erstfeld Amsteg Constructors Web Site (many Photos and Designs)
• (German)/(Italian) Faido Bodio Constructors Web Site (many Photos and Designs)