The tunnel is part of a larger project to limit the damage caused by road traffic in the Alps [Reuters]

The drilling of the world's longest tunnel has been completed in the Swiss Alps, clearing the path for a high-speed railway which will connect northern and southeastern Europe and shift lorry freight onto rail.

After 15 years of construction work, the 9.5-metre wide drilling machine bore through the last strip of rock on Friday, joining two ends of the 57km Gotthard Base tunnel about 2,000 metres under a mountain.

The event, attended by 200 dignitaries, was broadcast live on Swiss television and watched by European Union transport ministers at a meeting in Luxembourg.

"Here, in the heart of the Swiss Alps, one of the biggest environmental projects on the continent has become reality," Moritz Leuenberger, the Swiss transport minister, said.

Tunnel workers paid tribute to their colleagues who had died on the construction site with a minute's silence as the names of the eight victims were read out.

The tunnel is being hailed as an environmental triumph as much as an unprecedented engineering feat. It is part of a larger project to shift the haulage of goods from roads to rails, spurred mainly by a concern that heavy lorries are destroying Switzerland's pristine Alpine landscape.

About 1.2 million lorries currently move through Switzerland's mountainous countryside every year, harming rare plants and animals due to exhaust fumes while adding to the erosion of the Alps. The aim is to halve the traffic within two years from the tunnel's opening.

Swiss voters, who are paying more than $1,300 each to fund the project, approved its construction in a series of referendums almost 20 years ago and will have to wait several more before it is ready for rail traffic.

When it is opened for traffic in 2017, passengers will ultimately be able to speed from the Italian
city of Milan to Zurich in Switzerland in less than three hours and further north into Germany, cutting the journey time by an hour.

Source: Agencies