Static Equilibrium of the Triangular Running Skyline System: A Three Dimensionally Movable Cable System
Authors
Y. Suzuki
Kyoto University, Kyoto, Japan
E. S. Miyata
University of Washington, Seattle, USA
S. C. Iverson
University of Washington, Seattle, USA
Abstract
The static equilibrium of the Triangular Running Skyline (TRS) system was tested using a reduced scale model to see if and to what degree the carriage location and line tensions at the spars differed from the theoretically predicted ones. TRS is one of the promising environmentally sound methods for accessing the forest. The model has a span of three meters so that all conditions can be dealt with on a laboratory basis. In this test, line lengths of this model system were designed to have unstretched lengths derived from the theory of elastic catenary, to have the carriage set at a designated position. Then, the measured positions of the carriage and line tensions were compared with those derived from the theory. The results proved that the horizontal positioning error of the carriage is smaller than its vertical positioning error and that the carriage tends to be lower than its theoretical value. The greater theoretical line tension causes the error in line tension to be larger and the line tension tends to be lower than the theoretical value. In order to obtain more accurate positioning of the carriage, it is necessary to take loosening of lines, guy lines of spars, etc. into account.
