Gotthard Tunnel

Gestió d'infraestructures

57 km beneath the Swiss Alps: Gotthard, world’s longest tunnel

In June 2016 Switzerland will open a new rail link that will cut the journey time between Zurich and Milan to two hours. This is a revolutionary transport project, presented to the Catalan Professional Association of Civil Engineers by Dr. Renzo Simoni, CEO of Alp Transit Gotthard Ltd, and is being analysed by three Catalan civil engineers specialising in tunnels from the point of view of the administration, the contractor and the project manager.

Digging a 57-km structure under the Alps is not something to be taken lightly, much less in Switzerland. To meet this challenge, the Swiss have voted in two referendums, innovative techniques have been implemented and “enough material has been excavated to fill a train stretching from Zurich to Chicago,” said Alp Transit Gotthard Ltd CEO Dr. Renzo Simoni at the conference on the project held at the headquarters of the Catalan Professional Association of Civil Engineers on 16 October last. “Existing tracks have reached maximum capacity,” said Renzo Simoni, and our dream is to cut the journey from Zurich to Milan from its current four hours to a mere two and a half. This is a revolutionary proposal that will bring northern and southern Europe closer together than ever.

Early attempts

The desire to forge a quick route through the Alps is nothing new. The Gotthard Pass is a dangerous road linking northern Italy to the south of Switzerland, and efforts have been made over the years to find a way to make it safer. One is the construction of the legendary Devil’s Bridge, which was eventually replaced by the first Gotthard rail tunnel in 1882. Unfortunately, the building work for that tunnel claimed the lives of 177 workers.

That is why one of the conditions for Swiss citizens to give their approval to the New Railway Link though the Alps was that the new tunnel should last 100 years, in the understanding that the technical and safety measures should continue to be pioneering so that they would be valid despite the passage of time.

Not only that, but the tunnel’s capacity had to be sufficient to absorb current traffic congestion and meet future growth plans: when the new Gotthard tunnel opens to traffic on 2 June 2016, it will be able to handle up to 80 passenger trains per day and up to 260 freight trains at speeds of 250 and 160 kilometres per hour respectively. To ensure the highest possible level of safety once the tunnel is operational, two single-track tubes have been designed for each direction of travel. Thus, in the event of an accident, the opposite the tube could be used for evacuation purposes. There are also two emergency stations and cross passages connecting the two parallel tubes every 325 metres.

“The mistakes of the past serve to improve the present,” said Renzo Simoni at the Professional Association. Unfortunately, 9 workers have lost their lives during these 18 years of construction work to build the new Gotthard tunnel. According to Joan A. Serratosa, director of the Civil Engineering and Infrastructures Division of the Catalan Government, in Catalonia this figure would be “far lower” for the same length of tunnels bored. “In recent years we have learned a great deal about building tunnels and have significantly improved construction methods, particularly in checks on buildings to ensure that damage is negligible” he explained.

Direct supervision

When implementing rail projects, the Swiss government normally issues an order to the responsible body, Swiss Federal Railways, which then plans, builds and operates the project. However, in the case of the Gotthard tunnel, it opted for a different and innovative solution. Alp Transit Gotthard Ltd was set up on 12 May 1998. This subsidiary of Swiss Federal Railways (SFR) employs approximately 160 people, who were tasked with planning and building the project. This model allows direct parliamentary control: Alp Transit.

Gotthard Ltd reports directly to a parliamentary oversight committee six times a year. “Proper supervision of the entire project is therefore possible at all times. The organisation is compact, with few hierarchical levels, ensuring short decision-making routes and a fast response to new situations” explained a company representative. “Public funds should be supervised and must be fully transparent because they belong to everyone” agreed Felix Nolla, tunnel expert and head of the Civil Engineering Group of infrastructure firm Dragados. Mr Serratosa also feels “it is a very good idea for the administration to report directly to Parliament on monitoring the financing of large infrastructure projects”, although he considered that procedures for public participation prior to the construction of large infrastructure projects used in Catalonia and Spain are ‘adequate’ “to ensure respect for public opinion.”

In this connection, another demand from Swiss citizens was that project development should respect the environment. “Most of the concrete that was needed in the tunnels comes from excavation. The spoil was also used for filling, for example, in the delta of Lake Uri. Various artificial islands were created on an arm of Lake Lucerne – one is a bathing island, the others are nature reserves. Only a small proportion of the material had to be deposited in landfills” we were told by Alp Transit Gotthard Ltd.

On this matter, Ferran Biosca, Senior Tunnel Engineer for Samsung+OHL+QBC for the Metro in Doha (Qatar) who has experience in tunnels around the world, stated “as a matter of economy, you would always try to compensate for the movement of materials to avoid buying in what you need and paying to throw away what is left” or “to strike agreements with other projects being performed nearby at the same time.” As a comparison, building Line 9 of the Barcelona Metro system has involved the movement of 9 million tonnes of earth, one third of the amount involved in the Gotthard tunnel, but within an urban area. The New Railway Link through the Alps, which includes the Gotthard tunnel, has a budget of 19.1 billion euros.

The project in figures:

• Newly constructed twin-track route

• Mixed operation

• Maximum speed passenger trains: 250 km/h

• Maximum speed goods trains: 160 km/h

• 50-80 per day passenger trains

• 220-260 per day goods trains

• Loaded vehicles: max. height 4.2 m

• Max. gradient: ≤ 12.5 ‰

• Min. radius: ≥ 5,000 metres

• Max. temperature: 40° C

• Useful life: 100 years

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