Feature: Quarrying equipment

As daily production targets at quarries increase to meet rising global demand for construction materials, quarry operators are modernising their fleets with the aim of increasing efficiency - and there is no shortage new equipment to choose from.

A big driver behind this year's string of equipment launches for the US and European markets has been the new US Interim Tier 4 regulations on exhaust emissions, and the equivalent European legislation, Stage IIIB.

The first set of laws that came into force at the start of the year applied to 130 kW to 560 kW diesel engines, and manufacturers have responded by launching new generations of heavy machinery fitted with new fuel-efficient and emissions-compliant engines.
Security and efficiency are also increasingly at the forefront of the latest designs, with remote monitoring systems being introduced as standard on some new equipment ranges. The latest machines for use in quarrying applications also feature improved transmissions and hydraulics as well as other technology.

The increased automation of quarrying machinery is another major trend. For example, automatic traction control (ATC) is a common feature in the latest articulated dump truck (ADT) launches from major manufacturers like Komatsu, Caterpillar, Volvo, Bell and John Deere, Terex and Doosan/Moxy.

Komatsu America, for example, has launched a new, emissions-compliant ADT which has been designed with increased automation, security and fuel efficiency in mind. The HM300-3 is powered by a 325 hp (242 kW) Komatsu SAA6D125E-6 Tier 4 Interim and Stage IIIB engine and is capable of hauling up to a 28 tonne payload.

The machine features both Komatsu 's traction control system (K-TCS), which automatically provides optimum traction for different ground conditions, as well as KOMTRAX fleet monitoring technology as standard. This is a wireless system which sends machine operating information such as daily fuel consumption, location and operation hours to a secure website.

Traction Control

John Deere has also launched its 46 ton (41.7 tonne) 460E - its largest ever ADT - this year. Power for comes from a US/EU emissions-compliant 13.5 l John Deere engine, and traction controls have also been automated to take the guesswork out of when to use the differential locks for inexperienced operators.

The 460E also comes with on-board scales as standard that lets the operators of both the ADT and loading machine know when the truck body is full to capacity.

Caterpillar's new generation of ADTs also features an automatic proportional differential locking system that adjusts itself to different transmission loads and works in harmony with the hydraulic steering system. The company launched three ADT models in March for the European and US markets - the 735B, offering a 32.7 tonne payload, the 740B with its 39.5 tonne payload, and the 740B EJ with an ejector body, carrying a
38 tonne payload.

And Volvo's latest ADT models, the F-Series - ranging from the 24 tonne A25F up to the 39 tonne A40F - also features ATC as standard, together with a full suspension option for the A35F and A40F models. This is another automatic system that continuously adapts as the ADT is driven to reduce bumps and vibration from uneven ground.

Full reports on the new ADTs from Caterpillar and Volvo, as well as their other Tier IV Interim / Stage IIIB equipment launches, can be found in the June issue of iC.

Fuel savings

Meanwhile, Volvo's Advanced Combustion Technology (V-ACT) emissions-complaint engines have produced fuel savings of up to 15% on some new machines, notably the company's new 35 tonne wheeled loader, the L250G, which was developed specifically for customers in aggregates and mining.

Designed to match the needs of on-highway trucks, the L250G's 290 kW (394 hp) engine produces the fuel saving by optimising the transmission and drivelines as well as benefitting from load-sensing hydraulics.

A raft of large wheeled loaders have been brought to the market this year, including New Holland's 20 tonne W230C machine with a 3.6 m³ bucket capacity. The W230C features heavy duty axles, making it well-suited for quarrying and materials handling applications.

Chinese company Changlin, too, has launched a new
16.7 tonne wheeled loader - the 957H. The machine can be fitted with either a Shanghai Diesel C6121 engine or an imported Cummins 6CTAA8.3 and can carry a 5 tonne load.
Manufacturers are concentrating on producing efficient, reliable and durable wheeled loaders - qualities that are essential for quarry operators as machines are often operated for 12 hours a day, seven days a week.

Indeed, avoiding costly downtime was a central concern for Scott Rommel, owner of Poland Sand and Gravel, a New York-based aggregates company which has just added a 25.5 tonne Doosan DL450 wheeled loader to its fleet.

Mr Rommel has been impressed with the DL450's abilities. "It's a fast and nimble machine, just a little bigger than our DL400," he said, adding that the machine also provided good visibility in all directions.

This year has also seen the launch of Doosan's DL500 wheeled loader, which sports buckets ranging from 5.9 to 6.8 cubic yards (4.5 m3 to 5.2 m3) and is well-suited for material handling applications in quarries and mines.

