Complicated process to replace chairlift cable at Christchurch Adventure Park
Replacing a 26-and-a-half tonne, 3.7-kilometre long chairlift tow rope is a complicated process, which is why they usually last a decade.
But just a year after the Christchurch Adventure Park (CAP) tow rope was installed, crews are at work replacing the fire-damaged steel rope that is now only good for scrap.
Lift company Doppelmayr, which installed the original, had a small team working to replace the cable this week. The job is expected to be finished on Monday, letting the lift company get on with re-attaching the chairs and completing electrical work and safety tests.
Doppelmayr project manager KJ Randall said the rope was worth hundreds of thousands of dollars.
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"The rope's so valuable that, even though it's big and heavy, you've actually got to be pretty gentle with it."
He said replacement was a difficult process because each metre of rope weighed about 7 kilograms, so even short lengths could not be picked up and walked with. When in place, the rope is under 16 tonnes of pressure on each side.
To get it done, a section of the old rope is pulled together mechanically while still on the lift and locked in position to create slack, which is cut. A section of the new rope, on a large drum, is spliced onto the old rope and the whole length of the new rope is pulled through the system.
The old rope, now on a separate drum, is then cut off and the new rope spliced together to form a loop. The final splice will be made on Monday.
Randall said the old rope was scrap that "can't be used for much at all". It now belongs to CAP's insurer.
The rope was replaced because the plastic core had melted, causing the rope to deform. Because of this, the chairs could no longer get enough friction to grip the rope. The plastic makes it more flexible so it can go through the chairlift stations at the top and bottom of the hill.
Randall said getting the rope replaced was "a big milestone" but only part of the work. All lift work was expected to be finished early to mid-November, but work would still be ongoing in the rest of the park.
CAP spokeswoman Anne Newman said a date for the park reopening would be announced within a month.
She said the park "will feel very different with no trees".
"What we do know is that when we open, we won't be opening with what we had pre-fire, just because of where we are with the trails."
CAP has applied for a temporary easement so it can run a logging road through Marleys Reserve to Summit Rd, to be removed when activity ceased. The Spreydon-Cashmere Community Board recommended the road be approved at its last meeting.
Newman said the road allow logging to continue when the park reopened.
CAP was developed by Canadian-based Select Contracts, which specialises in outdoor recreation facilities. It started working on CAP in 2011.
Earlier this week, it was announced Select Contracts would build an adventure park on Colonial Knob, near Porirua. Work is due to start next year and take two years to complete.
Chief executive Chris Sutton said the company first spoke with Porirua about building an adventure park there in early 2016.
He said Select Contracts did not have a stake in CAP, which is managed by Port Hills Leisure Ltd.