Difficult Access / Slope Stabilisation
Opotiki Slope Anchor Installation
A slip-damaged slope in the Waioweka Gorge near Opotiki had no road access — the work face sat at roughly 140m elevation, reached by a 180m climb through bush and a 40m abseil. Our four-person rope access crew flew in heavy gear by helicopter, then drilled, grouted, and shear-loaded eight soil nail anchors in two clusters, giving Tough Terrain's spider excavator the winch points it needed to descale the slope. Delivered in two weeks under an NZTA contract.
The challenge
What made this difficult
A slip-damaged slope in the Waioweka Gorge near Opotiki needed descaling by spider excavator, but the machine had no way to climb the face without anchor points to winch from. The site had no formed road access, with the work face sitting at around 140 metres elevation. The only way in was a 180-metre climb on foot through steep bush, then abseiling down from the ridge to the installation zone.
Specific issues
No formed access to the slope face, requiring a 180-metre approach on foot through steep bush
Heavy equipment (compressors, grout bowls, drilling rigs) too large to carry, requiring helicopter lifts
Work face at approximately 140m elevation, accessed by abseiling from the ridge above
Anchors needed to be shear-loaded to support spider excavator winching operations
The response
- 01
Carried all rope access gear 180m up through steep bush terrain on foot to set ropes at the ridge
- 02
Set up pulley rope systems to transport heavy equipment up and down the slope
- 03
Coordinated helicopter lifts for compressors, grout bowls, and drilling equipment
- 04
Abseiled approximately 40m from the ridge to the work face and drilled two clusters of four soil nail anchors into the cliff
- 05
Grouted and shear-loaded each cluster to serve as winch points for Tough Terrain's spider excavator
- 06
Four-person rope access crew worked through weekends over a two-week programme
- 07
Fully demobilised all equipment back down the slope on completion
Spec snapshot
The numbers on record
- 018 soil nail anchors installed in two clusters of four, drilled in a cross position
- 02All anchors grouted and shear-load verified as winch points
- 03Approx. 40m abseil from ridge to work face; work face at ~140m elevation
- 04Two-week programme including weekend work by a four-person rope access crew
- 05Helicopter lifts for compressors, grout bowls, and drilling equipment
The outcome
Work that holds up.
All eight anchors were installed, grouted, and verified for shear loading within two weeks. The anchor clusters gave Tough Terrain's spider excavator the hold it needed to climb the slope and carry out descaling works safely. Delivered under an NZTA contract through Tough Terrain. Everything was walked in, winched, or flown in by helicopter — and everything was demobilised off the slope on completion. It is the kind of difficult-access work Geo Mana was built for.
- Abseil drilling
- Soil nail installation
- Grouting
- Helicopter logistics
- Rope access
- Pulley rope transport systems
- Shear load anchoring
From the face
How it looked on site
Actual project photography
Your ground
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