Performance of Grapple Skidder in Different Ground Inclinations

Diniz, Carlos Cézar Cavassin; Nakajima, Nelson Yoshihiro; Robert, Renato César Gonçalves; Dolácio, Cícero Jorge Fonseca; Silva, Franciele Alba da; Balensiefer, Daniel Francisco

doi:10.5380/rf.v49i1.55744

Cited by 6 publications

(5 citation statements)

References 5 publications

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“…The operational cycle of the grapple skidder is divided into machine elements, which are composed of displacement without load, displacement with load, loading of wood, and unloading of wood. For displacements, the driving speed and engine power are higher-whereas for loading and unloading wood, they correspond to slow movements or movements only made by the machine's grapple [45].…”

Section: Discussionmentioning

confidence: 99%

Measurement Time in the Evaluation of Whole-Body Vibration: The Case of Mechanized Wood Extraction with Grapple Skidder

Lima,

Minette,

Simões

et al. 2023

Forests

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The grapple skidder is a self-propelled forestry machine that is used for the extraction of trees in wood harvesting—commonly used in full tree systems. Moving this machine can expose operators to occupational hazards of physical origin, among which whole body vibration stands out. However, the measurement of this risk agent does not have a standard measurement time, being performed for periods of approximately 30 min—disregarding the time of the daily workday. In view of this, it was analyzed whether occupational exposure to whole body vibration transmitted to grapple skidder operators using different measurement times complies with the guidelines for preventative purposes. Thus, measurements of whole-body vibration were carried out along three orthogonal axes over a period of one hour and over a daily workday of eight hours—by which were measured the daily (8 h) vibration exposure for the l-axis and the vibration value. The acceleration values in the three evaluated axes were higher for the daily working day, denoting the influence of the measurement time. In addition, the vibration dose value resulted in values above the action limit for both evaluations; however, the daily workload was highlighted—indicating the presence of higher vibration peaks over a longer measurement time. Thus, the assertiveness and influence of measurement times over the daily working day for whole-body vibration transmitted to grapple skidder operators is evidenced.

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Section: Discussionmentioning

confidence: 99%

Measurement Time in the Evaluation of Whole-Body Vibration: The Case of Mechanized Wood Extraction with Grapple Skidder

Lima,

Minette,

Simões

et al. 2023

Forests

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“…The slope was then reclassified in 10-percent interval break classes (Table 3). Our literature review found 0-20% presenting optimal conditions for wheeled equipment, such as harvesters, grapple skidders and tractors [9][10][11]30], and slopes of 30-40% resulting in severe productivity costs and machine dysfunction [6,10,12,30,31]. Our model used 10-percent breaks to denote decreasing machine operability, as 10 percent was the upper limit of the most optimal slope conditions found for harvesting equipment [41] and was used in other GIS terrain analyses [9].…”

Section: Slope Hoi Criterion Methodologymentioning

confidence: 99%

“…These two shapefiles were then converted into two raster layers on a 1-10 scale. Paved roads, (including all highways, rural roads and residential paved streets) received the lowest cost (1), unpaved roads (i.e., access roads) the median cost (5), and roadless areas the highest cost (10). These raster layers were then combined using a raster calculator to create the final 1-10 cost raster.…”

Section: Cost Distance To Highways Hoi Criterion Methodologymentioning

confidence: 99%

“…Studies have demonstrated that slopes beyond 30% pose safety and environmental limits for wheel-based equipment [6][7][8][9]. Additionally, steep slopes exhibit harvesting productivity challenges as slopes exceeding 49% can reduce the productivity of wheeled skidders by as much as 45% [10], and travel time of wheeled skidders has been shown to increase linearly with cross slopes that exceed 4% [11]. Skidding of timber is possible on slopes exceeding 40%, however in such conditions and in downhill skidding the blockage of the wheels which could lead to a vehicle slippage is probable [12].…”

Section: Introductionmentioning

confidence: 99%

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The Harvest Operability Index (HOI): A Decision Support Tool for Mechanized Timber Harvesting in Mountainous Terrain

