ETH students place second in tunnelling competition

Groundhog Alpha, the seven-metre, 2.5-ton tunnel boring machine developed by Swissloop Tunneling, bored a tunnel in the Nevada desert – just slightly less long than the tunnel bored by the team from TU Munich. Their machine dug a tunnel more than 18 metres long, whereas neither of the two machines managed to dig a full-length tunnel during the competition.

In summer 2020, Elon Musk’s Boring Company announced a tunnelling competition. While the SpaceX Hyperloop competitions asked teams to build high-speed capsules to travel through vacuum tubes, this competition was about building small-scale tunnelling machines. The objective was to dig a 30-metre, stable tunnel with a diameter of 50 centimetres.

Second-best of more than 400 teams

Out of more than 400 teams that applied, twelve finalists including Swissloop Tunneling were invited to take part in the Not-A-Boring Competition in Las Vegas. During the past week, these twelve teams underwent various checks by The Boring Company.

On Friday afternoon, the finalists were surprised by a sandstorm and a heavy thunderstorm with lightning bolts striking the competition site. The work was interrupted and the whole site was evacuated. On Saturday, after working through the night, Swissloop Tunneling was one of just two teams to be cleared to enter the final round on Sunday.

Machine prints tunnel tube in-situ

Besides coming in second, Swissloop Tunneling also won the Innovation & Design Award. Their machine was the only one that fabricated the supportive tunnel lining in situ thanks to a 3D printing mechanism. It applies a special polymer mix to the tunnel wall, where it hardens immediately. Two hydraulic grippers working alternately press against the newly created tunnel tube to propel the tunnelling machine forward continuously.

Stefan Kaspar, founder and president of Swissloop Tunneling, says: “This award validates our approach of taking the sometimes difficult but purposely innovative path.” Going forward, the team wants to further develop the technology in such a way that the machine can dig tunnels with a four-metre diameter – the width of the tunnels in the Hyperloop concept.