A highway project in one of Australia's fastest-growing regions has broken tunneling speed records, excavating up to 163 ft in a day. The $1.33-billion Legacy Way project (formerly known as Northern Link) in Brisbane is currently running six months ahead of its scheduled mid-2015 completion, say officials.
To build the 2.9-mile-long parallel tunnels between Brisbane's Toowong and Kelvin Grove, the two 41-ft-diameter, 361-ft-long Herrenknecht double-shield pair of tunnel boring machines (TBMs) excavated more than 35.3 million cu ft of spoil, consisting predominantly of Neranleigh Fernvale and Bunya Phyllite, says Fernando Fajardo, executive director at Acciona Infrastructure Australia and project director for the Transcity Consortium. The consortium consists of Australia's BMD Constructions, Italian tunneling company Ghella, and Spain's Acciona Infrastructure. The design alliance consisted of Australian firms Cardno, and GHD and San Francisco-based URS, with urban design provided by Australia's RPS. Transcity will be remain in charge of operations and maintenance for 10 years after opening.