The four-line model of the Triangular Running Skyline system: Scale model test

The four-line model of the Triangular Running Skyline (TRS) system is the theory generalized from the previous TRS theory to treat the main and slack-pulling lines separately. The previous theory,i.e., the three-line model, treated the main and slack-pulling lines as a single line to simplify the solution. The first part of this study developed numerical procedures for the four-line model. In this paper, to empirically ascertain the accuracy of the four-line model theory, a series of static equilibrium tests was carried out using a reduced scale model of the TRS system. The result proved that the theory of the four-line model has the same accuracy as that of the three-line model. However, the result also proved that the carriage may have to be located lower than the designated height. Thus, it has been proved that the development of a certain adjusting method is necessary to move the carriage of the TRS system closer to the designated point. A part of this paper was orally presented at the Second Annual Meeting of the Japanese Forest Engineering Association, November 18, 1995, Tokyo. This English title is a tentative translation from the original Japanese by the authors of this paper.