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AlpTransit Gotthard New traffic route through the heart of Switzerland The first flat route through the Swiss Alps is being built under the Gotthard. The new rail link runs from Altdorf to Lugano. It offers goods traffic a real alternative to the road. Passenger traffic benefits from improved connections and shorter journey times.




Swiss traffic policy NRLA under the Gotthard Flat rail link Goods traffic Passenger traffic Planning Financing Organisation

3 4 5 6 7 8 / 9 10 11

Gotthard Base Tunnel Ceneri Base Tunnel Surveying Geology Driving methods Tunnel lining Environmental protection Spoil processing

12 / 13 14 / 15 16 / 17 18 / 19 20 21 22 23

Tunnel infrastructure systems

24 – 27

Railway infrastructure systems

28–41 42 43–47

Commissioning Railway operations

Swiss traffic policy Sustainable and forward-looking With the New Rail Link through the Alps (NRLA), important goals of Swiss transport policy can be implemented: transfer of goods traffic from road to rail, and improvements in passenger traffic.

Switzerland is pursuing an environmentally compatible, efficient and financeable transport policy. It includes modernisation of the railway infrastructure and integration into the European highspeed network. Wherever possible, goods are to be transported by train. Transferring goods traffic from road to rail protects the sensitive Alpine region from the environmental burden of increasing traffic.

Frankfurt / Hamburg / Rotterdam







Berne Gotthard Lötschberg

The new transalpine link Switzerland is fulfilling the goals of its transport policy through various projects: Rail 2000, connection to the European high-speed network, noise mitigation, Rail 2030. At the centre, however, are the major projects of the New Rail Link through the Alps under the Lötschberg and Gotthard. Trains have already been travelling through the Lötschberg Base Tunnel since 2007. The Gotthard Base Tunnel is scheduled to become operational at the end of 2016, the Ceneri Base Tunnel at the end of 2019.

Goods train traverses the Gotthard




Milan Venice



Spain Rome Links to the European high-speed network Transit axes through Switzerland NRLA – New Rail Link through the Alps

The NRLA in the European railway network

NRLA under the Gotthard New route through the Alps Construction of the New Rail Link through the Alps (NRLA) is creating a fast and efficient railway link through the Gotthard. At its heart are the two base tunnels under the Gotthard and Ceneri.


The NRLA creates new perspectives for rail traffic through the Alps. Goods can be transported efficiently and environmentally compatibly by rail. Journey times in national andZürich international pasBasel senger traffic are massively shortened.

The Gotthard axis of the NRLA is Switzerland’s largest-ever construction project. It comprises the base tunnels through the Gotthard and Ceneri as well as their connections to existing railway lines.

In brief Gotthard Base Tunnel y Total

length: 57 km – the world’s longest railway tunnel

y Links the north portal at Erstfeld with the south portal at Bodio




Maximum rock overburden: 2,300 m

y Involved


in construction: 1,800 people

y Main tube drives: 75% tunnel boring machine, 25% drilling and blasting

Zurich Altdorf

y Two

multifunction stations: at Faido and Sedrun


y Max. speed: goods trains: 160 km/h passenger trains: 250 km/h


y Excavated



Gotthard Base Tunnel total length: 57 km

Scheduled opening: 2016

Ceneri Base Tunnel y Total

length: 15.4 km

y Links north portal at Vigana/ Camorino with south portal at Vezia/Lugano





Maximum rock overburden: 800 m


Involved in construction: 400 people


Driving: 100% drilling and blasting

y Max. speed: goods trains: 160 km/h passenger trains: 250 km/h

Giustizia AlpTransit route


Access adit Bellinzona

Existing railway line



Ceneri Base Tunnel total length: 15.4 km


Lugano Milan

Route of the Gotthard axis

rock: 28 million tonnes

Excavated rock: 8 million tonnes

y Scheduled

opening: 2019

Flat rail link Innovation increases productivity The first flat route through the Alps is being constructed under the Gotthard. With minimum gradients and curves, it runs from Altdorf to Lugano. The highest point is 550 metres above sea level – no higher than Switzerland’s capital city of Berne.

The flat route shortens the distance from Basel to Chiasso by 40 km with a maximum gradient of only 12 per thousand, substantially less than the Gotthard mountain route (26 per thousand).


Benefits for goods and passenger traffic The new routes shorten passenger journey times substantially. Passenger trains travel at speeds of up to 250 km/h. In total, around a quarter more passenger trains will travel on the north-south axis than today. The elimination of height differences allows more goods trains to pass. On the flat route they also require less energy than on the mountain route and, thanks to the shorter distance, reach their destination sooner.

South portal of the Gotthard Base Tunnel at Bodio

2,500 m 2,000 m 1,500 m Göschenen

1,000 m



500 m 0m


Chiasso Basel




Biasca Bellinzona

Gotthard Flat route through the Gotthard and Ceneri



Goods traffic Transfer from road to rail Transport of goods on the north-south axis is constantly increasing. Forecasts indicate that this will continue in the future. To protect the sensitive Alpine region, as many goods as possible must be transported by rail.


For the increased transfer of goods transport to the railways to be successful, rail must be able to compete with road. The flat route through the Gotthard will be a real alternative.

More transport capacity for goods traffic 220 to 260 trains per day can travel over the new route. That is substantially more than formerly on the mountain route (140 to 180). Long and heavy goods trains will also travel over the flat, almost straight railway route. 2,000-tonne loads can travel through Switzerland non-stop without an additional pushing locomotive, thus eliminating time-intensive shunting manoeuvres. This increases the annual transport capacity from around 20 million tonnes today to around 50 million tonnes. This is sufficient to master the forecast increase in goods traffic. Goods trains on the north-south axis Various goods trains will travel on the Gotthard axis. They are normally 750 metres long. Around one third of the goods trains will travel via Luino to the loading terminals in northern Italy. Slightly under two thirds of the goods trains will enter Italy via Chiasso. Of the goods trains travelling north-west, around one third travel via Basel to Antwerp. The other two thirds travel via Basel to the major industrial centres of Germany, the sea port of Rotterdam, or Scandinavia. A small proportion serve the Rhine port at Basel.

Southbound goods train in the Leventina Valley

Million tonnes 25 20 15 10 5 0 1980 Rail








Development of transalpine goods traffic in Switzerland 1981–2010


Passenger traffic Good connections, quicker travel For travellers, the NRLA through the Gotthard is a quantum leap. Zurich and Bellinzona come within commuting distance and the journey time to Milan is cut to under three hours.

The newly constructed Gotthard route will make rail travel competitive with road and air. This will benefit more than 20 million people in the catchment area between southern Germany and northern Italy.

Better connections for commuters and day tourists Based on the railway hubs of Zurich and Milan, the national and cross-border timetables are coordinated. Passenger trains will travel on the north-south axis at hourly intervals, on weekends and times of intense traffic even at half-

hourly intervals. With constantly higher passenger numbers, a general intensification of the timetable to half-hourly intervals is possible without restricting the capacity for goods traffic.

High speeds of up to 250 km/h The new Gotthard route is a high-speed rail link. Passenger trains can traverse the almost 60 kilometres length of the new route at maximum speeds of up to 250 km/h. This is made possible by the straight route with no tight curves and no level crossings on the overground sections. The infrastructure will allow

future travel times to be achieved of around one and a half hours from Zurich to the Ticino, and less than three hours from Zurich to Milan. However, this also depends on adaptations to the approach routes and expansions of the network, as well as the rolling stock that will then be used.

The New Rail Link through the Alps benefits travellers


Planning From idea to implementation The idea of a flat crossing of the Alps is not new. The first vision of a Gotthard base tunnel was already conceived in 1947. In the 1990s, in various referendums the Swiss people opened the way for the New Rail Link through the Alps. The first preparatory work on the Gotthard Base Tunnel began in 1993.


1940s and 1950s: first visions In 1947, the engineer and traffic planner Carl Eduard Gruner of Basel sketched a two-level combined road and rail tunnel between Amsteg and Bodio, which included an underground railway station at Sedrun. The Swiss government’s Gotthard Tunnel Study Group investigated various alternatives for a road tunnel. Recommendations included construction of a 45-kilometres-long twin-track railway tunnel from Amsteg to Giornico. 1960s and 1970s: political discussion of the route In 1963, the Swiss government set up the Railway Tunnel Through the Alps Committee to evaluate various alternatives for railway tunnels. In 1971, the

committee decided on a twin-track tunnel through the Gotthard, part of it divided into two single-track tunnels. Swiss Federal Railways were tasked by the government with elaborating the construction project for the Gotthard base line Erstfeld–Biasca. However, an economic recession as well as political disagreement between proponents of the Gotthard, Simplon and Splügen routes blocked the tunnel project.

1980s: decision on network variant In the mid-1980s, new variants and routes entered the political arena. In 1989, the Swiss government declared itself in favour of the “network variant”: a composite of transalpine railway links through the Gotthard and Lötschberg,

with a Hirzel Tunnel as link to eastern Switzerland.

