Critical Grade Drilling, Rock Drilling & Pipe Grinding

Critical Grade Drilling

Being a drainage based firm Hadlee and Brunton originally starting drilling to complement the drainage side of the firm. That meant developing techniques to accurately install sewer and stormwater drains on minimal grades.

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There is a negative attitude in the construction industry towards the ability of directional drills to achieve grade shots however this is because many people have been burnt in the past by drilling companies who cannot do them. There are only a handful of the very long standing drill operators in NZ who can confidently claim that they are capable of grade shots.

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Today all our grade shots are designed, surveyed and located by the same engineers who have been with the company since we got into drilling over 17 years ago. We have completed 100's of successful grade shots with some as low as 0.36%. Please refer to our projects page for examples.


Solid Rock Drilling

Hadlee and Brunton were the first company in New Zealand to specialize in rock drilling with all terrain machines. Please refer to our projects list.

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Our AT3020 is the largest Ditchwitch All Terrain Drill in New Zealand. It is designed to drill through solid rock.

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These machines are much more advanced than conventional drills using mud motor heads. The All Terrain machine uses an advanced dual-drive pipe system and a hydraulic, heavy duty anchor system. They use a fraction of the drilling fluid that a mud motor uses reducing the need for fluid reclamation and providing considerable savings to any project. They are also much faster and accurate. The information from the drilling head is coming from the front of the drill stem as opposed to a mud motor which can be over 5m behind the head.


Pipe Grinding

Pipe grinding is something Hadlee and Brunton have been doing for over 15 years. Pipe grinding involves the drill being inserted into an existing pipeline, once in place a grinding head is attached to the front of the drill rod along with the new pipe to be installed. The existing pipe is then ground out and the new pipe pulled into position at the same time.

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We specialize in replacing live sewer mains where we can replace over 500m at a time and have all the house laterals connected within a day.

Hadlee and Brunton have recently completed several large diameter grinding shots in Christchurch in the wake of the earthquake.


The advantages of pipe grinding over pneumatic pipe bursting are:

  • Less noise and vibration
  • Less risk of the ground humping as you are boring a new hole and grinding and floating out the existing pipe as opposed to cracking and displacing the existing pipe into the ground.
  • You don't risk damaging the pipe with broken shards of the existing pipe
  • The annulus around the pipe is filled with drill mud so there is no risk of voids
  • You can upsize to a much greater diameter pipe.

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