Northern and southern Europe will be better connected
4 Gripper TBMs for a wonder of the world
With mechanized tunnelling technology, four Herrenknecht Gripper TBMs conquered the mountain, breaking records in speed and length. Today the Gotthard Base Tunnel connects Erstfeld and Bodio at a length of 57 kilometers. On June 1, 2016, the longest railway tunnel in the world opened its doors. Forming the heart of the New Alpine Transversal (NEAT), it brings Switzerland and Europe closer together.
The main breakthrough at the Gotthard Base Tunnel on March 23, 2011 in the Western tunnel and on October 15, 2010 in the Eastern tunnel marks the most significant milestone on the way to completing the longest railway tunnel in the world. With the 2 times 57 kilometer long epoch-making project, Switzerland is connecting northern and southern Europe by rail through the Alps. Herrenknecht Gripper tunnel boring machines have excavated and secured more than 85km of the main tubes..
At the end of 2016, the first high-speed trains will travel through the Gotthard Base Tunnel at speeds of 200 to 250 kilometers per hour. After opening the entire NEAT, the journey time from Zurich to Milan will be cut by one hour to 2 hours and 40 minutes. Swiss Railways are expecting, in particular, to cut freight transport times – yet another important improvement in traffic logistics between Germany and Italy. A new era in trans-Alpine rail travel is dawning. Setting off from Bahnhofstrasse in Zurich for a morning’s leisurely shopping in the stylish Galleria Vittorio Emanuele II in Milan and returning the same afternoon with your shopping bags full of the best Italian designer wear. No dream. This vision is becoming a reality.
This quick jaunt between the two commercial centers will be made possible by a unique, epoch-making project – the construction of the new Gotthard Base Tunnel along with the Ceneri and Zimmerberg Base Tunnels. With a length of 57 kilometers and a maximum altitude of 550 meters above sea level, i.e. truly at the foot of the St.Gotthard mountain, two single-lane tunnel tubes will cross the Alpine range from valley floor to valley floor, as it were, on an almost level course. This will put an end to travel that was so slow, passengers could almost pick the flowers along the line, and the need for double locomotives to drive freight trains up steep gradients will be a thing of the past.
The world's longest railway tunnel at a glance: 2× 57km from Erstfeld to Bodio
The world's longest railway tunnel at a glance: 2× 57km from Erstfeld to Bodio
152 kilometers of tunnels, shafts, and galleries
A total of 152 kilometers of tunnels and shafts need to be created for the Gotthard Base Tunnel project. The planners have divided the two main tunnels and the almost 180 cross passages into five construction phases. The overall construction time could be considerably reduced, because work on the five sections could be carried out simultaneously. However, extensive logistics provisions were also necessary. Access and supply tunnels had to be built, and enormous underground caverns had to be excavated to serve as bases for the tunnelling activities or drill & blast operations.
Herrenknecht Gripper TBM for the northern lots, diameter 9.58m
Five times the volume of the Great Pyramid of Giza
More than 85km of the main tubes have been excavated and secured with Herrenknecht tunnel boring machines. These high-tech steel giants from Schwanau, with a length of more than 400 meters and cutterheads measuring 9.5 meters, tunnelled their way through the tremendously hard rock, while the crowds of skiers enjoying the snow some 2,000 meters above in the Lukmanier Pass remain oblivious to the ear-splitting noise and the machine’s brute force. Since beginning their mountain-munching journey in 2003, the cutting wheels of the four Herrenknecht machines have ‘swallowed’ around 10.5 million cubic meters of rock. In total, 13.5 million cubic meters of material are excavated at the Gotthard Base Tunnel - about five times the volume of the Pyramid of Cheops in Giza. Around 75 % of the tunnel’s main route have been excavated by these ‘mega-moles’, as the tunnel boring machines (TBMs) are sometimes known. However, with the sum total of 114 kilometers of parallel tunnels, the project is far from being complete.
Fault zones and geological challenges demanded maximum performance by machine and miners
Surprises can always occur when boring tunnels the size of the Gotthard project. It is not for nothing that tunnel constructors have great respect for their task. Their work is a tightrope walk between the highly planned and the unforeseeable. In spite of the many preparatory investigations, unexpected difficulties can always occur. For example, at the very beginning of tunnelling from the southern side of the Gotthard in February 2003 – after only 200 meters – work was interrupted by unconsolidated rock. The two TBMs that set off from Bodio – affectionately known to the tunnelling teams as ‘Sissi’ (S-210) in the eastern tube and ‘Heidi’ (S-211) in the western tube – encountered geological disturbance zones known as kakirite zones. Such geological conditions are too soft for Gripper TBMs, which are designed for very hard rock, and make rapid tunnelling progress almost impossible. Every meter of excavated tunnel must be secured in a complex process. The machines could not leave these disturbance zones behind them until August 2003, after around 400 meters of tunnelling.
