Review of tethered equipment for steep-slopes operations
In BC’s coastal and southeastern interior mountainous terrain, harvesting second growth and smaller old-growth favours mechanized operations with steep slope machines as an alternative to costly and hazardous options such as hand falling, yarding, and helicopter. New ground-based harvesting machines available today can often exceed the upper slope limits established in safety codes in many countries throughout the world. One way to increase machine stability on steep slopes and potentially address the concerns of safety codes is by tethering harvesting machines by winch and cable to anchor positions such as tree stumps and other stationary equipment.
FPInnovations completed a limited review of tethered logging equipment used or currently under development in other countries. Results of this review showed that traction aid winches have been used to tether wheeled harvesters and forwarders for a number of years on slopes between 35 and 50% in central Europe. The primary application is with cut-to-length systems and the primary motivation behind these developments is to minimize soil disturbance although improved safety is also a consideration. The incorporation of winches to the wheeled drive systems of European production machines appears to be well refined. In New Zealand, the incorporation of winches to tracked drive systems similar to the tracked feller-bunchers currently operating in BC is in the development stage.
For more information contact Jack MacDonald.