8 amazing facts about the world’s longest tunnel

Reuters

Europe just completed work on the longest and deepest train tunnel in the world.

The Gotthard Base Tunnel is a stunning feat of engineering.

Workers have bored nearly 100 miles of tunnels into the Alpine mountains, to create a route between the two Swiss cities of Erstfield and Bodio.

The tunnel's main purpose is to transport more people — and especially, freight — across the Alps, to reduce the number of traffic accidents and environmental damage from heavy trucks on Alpine roads.

Here are some crazy facts about this enormous tunnel:

• The tunnel is as long as 21 Golden Gate Bridges, according to CNN. It consists of two 35-mile-long tracks, and the total length of the new tunnel system, including cross-passages, access tunnels, and shafts, is more than 94 miles.
• 5 Giza pyramids' worth of rock had to be excavated, according to the Swiss news site SwissInfo. Tunnel workers used special drills to bore through more than 31 million tons of rock to create the tunnels.
• It's built from 52 Olympic swimming pools' worth of concrete, or about 171,000 cubic yards of concrete, according to CNN.
• It's also the deepest tunnel in the world, passing underneath more than 1.4 miles of solid rock. By comparison, Japan's Seikan Tunnel — the second longest and deepest — is only 790 feet deep.
• The amount of copper cable needed would span the distance from Madrid to Moscow, according to CNN. Almost 2,000 miles of copper cable were required to construct the tunnel.
• Trains will travel at speeds of more than 150 mph, which is possible because the tunnel is almost completely flat throughout its entire length, instead of having to twist around the Alps.
• The entired project costs $10.3 billion, or about 9.8 billion Swiss francs, financed entirely by Switzerland.
• Since 1999, almost 2,000 workers have worked on the tunnel, day and night. Building a tunnel under the Alps is hard, and sometimes dangerous work. Eight people were killed during it's construction, according to Discovery News.

This article was updated at 5:16 p.m. August 26 to correct the total length of the tunnel system.