Tunnelling Through Hawera Fault Starts

news release 10 July 2008

Tunnelling Through Hawera Fault Starts

Pike River Coal Limited (Pike River) has started tunnelling through a faulted zone in the Paparoa Ranges on the West Coast just 215 metres away from the 18 million tonne Brunner seam of hard coking coal

The Hawera fault was created when one side of the Paparoa Ranges was lifted 1,000 metres in ancient upheavals which fractured the rock along the fault line.

Pike River had previously announced a short delay to tunnelling through the fault while it advanced some construction works, which had safety and efficiency advantages, prior to starting the final 215 metre drive to the coal seam. “In the process we have now completed a series of steps that will help reduce the risk of delay west of the fault area by completing many of the tasks we would have done once through the fault” says General Manager Mines, Peter Whittall.

A contractor operated compressed air jumbo drilling machine will drill out the face of the fault (to allow explosive charges to be laid) and a combination of blasting, drilling, and tunnel support will be used to get through the crushed rock zone, expected to be up to 50 metres wide.

Once through the fault zone, the jumbo drilling machine is currently planned to be replaced by Pike River’s roadheader cutting unit which is flameproof equipment. The roadheader cuts a 4 by 5 metre roadway in the rock.

Pike River Chief Executive Mr Ward says “the final drive to the coal seam is expected to be completed by the previously announced date of around the end of August 2008”. A series of roadways will then be driven by Pike River’s roadheader in the coal and stone west of the Hawera fault as pit bottom is developed for further mine infrastructure including raw coal slurry ponds, the hydro-monitor pump station and a large water storage facility. An inseam drill rig will drill in that area to add more data to Pike River’s geological model and a roadway will also be driven to the bottom of the ventilation shaft site.

As scheduled, the first 100,000 tonnes of coal will be mined by the end of March 2009 and another 100,000 tonnes by the end of June 2009.

Thereafter, says Mr Ward, “production of premium hard coking coal at the mine will be in full swing to achieve our schedule of at least one million tonnes a year”.

ENDS

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