Switzerland to open world's longest and deepest rail tunnel two decades in the making

The 57km twin-bore Gotthard base tunnel will provide a high-speed rail link under the Swiss Alps between northern and southern Europe, creating a mainline rail connection between Rotterdam in the Netherlands and Genoa in Italy.

Switzerland says it will revolutionise European freight transport, the BBC reports.

Goods currently carried on the route by a million lorries a year will go by train instead.

The tunnel’s trajectory will be flat and straight, contrary to the previous routes circling through the mountains as was the case with the old rail tunnel and a road tunnel opened in 1980.

About 260 freight trains and 65 passenger trains will pass through the tunnel in as little as 17 minutes.

German chancellor Angela Merkel, French president Francois Hollande and Italy's prime minister Matteo Renzi are to attend the grand opening.

"It is just part of the Swiss identity," federal transport office director Peter Fueglistaler told Reuters news agency.

The €10 billion plus project was endorsed by Swiss voters in a referendum in 1992. Voters then backed a proposal from environmental groups to move all cargo travelling through Switzerland from road to rail two years later.

The completed tunnel travels up to 2.3 km below the surface of the mountains above and through rock that reaches temperatures of 46C.

Engineers had to dig and blast through 73 different kinds of rock of varying density, with more than 28 million tonnes of rock was excavated.

The tunnel is being financed by value-added and fuel taxes, road charges on heavy vehicles and state loans that are due to be repaid within a decade.

Swiss bank Credit Suisse is reported to have said its economic benefits will include the easier movement of goods and increased tourism.