POLLEGIO, Switzerland, June 1 (Reuters) - Switzerland opened the world's longest and deepest rail tunnel through the heart of the Alps on Wednesday in an engineering marvel hailed as a symbol of European unity at a time of increasing fragmentation.
The 57.1-km (35.5 mile)-long Gotthard Base Tunnel, 17 years under construction, is part of a 23 billion Swiss franc ($23 billion) infrastructure project to speed passengers and cargo by rail under the mountain chain dividing Europe's north and south.
Typically Swiss, the Gotthard tunnel that federal transport office director Peter Fueglistaler called "a masterpiece of timing, cost and policy" came in on schedule and on budget.
High-speed trains will whisk passengers in 17 minutes through the tunnel, a passage that took days until the first Alpine rail route opened in 1882. Around 260 freight trains and 65 passenger trains can traverse the two-tube tunnel daily once final testing ends later this year.
The Swiss threw an opening party that drew the leaders of all its neighboring countries in a show of European solidarity.
Swiss President Johann Schneider-Ammann said he would gently press German Chancellor Angela Merkel, Italian Prime Minister Matteo Renzi and French President Francois Hollande to compromise in a standoff over Swiss plans to launch unilateral curbs on EU immigration.
"We will come closer personally and that is decisive," he told reporters, adding talks would resume in earnest after Britain's June 23 vote on whether to quit the EU.
The European leaders hailed the project as an inspiration for all who want to live the dream of people circulating freely.
"I would like to see what binds us and understand how to use it. That is what the Gotthard Tunnel symbolizes," Merkel said.
"Switzerland has not just built a tunnel, but opened a route to the future of Europe," Hollande added, joking amid rail strikes at home that it would be a achievement to see trains traveling at 200 km/hour as they will through the tunnel.
CONQUERING THE ALPS
The tunnel along Europe's main rail line connecting the ports of Rotterdam in the north to Genoa in the south snakes through the mountains as much as 2.3 km below the surface and through rock as hot as 46 degrees Celsius (114.8°F).
The old rail route crosses the pass in a series of loops and tunnels. The new flat route means even heavy trains will need only one locomotive rather than two or three.
Engineers had to dig and blast through 73 kinds of rock as hard as granite and as soft as sugar. Nine workers died.
"It is just part of the Swiss identity," Fueglistaler said of the Swiss fondness for major engineering feats. Swiss voters supported the project in several referendums in the 1990s.
The first travelers through the tunnel were 500 lucky winners plus guests who entered a lottery for the trip.
The overall project includes the Loetschberg rail tunnel that has already opened, the Ceneri tunnel still being built and renovations to make rail tunnels at least 4 meters high at the corners to be able to handle big freight containers.
Swiss work is due to end in 2020, but Italy and above all Germany have lagged on infrastructure improvements on the route, something Merkel said on Wednesday she would address. ($1 = 0.9928 Swiss francs)