The Alps continue to be a transportation barrier as well as a cultural and commercial barrier across Europe. Since most of the traffic has been in transit rather than for Swiss producers or consumers, implications have been felt in Switzerland. A program to build highways and the opening of the Gotthard road tunnel in 1980 greatly boosted the amount of freight that was transported by road. The shock of the numerous fatalities in the Gotthard and Mont Blanc road tunnel accidents was added to the general worry.

Project in-depth: The Gotthard Base Tunnel, Switzerland - Sheet1
World’s longest and deepest rail tunnel_©

After nearly two decades of construction, the world’s longest and deepest rail tunnel—the main component of the New Rail Link through the NRLA—has finally been declared open in Switzerland. A high-speed rail link between northern and southern Europe will be made possible by the 57km (35 miles) twin-bore Gotthard base tunnel. In comparison to earlier tunnels through the massif on the BLS Lotschberg and SBB Gotthard routes, the new tunnels were to be relatively level alignments at lower levels. 

Project in-depth: The Gotthard Base Tunnel, Switzerland - Sheet2
The Gotthard Base Tunnel_©

GBT Project details

The surrounding EU nations only agreed to road freight restrictions in exchange for improved rail infrastructure, particularly at the Lotschberg and Gotthard pinch points. Although both north-south routes had dedicated Rollende Landstrasse (RoLa) trains for the transit of entire heavy goods vehicles, capacity was still limited due to the long, slow climbs on either side of the tunnels at the respective summits. The main obstacles to the introduction of more, faster, and longer trains on the vital Rotterdam-Milan rail corridor were to be eliminated with the help of the NEAT projects.

To complete the 57km (35.4 miles) Gotthard Base Tunnel project, AlpTransit Gotthard was founded in May 1998 as a wholly owned subsidiary of Swiss Federal Railways (SBB). Five sections of the project were divided, each with a specific consortium, starting in the north with: 

  1. Erstfeld (ARGE AGN), 
  2. Amsteg (ARGE AGN), 
  3. Sedrun (ARGE Transco-Sedrun), 
  4. Faido (ARGE TAT) and 
  5. Bodio (ARGE TAT)
Project in-depth: The Gotthard Base Tunnel, Switzerland - Sheet3
Tunnel multi-accesses_©

Many other facets of the project are the responsibility of other contractors. The Gotthard tunnel project’s final estimated cost was Sfr9.4 billion ($9 billion), and the related 15.4 kilometers (9.6 miles) Ceneri tunnel project was estimated to cost Sfr2.24 billion. These sums are higher than anticipated, and the Swiss parliament approved reserves for unforeseen circumstances such as geological conditions, engineering problems, and technological advancements, the latter of which was significant given the lengthy project timeline.

Project in-depth: The Gotthard Base Tunnel, Switzerland - Sheet4
Infrastructural challenges_©

Infrastructure at the Gotthard Base Tunnel

The base tunnel, which has a maximum elevation of 550 meters and is roughly 600 meters lower than the summit of the current line, makes the Gotthard route comparable to many other parts of the SBB network in terms of difficulty.

Project in-depth: The Gotthard Base Tunnel, Switzerland - Sheet5
High capacity rail tunnel_©

The Erstfeld, Amsteg, Sedrun, Bodio, and Faido points (which were dug as intermediate shafts to facilitate the project) will be integrated into the finished structure for servicing and emergency access. The supply chain for the materials, the work sites, and the spoil disposal all had strict environmental regulations in place.

With some drilling and blasting, tunnel boring machines were primarily used to build the tunnels. August 2007 saw the start of the final section, 7.7 km from Erstfeld, and June 2009 saw the tube’s breakthrough at Amsteg. In October 2010, the Gotthard Base Tunnel’s east tube experienced its final breakthrough. The tunnel’s two ends were joined by 2,500 workers over nearly 14 years. In March 2011, the west tube’s final development was finished.

Project in-depth: The Gotthard Base Tunnel, Switzerland - Sheet6
The Drilling Appratus_©

Rolling planning

Planning allows for improvements in goods vehicles to enable tunnel speeds of up to 160 km/h (100 mph). While goods trains must move at a minimum speed of 100 km/h, passenger trains are allowed to travel through the tunnel at a maximum speed of 249 km/h. Instead of 1,600t, goods trains can now move up to 2,000t. The ETR 610 from Alstom Ferroviaria, which began line testing in 2008, is the flagship high-speed unit running Cisalpino services between Switzerland and Italy. Cisalpino units are expected to cut the Zurich–Milan travel time by 50 minutes, to 2 hours and 50 minutes.

