After 17 years of construction: The longest rail tunnel in the world goes live

The Gotthard Tunnel in Switzerland covers 152 km of tunnel systems through the rock and at 57 km long is the world’s longest rail tunnel. Its two single-track tunnel tubes are connected every 325 m by cross-cuts and open the way through the Alps. Up to 260 freight trains and 65 passenger trains per day can go through the tunnel. The maximum speed for freight trains will be 160 km per hour and passenger trains can speed up to 250 km per hour.


Barrier between north and south is conquered

When the Base Tunnel is officially opened on 1 June 2016, the Gotthard, the barrier between north and south, will have finally been conquered. Thanks to the tunnel, trains will race through the Alps and scarcely have to climb. This is truly a milestone in transport and for mobility of the future.


Tunnel runs 2000m under the rock

The Gotthard Base Tunnel is something new and special in tunneling. It traverses one of the highest massifs in the Alps. Under the highest peaks, the tunnel runs some 2000 m under the rock and is only about 550 m above sea level at its summit. For heavy freight trains and modern high speed trains, this new line reduces the journey time from Zurich to Milan by about an hour.


A total of 152 km of tunnel section

The breakthrough on 15 October 2010 was the moment when it was clear that – with the Gotthard Base Tunnel – this 100-year construction project would be successfully completed. Eleven years after the first blasting operations, the 57 km long Gotthard tube was broken through. By the time of commissioning on 1 June 2016, a total of 152 km of tunnel section will have been built and 28 million tonnes of rock excavated from the mountain.


100-year construction project

More than 100 years ago, Sika’s success story also began in tunneling on the Gotthard. With the waterproofing for the rail tunnel electrification in 1918, Sika created the conditions for the success of the railway on the north–south axis and also the basis for the company’s global success. The Gotthard Base Tunnel posed similar challenges to those of 1918 along with some quite new ones.


Concrete lifespan of 100 years

It was not just the structural dimensions that placed huge demands on the tunneling engineers; above all it was the high underground temperatures of 30 to 40 °C which had to be managed. The high material and engineering specifications, such as the concrete lifespan of 100 years, were a central issue for this hundred year structure and had to be met.


40,000 tonnes of materials by Sika

This longest rail tunnel in the world now forms the heart of the new Alptransit rail link (NRLA). Sika was involved throughout the 14-year construction period, including the preliminary works from 1996, delivering 40,000 tonnes of materials, including 20,000 tonnes of admixtures. Sika supplied the waterproofing system, the building chemicals know-how and machine solutions on this project. Parts of the tunnel waterproofing system were also installed by Sika. The tunnel excavation is
stabilized by sprayed concrete using high-quality Sika admixtures and sprayed concrete machines.


Passengers now can enjoy short trips to Italy

As of June passengers can now enjoy short trips to Italy. The Gotthard tunnel itself is a contemporary witness to human efforts to build up an infrastructure which connects not only regions and cities, but also countries and even the whole European continent. The Alps should not be an obstacle any more. A project that has taken more than 100 years – and yes, it has been, after all, a considerable success.