Time Prediction Models and Cost Evaluation of Cut-To-Length (CTL) Harvesting Method in a Mountainous Forest

Ghaffariyan, Mohammad Reza; Naghdi, Ramin; Ghajar, Ismael; Nikooy, Mehrdad

doi:10.1007/s11842-012-9204-4

Cited by 25 publications

(22 citation statements)

References 6 publications

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“…There are many studies in the international literature that evaluated time consumption and productivity of motor-manual tree felling and processing and modeled them as a function of operational variables [11]. Productivity estimates from this study are generally in line with those reported by other case studies, which evaluated the productivity of tree felling when dealing with very large trees [18,66], following the general concepts of the "piece-volume law" [9]. In addition, the fuel and lubricant consumptions were rather low in this study, supporting similar facts reported in the scientific literature [67].…”

Section: Discussionsupporting

confidence: 75%

Workload, Exposure to Noise, and Risk of Musculoskeletal Disorders: A Case Study of Motor-Manual Tree Feeling and Processing in Poplar Clear Cuts

Cheţa

Marcu

Borz

2018

Forests

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Abstract:Motor-manual tree felling and processing (MMTFP) is among the most used options in timber harvesting operations and it is formally known to be a heavy job exposing the workers to safety hazards and harmful factors. Nevertheless, both workload and exposure depend on many operational, organizational, and worker-related parameters. Few studies have evaluated the ergonomics of such operations and fewer have been carried out using an integrated approach able to collect and interpret data for more than one ergonomic parameter. This study evaluated the ergonomic conditions of task-based MMTFP operations in flatland poplar forests by the means of workload, exposure to noise, and risk of musculoskeletal disorders. A fully-automatic approach was used to collect and pair the heart rate and noise exposure data that was complemented by video recording to collect postural data. Workload experienced by the worker was evaluated in terms of heart rate reserve (%HRR), indicating a heavy load during the productive time (%HRR = 46%); exposure to noise was calculated at the task and study level, exceeding (LAeq = 97.15 dB(A); L EX,8h = 96.18 dB(A)) the acceptable limits; and the risk of musculoskeletal disorders was evaluated using the concepts and procedures of the Ovako Working Posture Analysis System, indicating a high postural risk index (PRI = 275), which can cause musculoskeletal disorders (MSD). For more conclusive results, the research should be extended to cover the relevant variability factors.

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Section: Discussionsupporting

confidence: 75%

Workload, Exposure to Noise, and Risk of Musculoskeletal Disorders: A Case Study of Motor-Manual Tree Feeling and Processing in Poplar Clear Cuts

Cheţa

Marcu

Borz

2018

Forests

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“…Among the numerous factors which influence time consumption in tree felling operations, the research conducted so far has taken into consideration the species (Ghaffarian and Sobhani 2007), the distance between trees and the harvested stand basal area (Kluender and Stokes 1996;Wang et al 2004), the ground slope and route inclination where workers circulate among trees (Ghaffariyan et al 2012), the change in the technical felling direction as opposed to the natural felling direction of trees (Azarnoush and Fathi 2014), the treatment used -clear-cut, shelter wood, even-age selection, uneven-age selection (Lortz et al 1997) and the volume of marked trees. Snow, and especially snow thickness, may increase time consumption.…”

Section: Introductionmentioning

confidence: 99%

Time consumption and productivity in manual tree felling with a chainsaw – a case study of resinous stands from mountainous areas

Câmpu¹,

Ciubotaru²

2017

Silva Fenn.

