A train drives past the northern gates of the NEAT Gotthard Base Tunnel near the town of Erstfeld, Switzerland May 31, 2016.
Switzerland opens the world's longest and deepest rail tunnel through the heart of the Alps on Wednesday in an engineering marvel that stands 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 and designed to last a century, is part of a 23 billion Swiss franc infrastructure project to speed passengers and cargo by rail under the mountain chain that divides Europe's north and south.
Typically Swiss, the project 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 a passage that took days until the first Alpine rail tunnel opened in 1882. Around 260 freight trains and 65 passenger trains will traverse the two-tube tunnel daily once final testing ends later this year.
The Swiss, as a rule rail fanatics, are throwing a party to mark the event that will draw the leaders of all its neighboring countries in a show of European solidarity.
"It is just part of the Swiss identity," Fueglistaler said of the Swiss fondness for major engineering feats. "For us, conquering the Alps is like the Dutch exploring the oceans."
The tunnel along Europe's main rail line that connects the ports of Rotterdam in the north to Genoa in the south snakes through the mountains as much as 2.3 km below daylight and through rock as hot as 46 degrees Celsius (114.8°F).
The rail route goes over the pass now 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.
Swiss voters -- despite opposition at times from the government and parliament -- supported the gargantuan rail project in a series of binding referendums in the 1990s.
Fittingly, the first ones to travel the tunnel at the official opening will be 500 lucky winners plus guests from the 130,000 who entered a ticket lottery for the inaugural trip.
The overall project includes the Loetschberg rail tunnel that has already opened, the Cereti 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. Work is due to finish in 2020.
The mammoth rail venture 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.
Major contractors included Alpiq, Balfour Beatty, Thales and Heitkamp.