Bored of the Rings: Alice Goes Underground In New Zealand
Marked by the use of an independent self-propelled culvert gantry, New Zealand's largest-ever highway project passed the halfway mark on the first drive in Auckland. The first of parallel 2.4-kilometer-long tunnel bores, when completed this fall, will mark a major milestone for the $1.2-billion Waterview Connection, the last section of a Western Ring Route.
The milestone follows a brief hiatus and successful completion of essential maintenance work on the earth-pressure tunnel-boring machine (TBM), nicknamed Alice, in May. The Herrenknecht machine, manufactured at the company’s facility in China, cost $46 million dollars to build and transport to New Zealand. Alice underwent a 3-week replacement of hundreds of steel fiber brushes installed on its shield. The brushes help form a waterproof seal as the concrete segments that line the tunnel are lifted into place.