Project in-depth: The Gotthard Base Tunnel, Switzerland - Sheet7
World’s longest tunnel at glance_©

Multifunction Station

In the Gotthard Base Tunnel, there are two multifunction stations (MFS): one at Sedrun and one at Faido. After the corresponding intermediate access, the MFS was built. Because more heading faces were created thanks to the intermediate access, the overall construction time was reduced. The geological risk zones could also be excavated more quickly.

The MFS serves many objectives. They serve as the transition points between tunnels, the emergency security stops for trains, and they house all of the equipment required to run the tunnel. Electricity, communication, signaling, ventilation, and water are the main installations. The unexpected geological conditions that led to significant plastic deformations, rock bursts, and rockfalls made it difficult to construct the MFS Faido.

Project in-depth: The Gotthard Base Tunnel, Switzerland - Sheet8
MFS Faido_©

Re-utilization of the excavated material

The reuse of the excavated material (28.7 million tonnes total) was mandated as a policy from the beginning of the Gotthard Base Tunnel project. As much of the material was reused as possible, it was either used on-site or for other purposes like landfills, etc.

Concrete made from some of the materials was recycled and used in the tunnel. The quality of the concrete mix designs had to meet strict criteria. High temperatures, aggressive groundwaters, and durability are all requirements for the concrete. To determine the ideal concrete mix design, extensive evaluation tests on a 1:1 scale were conducted. All of the tests were created, conducted, and evaluated in the Hagerbach Test Gallery (VSH), under the supervision of VSH staff. The remainder of the material was disposed of for landfills, renaturalization, and landscape design.

Project in-depth: The Gotthard Base Tunnel, Switzerland - Sheet9
Excavation material re-application_©
Project in-depth: The Gotthard Base Tunnel, Switzerland - Sheet10
GBT Abstarct_©

Facts and figures

  • Length: 57 km (the longest rail tunnel in the world)
  • Two single-track tubes, connected by cross-cuts every 325 m
  • The total length of all the tunnels: 152 km
  • The Gotthard tunnel runs 2.3 km under the mountain at its deepest point
  • Northern portal in Erstfeld (UR), southern portal in Bodio (TI)
  • The highest point of the tunnel: 550 m above sea level
  • Maximum rock cover: 2,300 m
  • Construction time (excluding exploratory work): 17 years
  • Main tunnels drilled with tunnel boring machines (80%) and blasted (20%)
  • Excavated material: 28.2 million tonnes
  • Cost of the Gotthard Base Tunnel: CHF 9.7 billion (effective total cost: CHF 12.2 billion)
  • Cost of the entire NRLA, including the Lötschberg, Gotthard, and Ceneri Base Tunnels: CHF 18.2 billion (effective total cost: approx. CHF 23 billion)
  • Tunnel capacity: up to 260 freight trains and 65 passenger trains per day
  • Timetabled speed: freight trains 100 km/h; passenger trains up to 200 km/h
  • Maximum speed: freight trains 160 km/h; passenger trains 250 km/h
Tunnel grand opening_©

GBT repairs will extend into 2024

The world’s longest rail tunnel, the Gotthard Base Tunnel, sustained far more damage than initially thought in last week’s derailment, and the Swiss Federal Railways (SBB) predicted that it will be early 2024 before both bores are fully operational again. Following a derailment in the Gotthard Base Tunnel, passenger traffic will remain detoured over the original Gotthard pass route for the foreseeable future.


(No date) The Gotthard Base Tunnel – Available at: (Accessed: 28 August 2023). 

(No date a) Gotthard Base Tunnel – Herrenknecht AG. Available at: (Accessed: 28 August 2023). 

Jorio, L. (2017) Engineers meet challenge of Gotthard Tunnel, SWI Available at: (Accessed: 29 August 2023). 

Gotthard Tunnel: World’s longest and deepest rail tunnel opens in Switzerland (2016) BBC News. Available at: (Accessed: 29 August 2023). 

says:, P.M. et al. (no date) Gotthard base tunnel repairs will extend into 2024, Trains. Available at: (Accessed: 29 August 2023). 

{$} (no date) Gotthard Base Tunnel, Amberg Group. Available at: (Accessed: 29 August 2023). 


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