Since July 2007, Cemex OstZement GmbH has been operating a large Liebherr R 9350 Litronic hydraulic excavator in Rüdersdorf, about 40 kilometres east of Berlin. Weighing approximately 300 metric tons, it is the biggest crawler excavator currently in use in Germany, and was acquired to excavate limestone without the use of explosives.

In order to achieve the exceptionally high penetration forces needed in direct quarrying work, the R 9350 Litronic working in Rüdersdorf is equipped with a particularly narrow folding shovel specially developed for the task, said an official spokesman.

It is 2.55 metres wide and holds 8.3 cubic metres. With this equipment the excavator, which is powered by a 1,120 kW (1,500 hp) Cummins engine, can develop a penetration force of up to 1,548 kN. This special configuration enables up to a million tons of limestone annually to be quarried directly.

Limestone has been quarried in Rüdersdorf for more than 750 years. The current site is 4,000 metres long, up to 1,000 metres wide and up to 120 metres deep. Since work takes place in some cases only about 60 metres from a residential area, conventional blasting methods are no longer permitted on account of noise emissions and earth tremors.

Noise emissions from direct excavation work also have to be kept to a minimum, and the R 9350 Litronic is therefore equipped with a special noise suppression package, including side-mounted noise absorbing boxes and a special final-stage exhaust silencer.

The standard version of this 300 metric-ton excavator is equipped with folding shovel holding 18 cubic metres of material at a specific weight of up to 1.8 t/sq. m. The driver's cab of the R 9350 Litronic excavator is identical in size, equipment and ergonomic layout to the R 996 Litronic, Liebherr's largest hydraulic excavator with a service weight of 670 metric tons.

The cab is fully air conditioned and the driver protected additionally against direct sunlight and noise by Venetian blinds, tinted windows and a high standard of insulation. The seat can be adjusted to suit the driver's stature and weight. Large-area cab windows provide an excellent view of the work area.

The R 9350 Litronic's electronic pilot control system makes operation of the excavator simple, safe and precise. The driver can call up all the current operating data at any time on an ergonomically positioned display.

The engine and pump compartment, also of generous size, enables service personnel to work while standing erect, and offers them excellent access to driveline components for maintenance. Their work is also simplified by the layout of the passage between the engine and the counterweight.

All service points on the R 9350 Litronic can easily be reached, and are grouped together in central positions wherever possible. For example, the service flap at chest height in the rear section of the superstructure can be actuated hydraulically and provides the best possible access to the connections for lubricants, other oils, oil changes, windscreen washer fluid and fuel. When the service flap is closed, the risk of damage to the connections is reliably avoided.- TradeArabia News Service