New loading models are making a big difference to quarry customers operating efficiency
First publishedin Aggregates Business Europe & International
A new Hitachi ZX530LCH-6 excavator is a key loading model at Guena granite quarry in Brest, northwest France
Efficient loading is crucial to the long-term success of any quarry operation. Guy Woodford looks at two of the most eye-catching new models for such applications.
In northwest France, Brest lies in a sheltered position not far from the Breton peninsula. During the Second World War, the city was almost totally destroyed and only a few buildings were left standing.
At the end of the conflict, large parts of Brest were constructed with with utilitarian granite and concrete buildings, as it became established as an important harbour and the second largest French military port. The majority of the materials required for the city’s post-war construction process were sourced locally from sites including the Guena granite quarry.
Guena is part of the Sotravi Group and is located at Saint-Renan, 15km from Brest. The company’s quarry opened in 1945 after the end of the war to help supply the vast quantities of aggregrates that were required.
In 2008, Guena received permission from the local authorities to extract materials from the quarry for another 30 years. With the capacity to reach 300tonnes/hour (1,500tonnes/day) the company is currently producing 300,000tonnes of aggregates annually on the 13-hectare site.
This is achieved by blasting the rock, and then excavating and loading the stone on to two long-lasting Euclid rigid dump trucks with a new Hitachi ZX530LCH-6 – one of the first of the new generation of Zaxis-6 excavators in Europe. The trucks haul the materials to the on-site crushers, where they are dumped to feed the production process.
Guena also has the equipment required to wash the extracted sand and gravel products, mix the aggregates and produce asphalt. In addition, the volume of waste is reduced through the recycling of construction materials.
The president of the Sotravi Group, Freddy Talarmin, took over from his father in January 2016 having worked for the company for the previous 16 years. “We bought our first Hitachi machine in 1989 and we have bought 14 Hitachi excavators since then, as well as several ZW wheel loaders and an EH750 rigid dump truck,” he says. “We remain loyal to Hitachi construction machinery due to the undoubted reliability of the products.
“We also enjoy an excellent working relationship with our local Hitachi dealer, Cobemat, and we are happy with the latest addition to our fleet, the new ZX530LCH-6. We aim to change machines after 14,000 hours and this impressive model has been selected because of its stability, strength and durability.”
Operator Eugene Laot has 40 years’ experience and his latest excavator arrived on his birthday in April 2016 thanks to the generosity of Monsieur Talarmin. “I’m delighted with the new machine,” he enthuses about his ‘present’.
The R 980 SME and Liebherr's other SME crawler excavators are adapted to the difficult and demanding conditions in quarries
“I used to operate a ZX520LCH-5 and so I can offer a direct comparison with the latest model. The new machine is fast, powerful and stable – even with a full bucket. And in my opinion, one of the highlights is the reversible fan, which makes the maintenance easier on a daily basis.”
The German family-run company, Pongratz Schotterwerk & Co, based in Ensdorf-Wolfsbach, Bavaria, has been using a Liebherr R 980 SME (Super Mass Excavation) crawler excavator in its limestone quarry since May 2016. The 100tonne excavator is being used at the face of the quarry for loading the dumper trucks and in the overburden.
Developed and manufactured in Colmar, France, the 420kW stage IIIB / tier 4i interim diesel engine powered R 980 SME has replaced the Liebherr R 954 S-HD model at Pongratz’s limestone quarry. The new R980 SME excavator is working alongside a Liebherr L 586 wheeled loader.
Pongratz’s R 980 SME unit is configured with a 6m³ HD bucket and designed to process 400 tonnes/hour of material. The new Liebherr crawler excavator is said to be tailored to the throughput of the limestone quarry’s crusher.
“The new excavator loads a dumper truck with 40 tonnes in four cycles and a dumper truck with 50 tonnes in five cycles,” explains Ulrike Pongratz. “There is time then between the loading cycles for sorting and the drop ball operation,” she adds.
The further development of the 15-hectare limestone quarry in requires a crawler excavator with high capacity. The tough geological conditions characterised by uneven excavation beds and a large area of solid rock can now be tackled in the coming years using the R 980 SME.
“The experience and the technical know-how and expertise of Liebherr were also decisive factors for influencing our buying decision. The numerous protective devices available on the machine, together with a product range adapted especially for operation in the quarry, naturally played a huge role,” explains Alexander Pongratz, the technical head of the company.
Pongratz has been placing its trust in Liebherr for over 20 years now. There are good, long-standing relations between the customer, the authorised dealer and the production plant in Colmar. “We have always had good experiences with the crawler excavators from Liebherr. Even when there were problems, a solution was always found,” adds Alexander.
Liebherr developed a special product range, the SME crawler excavators, for difficult and demanding conditions in quarries’. These crawler excavators are equipped with a reinforced undercarriage featuring suspension components from the next model up in the standard range. In the R 980 SME this is the undercarriage of the R 9100 mining excavator. Combined with a heavy counterweight, the larger undercarriage improves the stability and service life of the machine and enables the use of large capacity buckets. The equipment, such as stick and bucket cylinder, has larger dimensions and offers higher digging and breakout forces with the adapted kinematics.
The Liebherr R 980 SME crawler excavator has a low average fuel consumption of 51 litres/hour, achieved with the German manufacturer’s excavator system technology. This concept is based on the development of a special hydraulic system. It is designed with its own electronics and attains optimal efficiency thanks to its strategically positioned sensors.
With every steering action by the excavator driver, the operation of the engine and the hydraulic system are continuously optimised via a control computer. This allows fast, fluid and precise work. The circuits are separated or reconnected as needed, guaranteeing optimal energy consumption.
A third circuit is responsible for the rotation of the upper carriage and is said to guarantee consistent maximum performance and maximum swing torque, irrespective of the workload on the other circuits. As a result, maximum power and speed can be delivered with combined movements.