On the right track

An isolated coastal quarry in the Scottish Highlands is the new home of a 115t Liebherr R 984C excavator and this piece of kit has its work cut out.

Opened by Foster Yeoman in 1982, Glensanda quarry has around 400 million tonnes of exisitng reserves and planning permission until 2042. The quarry currently provides seven different granite products and produces around six million tonnes a year. Among its many tasks, the Liebherr R 984C is involved in overburden removal, back wall dressing down, road construction and maintenance.

Powered by a straight six-cylinder Cummins diesel engine, the machine at Glensanda has been supplied to full quarry specifications, including 500mm wide trackpads, FOPS protection and an upgraded HDV6.70cm3 capacity bucket with additional wear shroud. The gooseneck boom is 7.8m long with a 3.4m dipper and the machine's power and reach allows it to supplement the shovel activity on site when it is used to load blasted rock on to the quarry's dump truck fleet.

The continued momentum in the bulk aggregate extraction market over the last few years also prompted JCB to produce its biggest-ever tracked excavator - the JS460.

Weighing in at 46t, the machine replaced the company's JS450 and is perceived as the flagship of JCB's tracked excavator range as it completes its 16-strong heavy products' range of tracked excavators.

According to the manufacturer, a major feature on the JS460 is the advanced management system which controls the efficient use of hydraulic power and which can be set up to suit the operator's individual needs.

At the heart of the JS460 is an Isuzu turbo-diesel engine. Other features include three-speed tracking, more powerful track motors, a high-speed slew motor for handling on steep slopes and a 10% hydraulic boost system for extra power at the dig-end.

Volvo machines are no strangers to quarrying and aggregate applications either.

Leiths of Aberdeen took possession of a 46t EC460BLC last year that underwent some modifications to handle an operation that involved feeding a mobile crusher with blasted material.

The changes comprised adding a heavy-duty 20mm belly plate along with 600mm double grouser track plates.

Powered by a six-cylinder turbocharged Volvo D12C engine, the manufacturer says the EC460B is fuel-efficient in that 306hp and maximum torque of 1,549Nm can be achieved at just 1,400rpm.

To enhance the machine's endurance in the tough conditions of a quarry, chrome pins are said to extend machine life, while internal cylinder cushioning protects the units from impact damage.

Moving on up the scale, Case produces an 80t machine - the CX800 hydraulic excavator - which thanks to a six-cylinder turbocharged engine offers an output of 331kW.

Case is keen to point out that a major feature of the machine is its hydraulic system. The control system includes four selectable working modes: pre-selectable attachment work mode; free swing; one-touch decelerator; and an auto idling system.

For ease of operation, control levers are located in a four-position tilting control console and a maintenance system, including self-diagnostics, has been incorporated into the machine. Greasing intervals can be extended for all attachment pins to 1,000 hours or six months, whichever comes first.

The CX800 has two boom lengths - a 7.25m mass excavation boom and a longer alternative 8.4m boom, as well as a selection of dipper arms - 2.95m, 3.64m, 4.4m and 5.6m. Buckets span from 2.2m3 up to 3.06m3.

In maximum configuration, when equipped with the 8.4m boom and 5.6m dipper arm, the CX800 is said to be capable of excavating to a depth of 10.64m with a dump height of 9.55m and a digging radius of 15.89m.

Maximum breakout forces with the mass boom and in power up mode are 38,200kg and 41,800kg respectively.

In Eire, a 50t Hitachi Zaxis 500LC machine has replaced a FH 400 to deal with blasted basalt, a particularly hard material to work with. Expected to work around 2,000 hours a year, the Zaxis 500lc takes the place of the FH 400 kit that had given the client 15,000 hours of good work.

When fitted with a 7m boom and 3.4m arm, the Zaxis 500lc offers a maximum digging reach of 12.05m and a digging depth of 7.6m. The standard bucket capacity is 2.1m3 for rock and 2.3m3 for other materials.

Eire is also the location for some Komatsu machines. According to Allen Smith, general manager of mines, quarries and special applications at Komatsu, there is a PC750 currently working in a stone quarry in Arklow for CRH, the world's fourth largest quarry group.

"The granite and basalt stone is glass hard," says Smith. "It is a very tough application and from the wear perspective gives the machines a real hammering."

Boasting a turbo-charged and intercooled engine that delivers 331KW, the PC750 also offers a shockless boom control designed to damp out the vibration and shock that is caused when the boom is stopped. As well as two different types of backhoe work equipment, a loading shovel version is also available.

Lastly, one name in the industry that has been conspicuously absent in terms of having a formal dealer is Fiat Kobelco. But although full dealership arrangements are yet to be confirmed, there is hope on the horizon with the recent announcement that Portishead-based Molson Holdings has been appointed Fiat Kobelco's distributor for most of England.

Among the machines affected by this change is the Fiat Hitachi 46+ EX455 which will now be badged Fiat Kobelco. However, according to Fiat Kobelco's sales and marketing vice president, Giuseppe Ferrulli, while the company is working on the development of machines above 45t, it has no plans to enter the mining sector above 90t. n