1990s: groundbreaking referendums In 1992, a 64% majority acceptance of the proposals for the New Rail Link through the Alps (NRLA) formed both the planning basis and the political justification for the projects under the Gotthard and Lötschberg. In 1996, the government redimensioned the NRLA: the Lötschberg was implemented partly single-track, the Hirzel Tunnel was dropped. In 1998, the electorate voted in favour of the phased NRLA. With their acceptance of the heavy vehicle tax (HVT), as well as the proposal for modernization of the railways (FinöV), the Swiss people finally cleared the way for

Milestones from planning to entry to service

The first bores for the Piora exploratory system are made. They continue until 1996. SBB establishes the AlpTransit project organisation.

First preparatory and exploratory work begins at Sedrun. Work begins on the access adit.

AlpTransit Gotthard Ltd. is established as a subsidiary of SBB. Its task: construction of the base tunnels under the Gotthard and Ceneri.

At Bodio, the bypass tunnel is excavated. This marks the start of construction work for the Gotthard Base Tunnel also south of the Alps.

Construction of the multifunction station at Faido begins. At Bodio, the first tunnel boring machine starts driving.







The present-day route of the Gotthard Base Tunnel is defined: the Swiss Federal Council approves the preliminary project.


At Sigirino, driving of the exploratory bore for the Ceneri Base Tunnel begins.


At Sedrun, construction of the main shaft begins. With a first blast at Amsteg, driving the Gotthard through the north side of the Alps begins. With the first blast at Faido, driving also begins on the south side.


Work begins on the overground section south (Bodio-Biasca).


Sketch of Carl Eduard Gruner’s vision (1947)

The first final breakthrough of the Gotthard Base Tunnel took place on October 15, 2010.

construction of the New Rail Link through the Alps. 1996 saw the start of preparatory work at Sedrun, followed in 1999 by Amsteg and Faido.

From 2000: the Ceneri Base Tunnel takes shape The first blast took place in July 2000 at Bodio, and in 2004 work began on the north portal at Erstfeld. In October 2010, fourteen years after preparatory work


began, the Gotthard Base Tunnel was completely broken through. In 2006 at Camorino, work began on the Ceneri Base Tunnel. The main drives started in 2010.

Preparatory work for driving also begins at Erstfeld: work is now in progress on all five construction sites of the Gotthard Base Tunnel.

At Sigirino, blasting for the access adit to the Ceneri Base Tunnel begins. Initial driving work begins by the north portal of the Gotthard Base Tunnel at Erstfeld.

Preparatory work for installation of the railway systems in the Gotthard Base Tunnel begins at Biasca.

Excavation of the Gotthard Base Tunnel is complete. Installation of railway systems in the Gotthard Base Tunnel begins also north of the Alps.

Scheduled opening of the Ceneri Base Tunnel.






The first tunnel boring machine for the Gotthard Base Tunnel North is completely assembled and sets off from Amsteg towards Sedrun.


The foundation stone for the Ceneri Base Tunnel is laid at Camorino.


The once-feared Piora Syncline is mastered.


The main drive of the Ceneri Base Tunnel as well as the two inward drives from the portals begin. In the Gotthard Base Tunnel between Sedrun and Faido, the final breakthrough takes place. Installation of the railway systems begins at Bodio.


Scheduled opening of the Gotthard Base Tunnel.

Financing Fund creates planning certainty To extensively modernise and expand the railway infrastructure in Switzerland, the federal government created a special financing concept. It assures the financing of a total of four major railway projects.


Financing through the FinöV fund In 1998 the Swiss people voted in favour of the “Proposal for the Construction and Financing of the Public Transport Infrastructure (FinöV)”. The FinöV fund that was approved is financed with revenues from the distance-related heavy vehicle tax (64%), the tax on petroleum products (13%), and value added tax (23%). It assures the reliable financing of four major railway projects: the NRLA through the Gotthard and Lötschberg; Rail 2000 and ZEB; connections from east and west Switzerland to the European high-speed network HGV; and noise-mitigation measures along existing railway lines.

Sources of funds

Application of funds

Tax on petroleum products approx. 13%

NRLA approx. 45% Rail 2000 Phase 1 and ZEB approx. 44%

Public transport fund (FinöV)

Value added tax approx. 23%

Noise mitigation approx. 7%

Heavy vehicle tax approx. 64%

Links to the European high-speed network approx. 4%

Financing the public transport infrastructure (FinöV)

Stable forecast of the final costs In 2008 the Swiss parliament approved a total credit of 19.1 billion Swiss francs for implementation of the NRLA. CHF 13.2 billion of this amount were earmarked for construction of the Gotthard axis. These figures are based on 1998 prices excluding inflation, value added tax and construction interest. For the last few years, the forecast of the final costs for construction of the NRLA Gotthard route with the Gotthard and Ceneri base tunnels has remained stable. AlpTransit Gotthard Ltd. expects the committed credit of 13.2 billion Swiss francs to be sufficient.

The Swiss parliament approves a total credit of 19.1 billion Swiss francs for the NRLA

Organisation Strong partners for major project A project like the NRLA Gotthard that costs billions and takes a generation to complete is complex. Around 2,200 people are involved in implementing the project. For successful control of the project, a well-functioning organisational structure is essential.

Specialists from highly diverse technical fields are working on the new flat rail link. In 1998, AlpTransit Gotthard Ltd. (ATG) was established as a subsidiary of SBB with responsibility for materialising both tunnel structures.

Management by AlpTransit Gotthard Ltd. ATG is tasked by the Swiss government (which ordered the tunnel) and SBB (the future operator) to construct the tunnel. ATG is responsible for the project management and risk management and ensuring that the built structures are produced on time, at minimum cost, and in the agreed quality. ATG is purely a management company which employs around 160 people at its headquarters in Lucerne and its branches in Altdorf, Sedrun, Faido and Bellinzona. It does not build or plan anything itself, but delegates this work to project engineers, construction companies and consortia.



AlpTransit Gotthard Ltd.




Affected parties



Society AlpTransit Gotthard Ltd. is central to the interests of different stakeholder groups

Networked with partners ATG maintains close contact with various partners and must reconcile numerous claims: The Swiss government The Swiss government has not only ordered the NRLA Gotthard but also approves, monitors, controls and finances it. Specialists at the Federal Office of Transport approve subprojects when they have been elaborated. The Parliamentary Supervisory Committee for the NRLA, a committee of the Swiss parliament, is responsible for the political supervision.

SBB as future operator of the railway tunnel When they are complete, the two base tunnels under the Gotthard and Ceneri will be operated by SBB. Already during the construction phase, and especially while commissioning, ATG and SBB work closely together. Private sector contractors For planning and executing the construction work, planners, construction companies and suppliers were contracted. They were selected in a public tendering process. Diverse public expectations A major project affects many people. The expectations placed upon ATG by residents, representatives of the economy, environmental organisations and politicians are correspondingly diverse.

Gotthard Base Tunnel The world’s longest railway tunnel The Gotthard Base Tunnel is composed of two 57-kilometres-long single-track tubes. These are connected together every 325 metres by cross passages. Including all cross passages, access tunnels and shafts, the total length of the tunnel system is over 152 km.


The tunnel system Two multifunction stations at Faido and Sedrun divide the two tubes into three approximately equally long sections. The multifunction stations each contain emergency-stop stations and two track crossovers. These allow trains to cross over from one single-track tube to the other. The air extraction system and numerous technical systems for railway operations are also accommodated here. Via the overground approach lines to the north and south of the two portals at Erstfeld and Bodio respectively, the base tunnel is connected to the existing SBB main line. Subdivision into sections For planning and construction purposes, the Gotthard Base Tunnel was subdivided into various sections. Access adits

provided access to the underground construction sites for workers, materials and machines. To save time and costs, construction work on the various sections was coordinated and sometimes simultaneous.

Gotthard North (4.4 km) The overground section between Altdorf/Rynächt and the north portal connects the new Gotthard link to the existing SBB main line. In addition to the new railway track, numerous structures such as underpasses and bridges were also built.

branch-off structures around 3 km south of the portal allow a possible future extension of the tunnel to the north.

Amsteg (11.3 km) To allow construction of the two tunnel tubes, a 1.8-kilometres-long access adit was first excavated. For later installation of the railway electric power supply, a tunnel boring machine cut an underground cable duct to link with Amsteg power station. From Amsteg, two tunnel boring machines cut the drives in the east and west tubes towards Sedrun.

