Begun in 1996, the 35 mile twin-bore Gotthard Base Tunnel (GBT) under the Swiss Alps is officially open and Switzerland says it will revolutionize European freight transport.
It was 68 years from idea to grand opening. The initial plan to build a flat, straight tunnel through the Alps was first proposed in 1947 by Carl Eduard Gruner, engineer and urban planner from Basel.
It took 11 years for the first tunneling breakthrough on 15 October 2010.
And it was thisclose - the aperture was out by less than 1/2 inch vertically and about 3 inches horizontally.
It took 125 workers in three shifts, 24/7, 43,800 hours nonstop to lay the slab track.
They used 171,341 cubic yards of concrete and 180 miles track.
Project cost $12.5 billion to build - more than the gross domestic product of Nicaragua.
At its deepest GBT is 1.43 miles below the surface of the Saint-Gotthard Massif mountains above.
It’s hot down there - the rock can reach temperatures of 115 degrees (F).
To cope with the tremendous weight above the tunnel tubes, engineers pioneered using flexible steel rings which partly closed under the pressure and prevented deformations.
GBT goes 1,968 feet underneath the old 9.33 mile-long Gotthard Rail Tunnel, built in 1882.
Every day, 260 freight trains (100 mph) and 65 passenger trains (124 mph) will pass through the GBT in a journey taking as little as 17 minutes.
Some trains will go up to 155 mph in the future
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.
Between 2002 and 2012, nine people were killed on the project. Four came from Germany, three from Italy, one from South Africa and one from Austria. A memorial service was held for them May 31.
80 percent of the drive in the main tubes was cut by tunnel boring machines, 20 percent by conventional drilling and blasting.
A total of 31.08 million tons of excavated rock was taken out of the tunnel, using 44 miles of conveyor belts.
To save time and cost, the GBT was split into five sections with separate access, and work proceeded on the sections simultaneously. For the Sedrun section, access was provided through a 3,280 foot-long tunnel and two 2,625 feet-deep vertical shafts.
In all, more than 93 miles of tunnels, galleries, cross passages and shafts had to be excavated for the GBT. (There are 178 cross passages between the two tubes, at 1,066 foot intervals.)
2,600 people worked on the tunnel, including top brass at AlpTransit Gotthard Ltd.
For more go to the Gottardo 2016 website here: