In quarrying and mining, articulated dump trucks (ADTs) have always been the go-to solution for arduous in-pit duties such as hauling run of mine (ROM) material from the quarry/mine face to the processing plants. Understandably, the ADT’s prowess in such tough underfoot conditions is unparalleled. While tipper trucks are a common sight on quarries, they have traditionally been relegated to light duty applications such as re-handling of ore and hauling of crushed material from the crushing plants to stockpiles, for example.
As cost pressures bite, quarries and mines continue to embrace new ideas. As part of this mindset shift, there is a growing acceptance of construction-type mining trucks, which are proven to be cheaper than dumpers – both to buy and to operate.
As this shift towards mining tippers gathers pace, Volvo Trucks South Africa has brought in what it believes to be a game-changer. The all-new Volvo FMX – which made its local debut late last year – sets a new benchmark with the heaviest axle in its class, which results in increased payload.
Eric Parry, senior manager: Sustainability at Volvo Group Southern Africa, says there has been a huge interest in the new truck since its launch last year. A couple of units are already in operation in South Africa, with several more on the way.
A key differentiator, explains Parry, is the brand-new heavy-duty axle designed in conjunction with sister company, Volvo Construction Equipment. With increased front axle loads of up to 20 t and a 38-t rear bogie, the new Volvo FMX makes light work of heavy quarrying and mining assignments. The 38-t bogie is a major improvement on the predecessor range’s 32-t rear-axle capacity.
“The front suspension has been updated, allowing for front axle loads of up to 10 t, and 20 t for double front axle units,” explains Parry. “On the 8×4 variant, for example, the two 10-t front axles with four full springs, combined with the 38-t rear bogie with huge parabolic springs, provide a gross vehicle mass (GVM) of 58 t.”
Depending on the type of the body and the specific gravity (SG) of the loaded material, the truck can achieve anything between 38 t and 41 t of payload. “Some customers choose the extra-wide body (3 m), because it lowers the centre of gravity of the vehicle, while offering good stability and payload. This, however, is not road-legal,” explains Parry. “Others prefer narrow and high bodies because they allow them to run the truck on certain sections of the national roads when empty.”
During testing at a haematite and fluorite ore operation in Limpopo recently, the Volvo FMX ticked all the right boxes in what is known to be an unforgiving application. Equipped with a standard width body, the truck carried 50% more payload than existing site ADTs, taking about nine scoops per load, compared with six for the articulated hauler.
“The client was sceptical about the truck’s ability to negotiate the steep gradients with a full load, especially given that the ADTs were already struggling with the sharp inclines from the pit to the processing plants. The truck outperformed the ADTs in every aspect – it pulled out of the pit faster, with greater payload,” he says.
Leveraging Volvo Trucks’ I-Shift with crawler gears technology, the truck could also pull off with a full load from a standstill position at the steepest of gradients with no difficulty. The I-Shift with crawler gears is a unique Volvo gearbox designed to provide power and extreme startability, which are crucial in heavy duty quarrying and mining assignments.
Safety to the fore
Visibility is of paramount significance in mining applications. For this reason, the FMX offers 10% better visibility than its predecessor, thanks to a lowered door line and new rear-view mirrors. This is enhanced by a standard camera that is installed on the passenger side, thus providing a complementary view of the side of the truck.
“With its ability to carry more payload and manoeuvre more easily in difficult conditions, while keeping the driver safe and comfortable, the Volvo FMX ushers in a new era of productivity and safety at quarries and mines,” says Parry.
One of the major advantages of the FMX over traditional ADTs is the lower total cost of ownership (TCO). Both investment and running costs are a lot lower than those of a comparable ADT. The light body results in lower fuel consumption and increased payload. Although the truck runs on specialised tyres (325/95R24 sizes), these are much cheaper than those of an ADT, thus further lowering TCO.
The versatility of the truck is yet another major benefit. While the FMX is designed to challenge traditional yellow metal dumpers in off-road applications, it can also be deployed on public roads when empty, provided it is equipped with a road legal body. Consequently, there is no need to hire costly lowbed trucks to transport the vehicle between sites.
However, Parry agrees that not all mining sites are ideal for the construction-type trucks. “There are some mining environments where the ADT is a better option, especially where tough underfoot conditions exist. However, in most quarrying applications where you have fairly smooth, well-maintained roads, the FMX will be the preferable choice. Quarry operators can therefore take advantage of the truck’s unmatched value proposition to ensure more profitable operations,” concludes Parry.