Erstfeld (7.8 km) In an open trench in the first 600 metres of the most northerly section, a cut-andcover tunnel was constructed which was covered over with soil. Two underground South portal Bodio Faido multifunction station with emergency-stop stations

Waste-air shaft

Faido access adit

Sedrun access adit Hoistway I and II Sedrun multifunction station with emergency-stop stations

Cross passage

Cross passage Cable tunnel

Amsteg access adit North portal Erstfeld The tunnel system under the Gotthard

Approx. 40 m

Altdorf Gotthard North length 4.4 km Erstfeld

Erstfeld length 7.8 km

Amsteg Amsteg length 11.3 km


Sedrun length 8.5 km

Faido length 13.5 km

Sedrun (8.5 km) For construction of the Sedrun section, access from the surface was through a 1-kilometre-long access tunnel and two 800-metres-deep vertical shafts. The location of the tunnel construction site deep under the mountains was a great logistical challenge. At the bottom of the shaft, the caverns for the future multifunction station were excavated. From there, the two tubes were blast-driven to the north and south. Because the deep rock overburden and high stresses threatened to deform the tunnel, special supporting means were necessary in some places. The engineers developed a novel, innovative concept with flexible steel rings. These contracted under the pressure of the rock and prevented deformations in the finished structure. Faido (13.5 km) A 2.7-kilometres-long access adit with a gradient of up to 13% provides access to the underground construction sites. The second multifunction station is located here. Because of unexpected geological difficulties with microearthquakes, the multifunction station had to be replanned while construction was in progress, and a track crossover was relocated towards the south. For the drive towards Sedrun, the same tunnel boring machines were used that had previously cut the Bodio section. Bodio (15.9 km) Also in the southernmost section, the first few metres of tunnel were cut and covered like at Erstfeld. These were followed by a short section of loose


Bodio length 15.9 km

AlpTransit route Bodio

Access adit Existing railway line

Gotthard South length 7.8 km

Portal Route of the Gotthard Base Tunnel

rock, before driving with tunnel boring machines through solid rock could begin. To allow earlier access to the underground assembly caverns for the machines, a bypass adit was constructed. Since breakthrough to the Faido section, and until 2013, the east tube serves as a transport tunnel. The west tube is the first section of the tunnel in which the railway systems are being installed.

Gotthard South (7.8 km) The overground line from the south portal at Bodio to the junction at Giustizia, south of Biasca, links the Gotthard Base Tunnel to the existing SBB main line. The construction of various bridges and underpasses permits an environmentally protective route through natural landscapes as well as densely populated areas.

Track crossover in the multifunction station at Sedrun

Ceneri Base Tunnel Second heart of the flat route Only with the 15.4-kilometres-long base tunnel under Monte Ceneri will the continuous flat route from Altdorf to Lugano become reality. After the Gotthard and Lötschberg base tunnels, the Ceneri Base Tunnel is Switzerland’s third-largest railway tunnel project.


The tunnel system Like the Gotthard Base Tunnel, the Ceneri Base Tunnel also consists of two single-track tubes around 40 metres apart which are joined together by cross passages. Because of its length, no track crossovers or multifunction stations are needed. At the request of the canton of Ticino, the Locarno–Lugano link is also being implemented to serve regional traffic in the Ticino. It will reduce the time to travel between Locarno and Lugano from today’s 55 minutes to 22 minutes.

Construction concept The Ceneri Base Tunnel is being excavated entirely by drilling and blasting. The maximum rock overburden is up to 900 metres, the least only a few metres. The majority of the excavation is being performed simultaneously in both directions from the intermediate heading at Sigirino. From the portals at Vigana and Vezia, inward drives were excavated to minimise time and costs. Near the portals only protective construction methods could be used, since work in these areas had to be performed in sensitive environments.

Camorino To link the Ceneri Base Tunnel to the existing railway line, various structures are being built at the Camorino hub. These include a new four-lane bridge over the A2 motorway and two new single-track railway viaducts over the four-lane cantonal road.

South portal Vezia

Future extension to the south Installation cavern

Cross passages

Sigirino access adit (2.3 km)

Branch-off structure Sigirino exploratory bore (3.1 km)

North portal Vigana/Camorino The tunnel system under the Ceneri


Linienführung Ceneri-Basistunnel

Ceneri Base Tunnel north portal with links to Locarno (left) and Bellinzona

Vigana The area around Vigana is the site of the north portal of the Ceneri Base Tunnel. Here, in loose rock, the tunnel had to pass at a depth of only nine metres under the A2 motorway. Shortly after the portal in both tubes are underground branch-off caverns which, in a later extension phase, will allow crossing of the Magadino plane. Sigirino Starting already in 1997, a 3.1-kilometres-long exploration tunnel was constructed from here which provided valuable geological information. In 2008, a tunnel boring machine cut a 2.3-kilometres-long access adit. At the end of this adit are two underground caverns which since 2010 are the starting points for the two drives each running both south and north. The caverns also accommodate construction site installations for the main drives and the tunnel lining, including, for example, a concrete production plant.

Vezia Vezia is the site of the south portal of the Ceneri Base Tunnel. About 2.5 km north of the portal, still inside the mountain, is the underground branch-off at Sarè which will allow future extension of the tunnel southwards to Chiasso and Como. To protect nearby populated areas and buildings – such as the heritage-protected Villa Negroni – driving in solid rock was performed with only minimal amounts of explosive. Further on, the railway tunnel passes only four metres above the new Vedeggio–Cassarate road tunnel of the Lugano bypass, which also called for protective construction methods. From the south portal of the Ceneri Base Tunnel a 200-metres-long overground section connects it to the existing railway line.

Bellinzona tunnel Camorino hub

Camorino Vigana



AlpTransit line Access adit Locarno–Lugano link Existing railway lines South corridor (future extension) Bellinzona bypass (future extension)

Route of the Ceneri Base Tunnel

Surveying Accurate to the millimetre The new high-speed route through the Alps places high demands on the precision of the built structures. Reliable and highly accurate surveying methods guarantee the required millimetre precision when the built structures are marked out.


Surveying the tunnel Using satellite measurement systems, a network of fixed points was set up over the entire area of the project. These form a link between the plans and the surface terrain, and serve as starting points for marking out the tunnel below ground. By means of the traverse principle, successive angles and distances are measured into the tunnel.

blasted drives are also controlled with surveying data. All data of the surveypoint network must be constantly updated. The surveying tasks also include monitoring the built structure and detecting deformations.

Controlling the driving direction The surveying tasks inside the tunnel are highly diverse. They relate in particular to marking out built structures, railway system installations, and installed equipment. The tunnel boring machines and

Compensating for distorting factors The enormous dimensions in the long underground tunnels make surveying difficult. The numerous construction sites, their complex interconnections, and 24-hour construction activity make its organisation particularly challenging. Account must also be taken of influences that distort the measurement results. Temperature differences between the

tunnel wall, with its high rock temperatures, and the cooler centre of the tunnel can deflect the laser beams used by the surveyors (refraction). For this reason, whenever possible the surveying tripods are positioned in the centre of the tunnel. The effects of the geoid must also be taken into account. The geoid is the true shape of the earth which, because of the varying density of the earth’s crust and the mountain chains on its surface, is not perfectly spherical. If these influences were not taken into account by modelling, surveying errors amounting to metres would have to be expected.

Satellites Portal network Traverse Plumbing Gyroscopic measurement








steg d


Sedrun Network of survey points between Amsteg and Sedrun


Tacheometer measurements at Faido–Sedrun final breakthrough

Surveying instruments Tacheometer: Allows high-precision measurement of direction, distance, and vertical angle. Modern tacheometers are motorised and computer-controlled. They emit infrared light waves which are aimed at reflectors. Surveying gyroscope: Allows accurate determination of direction inside the tunnel. The pendular motion of a gyroscope is influenced by the rotation of the earth and thereby indicates geographic north. Laser scanner: Can register up to 500,000 points per second and allows the measurement of photo-realistic three-dimensional models. Because laser scanners can detect even minute cracks in concrete, they are used in acceptance testing of the tunnel structure. They provide valuable information for installation of the railway systems, as well as their operation and maintenance.

Deviations at the breakthroughs of the Gotthard Base Tunnel Breakthrough

Month, year

Bodio–Faido Amsteg–Sedrun Erstfeld–Amsteg Faido–Sedrun

September 2006 October 2007 June 2009 October 2010

Surface deformations under observation A further surveying task is monitoring the earth’s surface. For example, above the Gotthard Base Tunnel the areas around the Curnera, Nalps and Santa Maria dams are monitored for movements caused by construction work. At the north portal of the Ceneri, the tunnel passes only a very short distance under a motorway. To give warning of unexpected subsidence of the road surface, a monitoring and alarm system was installed.

Horizontal 92 137 14 80

mm mm mm mm

Vertical 17 3 5 10

mm mm mm mm

Challenge of the Sedrun shafts Surveying the two 800-metres-deep shafts of the Gotthard Base Tunnel at Sedrun called for innovative solutions. The high accuracy that was required for transmission of the position and direction data from the shaft-head cavern down to the level of the tunnel presented a major challenge. The problem was solved using mechanical and optical plumbing systems and surveying gyroscopes. Precise breakthroughs in the Gotthard Base Tunnel In the 57-kilometres-long Gotthard Base Tunnel, the world’s longest tunnel, the surveyors attained maximum-precision results at all breakthroughs.

