The World’s Longest Railway Tunnel

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Map of the Tunnel

By Eric Mackenzie-Lamb

Map of the Tunnel

AMSTEG, SWISS ALPS: The sound of cowbells, the bleating of sheep. The gentle whistling of wind as it flows down from spectacular mountain passes and across colorful fields of wild flowers. A rushing waterfall. In the distance, a rustic stone hut once used as a shepherd’s shelter, probably dating back two centuries or more. Peace, tranquility, the magnificence of Mother Nature-all rolled into one pastoral scene. Here, it seems, little has changed since the days of William Tell.

Alpine Scenery

On the surface of things, maybe not. But two thousand feet below where your feet are standing, it’s a very different picture.

Tunneling in process

One of the most complex and challenging construction projects of its kind ever undertaken, and more than 20 years in the making, the AlpTransit Gotthard tunnel is scheduled to be fully operational by the summer of 2016 and will cover a distance of 57 kilometers (35.6 miles). Its deepest point is a mind-boggling 6,900 feet below the earth’s surface. The tunnel will serve as a vital link for passengers and freight by high-speed rail between northern and southern Europe. Goods trains will travel at a hundred miles per hour, while passenger trains will reach almost 160 MPH. This will enable travelers to get from Zurich to Milan in less than three hours, about half the time it takes now.

The new system, it is hoped, will also help to dramatically reduce chronic traffic jams at either end of the existing St Gotthard road tunnel, where bumper-to-bumper waiting times, especially during the busy summer months, can be as much as two hours or more.

Traffic jam at the St. Gotthard road tunnel

The project itself has involved an average number of 1,800 people, including geologists, surveyors, engineers, mechanics, explosives experts, environmental monitors, electricians, specialized equipment operators, laborers, and many more. To date, it’s estimated that 28 million tons of rock have been excavated-most of which has been recycled into concrete aggregate.

Three thousand feet underground

Innovative new machinery and tools have also been designed specifically for the project, including a gigantic boring machine which looks more like something you’d find bobbing around the International Space Station. There are even provisions for Internet and live telephone service, more than a mile underground, as well as devices to control tunnel temperature, humidity, and ventilation. Over 3,750 miles of cable have been installed. Exact locations of moving trains are monitored in real time, by both the driver and control center, through innovative devices similar to an underground GPS system installed between the tracks. As is the norm in Switzerland, and for which this small country is a global model, strict attention has been paid to environmental concerns, especially the project’s impact on surrounding communities. From ground level, you would never know that one of the planet’s most complex and advanced transportation systems was speeding its way under that tranquil cow pasture.

So exact was the project’s engineering, in fact, that when when the final breakthrough joining the north/south tunnels finally happened in 2010, the maximum deviation was less than 5.4 inches. (Yes, you read that right).

Breakthrough celebration, 2010, with tunnel boring machine in background.

But should we really be surprised? After all, don’t the Swiss make the world’s finest watches?

It’s all about precision.