The importance of an efficient load and haul system in achieving quarry productivity cannot be emphasised enough. Increasing productivity is one of the key drivers to counter diminishing profit margins as it effectively reduces operating costs. With that in mind, Liebherr’s R 970 SME (Super Mass Excavation) crawler excavator has a special design focus on both productivity and efficiency – the key parameters for every quarry owner.
In an environment characterised by long lead times for new machines, Tendayi Kudumba, General Manager – Earthmoving Technology at Liebherr-Africa, says local customers can take advantage of Liebherr-Africa’s readily available stock for the R 970 SME crawler excavator.
Productivity and efficiency
The R 970 SME is equipped with an array of features that speak directly to increased productivity. Central to this feat is the heavy D9G undercarriage equipped with 600 mm wide, two-bar track pads of the next size up machine, the 90-t R976 model, for greater rigidity and the much-needed machine stability to carry a larger bucket. The boom has a length of 7 m, with a 2,6-m-long stick.
A 14,5-t counterweight further increases the stability of the machine, allowing it to be equipped with a 5,2 m HD backhoe bucket. “Some larger competitor offerings in the 90-t class actually come with 4,5 m³ buckets,” says Kudumba. “The Liebherr R 970 SME therefore punches well above its weight with a larger bucket, allowing customers to improve their productivity.”
With an 80-t operating weight, the machine is ideally suited for loading 40-t dump trucks. Traditionally, a key parameter in achieving the optimal match factor is the number of scoops a loading tool takes to fill the truck. The rule of thumb, says Kudumba, is four to five scoops for a high production site where quicker cycle times are required. The R 970 SME fills a 40-t truck with four scoops.
Lavell Ruthman, Head of Sales – Earthmoving Technology at Liebherr-Africa, adds that special hydraulic cylinders give the machine outstanding digging and breakout forces in arduous mining and quarrying applications. In fact, digging and breakout forces have been increased to over 15% higher than the predecessor model. All-in-all, these measures ensure good performance and economy of the excavator.
The cast sprocket wheel with double tooth segment for longer life is another talking point, comments Kudumba, who says most competitor offerings in this range come with single tooth sprockets, resulting in high wear and ultimately reduced life of the component. Available for Liebherr’s 50-t and larger machines, the double tooth sprocket means that the machine is able to withstand higher operational forces, even in arduous mining and quarrying applications.
With efficiency in mind, the machine benefits from a complete range of Liebherr components, all the way from the engine to hydraulic pumps and electric systems. This is in line with Liebherr’s international strategy to install in-house components in its own equipment.
“Critically, we use our own components which are purpose- built for the machine. These components are made in house by Liebherr and are carefully designed to match each other to maximise machine performance and efficiency,” says Kudumba. Effectively, this one-stop shop approach means that the complete machine – from bucket to counterweight – carries Liebherr components, giving the customer the assurance of the Liebherr quality across the whole machine.
New features added to the uppercarriage of the R 970 SME increase safety for the excavator operator and also make it easier to service the machine. Platforms with galvanised surface protection located on both sides of the uppercarriage make the environment safer for the operator when cleaning and servicing the machine. Maintenance work is also made easier by the large maintenance access with the easy-to-open engine hood, thus maximising both safety and machine uptime.
Based on Liebherr’s understanding that a safe and comfortable operator is a productive one, the machine places value on ergonomics. According to Ruthman, the R 970 SME has the largest and quietest cab in this class size. “The cab has impact-resistant glass in the windscreen and skylight, which offers a much safer environment in which to work during quarrying,” concludes Ruthman.