Geology Risk factor until breakthrough Even with state-of-the-art technology, the geological conditions under the mountains cannot be precisely forecast, but exploratory bores and the predictions of experienced geologists reduced the risks.


Geology of the Gotthard Base Tunnel During construction of the Gotthard Base Tunnel, highly diverse rock strata had to be traversed. These ranged from various gneisses and hard granites of the Gotthard and Aare massifs to in some cases greatly fragmented sediments between these massifs. Difficult rock conditions Already before construction started, the Piora Syncline and the Tavetsch Intermediate Massif North were known to be constructionally difficult zones. y In the Piora Syncline the geologists expected “floating rock� conditions, i.e. water-saturated sugary dolomite under high pressure. Such conditions made the feasibility of the base tunnel questionable. However, test bores indicated that, at the level of the tunnel, dry conditions could be expected and the rock would be constructionally favourable dolomite. This turned out to be the case: in autumn 2008 the miners could traverse the Piora Syncline with the tunnel boring machine without problem in the east tube, and in February 2009 also in the west tube.

North portal Erstfeld



In addition to the Piora Syncline, the engineers and geologists also expected the northern section of the Tavetsch Intermediate Massif to be constructionally highly critical. The section between the Aare Massif and the Gotthard Massif would present strongly squeezing rock conditions for driving. Correspondingly innovative supporting

means had to be developed. By means of deformable steel rings and anchors, steadily increasing forces to counteract the deformations could be created. This novel concept allowed the large initial deformations that were necessary for a technically and economically viable lining process.

In the Tavetsch Intermediate Massif, innovative supporting means were successfully deployed


Tavetsch Intermediate Massif Longitudinal geological cross section of the Gotthard Base Tunnel

Piora Syncline Faido

South portal Bodio

Geology of the Ceneri Base Tunnel Already between 1997 and 2000 at Sigirino, a 3.1-kilometres-long exploration bore was cut to the future tunnel axis. Solid orthogneisses and other gneisses were encountered, which would not present any particularly difficult conditions for construction of the tunnel. Based on these findings, the definitive horizontal route of the singletrack tubes was determined.


Driving by mechanical digger in the Linea Val Colla fault zone in the Ceneri Base Tunnel

Many factors determine the route through the mountains Although the shortest distance between two points is a straight line, the routes of the Gotthard and Ceneri base tunnels are both curved. They were determined not only by geological factors, but also by geographical criteria such as the positions of dams, access routes to construction sites, the depth of overlying rock, and the utilisation of the surface land. The routes of the overground approach lines also had to consider local regional requirements. The aesthetic and environmentally compatible integration of the railway lines and portals into the landscape and populated areas also played an important role.

A core bore in summer 2008 in the Piora Syncline

North portal Vigana

Sigirino exploratory bore

Access adit installation cavern

Longitudinal geological cross section of the Ceneri Base Tunnel

South portal Vezia

Driving methods Boring or blasting Almost 75% of the Gotthard Base Tunnel was cut by four tunnel boring machines, whereas the Ceneri Base Tunnel is being driven entirely by conventional drilling and blasting.


with cutting-head diameters of up to 9.5 metres were used. The investment costs for a tunnel boring machine are around 30 million Swiss francs. Since the acquisition and preparation of the installations takes longer than for conventional driving, tunnel boring machines are generally only economical for longer drive lengths.

The choice of driving method depends not only on the rock conditions that are expected but also on the access possibilities, the environmental situation and economic considerations. The section length and total construction time available also play a role.

Boring A tunnel boring machine, including the entire driving equipment (backup construction), is around 450 metres long. Thanks to the standardised and mechanised procedures, under good rock conditions high daily advance rates are possible. In the Gotthard Base Tunnel, a total of four tunnel boring machines

adapted to the conditions that are encountered. The rock is loosened either mechanically or by blasting. The work steps involved in drill-and-blast driving are standardised. First, holes are drilled and filled with explosive. This is followed by blasting, and then ventilation and support of the blasted area. Finally, in the “mucking� operation, the miners clear the excavated rock and transport it away. In the Gotthard Base Tunnel, particularly the Sedrun section, the access adits and shafts as well as the cross passages were conventionally excavated by mechanical drilling and blasting.

Blasting Drilling and blasting is a highly adaptable construction method. The cross section and length to be excavated, and the supporting means used, such as shotcrete, anchors, steel inserts or reinforcing mesh, can be continuously

Control Control cabin cabin

Hoisting Hoisting crane crane

Belt Belt conveyor conveyor

Shotcreting Shotcreting system system

Mesh Mesh installer installer

Gripper Gripper

Cutting Cutting head head

Tunnel boring machine (TBM) drive

Excavate Excavate bench bench

Support Support crown crown

Excavate Excavate crown crown

Rock Rock anchor anchor Fresh Fresh air air

Concrete Concrete truck truck

Dumper Dumper truck truck

Conventional drill-and-blast drive

Loader Loader

Drilling Drilling jumbo jumbo

Shotcreter Shotcreter

Drilling Drilling jumbo jumbo

Tunnel lining Built to last for at least 100 years The lining and support structures of the base tunnels must have a life span of 100 years without major maintenance. The construction materials for sealing and lining the tunnel must therefore be of high quality and long durability.

The initial support prevents rock falling from the roof, and protects the workers, before the permanent supporting measures are installed. The initial support is in direct contact with the rock, and therefore exposed to the effects of rock pressure and ground water.

Different strengths of supporting means Depending on the geology, different strengths of supporting means are used: anchors, shotcrete, and steel arches can be modularly combined. They can be deployed in various numbers and strengths. If the rock conditions make them necessary, additional measures to improve the rock conditions or seal the rock must be used. Such measures may include diamond screens, pipe screens, drainage bores and injections. Lining with foil and concrete After the initial supporting measures, a specially developed sealing foil protects the tunnel tubes from water ingress along the entire length of the tunnel. This foil must withstand high temperatures, ground water and rock pressure throughout the 100-year service life of the tunnel. Because commercially available seals would not fulfil the special requirements, corresponding systems appropriate for the Gotthard Base Tunnel were developed. The concrete aggregates for the inner lining are composed almost entirely of excavated rock. Because very little experience was available, corresponding experiments were made to obtain the necessary


Installing the sealing foils

Initial support with shotcrete Max. thickness = 20 cm Deformation = 15 cm In situ concrete lining Min. = 30 cm Sealing foil

Tunnel cross section TBM drive

evidence of quality. The inner lining has a minimum thickness of 30 cm.

Environmental protection In harmony with nature With construction of the new Gotthard rail link, Switzerland is implementing one of Europe’s largest environmental protection projects. The flat route contributes to protecting the Alpine environment. Construction is also taking place as environmentally compatibly as possible.


Already at the planning phase, as well as during construction of the new Gotthard link, comprehensive measures reduce the impact on people, animals, air and water. Dialog with environmental authorities assists in finding workable solutions.

Environmentally compatible transport ensures clean air Air pollution must be kept as low as possible. Most material is therefore transported by belt conveyor, rail or boat. To minimise the quantities of pollutants entering the air, construction contractors must equip their vehicles and machines with particle filters. Strict rules for waste water Construction site traffic and operations pollute the ground water and tunnel water. It is purified and cooled according to legal regulations before being fed back into the rivers.

Landfill irrigation reduces dust emissions

Dust and noise protection Dust and noise from the construction sites can be annoying for local residents. To prevent noise, temporarily stored humus and topsoil are piled up into noise-mitigation embankments. Out of consideration for residents, the operating times of the construction sites are restricted. At Sigirino, for noise protection reasons the construction site is partly located in a cavern inside the mountain. To avoid dust, the construction sites and temporary storage sites for excavated rock are irrigated and vehicles are regularly cleaned.

Protection of flora and fauna Construction of the new Gotthard link also affects the habitats of animals and plants. In some cases the impact is only temporary and subsequently remediated. If the change in use is permanent, compensation measures are implemented: felled trees are suitably replaced, streams are renatured or their banks naturalised. Along the overground sections, noisemitigation walls are erected or noise and vibration prevention measures implemented. Revitalised Aue Insla, Sedrun

Spoil processing Recycling of a special kind Excavation of the tunnels creates gigantic quantities of spoil: 28 million tonnes from the Gotthard and 8 million tonnes from the Ceneri Base Tunnel. These mountains of excavated rock are valuable raw materials.

To conserve natural resources, a large part of the spoil is used to make concrete for the inner lining of the tunnel. The remaining material is used, for example, for landscaping or embankments. Only a small proportion of the material has to be deposited in landfills.

