Delimbing and Cross-cutting of Coniferous Trees–Time Consumption, Work Productivity and Performance

Ciubotaru, A.; Câmpu, Răzvan V.

doi:10.3390/f9040206

Cited by 11 publications

(11 citation statements)

References 15 publications

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“…Working time structure has been studied by numerous researchers, because working time consumption depends on many factors. Câmpu and Ciubotaru [34] and Ciubotaru and Câmpu [35] studied timber harvesting using chainsaws in Carpathian mountain stands. Wójcik and Petrów [36] investigated the impact of loggers' experience on productivity and labour consumption during the harvesting of timber from mature stands.…”

Section: Introductionmentioning

confidence: 99%

The Impact of Season on Productivity and Time Consumption in Timber Harvesting from Young Alder Stands in Lowland Poland

Grzywiński

Turowski²,

Naskrent

et al. 2020

Forests

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The purpose of this study was to establish the impact of season on productivity, labour consumption, and working time structure during timber harvesting from young alder stands (Alnus glutinosa Gaertn.). An early thinning process was performed in summer and winter in pure alder stands (38 and 40 years old) in the Płaska Forest Division (NE Poland). The felling and processing operations were performed by experienced loggers using the cut-to-length (CTL) system, and forwarding with manual loading and unloading involved the use of a Zetor 7045 (65 HP) farming tractor and trailer. In both summer and winter, the loggers spent most of their labour time on felling trees (approx. 23%) and bucking (approx. 36%). Assistant loggers spent most of their time stacking logs (49.2% in summer and 58% in winter). The most time-consuming activities in forwarding were loading, unloading, and transportation. The average time consumption of tree felling and processing amounted to 0.36 ± 0.11 h/m3; that of forwarding was lower, at 0.24 ± 0.07 h/m3. No statistically significant differences in the labour consumption of tree felling were identified between winter and summer (p = 0.863). For forwarding, labour consumption was significantly higher in winter (0.28 h/m3) than in summer (0.19 h/m3, p = 0.001). Average productivity was 3.02 ± 1.09 m3/h for tree felling and 4.76 ± 1.80 m3/h for forwarding. The productivity of felling was similar in winter (2.83 m3/h) and in summer (3.22 m3/h). For forwarding, productivity was significantly higher in summer (5.70 m3/h) than in winter (3.81 m3/h, p < 0.01).

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Section: Introductionmentioning

confidence: 99%

The Impact of Season on Productivity and Time Consumption in Timber Harvesting from Young Alder Stands in Lowland Poland

Grzywiński

Turowski²,

Naskrent

et al. 2020

Forests

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“…It is well known in literature in the field that, under the same working conditions, different work teams have a different work productivity [31]. The operator greatly influences work productivity in most forest works [32,39]. Actually, out of all factors that influence time consumption, the one most difficult to keep constant is the human factor [32,39].…”

Section: Field Data Collectionmentioning

confidence: 99%

“…The operator greatly influences work productivity in most forest works [32,39]. Actually, out of all factors that influence time consumption, the one most difficult to keep constant is the human factor [32,39]. Table 3.…”

Section: Field Data Collectionmentioning

confidence: 99%

“…As far as operations performed with the chainsaw are concerned, the highest number of studies were conducted with respect to felling, delimbing, and cross-cutting. The main purpose of these studies was to determine injury risk and the impact of working conditions on workers' health, on the one hand, [8,15,[23][24][25], and time consumption and work productivity, on the other hand [26][27][28][29][30][31][32]. Unlike tree felling, the felling of hung up trees cannot be planned as the situation occurs accidentally.…”

Section: Introductionmentioning

confidence: 99%

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The Felling of Hung Up Trees—A Work Safety and Productivity Issue

