Australian distributor Semco has recently released the Astec RT1160 trencher with rubber tracks in place of wheels. The track system retains the steering of a wheeled machine (for reduced ground disturbance) with the low ground pressure of a tracked machine. It has proved itself in cable ploughing applications in North America, where it applies greater drawbar pull than a wheeled machine without introducing wheel spin. It also allows the machine to work in soft soils and boggy ground that would stop a wheeled machine. On a larger scale, Ditch Witch Australia has introduced the Tesmec brand of trenchers to the Australian market. A bucket wheel trencher has been sold to AJ Lucas while Redline Contracting (Cleveland, Queensland) has bought an M5 trencher with mechanical chain drive. The M5 is Tesmec’s first mechanical chain drive machine, but a smaller machine of this type is already in planning. The mechanical drive with slow chain speed, combined with the tooth pattern on the chain which has a relatively small number of teeth, is designed to maximise the force applied to the rock and the contact time between the tooth and the rock, to fracture the rock rather than grind it.
