Tag Archives: tunnel

Longest and deepest rail tunnel opens

After 17 years of construction, the world’s longest and deepest rail tunnel has opened today in Switzerland.

If you take into account the two main tubes that comprise the Gotthard Base Tunnel and its various shafts, cross passages and access tunnels, it actually has 152 km (94 mi) of tunnels in total. It is also said to have virtually no gradients.

The initial idea for the tunnel was conceived 68 years ago, but the plans were redrawn on a number of occasions. Once construction finally commenced, there were 2,400 workers on site at peak times. Nine workers also lost their lives during the build.

Under Seattle Bertha has stopped drilling because something is in the way.

Under Seattle Bertha has stopped drilling because something is in the way.

Something unknown, engineers say — and all the more intriguing to many residents for being unknown — has blocked the progress of the biggest-diameter tunnel-boring machine in use on the planet, a high-tech, largely automated wonder called Bertha. At five stories high with a crew of 20, the cigar-shaped behemoth was grinding away underground on a two-mile-long, $3.1 billion highway tunnel under the city’s waterfront on Dec. 6 when it encountered something in its path that managers still simply refer to as “the object.”

The object’s composition and provenance remain unknown almost two weeks after first contact because in a state-of-the-art tunneling machine, as it turns out, you can’t exactly poke your head out the window and look.