Sunday, Dec. 11, 2016 is the opening of one of the world’s engineering marvels: the Gotthard Base Tunnel under the Swiss Alps, the world’s longest and deepest railway tunnel.
The 35.3-mile-long (57 km) double-track tunnel will enable passengers to speed under the Alps in some 17 minutes, bringing northern and southern Switzerland closer together, reducing travel time by 30 to 40 minutes between German-language and Italian-language Switzerland. It is 7,546 feet (2,300 meters) beneath the Gotthard massif at its deepest point. The Swiss Federal Railways (SBB) has now finished exhaustive safety and technical tests.
Why construct the Gotthard Base Tunnel? “The mobility requirements of Switzerland’s growing population have increased greatly over the past 100 years,” say officials. “Current forecasts indicate that the country’s transport sector will continue to expand. In addition, Switzerland’s strategic location at the crossroads of the continent makes it a highly important hub for European goods traffic. Swiss government policy is to ensure sustained mobility by increasing the public transport share of overall traffic and providing reliable basic services nationwide. Within this long-term program, protection of the environment and the population has been accorded high priority.
“The NRLA (New Railway Link through the Alps) is one of four ambitious projects undertaken by the government, of which the Gotthard Base Tunnel is the flagship focal point. As a level transalpine railway link with few gradients, the tunnel complements Switzerland’s existing mountain rail routes. It will also enable higher traveling speeds and permit the use of heavy freight trains.”
Construction of the Gotthard Base Tunnel was financed initially through a nationwide vote in 1998, when the Swiss electorate approved funding for the construction of the NRLA. Voters backed the “FinöV” program for the long-term funding of public transport, through revenues generated by Value Added Tax (VAT), a performance-linked levy on heavy traffic, and a mineral oil tax.
Wholly owned SBB subsidiary Alp Transit Gotthard constructed the Gotthard segment of NRLA. A general contractor was tasked with installing the railway systems and above-ground sections. The Transtec Gotthard Consortium (Alpiq, Alcatel-Lucent/Thales, Renaissance and Balfour Beatty Rail) handled planning, installation and commissioning of the railway systems. The construction work and installation of the railway infrastructure were completed by early June 2016. Alp Transit Gotthard then handed over the tunnel to the government and to operator SBB for final test runs.
It has taken 23 years to construct the Gotthard Base Tunnel. The first examination of the geological fault zone in the Gotthard Massif was carried out in 1993 with the construction of an exploratory tunnel. The second NRLA construction site was opened three years later. The first drill-and-blast operation was undertaken in 1999. The first breakthrough in one of the tunnels was in October 2010, and 2011 saw excavation completed. Work on the infrastructure (including track, catenary, electricity supply, telecommunications and safety systems) ended with the handover to SBB on June 1, 2016 for the operational testing phase.
With the construction of the Gotthard Base Tunnel, Switzerland implemented one of Europe’s most ambitious environmental protection projects. From concept to completion, construction was carried out as environmentally compatible as possible. Measures were taken to reduce the impact on people, wildlife, water and air. Alp Transit Gotthard said it “was in constant dialogue with environmental authorities in finding workable solutions.” Measures included environmentally compatible material transport to ensure clean air, strict guidelines concerning waste water, dust and noise protection, protection of flora and fauna as well as sustainable use of the stone extracted from the mountain.
“The Gotthard Base Tunnel’s top priority is passenger safety, necessitating implementation of a modern safety concept,” official said. “The tunnel system consists of two directionally separated single-track tubes connected by cross passages located every 1,066 feet (32 meters). In an emergency these would serve as rapidly accessible evacuation routes into the other tube. At the one-third-way points of the tunnel at Faido and Sedrun, emergency-stop stations in both tubes are connected to the parallel tube through six connection tunnels. The way to these tunnels is indicated by signs, emergency lights, and handrails. In the event of evacuation, trained railway personnel will provide assistance. Overpressure ensures that the air remains smoke free. Fans provide fresh air in the emergency stop stations; hot fumes are sucked out through extraction openings. Travelers can then be collected in the opposite tube by an evacuation train.”
The Gotthard Base Tunnel reduces travel times by 30 to 40 minutes, compared to the existing Alpine railway link over the Gotthard. Travel between Milan and Zurich, for example, is reduced from 4 hours, 3 minutes to 3 hours, 33 minutes. The existing Alpine railway link with its numerous bridges, loop tunnels and summit tunnel (built in 1882) will continue in service, but reduced to an hourly schedule, with a RegioExpress connecting with intercity trains in Erstfeld, Bellinzona and Lugano.
The other piece of the NRLA is the Lötschberg Base Tunnel, which became operational in December 2007. Today, some 50 passenger trains and up to 60 freight trains operate through the Lötschberg tunnel each day. By comparison, figures for the Gotthard Base Tunnel are up to 160 freight trains and 50 passenger trains daily.
Several fact sheets on the Gotthard Base Tunnel can be downloaded from the links below.
Download attachments: Facts and Figures, Engineering Fact Sheet, Geology Fact Sheet, History and Timeline