Abstract
In order to establish the optimum yarding operation system with a mobile tower-yarder, yarding operation system and optimum setting-up spacing, optimum lateral yarding distance, optimum yarding distance were investigated. In correlation of lateral wire traction distance and wire traction time, downhill traction and thinning operation than uphill traction and clear cutting were more fast. In correlation of lateral yarding distance and time, an obstacle by residual trees is shown largely in a case of the line thinning yarding operation. In correlation of yarding distance and time, uphill yarding than downhill yarding is more fast. Correlation of lateral yarding distance and cycle time in the line thinning yarding and the clear cutting yarding is low and it's deviation is shown large. Downhill yarding operation of the clear cutting yarding has greatly affected the cycle time in correlation of yarding distance and cycle time. Therefore, it is effective to slacken the wire rope and to reduce an obstacle by residual trees in the line thinning yarding operation and to consider the direction of wire traction for the lateral yarding. It was effective to establish the yarding operation for uphill yarding, and it was profitable to make longer the yarding distance in the line thinning yarding and the uphill yarding. Because the setting-up spacing of skyline have affect on the yarding operation efficiency and productivity, optimum setting-up spacing and lateral yarding distance is important factor. In the line thinning yarding operation and the clear cutting of this investigation location, optimum setting-up spacing is 18.9m and 10.5m, respectively. It was effective to yard three and three of right and left. And, when the setting-up and dismantling time with Tower-yarder is applied to 60 minutes in this investigation location, the optimum lateral yarding distance in the line thinning yarding and the clear cutting yarding is shown 6.7m and 7.2m, respectively, in a case of that the maximum yarding distance is 60m, and the optimum yarding distance in the line thinning yarding and the clear cutting yarding is shown 27.2m and 22.6m, respectively, in a case of that the maximum lateral yarding distance is 10m