Six and nine months ahead of schedule: The two northern machines arrive in Sedrun in record time
In June and October 2006 the construction teams in the north celebrated the end of tunnelling in the Amsteg – Sedrun section with a spectacular performance. The machines sped towards the end of the construction lot six and nine months ahead of schedule, respectively. But it all ended with an anticlimax. Just before the end of the lot they met with a geological obstacle – kakirite. This is why the TBMs were dismantled in advance in the solid rock zone. The workers then transported the machine components out of the tunnel with the tunnel train..
All-clear: The Piora Basin was not as challenging as expected
The mountain pressure in some sections was so high that the usual method of increasing the target dimensions of the excavating cross section was of no use. Normally, this gives the mountain the opportunity to ‘let off steam’ – the more it deforms, the more mountain pressure is released. But in the critical zones of the Gotthard Base Tunnel, stability could not be achieved by just permitting deformation A counterforce was needed against the mountain to stop the cavity from reclosing completely. The solution was to use telescopically slidable rings. In this method, two telescopically slidable steel half-rings are connected to form full rings inside the tunnel cross section, excavated with an overcut of about 70 centimeters. The ring segments slide slowly together under the mountain pressure until their ends meet and they stabilize each other.
High-speed tunnelling for high-speed trains
After a major overhaul, the two Herrenknecht Gripper TBMs, Gabi 1 and 2, completed the northern Erstfeld-Amsteg section with a length of just over 7 kilometers in 2009. The geological conditions there were almost ideal. This meant a Gotthard tunnelling record could be set in late summer 2009. In the space of only 24 hours, Gabi 2 chomped its way through no less than 56 meters of mountain – a world record for a tunnel boring machine of such dimensions. On June 16 and September 16, 2009, the construction site teams in the north reached their destinations in Amsteg after only 18 months, that is, six months ahead of schedule. This breakthrough was a prime example of the tunnel builders’ and the machines’ precision. Both TBMs had deviated from the ideal line, horizontally by 4 millimeters and vertically by 8 millimeters – millimeter precision in the truest sense.
June 16, 2009: Breakthrough in Amsteg, eastern tunnel
At this time, Sissi and Heidi were still working in the mountain in the south. Although Heidi had some problems with a rock collapse in the western tube between Faido and Sedrun in March 2010, the subsequent stabilization measures only interrupted tunnelling until July 2010. Luckily enough, this event had almost no impact whatsoever on the project schedule. Work continues, including that of the two (vault) lining units supplied by the Herrenknecht branch company Maschinen- und Stahlbau Dresden, which follow the two tunnelling ‘ladies’ at a respectful distance. These 600-meter-long ‘worms’ lay drainage pipes, install sealing systems and concrete the vaults in twelve-meter stages. In a nutshell, they prepare the tunnel tubes, with top monthly performances of 600 meters, for the installation of the railway technology.
The main breakthrough at the Gotthard Base Tunnel is a milestone in tunnel construction
On March 23, 2011 breakthrough was achived in the Western tube and October 15, 2010 in the eastern tube and an “unhindered view of the Mediterranean” has become a reality. A few years of finishing work followed, to turn the tunnel into a functioning high-speed rail route with massive security precautions, for example the two emergency stations where trains can stop in case of danger.
To be part of such a once-in-a-century project is a unique gift for any entrepreneur and engineer. I am very proud that our engineers and machinery have been able to show their best performance. There really isn’t anything more satisfying!
Dr.-Ing. E. h. Martin Herrenknecht, Chairman of the Board of Management
Ab Ende 2016 werden die ersten Züge durch den neuen Basistunnel eilen.
Here, passengers will be able to move quickly from one tunnel to the other – each of the two tubes serves as an escape route for its twin. This is a clever solution, which came after lengthy consideration of all the alternatives by all those involved in Switzerland. The work of the tunnel builders and the machines is now approaching its end. And the results are very satisfying. All risks were dealt with, all setbacks were overcome, all emotional rollercoaster rides were survived. And schedules were adhered to, despite the almost unimaginable complexity of the project. Time lost in one place was made up for elsewhere. On the occasion of the last stage goal, the Erstfeld – Amsteg breakthrough – Moritz Leuenberger, Member of the Swiss Federal Council, spoke of a triumphant victory over the doubters and moaners”. His motto was “no matter how high the mountain and no matter how hard the rock, where there’s a will there’s a way. We can do it, because we want it.”
