Differentiated Processing in Motor Manual and Mechanized Logging

This paper presents results from comparative studies of conventional Scandinavian shortwood processing vs a differentiated processing method. The latter signifies processing only sawlogs at the logging site. Pulpwood and forest fuel are transported off the site as undelimbed tree sections. The objective of the studies was to contribute to the development of new methods suitable for integrated harvesting of forest fuel and conventional forest products for industrial use. Study methods include direct measurement of workpiece and output and a precise indirect time measurement and working pattern evaluation, both by using videogrammetry. Both a motor manual and a mechanized system was studied. For motor manual logging, differentiated processing was found to be recommendable for ergonomical, economical, and efficiency reasons. For the studied mechanized system – single-grip harvester in thinning – the productivity of differentiated processing did not match conventional logging. The main reason for this seems to be that crane handling and not processing is the weak point of the harvester system. According to the study, the amount of crane handling increased when differentiated processing was applied in mechanized logging. The output of forest fuel was markedly lower than that of the motor manual version.