With a theme of “Safe Tunneling for the City and Environment”, Terry concluded that the key topics of interest at conference were:
- Concepts have expanded from tunnels to the use of underground space
- Major interest in long rail tunnels to get freight off high mountain passes
- Huge investment in urban metro systems
The best innovation Terry saw was a boring machine that can start and stop at ground level and excavate square underpasses under busy intersections. “It’s really very clever,” says Terry. “We could use that here in New Zealand for the grade separating busy intersections, rail crossings and more innovative motorway connections.”
He also saw first hand construction elements on a new Metro line using two 6 m tunnel boring machines for the Danube crossing. The proposed City Link rail tunnel from Britomart to Mt Eden would require machines of 7+m.