NZ’s largest-ever construction blast
New Zealand’s largest-ever construction blast to cut through ALPURT B2
Between 4 and 5pm tommorrow, the Northern Gateway Alliance will conduct New Zealand’s largest-ever construction blast as part of construction works for the SH1:Northern Motorway extension (ALPURT B2) project.
The controlled blast will use approximately twenty tonnes (two truck loads) of explosives and is expected to move about 19,000 cubic metres of rock. A typical quarry blast in New Zealand uses 7 – 8 tonnes of explosives.
The aim of the blast is to progress the 55-metre deep cut through Chin Hill, the highest geographical point along the ALPURT B2 alignment. Chin Hill is located approximately 2 km northwest of Hatfield’s Beach and sits on the ridge between the Otanerua and Waiwera Valleys.
The Chin Hill cut is believed to be the largest in New Zealand and will become one of the landmark features of the new motorway. To provide some idea of scale, the Auckland Harbour Bridge stands about 40 metres above the sea.
ALPURT B2 is the largest single roading project ever undertaken in New Zealand, costing $359 million. It is also the first state highway project to be brought forward by tolling, as enabled under the Land Transport Management Act 2003.
The new 7.5 kilometre motorway between Orewa and Puhoi, will give motorists a quick, efficient, integrated and safe route between Auckland and Northland. The Northern Gateway Alliance is delivering the project for Transit. Participants in the Alliance are Transit New Zealand, Fulton Hogan, Leighton Contractors, URS New Zealand, Tonkin & Taylor and Boffa Miskell. Completion of the new road is scheduled for mid-2009.