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Volvo paver used in Kiruna almost two kilometers below the ground

KIRUNA/SWEDEN, March 5, 2015 - A Volvo paver was adapted to suit conditions nearly two kilometres below the ground in the world’s largest iron ore mine.

The discovery of a massive iron ore deposit led to the birth of the Arctic town of Kiruna. Located 300 km north of the Arctic Circle in Swedish Lapland, Kiruna sits atop a huge slab of  magnetite that plunges 4 km into the ground, is 2 km deep and has an average width of 80 m.

Mining began in 1898, first via open pits. In the early days, miners transported the ore in horse-drawn carts. It was not until the 1960s that Sweden’s state-owned mining company Luossavaara-Kiirunavaara Aktiebolag (LKAB) switched to underground mining.

Today, Kiruna is home to one of the largest and most modern underground iron ore mines in the world. A railway and road network spreads out to a depth of 1,542 m below ground and Kiruna is literally a town on the move. Over the next two decades, part of the town’s population will be relocated to new homes allowing the mine to expand.

Volvo p7820c in action in the mine below Kirona

The p7820C from Volvo Construction Equipment in the mine far below Kiruna. | photo: Jonathan Nackstrand


Foreman Mathias Enlund leads a team of seven asphalt-paving professionals who are laying the mine’s 400 km underground network of roads. The asphalt is mixed at a site located 17 km away from the mine before being transported underground to the paving team. According to Enlund, their task was made easier with the arrival of a Volvo Construction Equipment (Volvo CE) P7820C tracked paver. “We used to work with a wheel-equipped paver,” says Enlund. “But now we don´t get stuck because this machine is track-equipped and reliable. The work doesn’t get held up and the paver is equipped with a clean combustion engine with low noise and efficient fuel consumption.” Like the rest of his team Enlund works four days a week for the entire summer season, from May through to October. Asphalt is laid between June and September and it was early this year when the team switched machines. Almost all the paving is uphill and the new Volvo paver is able to push 55-tonne mining trucks, delivering asphalt to the tunnel up slopes with a gradient of 7%.

When LKAB contracted NCC Roads – a construction and property development company in the Nordic region – to carry out underground paving and road repairs in the Kiruna mine, the company contacted authorized Volvo dealer, Swecon, to check if they could offer suitable equipment. Volvo CE provided the P7820C, which was then modified and taken nearly 1.5 km below ground – this took several hours since the paver runs at a maximum speed of 4 km per hour. “The P7820C had to be adapted to suit the particular conditions that exist in the mine,” explains Svante Bodare, a product specialist for road machinery at Swecon. “The underground tunnels are dark, the ceilings are low and the roads have a near constant gradient of 7%. So, we removed the roof of the paver, the exhaust pipe was shortened and extra lights were mounted on the machine. In this country, 98% of paving is done above ground and with wheel-equipped machines. We also tend to transport those machines between job sites with the help of trucks, but in the mine they drive the P7820C between the paving sites.”NCC Roads site manager Johan Pettersson claims the paver made a noticeable difference to his team’s work. “This paver assures that we can carry out the work efficiently and without disruption.”
 
Whilst the operators are pleased with the paver, the biggest challenge, says Pettersson, is moving it at the end of a work shift because that is a slow process. And in the tough conditions, proper maintenance is important.The paver is leased from Swecon, so service and maintenance for the machine is assured, as they are running a workshop in Kiruna.“Around 20,000 tonnes of asphalt has been laid under-ground this year, which is probably the largest amount ever in the history of an underground mine,” says Pettersson. “We would like to keep using the paver as it will be useful for road maintenance and there is a constant market underground.”


original by Nathalie Rothschild

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