Mercury’s wind farm contractors have engineered a way out of a tricky problem – how to get the massive turbine blades to the top of the Tararua Range above Palmerston North.
The corners on the Pahīatua Track were too tight to get the 55-metre blades around and an attempt to create a bypass track collapsed in a slip.
The solution, given the road could not be made straighter, was to make the blades shorter.
The innovative technology, the blade manipulator, enables the Vestas blades to be tilted up to a 60-degree angle, making them effectively 27 metres shorter than a blade carried flat.
The gear was imported from Korea and enhanced by Smith Crane and Construction, the contractors responsible for crane work on site, including lifting the towers and blades into position.
Smith Crane and Construction transport manager Mark Thompson is putting on a nightly show in Palmerston North, standing in a cage on the side of the trailer, in charge of steering and tilting.
“I’m like the Fat Controller.”
Although turbine suppliers Vestas have used blade manipulators on other projects around the world, this was the first time the technology had been used in New Zealand or Australia.
Vestas senior project manager Kenn Wood said the company was proud to be part of pioneering the use of the transport solution in Australasia.
“From the point of conception, it has been a huge effort to realise the blade manipulator through many trial runs, workshops and ongoing consultation with Smiths Cranes.”
So far, more than a dozen of the giant 15-tonne blades have been transported from a storage yard in Rangitīkei St, around the city, out to Ashhurst, along State Highway 57 to the Aokautere to Pahīatua road and up the hill.
Accompanied by five pilot vehicles and drivers, the feat has become a source of evening entertainment for people along the route.
At first, the mission took six, slow hours.
Now the crews are familiar with every bend and incline and hazard, including traffic lights, they have it down to three hours, and can transport two blades, one at a time each night, wind conditions allowing.
The successful delivery has enabled three of the 33 turbines in the first, northern stage of the 60-turbine, $465 million wind farm to be completed.
Mercury’s generation development manager Dennis Radich said it was a relief that the contractors had designed a technique for getting the blades to the site.
In the original plans, the blades had been expected to arrive in New Zealand through the Port of Napier and be carted up the hill from the east.
The challenge arose when Napier could not provide space for storing the blades, so they arrived through Taranaki instead.
Most of the 99 blades destined for the northern stage of the wind farm were carried by road to Palmerston North during the Covid-19 lockdown in 2020.
The failure of the bypass track up to the wind farm created “an enormous problem”.
An alternative route from the north through existing wind farms was being investigated, but has not yet been consented.
“Getting the turbine blades up to the wind farm site was the last piece of the puzzle when it came to getting the kit in place,” Radich said.
“We’re very pleased to see the first complete turbines now standing on the hill.
“According to Vestas’ scheduling, the 33 northern turbines should all be supplying power to the grid by October this year.”
Once fully commissioned, the wind farm will contribute a further 2 per cent of renewable electricity to the national grid.