Ministry of Transport officials Gareth Chaplin and David Greig visited Kaikoura recently to see first hand, the progress on the roads and railway network in and around Kaikoura. Their visit took in the coastal route and the alternative route through Murchison and Lewis Pass, and the Kaikoura coast. We talk to David Greig...
“The section north of Kaikoura is closed by nine large and many smaller slips. The priority for the next month will continue to be sluicing rock and debris from the three biggest slips, so it doesn’t fall onto work crews when they start clearing the slips.
“At each of these three slips, helicopters are combining to drop a 1,200 litre monsoon bucket of sea water every minute.
“The most spectacular moment for us was flying from inland over the bush, and suddenly seeing one of the slip faces under us,” says Greig.
“From the air, the sluicing helicopters look like small, busy insects against the huge slips. The pilots talk to each other all the time about their relative positions, winds, and what areas need doing next.
“Although most of the road and railway on the coastal route looks normal, parts are wrecked,” says Greig. “Abseilers are now working down from the top to assess the biggest slips to determine whether they are stable or need more work before rock removal and road construction below begins,” Mr Greig says.
An infrastructure alliance has been established to manage the rebuild. The Alliance includes the NZ Transport Agency, KiwiRail, Fulton Hogan, Downer, Higgins and HEB Construction.
Accelerated maintenance on the alternative route involves a range of work, including: reactive maintenance (such as filling potholes and applying patches quickly); reseals; rehabilitation (which is deeper than a reseal, but less than full reconstruction); drainage; improving shoulders; widening; bridge improvements (bailey bridges, culverts, traffic management); improving cell phone coverage and installing a new Lewis Pass weather station.
“We noticed that the section of the route facing the greatest increase in truck travel is State Highway 63, through the Wairau Valley (south from Blenheim), St Arnaud (Lake Rotoiti) and Kawateri Junction. To put it in perspective, heavy vehicles there have gone up from 40 a day to a peak of 700 a day.
“It’s vital to keep water out of the road structure, as it greatly reduces its strength. This means it’s important to fix potholes, patch, seal and fix drains. The most urgent sealing tasks were done by Christmas, and the remainder are being done this summer/autumn before the weather deteriorates. “Driving the route, we see many more roadwork sites than normal. “Apart from short closures, one lane is being kept open alongside each work site, and traffic is generally flowing smoothly. Fortunately, traffic levels are not as high as in more populated parts of the country. The height of the NZ holiday season has now almost passed, but trucking is resuming its normal level after the Christmas lull,” Mr Greig says.
The section from Kawatiri Junction to near Murchison (SH6) is the region’s jugular, as there is no alternative. However, if there is a slip or other problem, there are now a lot of road building resources in the area and the response will be quick. The rest of the route via Springs Junction (SH65) and Lewis Pass (SH7) is in reasonable shape. Some extra slow-traffic bays are being put in.
“At several places along the route, new pop up businesses are taking advantage of the large increase in traffic. Some of these stories have been covered in the media.
“The two roads leading from the south to Kaikoura are both open, though with a lot of road works especially on SH1 at the Kaikoura end. The slips have been cleared but there are several one-way sections where more work is being done to reduce fragility. Failed bridges are being bypassed with bailey bridges or dry-weather fords.
“Our final sight in Kaikoura was an old one-way wooden bridge in a sorry state – it’s being repaired,” concludes Greig.
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