At the 2010 ‘Bauma’ trade fair, Liebherr is exhibiting the R 924 Compact Tunnel, a new special-purpose excavator for tunnelling work. It weighs 32.4 metric tons, is driven by a 130 kW (176 hp) Liebherr diesel engine and has a crowding length of up to 2.50 metres. The maximum tearout force is 135 kN, the maximum breakaway force is 85 kN. As well as operating with a spoil shovel, the R 924 Compact Tunnel can be equipped with a hammer of up to 1.7 metric tons or a rotary cutter in the up to 80 kW (108 hp) power-input category.

Thanks to its short-tail design, the R 924 Compact Tunnel is exceptionally compact and can be used with all three frequently-used tunnel driving methods. It can excavate cross-tunnels after the tunnel driving machine has moved on; if blasting is used, it can produce the final profile, or it can excavate spoil from the tunnel face directly. In view of the limited working space available when tunnelling, the short-tail concept with its low rear-end slewing radius possesses significant advantages.

The tunnelling excavator’s cab is protected to FOPS and FGPS standards. The windows at the right and to the rear are glazed with polycarbonate, for a high level of impact protection and excellent optical performance. As an optional extra the complete cab can be ordered with polycarbonate windows.