Mammoth mine plant moved with ease
It’s 10 storeys high, weighs 320 tonnes, is worth $4.5 million, and had to move 5 kilometres.
It took five trucks, a 240-wheeled trailer and 12 months of planning to move Waikaia Gold’s mining plant from one mine site to another down the road this week.
The plant, which sits on a pontoon in the company’s mine pond near Waikaia in northern Southland, processes about 1 million cubic metres of gravel a year and produces about three to five ounces of gold an hour.
The gold mining company has completed stage two of its sevenyear gold mining operation near the Dome Burn, near Waikaia.
It began mining operations in 2013 and by November 2017 had recovered 2 tonnes of gold.
Phase three of the operation is at Freshford, 5km away from the current mine, across farm paddocks and a main road.
It took a year to plan moving the massive plant, and none of the machinery inside was removed before the move, operations manager Noel Becker said. ‘‘It’s going lock, stock and barrel. Moving it was the cheapest option in terms of downtime. It would have taken four months of lost production if we had disassembled it and rebuilt it again.’’
Last week Waikaia Gold raised the height of the mine pond the plant was in and floated it on to a dock, before dropping the water level again, leaving it high and dry. Enter Manukau heavy haulage company Tranzcarr and boss Dave Carr.
On Tuesday morning, the company backed a 30-axle, Germanbuilt trailer down the slope into the mine, placed it under the pontoon, raised it, and slowly towed it out of the 16m deep hole.
‘‘The trailer is actually seven trailers all joined together and we can raise it up and down with hydraulics,’’ Carr said.
With a gradient of 1:11 it took two Kenworths, a Mack, a Scania and a Volvo dumptruck owned by Rosco Contractors Ltd, which has the contract for earthworks at the mine, to tow the plant up the slope on to flat ground, Becker said.
Tranzcarr’s Macks and Kenworths can tow 250 tonnes each, but at 320 tonnes the plant was a lightweight for Carr and his team – they’ve dealt with 1000-tonne loads before.
The plant was then towed across farmland that had been mined and returned to pasture, to Freshford.