An analysis of cable tension in yarding operation by a Mobile-Yarder.

Abstract

In order to establish safe and efficient logging operations in yarding with tower-yarders, we analysed for the cable tension of mainline, haulbackline and the rotation frequency of drums on a tower-yarder with a running skyline cable system. We also investigated for the safety of tower-yarders according to the relation of loading weight and midspan percent deflection. The running of unloaded and loaded carriages was confirmed to be efficient under the condition of inter-locking. Setting an angle of 45 degrees to the yarding direction was an efficient way to method for the dragging and hoisting of mainline in the lateral yarding. In the running of unloaded carriages, not accelerating the rotation frequency of the drum was safe and efficient in both the condition of inter-locking and uninter-locking. However, accelerating the rotation frequency of drum was safe and efficient in the running of loaded carriages. This showed us that the yarding with tower-yarder is operated to safe yarding.