From spoil to concrete aggregate In the past, the fine-grained chip-like material cut by the tunnel boring machines was considered unsuitable for concrete production. However, universities and industry developed innovative techniques and novel systems to allow the gigantic quantities of material to be used as concrete aggregate nevertheless. In laboratories and on construction sites, research and tests were carried out until proof of its suitability was established. Conversion into concrete aggregate takes place directly on the construction sites’ own gravel and concrete production plants. A testing system ensures that the required high quality of the concrete is constantly attained.


From spoil heap to island paradise: Lake Uri

Lakefill in the canton of Uri Spoil that was unsuitable for recycling was taken by train and boat to Lake Uri. Here it was used for regeneration of the shallow water zone. Three nature reserves and three bathing islands were created.

28.2 million tonnes ~ = 7,160 km



North Atlantic Ocean

The rock excavated from the Gotthard would fill a train from Zurich to Chicago

Tunnel infrastructure systems State-of-the-art technology Before the railway systems are installed, the base tunnels are equipped with mechanical and electromechanical systems. Most of these installations are accommodated in the cross passages and the two multifunction stations.


The tunnel infrastructure systems include ventilation, water supply and drainage systems, air-conditioning systems for buildings, cranes, doors, technical floors and metal structures, as well as electrical and fire-protection installations. Most of the systems are installed in the cross passages and the two multifunction stations of the Gotthard Base Tunnel, some also in the tunnel tubes and around the portals.

Equipping the cross passages Through installation of the respective tunnel infrastructure systems, the 176 cross passages of the Gotthard Base Tunnel and the 46 cross passages of the Ceneri Base Tunnel take on various different functions: y Cross passages form protected spaces to accommodate cabinets with railway infrastructure systems. So that the temperature does not rise above 35째C and thereby impair the high availability and long life of the systems, the cross passages are equipped with ventilation systems. The installation of technical floors simplifies the cabling of all systems.


In the event of an incident, the cross passages serve as evacuation routes into the opposite tube. For this reason, they are closed off with evacuation and fire-protection doors. These crosspassage doors must be capable of fast and easy opening, as well as being highly heat-resistant and having a long service life. To fulfil these requirements, they are extensively tested and customised.

Fresh-air fan Waste-air fan West door control cabinet Cross-passage ventilation control cabinet Single-track tube Cross-passage door Technical floor Railway systems control cabinets Fresh air supply

Diagram of cross-passage equipment

East door control cabinet

Equipping the multifunction stations and auxiliary structures y In the track crossovers of the two multifunction stations, trains can cross from one tube to the other. At these points there are special doors which during normal operation are closed and thereby serve to aerodynamically separate the tunnel tubes. In case of need, for example for maintenance work, they can be opened to allow trains to pass. y All technical rooms in the auxiliary structures must be air conditioned and are equipped with cooling and ventilation systems for this purpose. y Shaft I at Sedrun serves not only as a fresh-air duct to the Gotthard Base Tunnel under operating conditions. It also houses various cables for the railway systems and a water pipeline for the multifunction station. To allow the vault and the installed pipelines to be inspected, maintained and repaired, a work elevator with inspection platform has been installed. y In each of the multifunction stations of the Gotthard Base Tunnel at Faido and Sedrun there are two emergency-stop stations for use in case of incidents. The doors of these emergency-stop stations can be opened and closed by remote control and serve a dual purpose: as evacuation doors, and to regulate the fresh air supply.


Work elevator with inspection platform, Shaft I, Sedrun

The cross-passage doors must function even under the most extreme conditions

Tunnel infrastructure systems Fresh air for the base tunnels In normal operation, the Gotthard Base Tunnel is not actively ventilated. However, in the event of a fire in the tunnel, an operational ventilation system sucks smoke out and blows fresh air in. The operational ventilation also ensures an optimal working climate during maintenance work.


For normal traffic operations, no active ventilation of the tunnel is necessary. Through the “piston effect” of the trains, sufficient air is pulled in as they travel through. The air in both tubes of the tunnel is thereby mixed with air from outside.

Ventilation of the Gotthard Base Tunnel The operational ventilation of the Gotthard Base Tunnel is based on two ventilation centres. These are located in the shaft head at Sedrun and in the portal of the access adit at Faido, and are equipped with air intake and extraction fans. Six jet fans are mounted close to the portal of each tube, making a total of 24 fans overall. All of these components of the operational ventilation are 100 % redundant, so that in case of failure a backup is assured. Ventilation in the Ceneri Base Tunnel In contrast to the Gotthard Base Tunnel, in the Ceneri Base Tunnel no ventilation centre is provided. More than 50 jet fans, which are mounted near the portals and in the middle of the tunnel, provide the necessary ventilation of the tunnel. Climate for maintenance work If the temperature in the tunnel is too high, the operational ventilation can blow air in to cool it. During maintenance work it creates the required working climate for the personnel. In the respective section where maintenance is being performed, the temperatures, flow

velocity of the air, and pressure fluctuations must be correspondingly regulated.

Tunnel climate An optimal operating climate in the tunnel is important for the high availability and long life of the technical systems. In summer, the temperature will be around 36 to 37°C, in winter around 35°C. The tunnel temperature is determined, among

other things, by the rock temperature, the temperature of the train when it enters the tunnel, heat emitted by the technical installations, and the ground water temperature. In the tunnel entrance areas, the relative humidity of the air can be over 70 %. With increasing air temperature in the direction of travel, the relative humidity decreases until at the exit portal it is between 20 and 40 %.

Waste air

Fresh air

3-D view of air intake and outlet ducts at the Faido ventilation centre

Sketch of ventilation building at portal of Faido access adit

Tunnel infrastructure systems Responsible water management Large volumes of water enter the tunnel tubes. In the Gotthard Base Tunnel, the ground water and soiled water are drained out of the tunnel in separate pipelines. By contrast, the Ceneri Base Tunnel has a mixed system.

Sealed against ground water The tunnel vaults are constantly exposed to ground water ingress. The water runs along a special sealing foil to the vault base and the vault drainage pipeline. Every 100 metres, the vault drainage pipeline runs into the main drainage pipeline, which is located under the railway track. Separate drain for tunnel water If an incident in the Gotthard Base Tunnel results in soiled water in the area of the railway track, it is collected every 100 meters in a shaft and fed into a separate pipeline; that is why it is called a “separated system”. The soiled water drains into a collection basin outside the tunnel, where it is analysed. Depending on its composition, the water is processed and then discharged into natural watercourses.


Initial support Sealing foil Tunnel vault (inner lining)

Drainage gravel Vault drainage Main drainage pipeline Ø 600 mm In situ concrete invert Soiled-water pipeline Ø 250 mm

Gotthard Base Tunnel drainage system

Ceneri: common pipeline for ground and soiled water In contrast to the Gotthard Base Tunnel, in the Ceneri Base Tunnel the ground water and soiled water are not drained separately. Here, the much smaller volume of ground water allows a mixed drainage system.

Water purification plant at Erstfeld

Railway infrastructure systems Track, power, radio Railway operations in the Gotthard and Ceneri base tunnels only become possible with the railway infrastructure systems. They integrate the new track systems into the existing railway network.


The railway systems include permanent systems such as tracks, points, overhead conductor, electric power supply, radio and telephone links, as well as signalling systems for trains that travel through the base tunnels at speeds of up to 250 km/h.

Temporary buildings and installations sites In addition to the systems for operation, extensive temporary buildings and temporary services are necessary for the in-

Amplification wire Return wire

stallation. The railway systems installations sites near the portals form the logistical basis for the installation process. But the concrete train for laying the railway track, the construction site ventilation and cooling system, as well as the construction site electric power supply, also form part of it.

State-of-the-art systems The railway systems installations are planned and executed at the highest technical level. The long planning and

execution time is a major challenge, since all components must be state of the art when the tunnel is opened.

Extensive tests The railway systems form a complex technical system. Despite this, already at the planning stage attention was paid to constructing the systems as simply as possible and with as few interfaces as possible. Already a long time before the installation phase, extensive factory, material, laboratory and prototype tests

Return wire Overhead conductor support Radio antenna cable Overhead conductor tensioning system

EBV 4 loading gauge (incl. S3 pantograph)

Main signal, warning sign

Handrail Emergency lighting in the tunnel Data cable Low-voltage cable Balise

Tunnel cross section with railway equipment

High-voltage cable Railway track

Tractive power equipment

Radio antenna cable

Single-track tube

were performed for the various parts of the railway systems. These increased the planning safety for commissioning. Close and early coordination with authorities and involved parties is necessary.

Railway track

Cross passage

Safety and automation systems

Electrical and telecommunication systems Cables

Railway equipment in the Gotthard Base Tunnel

Coordinated installation Already before installation, close coordination between the individual areas of the railway systems, as well as between the companies in the areas of the tunnel structure and tunnel infrastructure systems, is important. In some cases, installation of the railway systems is proceeding in parallel with completion of the tunnel structure and technical infrastructure. The requirements for space and time, as well as the material logistics, must be thoroughly coordinated down to the last detail.

