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Biomass Logistics
Published in Jay J. Cheng, Biomass to Renewable Energy Processes, 2017
In a tree-length system, trees are harvested using a feller-buncher which cuts a tree using a large spinning disk saw and then lays the tree in a pile or bunch. Next, a skidder uses a large grapple to pick up the tree piles at one end and drag them to a central location at the logging site called the logging deck. Along the way, skidders may push the trees in reverse though a delimbing gate to break off the limbs and tops. If a delimbing gate is not employed, the limbs and tops will be removed either manually with a chainsaw or using a pull through delimber and loader. The loader will pick individual trees from the pile and pull them to the deck by the skidder. The loader can sort the trees according to size, perform the delimbing and topping operations, and place the trees on the truck for shipping.
Assessing productivity and cost of timber harvesting during longleaf pine ecosystem restoration
Published in International Journal of Forest Engineering, 2023
Jacob Murray, Patrick Hiesl, Donald Hagan, Robert Baldwin
We found a significant decline in the utilization rate of our knuckle-boom loader because machine operations were only observed when machines were on, and only one operator would control the feller-buncher. Therefore, if the feller-buncher was active, the skidder operator would frequently switch between loading and skidding depending on wood availability and trucking demands. This increased the idling time for the grapple skidder but was more influential on the loader. If the primary operator was operating the knuckle-boom loader, the feller-buncher was most likely not running, and the skidder operator was exclusively operating that machine. Thus, the feller-buncher experienced the least amount of idling time because if it was not in use, it was off, and the knuckle-boom loader experienced the greatest amount of idling time because it was continually in use or waiting to be used.
Productivity measurement of New Zealand forest harvesting sector using the DEA-Malmquist index
Published in International Journal of Forest Engineering, 2020
This study utilizes the Forest Growers Research (https://fgr.nz/) benchmarking database managed by the University of Canterbury, New Zealand that contains system, stand, and terrain factors on plantation forest harvesting operations in New Zealand from 2008 to date. An important uniqueness of the database is that it offers data on individual forest harvesting operations thus offering higher variability unlike aggregated data with reduced variability and potentially lower efficient frontier (Helvoigt and Adams 2009). The data were screened to remove entries with missing or invalid data/outliers. A panel data for the year-to-year analysis were obtained from the database comprising 73 DMUs (i.e. individual forest harvesting operations) per year from 2009–2018. This resulted in a total of 730 DMUs for the entire study period of 10 years from 2009–2018. While the harvest operations in New Zealand are mostly clear fell, about 62% of the harvest were ground-based while 38% were cable logging with the felling method for the operations evenly split between chainsaw (50.5%) and mechanized felling (49.5%). Extraction machines utilized in the operations include grapple skidder, cable skidder, forwarder, hauler, shovel, swing yarder, and tractor. However, grapple skidder was the most common extraction method as it accounted for 45% of all extractions for the 730 harvest entries.
Application of spiroergometry to determine work metabolism related strain in the course of cable work with a mini forestry crawler
Published in International Journal of Forest Engineering, 2020
Ferréol Berendt, Stephan Hoffmann, Dirk Jaeger, Stephan Prettin, Janine Schweier
Winching operations are usually conducted using the winch of a skidder; a forestry fitted tractor; or a remote-controlled mini forestry crawler. In Southwest Germany, the latter has become increasingly popular in forest operations. Reasons are the high maneuverability of mini forestry crawlers and their versatile uses, as well as the economic benefits of using a passenger car trailer for transportation to and from work sites. Moreover, mini forestry crawlers have low fuel consumption, which results in low operational impact (Tschannen 2013; Berendt et al. 2018). However, pulling out a steel cable from winch to felling site is highly physical work (Pandur et al. 2012; Magagnotti et al. 2016) that places strain on forest workers that is not present in conventional fully mechanized operations. Therefore, in order to conduct a comprehensive sustainability assessment of an improved work system, consideration of human factors through complex ergonomic rating approaches is also required (Zink 2014).