In keeping with the scale of the enterprise, the machines that do much of the work are huge. The gigantic creeping machine known as "The Worm," which applies the concrete lining to and lays the drainage pipes, is nearly 600 meters (1,970 feet) long. A mere 400 meters (1,310 feet) long but vastly more powerful are four 10-meter (33-foot) diameter Tunnel Boring Machines—TBMs in tunneling parlance. In a typical day each of these 2,700-ton behemoths will gouge from 20 to 25 meters (66 to 82 feet) of solid rock, securing newly dug lengths of tunnel with bolts, shotcrete and steel mesh. Each day they'll consume enough electricity to power 5,000 average suburban homes. Like ships, they have names: Sissi, Heidi, Gabi 1 and Gabi 2.
These girlish monikers, together with a few shrines to St. Barbara, patron saint of miners, represent the distaff side of humanity down here. Of the 2,000 or so miners working on the Gotthard Base Tunnel, none are women.
Over the years the sectors linked up, one by one, and with astonishing precision. When the Gabi 1, burrowing south from Erstfeld, reached Amsteg, in June 2009, it was a mere five millimeters off course.
The current tunnel builders are following in a long history of Swiss engineering achievement at the Gotthard Massif. Back in the 13th century, a medieval stone mason succeeded in throwing an arched span over the fearsome Schöllenen Gorge that guards the approach to the pass, and with it opened a lucrative trade route into Lombardy.
Later generations came to see the sights. By the early 1800s the road had to be widened and a sturdier bridge built to accommodate the horse-and-carriage trade of the Grand Tour. The poet William Wordsworth, who passed through on his way to Italy in 1820, bemoaned the "arbitrary, pitiless, godless wretches who have removed nature's landmarks by cutting roads through Alps…"
Little could he have imagined what was to follow. By 1870 the railway had arrived, bringing modernity in its wake. It was a monumental undertaking that included blasting a tunnel 15 kilometers (9 miles) long through the tough granite shoulder of one of the Continent's mightiest ranges.
That 19th-century tunnel took ten years to dig and cost at least 199 lives. Louis Favre, the brilliant Swiss engineer who built it, died of a stroke while inspecting the work, aged 53, only months before the tunnel was complete. The inaugural train ran through in 1882, passengers sipping champagne as they covered the distance between Milan and Lucerne in ten hours. Within the first year, a quarter of a million people had taken the trip. And still the numbers grew. A century later, in 1980, another tunnel was opened through the pass, this time for automobiles—at 16.9 kilometers (10.5 miles) the world's longest road tunnel at the time. A narrow, two-lane affair, it was never designed for trucks, but they came all the same. Gotthard Pass has always been one of the most direct north-south routes through the Alps.
Only one final stretch of virgin rock remained to be dug on the cold and snowy March afternoon when I accompanied AlpTransit's chief engineer, Heinz Ehrbar, on a site visit. By that time, a mere 2.4 kilometers (1.5 miles) of granite and gneiss separated the miners tunneling south from the ski village of Sedrun from those boring north from Faido.
For Ehrbar, Sedrun was where it all began, fifteen years ago, when he was offered the job of project managing this portion of the tunnel. Although he has since been promoted to chief engineer for the whole project, the sector starting from Sedrun remains special—"Heinz's baby," as one of AlpTransit's surveyors put it—not just for old time's sake, but because this was the toughest stretch, where the geology was the most fickle and complex and the tunnel ran the deepest, up to 2,450 meters (8,038 feet) below the mountaintops.
"I enjoyed it," he confided as we donned safety gear—boots, hardhat, miner's lamp, high-visibility overalls and a knapsack with a half-hour's supply of oxygen. "A TBM is an impressive piece of machinery but sitting in an operator's chair, watching dials, isn't as satisfying as blasting your way through the rock."
And some of it really needed working. There was no hope of driving a TBM through the rock in the Sedrun sector. Every meter had to be won the old-fashioned way, by blasting or excavating with conventional machines and shoring up. One 1,100-meter-long (3,610-foot-long) section of a deformed gneiss known as Kakirit took three years to go through—a rate that would have seen the tunnel as a whole take a century to dig. It was nightmarish stuff for tunneling, buttery soft, prone to collapse, and lacking any structural integrity. To keep the immense weight of the mountain from warping the tunnel out of shape, Ehrbar enlarged the passage, then shored it up with huge constricting steel rings that would give slightly under pressure, slowly easing the walls and ceiling into the desired shape and size.
Just getting to the diggings from Sedrun is an adventure. To reach the bowels of the massif, miners had to burrow into a nearby mountainside, then drill a pair of shafts down 800 meters (2,625 feet)—twice as deep as the Empire State Building is tall—and install lifts, one to carry workers and materials up and down; the other for heavy equipment. Engineers from South Africa's famously deep gold mines were flown in to sink the shafts.
It's an exhilarating ride, a whooshing plunge in a steel cage with dust and wind whipping all around. "Better than taking the stairs though," Ehrbar quipped as we stepped out at the bottom into a hot damp subterranean world. We hung our jackets on iron pegs hammered into the rock and boarded a jolting, squealing narrow-gauge miner's train for the long ride to the excavation front. They were between blasts when we arrived, the bucket loaders scooping up debris in one bore of the tunnel, the blasting team prepping the face of the other, pumping explosives into a hundred drill holes, and wiring up the charges.
In a few hours they'd blast again, and push the passage another three meters deeper. Meanwhile somewhere on the other side of the rock face, about 2.4 kilometers (1.5 miles) away, Sissi and Heidi were clawing ever closer through the rock.
On the way back to the lift, Ehrbar pointed out the section they'd labored over, meter by meter, for those three years. "When this is all finished," he said, "I want to go on a test ride through it. They tested the Lötschberg at 288 kilometers an hour (179 miles an hour). We've got a longer tunnel. I want to speed through here like that."
A swift smooth ride through the Alps in comforting darkness: Adam of Usk would have loved it.