It says something for the growth of our dairy industry that they’ve had to build a new road round the original Edendale factory, and this roading project is the biggest in the Southland region for many years. Hugh de Lacy checks it out.
A herd of 300 cows was the basis for the country’s first dairy factory, at Edendale, 40 kilometres north of Invercargill, but Thomas Brydone knew what he was about when he established it in 1881.
That herd has since exploded to more than half a million cows in Southland alone (6.5 million nationally) and entrepreneurial Scotsman Brydone, the superintendent of the Australia and New Zealand Land Company, would have been as proud of that achievement as of the similar expansion of the frozen meat export industry he also had a hand in founding.
A little township grew up around Brydone’s dairy factory, now part of the co-operative Fonterra dairy giant’s vast assets, and the factory itself and the traffic to and from it have likewise so ballooned in size that they’ve had to realign SH1 around it for the peace and safety of residents and the convenience of road-users.
Fulton Hogan has the $13 million contract to build a 2.6 kilometre realignment of SH1 round the Edendale factory, the country’s biggest, to future-proof the highway against increasing heavy truck traffic, and to support Fonterra’s rail option and further expansion at the site.
It will also take the traffic away from Edendale village and shorten the travel times between Invercargill and Gore.
At present traffic has to navigate a succession of tight curves, intersections and two railway crossings, but the realignment will by-pass all that with the key element being a roundabout south of the factory.
SH1 presently passes through the north-east of Edendale, past the factory, the primary school, a sports field and private residences, by way of a 45kph curve and no fewer than three different speed limits.
Traffic along the highway is also disrupted daily by trains crossing it to access the two rail sidings at the factory.
The greenfields project will lead SH1 from south of the factory to a four-legged roundabout where it will make a westward 90-degree turn before curving north and west again to link up with the existing highway north of the township.
The speed limit will be a consistent 100kph for the length of the realignment.
One of the roundabout’s other two legs will lead directly to the factory while the second will give access to the township via Salford Street.
There will be a passing lane for northbound traffic, aimed at addressing the shortage of passing opportunities between Invercargill and Gore which has been a persistent source of driver frustration.
An underpass will give livestock and light farm vehicles access to the surrounding dairy farms without their having to cross the road.
Construction started in early June, and the first two months were devoted to removing and lowering 28 pipe and control lines that service the factory, along with installing eight spare ducts under the new alignment for future-proofing.
With that all but completed by late July, the earthworks could begin, involving the shifting of about 50,000m3 of topsoil and waste, and the laying of an estimated 250,000 tonnes of aggregate to form the base of the new section.
The road will be founded on granular fill ranging from 0.34 metres to 1.9m deep, followed by 0.23m of AP53 sub-base and 0.17m of AP40 base-course on top.
Project manager Dave Connell tells Contractor that the clay sub-grade is proving to be a particularly stable base that, thanks to a mild and dry winter, has allowed construction to proceed without the danger of moisture damage. so far never bogged up.
One of the biggest roading projects in Southland in years, the realignment has allowed the extensive use of 3D-controlled machinery within the region for the first time.
The technology is fitted to a bull-dozer and a 20-tonne excavator belonging to local sub-contractor Linton Contracting from nearby Winton, and later Connell will be whistling in a range of similarly modified Fulton Hogan machinery released from other works in Central Otago and Canterbury.
The technology has been in use for the last couple of years in the big projects further up both islands, but the Edendale realignment will be its first major use by the company in Southland.
The project currently employs three 18-to-22 tonne excavators, backed up by a 14-tonner to do the fiddly work, assisted by a 22t pneumatic tyredroller, a 12t construction roller and various low rollers.
The workforce varies, but generally there are at least 15 people working on-site each day.
The local community is welcoming of the changes, and Fulton Hogan is taking care in its planning so as not to disrupt a big annual event that takes place across several large paddocks in the immediate vicinity of the factory and construction works.
This is the Edendale Crank-up Day, held on the last weekend in January, when traction engines by the dozen and agricultural and contracting machines by the score convene to display Southland’s love affair with the farming technology on which its economy is based.
With the project not expected to be completed until mid-2020, two of these events will by then have briefly challenged Fulton Hogan’s traffic management skills, which have otherwise been tested only by its own trucks crossing the highway.
The project, its scale and ability to use full 3D technology on machinery is proving particularly satisfying to Dave Connell himself.
A born-and-bred Southlander, he’s all too well aware of the benefits such a big project will bring to the region.
“It’s great to be part of such an important project for Southland – the biggest for a long time,” he tells Contractor.
“It’s going to make a huge difference when it’s finished, and as a local it’s especially good to be part of something so significant.”