Client:        Pike River Coal Company Limited
Location:    Greymouth, South Island
Contract:    Design & Construct
Currency:    July 2009

Project Summary

Construction of a 2.3 km mine access tunnel, associated passing bays, and sumps for a 1 million tpa coal mine located within the confines of a virgin rain forest in the Paparoa National Park. The D profiled tunnel was excavated at various inclined grades to pass under located surface features. Ancillary works included construction of a 165 m high, 4 m2 ventilation shaft, a full length conveyor and support systems at the portal.

The Challenge

Unexpected rock conditions encountered early in the project and the high altitude of the project site presented significant challenges.  The top of the ventilation shaft, covered in snow and subject to high winds during winter, could only be constructed during peak summer and could only be accessed by helicopter. 

The Solution

The MacDow team overcame these challenges using unique construction solutions. The difficult conditions, especially through the Hawera Fault, required a change to the drill and blast methodologies. These difficulties were overcome with the procurement of specialised equipment.

MacDow respected the cultural and environmental sensitivities associated with working inside a national park. Works were planned to avoid the clearing of significant native flora. The cultural beliefs of the local indigenous community were respected with bans on the drawing of water from local waterways.

Key to Success

A flexible, competent management team with excellent risk management and programming skills ensured we completed the tunnel well ahead of the revised program.

Project Stats

• 2.3km access tunnel
• 110 metre deep ventilation shaft
• 13600 cubic metres of rock excavated
• 1 Hirepool Construction Award for Excellence