Skyline force estimation and limitation during cable yarding: A novel technical solution for within the carriage

Forest operations are one of the most dangerous jobs in all fields of industrial production. Studies have shown that cable logging accidents are frequently caused by inadequate safety factors. Due to the limited reliability of theoretical models of cableway installations and the inefficacy of load limiters of existing machines, technical solutions for continuous skyline tensile force monitoring should be developed. This work proposes a novel concept and model to determine the skyline tensile force in real time, based on a non-invasive measurement and evaluation system built into the carriage. This information can be harnessed to improve the logging operational safety automatically and dynamically. The concept was tested with the help of a miniature cableway setup. The mean absolute error between the predicted and measured skyline tension for a total of 55 measurements was 14 %, and the maximum error was 29 %. This confirms the validity of the proposed approach.