- Hiesl, Patrick
University of Maine Graduate School
The forest industry is a highly cost intensive business and therefore effective management is necessary. Information about productivity and time consumption of harvesting equipment in a variety of stand and site conditions can help operation managers to be efficient. In the state of Maine there have not been any productivity related publications within the past 25 years. Due to this lack of information and the need for information on productivity, especially in small diameter stands, the presented research developed. The focus of this study is on whole-tree harvesting systems including feller-buncher, grapple skidder and stroke delimber, as well as cut-to-length harvesting systems consisting of harvester and forwarder.
Time and motion studies have been carried out during the summer of 2012 during the observation of seven whole trees and five cut to length operations. All operations were carried out in high density, small diameter wood stands common to Maine and this region. In addition to time, tree volume and residual stand damage data was collected. Results of this study present a new model for feller-buncher harvesting time prediction, which includes an algorithm that accounts for the specific harvesting conditions in this region. Further the results show the variation in productivity for the remaining four pieces of equipment. Predictive models are presented for productivity and time estimation. the analyses of the influence of the combination of operator, machine and site conditions shows that this influence explains between 5% and over 50% of the variation in data for individual machine types (e.g. feller-buncher, grapple skidder). A residual stand damage analysis carried out for the harvesting machines only (feller-buncher, harvester), shows that the damage ranges from less than 10% to over 50% of the residual trees. With the small sample size no significant differences could be found between the two harvesting machines and the stand damage caused.