Câmpu

Bratu

Ciocîrlan

2020

Forests

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Research Highlights: The felling of hung up trees is considered by literature in the field as an activity with a high injury risk. The low work productivity in the felling of hung up trees is wrongly cited by workers in order to justify various more or less safe work techniques. Background and objectives: The purpose of this paper was to determine work productivity in the felling of hung up trees when this activity has a well-defined structure with stages and specific activities that would allow workers to assess injury risk correctly. In addition, this paper aims to identify the moment when workers should give up the manual felling of hung up trees with a hand winch and start using specialized logging equipment. Materials and methods: The research was conducted in the Eastern Carpathians in a spruce (Picea abies (L.) H. Karst.) tree stand where clear cutting normally takes place. A single team of workers was used consisting of two chainsaw operators—a main one and a secondary one. This team had a high level of qualification and experience in the operations performed. For the felling of hung up trees, the technique based on rotating the tree around a pivot with a hand winch was used. Time was measured in seconds by using the continuous time study method. Results: The results indicated that work productivity decreases with the number of times the traction line needs to be repositioned. It decreases from 3.477 trees·h−1 (in trees where no repositioning is necessary) to 1.402 trees·h−1 (when the repositioning takes place twice). In trees that needed the repositioning of the traction line, safety rules were broken in the following ways: crossing over the tensioned cable of the traction line, the main chainsaw operator being positioned inside the triangle formed by the hung up trees and the anchorage points of the pulley and the hand winch as well as the operator being positioned very close to the hung up tree stem base while the latter is being tied. That is why, if the repositioning of the traction line is necessary, the question is—would it be better to give up the manual felling of hung up trees and start using specialized equipment? Conclusion: The felling of hung up trees must be regarded and understood, first and foremost, through the perspective of reducing injury risk and protecting workers. Thus, the work productivity of 3.477 trees·h−1 can be considered acceptable for trees that need no extra repositioning of the traction line or when the time consumed does not go over 17 min·tree−1.

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“…cutting efficiency) and duration of felling, and cross-cutting in motor-manual operations using chainsaws (e.g. Câmpu and Ciubotaru 2017;Marenče et al 2017;Ciubotaru and Câmpu 2018). However, only a limited number of studies are available on mechanised harvesting using CTL harvesters.…”

Section: Introductionmentioning

confidence: 99%

Cutting duration and performance parameters of a harvester’s sawing unit under real working conditions

2020

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Amongst all the working elements of single grip harvesters, the working elements of felling and processing play an important role within the cut-to-length (CTL) harvester’s working phases. This includes the felling cutting and cross-cutting of stems within the felling and processing operation. The detailed investigation of such individual machine activities may help to analyse and improve the performance of forest machines. The objective of this study was to investigate the cutting duration and other performance parameters, including the fuel consumption, of a CTL harvester’s sawing unit under real working conditions. Detailed information on the felling cutting and cross-cutting performance was collected at short intervals using CAN bus data of two single grip harvesters in final felling from two different sites in Eastern Finland. As a result, models for effective time consumption in the work phase of cutting as a function of stem size were developed, both for felling cutting and cross-cutting. Felling cutting and cross-cutting durations were somewhat identical until the cutting diameters of 400–450 mm, depending on the site. Thereafter, the cutting time difference increased and was higher in felling cutting. At the site with large diameters of 550–650 mm, the difference varied between 15% and 28%, between the comparisons of formulae. In addition, other performance parameters, including the respective fuel consumption of this working phase, were part of the study. The study revealed a higher hourly based fuel consumption for the entire guide bar movement time compared to the pure cutting time in cross-cutting with stem diameters below 400 mm. Detailed knowledge of the performance of the sawing unit’s activities might help the planning process of future studies, as well as support the future development of efficient and intelligent machinery.

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Delimbing and Cross-cutting of Coniferous Trees–Time Consumption, Work Productivity and Performance

Cited by 11 publications

References 15 publications

The Impact of Season on Productivity and Time Consumption in Timber Harvesting from Young Alder Stands in Lowland Poland

The Impact of Season on Productivity and Time Consumption in Timber Harvesting from Young Alder Stands in Lowland Poland

The Felling of Hung Up Trees—A Work Safety and Productivity Issue

Cutting duration and performance parameters of a harvester’s sawing unit under real working conditions

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