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Swiss dig world's longest tunnel

2009-06-17 06:14:35

By Imogen Foulkes

BBC News, Berne

For centuries, the Alps have served as a natural trade barrier between northern

and southern Europe.

Sending Italian wine to the Netherlands, or German washing machines to Greece,

means a long, slow journey along narrow alpine valleys, through tunnels and

over passes.

The amount of freight crossing the Alps in heavy goods vehicles has risen

sharply over the last two decades. In 1990 an estimated 40m tonnes went by

road, in 2001 that had risen to 90m tonnes, with further big increases expected

by 2010.

But concerns for the Alpine environment and fears over safety have led to big

pressure to move freight off the roads and onto the railways.

Both Switzerland's Gotthard road tunnel and France's Mont Blanc road tunnel

have suffered major fires in the last 10 years in which many died.

Faster than flying

As long ago as 1994, the Swiss voted in a nationwide referendum to put all

freight crossing their country onto the railways. Naturally, such an ambitious

plan was not going to happen overnight, but now the project dubbed the

engineering feat of the 21st Century is slowly taking shape.

Deep beneath the Alps, the Swiss are building a high-speed rail link between

Zurich and Milan. It will include, at 57 kilometres (35 miles), the world's

longest tunnel.

A key feature of the project, which is new to alpine transport, is the fact

that the entire railway line will stay at the same altitude of 500 metres

(1,650ft) above sea level.

This will allow trains using the line to reach speeds of 240km/h (149mph),

reducing the travel time between Zurich and Milan from today's four hours to

just two-and-a-half. That would make the journey faster than flying.

To see the work in progress, it is necessary to travel two kilometres

underground, to the construction site between the southern Swiss towns of Faido

and Biasca.

The scale of the work going on is enormous: 2,000 people are working on the

tunnel, 24 hours a day, 365 days a year. Besides the two main railway tubes,

the construction workers have to dig access tunnels for people and equipment.

Huge fans ensure a fresh supply of air and cool things down. Yet the

temperature is above 30C.

"We've got two-and-a-half kilometres of Alps above us," explains engineer

Albert Schmid. "That means millions and millions of cubic metres of earth

pressing down on us, that increases the pressure and the temperature."

Difficult work

It also means that every time the workers dig out another few metres of the

tunnel, mother nature tries to close it up again. Along the tunnel's length,

reinforced steel rings have to be inserted, to prevent it collapsing in on

itself.

Building the tunnel requires a variety of techniques. At one section the

workers are blasting away the rock, and the air reeks of ammonia from the

explosives.

At another section the world's biggest tunnel-boring machine is in operation;

it is ten metres in diameter and covered in dozens of rock-cutting blades,

which as the machine turns, hack away at the rock face.

"With this machine, in good conditions, we can excavate 40 metres in a day,"

says Mr Schmid. "That's an absolute record."

But conditions are not always good. The tunnel workers have run into serious

geological problems; in some areas the rock is as soft as butter, making

digging it out more complicated.

"In poor rock conditions, where the rock is very soft, we can only excavate

around half a metre a day," says Mr Schmid. "So in these situations, the work

is delayed, and the costs rise."

Soaring costs

In fact the price tag for the entire rail link has soared from about $8bn (

4bn) to almost $15bn and final completion is unlikely to be before 2018.

But that has not stopped the alpine communities from supporting the project,

and from trying to ensure that the rail link brings some social benefits too.

The tiny village of Sedrun, population 1,500, lies along the tunnel's route,

and while residents are pleased to be relieved of the heavy lorries, they are

concerned that the tunnel may marginalise their community.

"The thing about this tunnel is that it makes the Alps disappear," explains

local architect Arthur Loretz. "At the moment, when you drive from Zurich to

Milan, you get a beautiful panoramic view. But this tunnel turns the Alps into

a big black hole."

Alpine gateway

The original plans for the tunnel involved trains rushing beneath the Alps

without stopping. But in Sedrun a 1,000-metre elevator and underground railway

station have been built just to get the workers to the construction site.

"All the infrastructure is already there," points out Arthur Loretz. "What we

want to do is use it in the future." The plan is to create a station, deep in

the mountains, known as "Porta Alpina" (Gateway to the Alps).

Tourists will be able to arrive by train in the Alps in record time, and then

be whisked up to fresh mountain air by way of the world's longest elevator.

"I think it will have great benefits," says Mr Loretz. "Not just for tourists,

but for us. Look, over that mountain people speak Italian, and over that one

there they speak German."

"And here we speak Reto Romansch - a language only spoken by around 50,000

people. Traditionally the mountains have divided us, but with this rail link,

and with Porta Alpina, we can bring people together."