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Highlights• An important preoccupation in sustainable logging management is represented by the analysis of work time structure and productivity level in manual tree felling with a chainsaw.• Sound knowledge of the factors which influence work time allows better planning of harvesting operations so that deadlines could be met and damage to forest ecosystems be minimized. AbstractThe purpose of this research is to establish time consumption and productivity when using Husqvarna 365 chainsaw for resinous tree felling in mountainous regions. The research was conducted in the Romanian Southern Carpathians, in two mixed spruce (Picea abies (L.) H. Karst.) and fir (Abies alba Mill.) tree stands (S1 and S2). Only one team of workers, made up of a feller and an assistant, was used in the felling operation. This was divided into nine specific stages for which work times were measured. Work time structure used here includes WP -workplace time (PW -productive work time; SW -supportive work time, NT -non-work time) and NW -non-workplace time. The results indicated a productivity of 10.138 m 3 h -1 (4.55 tree h -1 ) in S1 and of 11.374 m 3 h -1 (4.33 tree h -1 ) in S2. Work time structure was WP 88.61% (PW 19.59%; SW 33.88%; NT 35.14%) and NW 11.39% in S1 and WP 83.77% (PW 17.66%; SW 30.73%; NT 35.38%) and NW 16.23% in S2. The results obtained showed that the power function best describes the relationship between productivity expressed by tree h -1 and breast height diameter (dbh) (R 2 = 0.89 in S1 and R 2 = 0.94 in S2). When productivity is expressed by m 3 h -1 the results obtained in the case of power, exponential and linear functions are comparable (R 2 = 0.65 to 0.67 in S1 and R 2 = 0.81 to 0.92 in S2). Productivity is also influenced by stump diameter and the distance between trees. Their influence on productivity was emphasized by linear regression equations.

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“…Therefore, one of the important issues in harvesting operations is the amount of wood which may be potentially lost due to the use of certain equipment or operational procedures. While the level of mechanization differs from region to region depending on forest types, wood species, management methods, terrain, and climatic conditions (Vusić et al 2013), the use of motor-manual tree felling is still very common in Europe (Brachetti Montorselli et al 2010;Gerasimov and Seliverstov 2010;Zinkevicius et al 2012;Borz and Ciobanu 2013) and around the world (Wang et al 2004;Behjou et al 2009;Mousavi et al 2011;Balimunsi et al 2012;Ghaffariyan et al 2013;Jourgholami et al 2013;Nikooy et al 2013). On the one hand, it is well known that by using a chainsaw in tree felling operations, a certain quantity of wood would be lost as a consequence of the cuts performed in order to fell the tree (Oprea and Sbera 2004).…”

Section: Introductionmentioning

confidence: 99%

Small Gains in Wood Recovery Rate when Disobeying the Recommended Motor-Manual Tree Felling Procedures: Another Reason to Use the Proper Technical Prescriptions

Borz¹,

Ignea²,

Vasilescu³

2014

BioResources

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An efficient wood harvesting activity aims to fully recover wood as a measure to increase the profit, but safety prescriptions should be obeyed each time when harvesting operations are performed. A study was carried out in three forest compartments in order to determine whether the actual tree felling procedures match the recommended ones and, if not, to compare how the used practices may affect the wood recovery when felling trees using a conventional undercut. The study yielded significant statistical differences between the recommended and used cuts dimensions, as well as significant differences between the procedures used by three studied work teams. The general trend was to make deeper cuts and smaller openness when performing undercuts. Since one reason for such tree felling procedures may be the increment of wood recovery rate, we conducted a comparative analysis between the potential volume loss in the two mentioned scenarios, and only small differences were found; this should discourage the use of such tree felling techniques. The present estimates suggest that the potential volume loss was 0.89 to 1.20% of the harvested volume, yielding small gains in terms of wood recovery if compared to that of 1.74 to 3.17% corresponding to the recommended practices.

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Time Prediction Models and Cost Evaluation of Cut-To-Length (CTL) Harvesting Method in a Mountainous Forest

Cited by 25 publications

References 6 publications

Workload, Exposure to Noise, and Risk of Musculoskeletal Disorders: A Case Study of Motor-Manual Tree Feeling and Processing in Poplar Clear Cuts

Workload, Exposure to Noise, and Risk of Musculoskeletal Disorders: A Case Study of Motor-Manual Tree Feeling and Processing in Poplar Clear Cuts

Time consumption and productivity in manual tree felling with a chainsaw – a case study of resinous stands from mountainous areas

Small Gains in Wood Recovery Rate when Disobeying the Recommended Motor-Manual Tree Felling Procedures: Another Reason to Use the Proper Technical Prescriptions

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