The Scottish Coal Company Limited Takes Four Liebherr Mining Machines

Delivery last month of the first two of four Liebherr R 9350 Litronic mining machines to The Scottish Coal Company Limited heralds one of the largest single orders for hydraulic excavators ever received by Liebherr-Great Britain Limited. After detailed and extensive machine comparisons over a considerable period of time, these massive 300 tonnes+ class hydraulic excavators have been selected by The Scottish Coal Company Limited - part of the Scottish Resources Group - as the main production equipment for the Broken Cross Open Cast Coal Site in Lanarkshire. Scottish Coal has taken two backhoe and two face shovel versions of the R 9350 Litronic; one of each are already at work with the remaining two scheduled for delivery to Broken Cross OCCS early in 2009.

The R 9350 Litronic weighs in at between 302 and 310 metric tonnes, depending on configuration. With backhoe and face shovel bucket capacities available from 15.30m³-20m³, this is a truly powerful production machine designed and built specifically for optimum outputs in quarrying, mining and opencast applications. For The Scottish Coal Company Limited, the R 9350 Litronic backhoe model is fitted with a 9.30m gooseneck boom, a 4.20m stick and a 17 cubic metres capacity bucket. The face shovel version has a 6.75m boom and a 4.20m shovel stick; the bottom dump bucket also has a capacity of 17 cubic metres. Bucket capacities on both configurations have been reduced to suit the application and the dump truck fleet on site. Initial workings show that the R 9350 machines are consistently filling Cat 777 and Terex TR100 dump trucks in three passes and in under a minute!

Power on the R 9350 Litronic is provided by a V12, turbo-charged, after-cooled Cummins engine model QSK45 which develops 1,120kW at 1,800RPM. The undercarriage is of 3-piece design, featuring box-type structures for centre piece and the side frames have stress-relieved steelwork componentry as standard. Two axial piston motors are fitted to each side frame and the planetary reduction gears are made by Liebherr. Track components feature D12 type, maintenance-free, forged double grouser pads and the track width on these particular machines is 850mm. Pressurised hydraulic cylinders with accumulators provide automatic track tensioning and the entire undercarriage sideframes are removable for transport.

Travel speeds are infinitely variable up to 3.1km/h. Swing drive hydraulics is via two Liebherr axial piston motors and the swing  gear is via Liebherr planetary reduction gears, with the sealed triple roller and internal toothed slewing ring again made by Liebherr. Slewing speed is up to 3.7RPM. The upper carriage is of torque-resistant design with the upper frame of box-type construction for superior strength and durability. Catwalks are situated in front of the pumps and in the counterweight and there is an additional emergency ladder in front of the cab; the left hand side catwalk is equipped with an hydraulically driven access ladder. Automatic central lubrication is fitted as standard. For regular checks, maintenance, servicing and refuelling, the R 9350 Litronic is equipped with an hydraulically actuated service door, complete with lighting, which gives excellent access at ground level for oil changes, replenishment of the automatic central lubrication system reservoir and fast, convenient refilling of the fuel tank which has been enlarged by 460 litres to a total capacity of 6275 litres.

The spacious ROPS/FOPS operator's cab is fully air-conditioned and the driver is protected against sunlight and noise by blinds, tinted windows and high quality sound insulation. The air-suspended and heated driver's seat can be adjusted to cater for the individual size and weight of the operator. The generously dimensioned glazing provides an excellent view of the work area and, because of its comfort and ergonomic layout, the cab provides ideal conditions for minimising operator fatigue and promoting optimum working efficiency throughout the shift. The electro-hydraulic twin multi-directional joystick controls are responsive and precise, making the machine easy and safe to operate. The driver can obtain up-to-the-minute engine and hydraulics system operational data via the Litronic system and its ergonomically designed monitoring display.

As would be expected of a powerful production machine of this size from Liebherr, the digging envelope produces some impressive figures. On backhoe, the maximum reach at ground level is 16.30 metres, maximum teeth height is 15.40 metres with a dump height of 10.20 metres. Optimum digging depth is 9.50 metres. Digging and breakout forces are 880kN and 1020kN respectively. On face shovel, maximum reach at ground level is 13.75 metres, maximum dump height is 11.20 metres and crowd length maximum is 5.20 metres. Optimum crowd force is 1300kN and, at ground level, 1040kN. Breakout force is 1060kN.

Additional operating safety features specified by Scottish Coal for their machines include supplementary xenon lighting and fully automatic fire-fighting equipment (both powder and foam). Each machine has been equipped with additional mirrors, travel alarms and three CCTV cameras with in-cab monitors for maximum all-round visibility and operating safety.

As part of their commitment to this impressive project investment, Liebherr-Great Britain has taken significant steps to provide comprehensive on-site after sales product support for Scottish Coal. Not only is there a two-storey site office and a warehouse containing spares to a value of around £2.5 million, but there is also a fleet of support vehicles, including a crane-equipped flatbed, a 4X4 service vehicle, an access platform and a Liebherr telehandler. Liebherr personnel dedicated to the project include an on-site after sales administrator, project supervisor and field service engineers to complete the product support picture.

For further information, please contact:                         

Liebherr-Great Britain Limited
Tel: 01767-602100
Fax: 01767-602110