|
|
New Zealanders should give a collective thumbs-up to the nation’s premier state highway finally being sealed from end to end. Completion of the last few kilometres to Cape Reinga was United Civil Construction’s biggest ever project, and the company has done the job in style. BY GAVIN RILEY
Sealing and upgrading of the final 19 kilometre-plus from Waitiki Landing to the cape lighthouse, which began in September 2007, has been finished by United Civil Construction eight months ahead of the original contract period, despite having to carry out additional work for the Department of Conservation. The total cost of the project was just over $22 million, of which $19.4 million was for the seal extension works. “We’re stoked,” United managing director Andrew Campbell says of the early finish. “Despite a significant increase in scope soon after the award we were intent on delivering the project within the original contract time-frames.” This was no easy task, since the confluence of the Tasman Sea and Pacific Ocean off Cape Reinga produces an unpredictable climate in the region. “In February 2008 there was some pretty ugly weather,” Andrew says. “The summer and autumn of 2009 were also adversely weather affected, with several big storms playing havoc with the earthworks operation. But the winter was drier than previously and good progress was made. And this year it’s been brilliant up there.”
“It [the constant alignment adjustments] played havoc with our survey budget and required constant revision to the earthworks programme,” Andrew says. There were other brakes on swift progress. In such an environmentally sensitive area, all trucks and construction machinery, even bitumen sprayers, had to be inspected by Department of Conservation staff at Kaitaia, one hour to the south, before travelling to the site. A rare type of lizard had to be trapped in advance of clearing and earthworks. And highly variable and sensitive subgrades, with a high percentage of allophane, required particular care to be taken when cutting to fill. One month after Contractor published a report on the project’s progress in November 2008, sealing had been completed to the six kilometre mark and bulk earthworks were generally completed to 8.3 kilometres. “While tracking within requisite time-frames, this was somewhat slower than we had hoped for, and it was apparent that all the additional works associated with the development of a carpark, walking path and visitor facilities at Cape Reinga, for DoC, were having a greater-than-expected impact on the progress of the road-construction effort,” Andrew says.
The original NZ Transport Agency contract called for the construction of around $500,000 of minor earthworks, stormwater drainage and pavement construction associated with the development of a new carpark at the northernmost end of SH1. United Civil ended up undertaking not only this work but constructing in the area, as a variation to the NZTA contract:
Elsewhere, along and adjacent to the SH1 road works, United Civil constructed other walking tracks, viewing platforms, and small carparks for DoC as part of the NZTA contract. By December last year earthworks were completed to 16.5 kilometres and sealing to 12.5 kilometres. The earthworks were completed by the end of February this year and the sealing by late April.
The project required 56,000 cubic metres (solid) of premixed stabilised aggregates, 3500 metres of pipe culverts, 5700 metres of subsoil drains, 9000 metres of concrete dish channels, 145,000 square metres of subgrade stabilisation, 127,000 square metres of chip sealing, 14,300 metres of fencing, and 255,000 cubic metres of earthworks. Premixed stabilised aggregates, using a pugmill specially bought for the purpose, was a United Civil initiative aimed at producing environmental benefits and time savings. As part of the road improvements, the NZTA has worked with Maori and DoC to protect and enhance the environment. A plant nursery run by local iwi has been growing more than 300,000 native seedlings from plants unique to the Cape Reinga area and these are being used to restore beauty to a region of spiritual importance to Maori and to help prevent erosion. Andrew Campbell says the Cape Reinga SH1 sealing and associated works is by far the biggest project ever undertaken by United Civil Construction, which won a Contractors’ Federation construction award last year for stage three of the $16.5 million Whangarei Heads sewerage scheme.
“They were really-engaged client representatives who were interested in solving problems, not just pointing them out.” He also praises the “great effort” by the subcontractors – Magnum Construction (earthworks), Higgins Contractors (sealing), Northland Road Stabilizers (in-situ stablising of existing subgrade with lime), Stonecraft Construction (concrete dish channels), B3 (drainage and culverts) and Bellingham Quarries (aggregate supply). And Andrew says he is indebted to the local community for the support it gave the project team. “It’s been a real privilege to work in that part of the country – it’s a pretty special place and environment. We had our difficulties, but all in all we’re very happy with the outcome.” With several minor tasks on the project to be attended to over the next few weeks, the NZTA plans to hold an official opening ceremony at Cape Reinga at the beginning of July.
Contractor Vol.34 No.4 May 2010 |
Roading history was made in late April when completion of a major project in the far north meant the entire 2022 kilometres of State Highway 1 is now sealed, from Cape Reinga to Bluff.
Working close to the cape had special challenges apart from the weather. The site is 275 kilometres north of United’s Whangarei base, 20 people had to be taken on and trained to fit into the 25-strong workforce as part of a plan to provide jobs for locals, and the route alignment had to be continually revised to minimise the environmental footprint, limiting the extent of cut and fill.
“At this point we made changes to the site management team, bringing in a new project manager, Chris Francis, and site foremen, and moving some of the slower subcontractors off critical-path activities. Where we could we also fast-tracked various aspects of the programme.”
Upgrading the last 19 kilometres-plus of SH1’s northern extremity involved widening the carriageway in places to a standard 7.2 metres and straightening out many of the more than 100 bends of what was originally a dusty, gravelly farm track. The improvements were necessary to cater for the safety and comfort of visitors to Cape Reinga, currently 120,000 a year and increasing by five percent annually.
He says the successful contract delivery at the cape is the result of the efforts of the wider project team, in particular NZTA project manager Howard Marshall, engineer’s representative Terry Buckley of AECOM, and John Maxwell of the Department of Conservation.