Visualisation of railway equipment and temporary installations

One general contractor In the Gotthard Base Tunnel a single general contractor is tasked with installing the railway systems. With a contract value of around 1.7 billion Swiss francs, the work contract is the largest contract awarded by AlpTransit Gotthard Ltd. and also one of the world’s largest contracts for railway infrastructure. During the main installation phase, approximately 700 people, including many specialists, will be occupied with the installation work.


Railway infrastructure systems Phased installation Installation of the railway systems is no easy task for the specialists. Intensive preparations are necessary and highly complex requirements must be fulfilled.



For installation as well as maintenance of the railway installations, access is limited. The portals are effectively the only available access points. Very long transport routes require sophisticated logistics. y Inside the tunnel, space is very tight. Tyred vehicles cannot turn around. Installation of the railway systems is therefore taking place largely by rail. y The climatic conditions are extreme – a challenge for people as well as the technical systems. To prevent high temperatures and high humidity, railway infrastructure systems are accommodated in special cabinets in the cross passages. During the construction phase, ventilation and cooling are necessary. y The high speeds of the trains, as well as the requirements for work safety, increase the level of difficulty for installation of the railway systems.

Laying the rails for the non-ballasted track

Installation work steps In each section of the tunnel, installation of the railway systems follows the same sequence. First, temporary construction facilities and cables are installed, then the non-ballasted track. These provide the rail-based transport logistics for the remaining activities. After this, the catenary

2011/2012 East and west tube Erstfeld−Sedrun

2013/2014 East and west tube Sedrun−Faido

supports are installed and the cross passages fitted out. In a further work step, the tunnel tubes are fitted with emergency lighting and handrails, and the catenary is pulled in. This is followed by connection of the data nodes and technical systems and finally, by commissioning.

2014 East tube Bodio

2010/2011 West tube Bodio Railway equipment installation phases and directions


Installing the radio antenna cable in the Gotthard Base Tunnel

Installation in phases In the Gotthard Base Tunnel, fitting out with the railway system installations is taking place from the south in the west tube at Bodio. Installation will then continue from the north. As work progresses, transport distances will increase to as much as 40 km. Finally, the east tube at Bodio will be equipped, also from the south. The pilot section The west tube in the Bodio section of the Gotthard Base Tunnel will be the first to be completely equipped with all railway system components. On this approximately 15-kilometres-long section in 2014, tests of all aspects of the railway systems will be performed under conditions that are as realistic as possible. The pilot section can be travelled over at speeds of up to 230 km/h. This will allow potential optimisations for the installation to be identified, and the risks associated with commissioning to be minimised. Challenging material logistics So that the right railway system components are available at exactly the right place in the tunnel at the planned time, efficient material logistics are essential. Many elements are specially made. They

must be ordered in good time, produced in the desired quality, pretested, and delivered. On the installation sites the components are temporarily stored, batched according to the daily requirements, and transported into the tunnel for installation. Large quantities of material must be delivered for installation at exactly the right time.

Gotthard Base Tunnel y 2,860 overhead conductor supports y 250 transformer stations y 6,000 km cable y 930 balises Ceneri Base Tunnel y 900 overhead conductor supports y 85 transformer stations y 2,055 km cable y 200 balises

Railway infrastructure systems Track for high speeds In the base tunnels under the Gotthard and Ceneri, in contrast to the overground sections, a non-ballasted track is being laid. So that trains can travel over it at speeds of up to 250 km/h, highest precision is called for.


By comparison with a ballasted track, a non-ballasted track has two advantages: it is less high and has greater positional stability. Maintenance requirements are thereby reduced and travel comfort is increased.

Components of the non-ballasted track The track consists essentially of only a few parts, but which have to be installed in large numbers. The requirements for the two base tunnels are approximately y 400 km of rails, y 480,000 concrete sleeper blocks for the non-ballasted track, y 90,000 concrete sleepers for the ballasted track, y 170,000 cubic metres of concrete. Track-laying with concrete train Once the sleepers have been concreted into place, the track geometry of the non-ballasted track can no longer be corrected. High specifications must

Sleeper (incl. rail fastener) Concrete slab Rails

Components of the non-ballasted track

therefore be fulfilled during installation. Installation takes place in 2-kilometreslong sections. After all material such as sleepers and rails has been delivered into the tunnel, the track must be aligned

with extreme accuracy and surveyed with a track-surveying car. Only then are the sleepers permanently concreted into place. For this purpose, for the Gotthard Base Tunnel the contractor developed a

Installing the railway track

agen: 21 Wagen, Gewicht: ca.1000 t, Länge: ca. 500 m

The 120-metres-long rails are pulled off the train, laid on the tunnel

are delivered into the tunnel on special wagons “just in time” and

enenpaar der 120m langen Langschienentogether wird abgezogen, auf Nach dem Auslegen über to einethe Länge vonposition. mehr als 2‘000 m den Spezialwaggons floor, and connected with distance gauges. After layingder Schienen straight laying The blocks are Auf packed in such a way sind Schienen fes den verlegt und mit Spurhaltern untereinander verbunden. Damit werden die Schwellenblöcke angefahren. Die Schwellenblöcke kommen auf Zuglänge längs bewegen kann. Der Portalk the rails over a length of more than 2,000 m, the sleeper blocks that they do not have to be repacked for laying, and can be laid as isorische Rampe als Übergang zwischen dem bereits fertig gestell- Spezialwagen «just in time» in den Tunnel direkt zur Einbaustelle. Die Blöcke transportiert diese bis zum 1. Wagen. Die ten Fahrbahn und dem nächsten Einbauabschnitt geschaffen. sind so gepackt, dass diese zur Verlegung nicht umgepackt werden müssen im Boden, durch welche die Schwellenblöc ampe besteht nun im Weiteren die Möglichkeit die folgenden und nach Entfernen der Transportverpackung abgelegt werden können. legt werden können.. paare abzuziehen, auszulegen und miteinander zu verschweissen.

Concrete and installation train for concreting the tracks

train-borne concrete production plant. Concrete is produced on site in the tunnel, which results in a higher quality of concrete since the transport distance between the production and laying sites is eliminated. The finished track forms the basis for the track-based installation of the remaining railway system installations.

Innovative points actuator Because of the shortage of space in the single-track tubes, the points are equipped with an actuator system that is new in Switzerland. Instead of mechanical forces being transmitted by levers, a hydraulic actuator is employed.

Overground sections In the overground sections to the north and south of the two base tunnels, a conventional ballasted track with concrete sleepers is being laid. To increase their life span, the concrete sleepers are fitted with an elastic sole.

Workshop at Biasca with laid-out test track

Ballasted track on the Biasca overground section

soon as the transport packaging has been removed. With the aid

sleepers have been laid, they are aligned for installation.

st montiert überof welchen sichcrane, ein Portalkran über Nachdem alle Schwellen sind erfolgtsystem das Ausrichten Schwellenblöcke The supporting is then der installed, followedfür byden theEinbau. rails. a gantry a length of die 60komplette sleepers is raised in a single hoist, ausgelegt kran nimmt eine Schwellenreihe (60Stk) mit einem Hub auf und Die Block an Block liegenden Schwellenblöcke werden auseinander gezogen, ausgerichtet, um 90° transported, and laid on the floor between the rails. After the eser Wagen ist ein Flachwagen mit spezieller Durchführöffnung gedreht und auf der Horizontalschubplatte abgelegt. Daran anschliessend erfolgt die Montage des cke auf dem Boden zwischen den Schienen Block an Block abgeStützsystems und das Einrichten des Gleisrostes.


Railway infrastructure systems Energy for the technical systems All of the technical equipment in the base tunnels and along the overground sections requires electrical energy. The necessary 50 Hz power supply must be extremely reliable and constantly available.


Equipment such as control, safety, communication, and monitoring systems, as well as systems for lighting, ventilation, building control, and drainage place heavy demands on the power supply.

These must function even under exceptional conditions such as high temperatures and dusty air.

Power from public networks The 50 Hz power supply is obtained as a so-called normal network from the public supply networks. For the Gotthard Base Tunnel there are five feed-in points: at Erstfeld, Amsteg, Sedrun, Faido and Bodio. For the Ceneri Base Tunnel there is one each at Vigana and Vezia. In addition, at each of these points two diesel generators are installed which supply a backup network in an emergency. In the event of failure of the normal network, this backup network automatically takes over the power supply. Safety and control systems All systems are visualised, monitored and controlled via the control system. If faults occur in the electric power supply, they are detected by appropriate protection devices and the affected parts of the system are switched off. For the electric power supply in the Gotthard Base Tunnel, 3,200 km of cable are required, and for data communication

Existing substation at Faido

15 kV distribution network

North portal Amsteg Erstfeld access adit

16 kV distribution network

Sedrun multifunction station

Main feed-in point from the public power supply networks

16 kV distribution network

Faido multifunction station

South portal Bodio


Low voltage: 400 V 50 Hz

Medium voltage: 16 kV 50 Hz and 6 kV 50 Hz

Cables in tube blocks in the tunnel side benches

2,600 km. The reliability of the cable is essential for the availability of the 50 Hz power supply. To prevent mechanical damage, the cables are laid in tube blocks in the side benches of the tunnel. Cables with different voltage levels and functions are locationally separated.