Phelps

Hiesl

Hagan

et al. 2021

Forests

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Forest operations have become increasingly reliant on mechanized harvesting equipment due to their increased production capacities in competitive markets. However, operating heavy machinery in mountainous terrain poses numerous operational and accessibility challenges from steep slopes, erosion risk, and poor road access. Geographic Information Systems (GIS) have effectively been used in various studies to identify areas in mountainous landscapes that pose no or reduced constraints for harvesting equipment operation. This study introduces the Harvest Operability Index (HOI), which rates a landscape for wheel-based equipment suitability (i.e., operability) and assesses its application in 13,118 ha of the Jocassee Gorges Natural Resource Area, situated on the Southern Blue Ridge Escarpment in Northwestern South Carolina, USA. The HOI incorporated slope, distance from roads, cost distance from major highways, primary Streamside Management Zones (SMZ), stand age, and soil suitability ratings for harvesting equipment operation. Upon reclassification to a 5-tier suitability scale, the HOI revealed 60% (7824 ha) of the case study area was in a Slope Exclusion Zone, or land area inoperable for wheel-based equipment due to steep slopes. Values of Very Poor and Poor Operability occupied less than 1% (213 ha) of land area whereas Moderate Operability values were 9% of the land area (1257 ha). Values of Good Operability occupied 18% (2442 ha) of the study area and values of Very Good Operability occupied 10% (1381 ha). These results reflected the challenges of mechanized harvesting in the study area due to a preponderance of steep slopes and poorly suited soil. Our model delineated areas of high equipment operability in two locations in the study area, despite a lack of recent logging activity around them. Results of the HOI analysis offer an accessible way for forest managers to better prioritize logging operations in areas that are highly operable and therefore more likely to possess lower overall harvesting costs, for wheel-based harvesting systems. The HOI can also be used as an asset for other forest management priorities, such as identifying highly operable areas that can use timber harvesting for fuel reduction and ecological restoration in fire-dependent forests. This model can be applied to various other regions where mountainous terrain poses a limitation to wheel-based harvesting equipment operation- and where wheel-based equipment is essential to advance the pace and scale of harvesting for ecological restoration.

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“…However, this factor had no significant effect on T cycle and P PMH , which possibly occurred because the maximum inclination observed in this study was only 9 degrees and, therefore, did not impose any major restrictions on equipment mobility. In clearcutting of a Pinus plantation with a lower mean individual tree volume, Diniz et al (2018b) reported that the wheeler skidder performance only tended to be negatively affected when the slope was above 26 degrees. On lesser slopes, the operator was able to compensate for increased cycle times on steeper areas by working more quickly on the flatter areas, thus avoiding any productivity reduction.…”

Section: Factors Affecting Performance and Modelling Of Productivitymentioning

confidence: 99%

Performance of a whole tree mechanised timber harvesting system when clear-felling a 32-year-old Pinus taeda L. stand

Pitz

Sampietro

Tonett

et al. 2021

NZJFS

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Background: Work studies are fundamental for the development and assessment of timber harvesting systems aimed at rationalising and improving forest management activities. Methods: This study evaluated the operational performance of a mechanised whole-tree harvesting system in 32-year-old Pinus taeda L. stands producing multiple timber products. A time and motion study at the cycle element level was conducted to evaluate the operational performance of each component of the harvesting system. Equations were developed to estimate the productivity of tree extraction activity with a wheeled skidder and log loading with a mechanical loader. Results: Tree felling with an excavator-based harvester had the highest mean productivity (135 m3 per productive machine hour), followed by tree extraction with a wheeled skidder (117 m3 per productive machine hour), while manually processing larger logs with a chainsaw had the lowest productivity (25.7 m3 per productive machine hour). Operator, extraction distance and mean log volume had a significant effect on the performance of different activities and were included in productivity models. Conclusions: Operational performance of equipment was variable and dependent on the effect of the operator, extraction distance and log volume. Thus, the use of models to estimate productivity considering such factors, coupled with reduced delays to increase utilisation of equipment, will contribute to the better management and planning of forest harvesting operations under the evaluated conditions.

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Performance of Grapple Skidder in Different Ground Inclinations

Cited by 6 publications

References 5 publications

Measurement Time in the Evaluation of Whole-Body Vibration: The Case of Mechanized Wood Extraction with Grapple Skidder

Measurement Time in the Evaluation of Whole-Body Vibration: The Case of Mechanized Wood Extraction with Grapple Skidder

The Harvest Operability Index (HOI): A Decision Support Tool for Mechanized Timber Harvesting in Mountainous Terrain

Performance of a whole tree mechanised timber harvesting system when clear-felling a 32-year-old Pinus taeda L. stand

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