COMPARISON OF CLAMPED AND UNCLAMPED CARRIAGES FOR DOWNHILL YARDING INPARTIAL CUT SITUATIONS

A three-dimensional model of a running skyline yarding system was util ized to test the technical feasibility of a clamping carriage for impr oving control of carriage position during lateral yarding on downhill sections of yarding corridors. A field trial was used to compare an ex perimental clamping carriage with a traditional nonclamping carriage i n a two-dimensional situation. The results of both modeling and field trials showed that the clamping carriage is feasible and beneficial. W hen using a clamping carriage, precautions must be taken to avoid over tensioning of the section of the haulback between the carriage and th e tailhold.