Lighting in the tunnels and cross passages The lighting in the base tunnels is not switched on under normal operating conditions. The approximately 9,500 luminaires in the Gotthard Base Tunnel serve as emergency lighting for train passengers along the evacuation routes or for maintenance work.

Handrail and emergency lighting in the tunnel Pulling cables in the Bodio West section

Railway infrastructure systems Power from overhead conductor High-speed trains as well as heavy goods trains travel over the new Gotthard link. The long tunnel distances, the short time intervals between trains, and the necessary high availability make the supply of tractive power a real challenge.


Tractive power supply The tractive power supply is provided from substations that are fed from the SBB high-voltage network. To supply the base tunnels, a total of five substations have been newly built or enlarged. They transform the very high 132,000 volts to the 15,000 volts needed for the tractive

vehicles. If one of the substations fails, the others can still provide a sufficient supply to the section. The east and west tubes have separate independent tractive power supplies. They also have separate switching and protection systems.

Overhead conductor for fast and heavy trains The overhead conductors supply the trains with electric current. To allow high-speed trains and heavy goods trains to travel simultaneously, the overhead conductor in each tube must be capable of carrying currents of up to 2,400 am-



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Faido Lavorgo Giornico Enlarged substation Bodio New substation Existing substation Amsteg power station Gotthard Base Tunnel and approach lines

Pollegio Biasca

Access adits Existing railway line Feed-in points for Gotthard Base Tunnel power supply

Installing the tractive power system

Amplification wire

Return wire Catenary Tunnel radio antenna cable

Loading gauge including pantograph

Overhead conductor tensioning system

Details of overhead conductor installation

peres. An uninterrupted power supply to the tractive vehicles is important even at high speeds.

Catenary for tensioning In the base tunnels under the Gotthard and Ceneri, a catenary system is installed. The overhead conductor is made of silver-alloyed copper. It is suspended from a supporting wire of bronze by hangers with a maximum length of 90 cm. Every 48 metres, the suspension wires are fastened to the supporting sys-

tem in the tunnel vault. For fine adjustment of the entire overhead conductor, tensioning devices are provided every 1,300 metres. For this reason, the construction is called a fully tensioned overhead conductor. In addition, running parallel to the catenary is a regularly connected amplifier wire. This helps to assure the high electric power requirement. The overhead conductor is dimensioned so that it can withstand the failure of a substation.

Earthing The tractive power is transported from the substation via the catenary and pantographs to the tractive vehicle. From there it passes through the wheels to the rails and the return conductors, by which it is fed back to the substation. The railway earth ensures that in the immediate vicinity of the railway track no dangerous voltages occur, so that people are not exposed to hazardous electric shocks.

Bellinzona Locarno Giubiasco Camorino Vigana Luino Rivera


Vezia Enlarged substation


New substation Existing substation Gotthard Base Tunnel and its connections Access adit Existing railway lines Pulling the overhead conductor into the tunnel

Feed-in points for Ceneri Base Tunnel power supply



Railway infrastructure systems Seamless telephony Thanks to the reliable radio and telephone network in the Gotthard and Ceneri base tunnels, passengers can use their mobile phones without difficulty. This network also carries large volumes of data for traffic operations.


Landline-based tunnel control system The landline telecommunications network provides the basis for the control system that remotely controls and monitors all tunnel-specific systems such as ventilation, drainage, doors and lighting. Also linked to the control system are further systems that assist the operating personnel in managing incidents or planning maintenance work. Overall control of these landline-based systems takes place in the Pollegio Control Centre (CEP).

The radio network is available to the following groups: y the train driver, who receives status information which is transmitted into the driver’s cab via a special digital radio system for railways (GSM-R); y intervention services such as police and firefighters, who use their own POLYCOM digital radio system for operations in the tunnels; y train passengers, who use the public GSM-P/UMTS digital radio systems to access the services of the public mobile telephony provider and can telephone from the train.

Landline telephone network The data network also forms the basis for the telephone link between the base tunnels and the surface buildings. For this operational communication, Voice Over IP technology is used. Corresponding telephones are installed in the railway systems buildings, the associated emergency columns in the tunnel portal areas, and in the cross passages. Radio network As well as the landline communication network, a wide-area radio network is also available for mobile communication. This is mainly used for tunnel operations and in case of incidents.

Visualisation of the Pollegio Control Centre (CEP)

Radio antenna cable

Emergency-call column in cross passage Electrical and telecommunication systems Mobile telephony via radio network

Train driver receives signals in driver’s cab via radio system

Antenna cable The radio transmission system makes use of antennae and, in the tunnels, antenna cables. The antenna cable functions similar to an irrigation hose: it has “holes” in the shield through which

radio waves can enter and leave. Installed near the portals are head-end stations which form the interface between the tunnel radio system and the radio services (GSM-R, POLYCOM, GSM-P, UMTS).

GSM-R antenna for transmission of status

The emergency-call columns in the cross

Communication between the base tunnel

information to the train driver

passages are connected to the data network

and the surface buildings is also via the data

The base tunnel is equipped with landline and radio telecommunication systems



Railway infrastructure systems Systems for safe operation The safety systems are used to control and monitor the movements of trains on the newly constructed overground sections as well as in the base tunnels. This ensures safer railway operations.


The safety systems assure seamless control and monitoring of the train traffic. They must fulfil very high requirements for safety and availability: y Signalling centres: The latest-generation electronic signalling centres control and monitor track elements such as points and track-release systems (axle counters). They also assure a clear path for the train. In the Gotthard Base Tunnel, four electronic signalling centres are used along with the associated external systems: one each for the

Radio Block Centre (RBC) and signalling centre

Rynächt area, Bodio/Pollegio, the east tube and the west tube. The Ceneri Base Tunnel will have one electronic signalling centre. y Radio Block Centre: The Radio Block Centre (RBC) is the central component of the driver’s cab signalling system. Travel authorisation and the corresponding block information is transmitted from the RBC via radio interface (GSM-R) direct to the trains. The base tunnels under the Gotthard and Ceneri each have a separate Radio Block Centre.


Railway control system: This is the actual control level and helps the traffic controller to control and monitor operations. The railway control system consists of the ILTIS network-wide control system used by SBB and the Tunnel Automatic Gotthard (TAG) system which is used specifically for the Gotthard Base Tunnel.

GSM-R radio system

The Radio Block Centre transmits the signal information and other track data to the train.

The ETCS transmits the train's location and other train data to the Radio Block Centre (RBC). The train driver reads the signal information from the displays in the driver’s cab.


Function of the ETCS train control system

As the train passes over a balise, the balise transmits the exact position of the train to the ETCS.

41 Employees of the test team in the Gotthard laboratory, Zurich

Automated railway operations The safety systems are operated from the Control Centre at Pollegio (CEP). Inside the tunnel the decentral systems − such as track-release and points control systems – are linked together via a data network. Railway operations are fully automated. Interventions by the traffic controller are unnecessary. Electronic cab signalling system The newly constructed sections of the Gotthard and Ceneri are equipped with the modern European Train Control System (ETCS) Level 2 electronic cab signalling system. The train driver wirelessly receives all information on the display in the driver’s cab. ETCS allows signalling at speeds over 160 km/h. It increases safety and allows capacities to be increased by shorter time intervals between trains. Since optical signals are eliminated, the trackside infrastructure is simplified. The signalling system is standardised throughout Europe and therefore assures interoperability and simplified access to networks.

Locomotive simulator in the Gotthard laboratory

Train intervals The newly constructed sections of the Gotthard and Ceneri routes are designed so that trains can travel at intervals of three minutes. This time interval, which for goods trains is very short, is assured by the safety systems: Gotthard Base Tunnel Balise pairs 930 Axle counters 370 (redundant)

Ceneri Base Tunnel Balise pairs 200 Axle counters 150 (redundant)

Commissioning Testing and training Before trains can travel through the world’s longest tunnel, all systems must be thoroughly tested, test runs performed and personnel trained. Only when everything functions smoothly will SBB receive its operating permit from the Swiss government.


Commissioning the two major constructions of the Gotthard and Ceneri base tunnels is highly complex and subdivided into phases. In subtests, each individual component and system is tested for its functionality. The interaction with the tunnel control system and integration into the overall system must also be

assured. This takes place partly during the installation phase.

