By Anna Sargent of RNZ

Sending a big rock sailing through the air then crashing into a valley far below gives a thrill that never grows old for Wayo Carson.

He loved it when he was a boy, out rock climbing, and decades later he still loves it and it is his career.

Back then he was throwing rocks. Now he shunts much bigger boulders down the hillsides using explosives and inflated rubber bags.

Carson works as a geotech abseiler, keeping our roads safe by hanging off ropes and managing loose rocks far above our highways.

He has been in the harness for more than 20 years.

“I got into it through rock climbing. I’ve rock climbed since I was a kid, and I guess as I grew up getting into the higher mountains it was always pretty fascinating throwing rocks off mountains and watching them crash down below, and then apparently it was something you could make a career out of,” Carson said.

Carson’s business CliffCare is based near Wānaka, but he travels a lot for his work.

“The geotech abseiler role is based around cliffs and rocks, unstable ones generally. Sometimes it can just be improvements or strengthening cliffs for something that might be happening underneath it ... for example we’re reinforcing a bank above a new water treatment station in Queenstown,” he said.

“It’s generally in fairly difficult to get to areas, always a bit of exposure and height. Sometimes we’re just 5m above a road or sometimes we’re a couple hundred metres above.”

The work was dangerous, but essential to make travelling on highways safe.

A large rockfall at the Epitaph rift, in South Westland, that left road workers cleaning up the several thousand cubic metres of material it released, in November. Photo / NZ Transport Agency / Waka Kotahi

“You need to think about what’s going on and you need a good team with you who are all sort of keeping an eye out on each other and working cohesively. A lot of people I work with are pretty outdoorsy. A lot them are rock climbers, which gives them good practical skills moving around on ropes. .. In terms of big geological hazards, that’s something only experience can teach you really,” Carson said.

Recently he has been involved in a significant rock removal project at the Epitaph Rift on State Highway 6, in South Westland. Record-breaking rain in the region in November caused slips, rockfall and cracking in the highway.

Carson said work was continuing there, to remove unstable rocks from the cliffside over summer, and this involved the use of explosives and 25-tonne capability airbags.

“We are using pneumatic airbags. They’re basically a big rubber kevlar mat, they get air pumped into them and they expand and if you put them into the cracks into the rocks, they expand the cracks and push off the big rocks. You can use multiple numbers of them stack them up to get different configurations,” he said.

Carson is still working on the Nevis Bluff rockface near Queenstown, which was one of the first jobs he did as a geotech abseiler.

“It’s nearly a kilometre long as a bluff, and up to 180m tall, so it’s big and it’s quite complicated. It’s got a lot of different features and things going on there,” he said

“We’ve done all sorts of work there now. We have bolted lots of bits back on with big rock bolts, we’ve blasted bits off, and we’ve used helicopters to wash bits off. We’ve used steel bars to just pry loose rocks off.”

Another abseiler, Troy Beaumont, who has done rock scaling in New Zealand and overseas for more than a decade, said the work could be very planned, or could be unplanned in the case of bad weather causing slips or landslides.

Beaumont owns rope access contracting business Heads Up Access, which is based in Queenstown and Christchurch.

He said when scaling a rockface after a disaster, a big part of planning was making sure rocks did not land where people were far below, so they needed to work out exclusion zones.

“Then we need to think about how to get up to the top to start ... that might involve some scaling ... just to get on the slope, and then we start from the top down, working our way down the slope. So you’re always scaling from good ground to bad,” Beaumont said.

In his spare time outside of work Carson is still not far from a rock.

“I do a bit of rock-climbing, mostly it’s limited to seeking out new cliffs and putting up new rock climbs in the Haast Pass Makarora area,” he said.

So far, his family did not share his love of scrambling over rocks, but he remained hopeful.

“I’ve got four kids, and pretty much the three older ones all hate rock climbing. That was the go-to family holiday for a pretty long time, camping and rock climbing. The other one is still getting dragged out there for a bit of rock climbing, he doesn’t mind it,” Carson said.

“Hopefully they’ll come back to it.”

He suffers all weather conditions, working out in the open, but: “It’s a good outdoor job, with lots of scenic lunch spots”.

- RNZ