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A train ride through the new Gotthard Base Tunnel will take only 20 minutes to connect the Swiss towns of Erstfeld and Bodio on either end.
CCSS: 6.RP.A.3.D, 7.RP.A.3, MP2, MP5
TEKS: 6.4H, 7.4B, 7.4E
The world’s longest and deepest rail tunnel is opening soon
Your favorite Toblerone chocolate may now reach you more quickly. In December, goods like the popular Swiss treat—along with rail passengers—will have a shorter journey through the Alps. That’s because the new Gotthard Base Tunnel in Switzerland is opening!
It took 20 years and $12 billion to build the tunnel. One of the biggest challenges was the high pressure on the rocks. The high pressure is caused by the weight of the mountain above pushing down on the tunnel, says Kalman Kovari, a professor of tunneling at the Federal Institute of Technology in Zurich, Switzerland, who worked on the project. “It’s what you would experience at 5,000 meters below the sea,” he says.
But the engineers completed the tunnel on time and on budget. “Many people had doubts we could finish the tunnel,” says Kovari, “but we did it.”
6,000,000 vehicles—carrying both people and goods—travel through the Alps annually. This creates heavy traffic on the route that passes through Switzerland, and connects northern and southern Europe. So in 1992, the Swiss voted to build the tunnel to reduce congestion and pollution.
35.5 miles of tunnel cut through the rock 1.4 miles below Gotthard Mountain. It’s now the world’s longest and deepest railway tunnel. It’s 2 miles longer than Japan’s Seikan Tunnel, the previous record holder.
1,345-foot-long drills and explosives were used to slice through the mountain. All told, workers excavated 28 million tons of rock—enough to fill five of the Giza pyramids in Egypt!
THE NEW TRIP
325 passenger and freight trains will be able to travel through the tunnel each day. Passenger trains can hit speeds of up to 150 miles per hour, taking only 20 minutes to connect the Swiss towns of Erstfeld and Bodio on either end.
It can be difficult to comprehend the size of large spaces and objects. A comparison with more familiar objects can help you get an idea of their scale. Here are some common objects used to compare different dimensions.
Some commonly used size comparisons are listed in the chart above. Use them to answer these questions about the Gotthard Base Tunnel. Round your answers to the nearest whole numbers.
The Gotthard Tunnel is 35.5 miles long. How many Golden Gate Bridges laid end to end would span this distance?
About 4,626,000 cubic feet of concrete was used to build the tunnel. How many Olympic-sized swimming pools would this concrete fill?
Standing on top of each other, 6 seventh-graders would be as tall as the tunnel. What’s the tunnel’s diameter?
During the tunnel’s construction, engineers used 4 powerful tunnel boring machines to cut through the mountain’s rock. Each boring machine weighed 2,700 tons. How many elephants are equal to the weight of all 4 machines combined?
The Gotthard Tunnel is 1.4 miles deep. That’s roughly 7,400 feet below the mountain’s peak. Is the combined height of 25 Statues of Liberty stacked on top of each other greater than the tunnel’s depth? By how much?