The test phases On completion of installation and successful subtesting of all components and installations, commissioning proper begins along the entire length of the

tunnel. Commissioning is subdivided into: y Test operation: AlpTransit Gotthard Ltd. as constructor proves the functionality and fulfilment of the safety requirements. In month-long test operation with running trains, the interplay of all tunnel components is thoroughly tested. y Trial operation: The subsequent trial operation takes place mainly under the responsibility of SBB, the future operator of the base tunnels. Only when it has been demonstrated that operation with passenger and goods trains, personnel deployment, and incident management function perfectly, will the responsible Federal Office of Transport issue its operating permit for scheduled train services.

Pilot section Bodio West

Main responsibility ATG

Main responsibility SBB



Tunnel structure Tunnel infrastructure systems Railway systems ❙

Pilot operation Bodio

Test operation: October 2015

Trial operation: June 2016

Testing ❙ Technical systems ❙ Operating processes ❙ Overall system integration

Rehearse operating processes ❙ Normal mode ❙ Maintenance mode ❙ Fault mode ❙ Intervention/incident rehearsals ❙ Approval runs with commercial trains

Operation Commercial operation with scheduled trains: December 2016 ❙

Completion work and billing

Entry to service 1





Release for pilot operation


Release for test operation

Entry to service of the Gotthard Base Tunnel




(Federal Office of Transport) Operating permit for trial operation


Operating permit for commercial operation

Railway operations Supervision and control Thanks to the modern technical equipment, operation of the railways and tunnels is largely automated. The responsibility for monitoring and controlling this system rests with the employees of the control centre.

The employees of the Pollegio Control Centre (CEP) control, monitor and assign all train traffic on the Gotthard axis between Arth-Goldau and the Italian border. The control centre also controls all the technical systems of the two base tunnels. The Pollegio Control Centre is also the contact point for coordination of the maintenance teams in the two base

tunnels. When an incident occurs, the commanders of the intervention services also operate from here.

tunnel which could cause harm to people, the Pollegio Control Centre can be switched over to emergency mode by the operator or by the system itself.

Normal and emergency operation Normal operation means that all systems of the railway control systems function correctly. Some faults cause trains to be delayed. If an incident occurs in the

Command centre and task force


Technical systems

Model of Pollegio Control Centre

Cross section through the model of Pollegio Control Centre


Railway operations Priority for safety and rescue In the Gotthard and Ceneri base tunnels, the safety of people has top priority. Incidents must be avoided wherever possible or, in the worst case, only minimally affect people, material and infrastructure. For this reason, a modern safety concept is implemented in both tunnels.


Safety concept Already at the concept phase of the base tunnel, a high safety standard was chosen. The tunnel system consists of two directionally separated single-track tubes. In the event of an incident, the opposite tube is therefore a protected space. Every 325 metres there are cross passages, which join the two parallel

tunnel tubes. In an emergency they serve as rapidly accessible evacuation routes into the other tube. Because of the exceptional length of 57 km, in the Gotthard Base Tunnel there are additional safety measures. At the one-third-way points of the tunnel at Faido and Sedrun there are emergency-stop stations in both tubes, which function as follows:


In case of an incident such as a fire in a train or a fault in the Gotthard Base Tunnel, whenever possible the affected train travels out of the tunnel y into the open air. If this is not possible, the train driver stops the train at an emergency-stop station. The control system can also order a halt. The passengers leave the train. Along a length

Faido multifunction station

South portal Bodio

Emergency-stop station Emergency-stop station

Sedrun multifunction station

Passenger crossover tunnel Emergency-stop station

Emergency-stop station Incident tube Track crossover Emergency-stop in the tunnel

North portal Erstfeld

Waste air Fresh air

Emergency-stop stations in the Gotthard Base Tunnel

Parallel tube / evacuation tunnel

Ceneri Base Tunnel without emergency-stop station Because of its shorter length of 15.4 km, no emergency-stop stations will be built in the Ceneri Base Tunnel. This is also the situation in other railway tunnels of comparable length. Internationally, emergency-stop stations are only provided in tunnels longer than 20 kilometres. Also in the Ceneri Base Tunnel, a necessary evacuation takes place by self-rescue through cross passages into the opposite tube.

East emergency-stop station


Tunnel crossover Bord Restaurant

Tunnel crossover Firefighting and rescue train


Evacuation train

West emergency-stop station

Evacuation and rescue concept

of 450 metres, the platforms are two metres wide and lit. There are also handrails to assist orientation. y Through any of six cross passages, the passengers walk to a parallel tunnel which is under overpressure and remains free of smoke. y Via a further system of passages which forms a bridge over the railway tracks, they reach the now closed opposite tube. There are signs to aid orientation. y In the opposite tube an evacuation train collects the passengers and transports them out of the tunnel.

Emergency-stop ventilation In the emergency-stop station, fans provide fresh air. Even before the affected train arrives, the evacuation doors are opened by remote control and fresh air is blown into the emergency-stop station. Hot fumes are sucked out through extraction openings over the emergencystop station and led out of the tunnel. Also in the opposite tube, where the passengers wait for the evacuation train, the air is safe to breathe because the overpressure prevents smoke fumes from entering.

Rescue concept When a train must be stopped immediately and the train driver can no longer drive it to the emergency-stop station, the cross passages can be used by the passengers for evacuation into the other tube. The principle here is self-rescue. With the aid of signs, handrails, emergency lighting, and instructions from the trained railway personnel, the passengers walk along the one-meter-wide bench to the next cross passage. The cross passage doors can be easily opened by hand. When they arrive in the opposite tube, the travellers wait until they are collected by an evacuation train. The construction-logistical access shafts and passages are not part of the rescue system, because rescue by rail is substantially faster and safer.

Railway operations Intervention and rescue In the event of an incident in the tunnel, firefighting and rescue trains are deployed. They bring first aid, accommodate passengers, fight fires, and tow trains away.


A firefighting and rescue train is parked at each portal. This is operated by the SBB firefighting and rescue service with support if necessary from regional and cantonal intervention services. Depending on the incident, further special services can be mobilised.

Every minute counts In the Gotthard Base Tunnel, the driving distance to the location of a possible incident can be long. Even so, no later than 45 minutes after the alarm is issued, the first rescue services will be on site in the tunnel. After no longer than 90 minutes, travellers whose train had to be evacuated should be transported out of the tunnel.

SBB firefighting and rescue train

Firefighting and rescue train The SBB firefighting and rescue trains are diesel-hydraulic powered and composed of a water-tank firefighting car, an apparatus car, and a rescue car. The firefighting car has a water tank with a volume of 50,000 litres and a tank for foam concentrate with a volume of 1,800 litres.

View into the rescue car

Equipment car

Firefighting car

Firefighting and rescue train in the Gotthard Base Tunnel

Rescue car 1

Rescue car 2

Railway operations Maintenance and repair work Even new tunnels must be maintained. For two nights every week, one tunnel tube is therefore completely closed. During this time maintenance and repair work can be performed.

Maintenance work is planned for times with less traffic, such as Saturday and Sunday nights. By closing an entire tube, the maintenance teams can work safely without hindering rail traffic.


Various activities simultaneously For normal maintenance work, trains travel into the tunnel tube from the north and the south. Equipment and machines required for the work are transported on various railway wagons and unloaded at the correct place in the tunnel. Specialists of various technical services work simultaneously in the maintenance section. In the Gotthard Base Tunnel, the lengths of the tubes requiring maintenance, and the various workplaces, present an additional challenge to the logistics. Temporary fault correction In many cases, repairs cannot be postponed until the next regular maintenance phase. To allow correction of faults, “joker intervals� are therefore defined for each section and coordinated with the timetable. In the Gotthard Base Tunnel they allow a tube to be closed between two track crossovers for a period of four hours. Investigation teams can then perform an on-site diagnosis of the damage and prepare the repairs.

A mobile door separates the fresh-air and waste-air flows for sufficient supply of fresh air during maintenance work

SBB diagnosis train

Published by AlpTransit Gotthard Ltd. Zentralstrasse 5 6003 Lucerne/Switzerland Phone +41 41 226 06 06 Text/design Media Office Gotthard AlpTransit Gotthard Ltd., Lucerne/Switzerland Translation Robert Jones, Meggen Images Evoq/Zurich, title image/photomontage SBB Fotoservice, pages 6, 7, 34, 39, 43 bottom, 46 © Das Schweizer Parlament, page 10 Keystone, pages 3, 18 Gruner AG, Engineers and Planners (Basel), page 9 Projekt Urner Seeschüttung, page 23 IG GBT Süd, page 26 Transtec Gotthard TTG, pages 29, 36 Siemens Schweiz AG, page 38 Thales Rail Signalling Solutions AG, page 41 Elkuch Bator, page 25 Bruno Fioretti Marquez Architects, page 47 Printing Engelberger Druck AG, Stans Print run 4/2012, 15,000 copies

© AlpTransit Gotthard AG, 2012

New traffic route through the heart of Switzerland  

New traffic route through the heart of Switzerland

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