Further Informationen: AlpTransit Gotthard AG
Tunnels have been built through the Gotthard-Range for more than three centuries. The Gotthard Base Tunnel will be the longest tunnel in the world. An epoch-making project.
June 01, 2016
The Gotthard Base Tunnel – the centerpiece of the new Alpine transversals – is scheduled to go into operation.
March 23, 2011
Main breakthrough in the Western tunnel between Sedrun and Faido.
October 15, 2010
Main breakthrough Tunnel in the Eastern tunnel between Sedrun and Faido.
2009
Mechanized tunnelling is successfully completed in the north.
2008
The dreaded Piora Basin is successfully crossed by the S-210.
2006
The Herrenknecht TBMs on the northern and southern sections of the Base Tunnel reach their first target –up to nine months ahead of schedule.
2003
Tunnelling work with the four Herrenknecht Gripper TBMs begins.
2001
The first machine orders are awarded to Herrenknecht.
1999
Excavating activities begin in Sedrun with the first blasting works.
1998
The Swiss government approves financing for the New Alpine Transversal (NEAT).
1996
The first preparatory and exploratory work for the Gotthard Base Tunnel begins in Sedrun.
1993
Exploratory drills begin at the Piora Basin.
1980
The first road tunnel is opened to traffic and connects Göschenen with Airolo.
1969
Construction of the first road tunnel through the Gotthard begins.
1882
The longest railway tunnel in the world at the time, with a length of 15 kilometers, goes into operation.
1880
Breakthrough is achieved on February 29, with impressive precision for that time.
1872
Construction of the first rail tunnel through the Gotthard begins, under the direction of the Swiss engineer Louis Favre.
1707
The master builder Morettini from Ticino chipped and blasted a 64-m-long tunnel through the Chilchberg mountain – it is known as the ‘Urner Loch’.
| Column 0 | Column 1 |
|---|---|
| 80% | The Alps, and in particular Switzerland, are key to transit traffic through Europe. Around 80% of freight transport between Italy and the other EU countries goes through the Alps. Until now, two thirds of that traffic has been by road, above all along the Brenner (Austria), Fréjus and Mont Cenis (France) and Gotthard (Switzerland) transport corridors. The European transport concept aims to transfer part of that road traffic onto the railways, in particular in Alpine regions. Switzerland's neighbors have bindingly agreed to provide high-speed rail corridors to serve as connections to the Gotthard. |
| 250 KM/H | The New Alpine Transversal (NEAT) will make this high-speed traffic through the Alps possible. The rail route will provide an alternative to air travel, since the passenger trains will reach speeds of 200 to 250km/h. The Zimmerberg Base Tunnel, the Gotthard Base Tunnel and the Ceneri Base Tunnel will reduce travelling times for passengers between Zurich and Milan from 4h 10min to 2h 40min. This will make a quick jaunt across the Alps for lunch possible. |
| 550 METERS | Road traffic through the Alps currently doubles in volume every eight years. Tailbacks of several kilometers have long become a daily occurrence at the Gotthard road tunnel. This is why freight transport is to be shifted to rail. The two NEAT axes at the Gotthard and Lötschberg mountains will more than double freight capacity from its current 20 million to around 50 million tonnes per year. They will not only allow more frequent rail traffic, the flat rail concept will also mean that trains can be considerably longer and twice as heavy (4,000t instead of the current 2,000t). This will make the helper locomotives, currently necessary on inclines, a thing of the past. The new highest point will be at the same altitude as the city of Bern, i.e. 550m above sea level. As a comparison, the highest point of the existing mountain railway is 1,150m above sea level. The route through Switzerland will thus become much more flat and 40km shorter. Freight trains will travel at speeds of up to 160km/h – twice as fast as now. |
| Column 0 | Column 1 |
|---|---|
| Project | Gotthard Base Tunnel |
| Client | AlpTransit Gotthard GmbH |
| Geology | Rock Gneiss, granite, slate |
| Tunnelling length | 85,425m |
| Machine data | 2x Gripper TBM: Diameter: 9,430mm Lining method: Rock support Cutterhead power: 3,500kW Torque: 8,526kNm 2x Gripper TBM: Diameter: 9,580mm Lining method: Rock support Cutterhead power: 3,500kW Torque: 8,526kNm |
We are ready!