Subscribe / Renew
|► Subscribe to our Free Weekly Newsletter|
June 9, 2017
Q. It took 2,600 workers toiling in round-the-clock shifts for 17 years to complete the project — at a cost of $12 billion dollars. What is this engineering wonder?
A. It's the 35.4-mile Gotthard Base Tunnel, the longest tunnel on earth, carved a mile and a half under the Swiss Alps to speed travel between the North Sea and the Mediterranean, says Rachel Nuwer in Smithsonian magazine. Four boring machines, each the length of four football fields and fitted with rock-chomping steel roller-cutters, advanced about 130 feet per day. When the final 18 miles were bored, the north and south tunnels met in the middle and “were off by only a few centimeters”! Reportedly, the 28 million tons of excavated rock were reused, much to form the concrete lining.
. . .