Operating efficiency

Bell has also focussed on improving the operating efficiency of its wheeled loaders, which it manufactures in partnership with shareholder John Deere. The company has developed an advanced payload system (APS) - onboard weighing technology that enables operators to enter a target load, make multiple material measurements, calibrate for multiple attachments and create mixed material batch loading data.

Neville Paynter, managing director of Bell Equipment UK, said, "Production costs are continually increasing, so we wanted to help our customers do what they can to improve efficiency".
The new APS is compatible with Bell's range seven wheeled loaders, from the utility class L1204E, L1506E, L1706E and L1806E, to the larger models, the L2106E, L2606E and L2706E.

Meanwhile, quarry operator Yorkshire Aggregates has said that the three new 17 tonne Case 821E wheeled loaders it bought earlier this year for its two quarries in South Yorkshire, UK, are helping to improve productivity and reduce maintenance time by up to 20 hours a week.

The 821Es are powered by a 159 kW engine and the contractor requested that one was fitted with enlarged 2800 l to 3300 l
(2.8 m3 to 3.3 m3) bucket capacity to improve efficiency by allowing more aggregates to be moved in one scoop.

Heavy-duty excavators

This year has also seen the launch of heavy-duty excavators with emissions-compliant engines for the US and European quarry industries. Caterpillar, for example, launched its 50 tonne class 349E, 74 tonne 374D and 90 tonne 390E, which replaces the 385D, at this year's ConExpo show, while Volvo's first Stage IIIB/Interim Tier 4 machines include the EC480D excavator, which covers the 50 tonne classes.

A comprehensive report on this year's excavator launches and the latest news from the market is also available in June's edition of iC.

Quarry managers are feeling the pressure to increase production - when Polish cement maker Cementownia Warta increased its daily production target to 3000 tonnes of cement, a larger excavator was required to work in its limestone quarry.

The company bought a 120 tonne-class Hitachi EX1200-6 excavator through dealer Tona, and found that the machine, which has a 6.5 m³ bucket, could extract the material without the need for blasting - resulting in cost and time savings.

Quarry manager Waldemar Rataj said, "The large bucket capacity has maximised the efficiency of the loading process. The EX1200-6 does the same work as four electric excavators, and it only needs one operator."

Similarly, quarry operator Agregat Oued Cherrat Morocco (AOC), bought four, 32 tonne Hitachi ZX330-3 excavators last year to help modernise operations a large quarry north of Casablanca.

The Hitachi excavators helped AOC increase the quarry's annual output to 1.8 million tonnes last year, from 1 million tonnes in 2009. Production is being ramped up to meet increased demand from Morocco's road-building sector as the government seeks to improve the national motorway network.

Versatility

Meanwhile, in the crushing and screening sector, Terex Finlay has introduced a new tracked screen to its range in the form of the 250 tonne/hour 863, which has been designed for use in quarrying, mining, construction and demolition applications in confined spaces. It can be fed by either a crusher or an excavator.
The machine is versatile and flexible and can be hydraulically folded and be ready for transport in less than 30 minutes.

Any advantage like this that could lead to cost-efficient increases in production is the name of the game for quarrying contractors. Indeed, Serbian sand and gravel producer PZP Valjevo d.o.o, saw dramatic improvements when it replaced an old rotor used for producing sand and aggregates with a Sandvik 85LP rotor - the company's production rate doubled, while energy consumption remained the same.

The company's old vertical shaft impact (VSI) crusher only manages to produce 12 to 18 tonnes per hour at full load, and Sandvik determined that the best way to improve production rates and reduce power requirements was to increase the speed of the crusher, and replace the PZP Valjevo's existing rotor with an 85LP.
The results were significant - the machine produced twice as much material per hour and used -25% less power, with less downtime and lower vibration levels, too.

Similarly, advanced screening technology has increased production at US limestone aggregate producer Hinkle Contracting Company by more than +25%, most notably because work no longer needs to stop each day to clean screens.

The Kentucky-based company installed Major Wire's Flex-Mat 3 Modular self-cleaning screen media on the majority of its screening machines. The 1 ft by 1 ft (0.3 m by 0.3 m) screen panels have individual "crowns" in the middle, running parallel to the flow, which provides the tension needed to allow the wires to vibrate effectively.

The company's Somerset plant has been able to double its production from 400 tonnes per hour to up to 800 tonnes per hour using Flex-Mat 3 screens and the business now operates at 96% uptime. Indeed, Hinkle said it was on track to meet its goal of 99% uptime for 2011.

This kind of productivity is a key requirement for quarry operators, who are seeking the most flexible equipment as the industry ramps up production to meet growing demand stemming from the global financial recovery. As the latest equipment and applications illustrate, modernising quarry machinery can have a real impact on margins, from fitting machines with the most sophisticated and efficient engines available to simply making a basic, but highly effective change to screening processes.