WorldWide Drilling Resource

Gotthard: What does it Take to Construct a World Record? Compiled by Jasmine Dodds, Associate Editor, or d ide D l ng Res u e W l W ril i o rc ® The Gotthard Base Tunnel was fi- nally opened for inaugural rides on June 1, 2016. Five hundred Swedish citizens, chosen by drawing, climbed upon a train to travel down the 35.5-mile tunnel bored under the Alps. This project is the longest and deepest traffic tunnel in the world (surpassing Japan’s Seiken Tunnel), call- ing for over $12.5 billion, 2600 workers, and over 20 years to complete. So what exactly is required to tackle such a mammoth undertaking? As it turns out, you need something never quite seen before. That’s right - four incredible grip- per tunnel boring machines (TBMs), Heidi, Sissi, Gabi, and Gabi II, were built by Herrenknecht of Germany with this specific project in mind. Before the machines’ creation, there simply wasn’t equipment durable enough or powerful enough to do the job. Over 23 million tons of rock were removed during the drilling and blasting of the tunnel, which is enough rock to rebuild the pyramids of Giza five times over. Average monthly tunneling performances peaked at approximately 1837 feet, with penetration rates of nearly a half inch per revolution. The daily performance record belongs to Sissi, who tunneled about 125 feet in just 24 hours. The TBMs reached breakthrough with vertical and horizontal deviations of mere millimeters, the same degree of accuracy achieved by a marksman hitting a coin at a distance of 6561 feet. The Gotthard Base Tunnel is scheduled to go into full operation in 2017 after scheduled test runs are finished. Photo courtesy of Herrenknecht. 37 WorldWide Drilling Resource ® AUGUST 2016