Longest, deepest rail tunnel in the world opens in the Swiss Alps

ERSTFELD , Switzerland, June 1 (UPI) -- The world's longest and deepest rail tunnel, 35.4 miles long and 1.4 miles below the Swiss Alps, opened Wednesday in Switzerland.

The Gotthard Base Tunnel, a 17-year project costing $12 billion and employing 2,400 people, was expected to be inaugurated with a ceremonial first run of a train capable of reaching speeds of up to 120 mph.

German Chancellor Angela Merkel, French president Francois Hollande, Italian Prime Minister Matteo Renzi and Swiss officials including Swiss President Johann Schneider-Ammann will be aboard. Full service is expected to begin in December.

The tunnel runs between the Swiss cities of Erstfeld and Bodio, and will reduce train travel between Zurich and Milan by an hour, to two hours and 40 minutes. It will also be an essential part of the Rhine-Alp corridor, a link between northern and southern cities in Europe. The tunnel's route is nearly flat, unlike the Gotthardbahn rail tunnel it replaces, the altitude of which rises and falls under the Alps.

The new tunnel is longer, by 1.8 miles, than Japan's Seikan rail tunnel, the current record holder, and 4.3 miles longer than the tunnel under the English Channel connecting France to Britain.