The biggest thing on wheels: 'Supertruck' brings 90-tonne heat exchanger to Ngāwhā power station

The supertruck was down to walking pace as it climbed Turntable Hill. Picture / Peter de Graaf

The biggest thing ever transported on Northland roads, which will form a key part of Top Energy's new geothermal power station at Ngāwhā, made a show (and traffic) stopping sight as it rumbled up SH1 last week.

The 90-tonne, 20.5m heat exchanger made was transported on an 18-axle, 144-wheel trailer pulled by two trucks and pushed by a third.

Even with all that pulling and pushing power, the 'supertruck' was down to walking pace as it travelled through Kawakawa and Moerewa, and climbed Turntable Hill, accompanied by a fleet of support vehicles.

The heat exchanger arrived by ship at Northport and was transported 120km to Ngāwhā by Palmerston North firm PTS Logistics.

Top Energy chief executive Russell Shaw said the Israeli-built heat exchanger, or pre-heater, would be used to extract energy from geothermal fluid drawn from deep underground. Heat from the fluid would turn pentane into a high-pressure gas, which would spin a series of turbines, which would turn a generator, making electricity.

The piece of kit was part of the second shipment of parts from Israel. The third and final shipment, which would include the generator, was expected in late January or early February. Mr Shaw apologised for any inconvenience to road users.

The heat exchanger is believed to be the biggest thing ever transported on Northland roads, eclipsing an 85-tonne transformer trucked from Marsden Pt to Kaitaia in 2015, also for Top Energy. That trip, via the Mangamuka Gorge (because the truck was too wide for the then one-lane Taipā Bridge), took two days.

The new power station is due to start producing electricity in August next year.