1997 Volume 12 Issue 3 Pages 193-202
It is important to think much of yarding direction, that is, uphill or downhill, especially when yarding using a tower yarder. Yarding direction is also related to the layout of forest roads. In this study, we applied a newly-developed tower yarder altered from a power shovel to the downhill yarding as well as the uphill yarding. We compared the productivity, work loads and trouble frequency between uphill yarding and downhill yarding and tested the performance of this yarder when applied to downhill yarding. As a result, the productivity of downhill yarding was 61.4% of that of uphill yarding. Trouble frequency of downhill yarding was also higher than that of uphill yarding. Moreover, in downhill yarding, setup and removal took more time and work load of carrying lines was much higher. The results showed that this tower yarder could be applied to downhill yarding although the productivity, trouble frequency and work loads were less advantageous compared with uphill yarding.
