Competing teams put their designs to the test in the final, held in Las Vegas, US on 12 September. They worked to a brief requiring a tunnel 30m-long and 500mm-wide to be constructed as quickly and as accurately as possible.

In its bid to increase tunnelling rates, TUM Boring’s winning concept combined established techniques such as pipejacking with other less conventional systems. This included:  

  • Machine propulsion by a jacking system using two clamps, each propelled by four hydraulic cylinders that can be operated in continuous mode. 
  • A revolving pipe-storage system that allows the 8.5m-long pipe sections to be installed quickly, minimising downtime. 
  • Six conveyor belts (four of which were integrated into the pipes used to build the tunnel) to remove the spoil.

The entire package was contained in a 20t shipping container.

The Munich team was the fastest to construct the tunnel; the fastest to provide a driving surface; and provided the most accurate guidance system. It beat entries from more than six countries vying for the accolade of having created the world’s fastest TBM.

Boring Company owner Elon Musk – the instigator behind the new tunnel at the Las Vegas Convention Centre – has previously claimed that he can increase TBM excavation rates by a factor of ten and reduce costs by the same factor. This has been greeted with a degree of scepticism by some in the tunnelling sector, although it is generally conceded that in the process, Musk has increased public awareness of tunnelling.