Young Chemists in Central Switzerland: Trains, Trains, Trains
In June of 2016, the world’s longest railway tunnel opened in Switzerland: the Gotthard Base Tunnel. The tunnel passes under the Alps and connects Erstfeld in the canton Uri with Bodio in the canton Ticino. It is also an important trade link between northern and southern Europe. With Young Chemist Award winners Antonella and Bibekananda, we took a tour of the engineering masterpiece.
After two rainy days in eastern Switzerland, our luck still didn’t change: on the third day of our Tour de Suisse, the weather was still grey, wet, and unpleasant. We left Herisau in the morning on the Voralpen-Express («Prealp Express»), a scenic train that travels along the Alpine foothills from St. Gallen to Lucerne. But the weather denied us the beautiful views that the route usually has to offer.
A Masterpiece of Engineering: The Gotthard Base Tunnel
About half an hour before the train’s arrival in Lucerne, we got off and took a local train to Erstfeld, the starting point of the Gotthard Base Tunnel (GBT) on the north side of the Alps. Our tour guide, who had been involved in the construction of the tunnel, met us at Erstfeld train station and took us to the Gotthard Base Tunnel Exhibition.
The construction of the GBT was first backed by the Swiss voters in a referendum in 1992. Work started with geologists surveying the rock along the planned route of the tunnel to determine the feasibility of the project and to estimate the duration of the excavation. They came to the conclusion that it would take 25 years to excavate 57 kilometers of tunnel in the challenging mix of rocks they found. But the time allowance was no more than 10 years.
Excavation began in 1999. Traditionally, tunnels are excavated from both ends until the two segments meet in the middle. To comply with the allowed time frame, the construction of the GBT was instead divided into five segments that were excavated simultaneously. The inner segments were accessed through side tunnels. The GBT exhibition is held in one of these four access tunnels, just a few kilometers outside Erstfeld, and it features a window to the GBT through which visitors can watch trains thunder past at up to 250 kilometers per hour.
Engineers and miners encountered innumerable challenges during the 17 years of construction. How to stabilize the tunnel underneath up to 2300 meters of rock? How to dispose the almost 30 million metric tons of excavated material—or put it to a useful purpose? How to provide a safe working environment for tunnel workers, including temperatures that don’t surpass the legal maximum of 28 °C when the temperature inside the mountain reaches up to 46 °C?
Somehow, by constantly adapting to unexpected circumstances, the 2600 people involved in the project were able to complete the tunnel. And they exceeded neither time nor budget allowance. By June of 2016, the tunnel was ready and tested, and trains started using it. In 2017, an average of 11’000 people passed the tunnel every day.
From Hightech to History
We closed our railway experience with refreshments in the cozy atmosphere of a historic railcar. SBB Historic, the heritage foundation of the Swiss Federal Railways, maintains old locomotives and railcars for such events, as well as for nostalgic train rides. Our host was a recently-retired pilot who now volunteers at SBB Historic.
The train enthusiast later took us to see some special historic locomotives, which were used to cross the Alps a long time ago, the most famous one being the Swiss Crocodile. Before the new Gotthard Base Tunnel was built, the locomotives crossing the Alps needed strong engines to overcome the steep ascents leading to the old Gotthard Tunnel at 1151 meters above sea level. Especially Bibekananda seemed to enjoy exploring the driver’s cabs and engine rooms of old locomotives.