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Effectiveness of scots pine longwood timber cut-to-length (CTL) logging

100%

Porter B.

Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria

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2012

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tom 11

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nr 3

In the last two decades the amount of timber harvested in Poland has almost doubled. On the other hand, in some regions of the country a decrease in the number of people willing to work in the forest can be observed. In such a situation, multioperational machines like harvesters and forwarders are being more frequently used in skidding and logging process. These machines operate mainly in the short-wood system, in which large- and medium-sized timber is bucked out of the butt part of the stem in form of logs, while in four of sections in the top part. Buyers are reluctant to buy cut-to-length (CTL) timber because of the widespread belief that timber produced as logs has a greater volume in comparison with longwood one. This paper presents preliminary results of research on CTL logging of large-sized pine longwood timber. Volume and value of timber provided in form of longwoods and logs were compared. The study was conducted in The “Lasy Mazurskie” Forest Promotional Complex (N Poland). The analysis showed that volume of CTL timber is usually smaller compared with the longwood one by a few percent, while the value is larger by several percent.

2

Selected workload elements of the machine operators working in timber harvesting. Ergonomic point of view

100%

Nowacka W. L.

Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria

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2012

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tom 11

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nr 3

Machine timber harvesting makes it possible to reduce substantially factors which have adverse impact on human health and which accompany manual-machine timber harvesting, presently predominating in Poland. The ergonomic factors classified into four following groups may be recognised as the main preconditions related to work with multi-operation machines: physical load – small energy expenditure, a very high value of repetitiveness and static efforts; mental load – high level of monotony, aesthenopia, a high level of stress; environmental load – significant limitation of hazard to operator’s hearing, work under conditions of thermal comfort, reduced vibration hazard; organisational load – a relatively low risk of work – related accidents, making it possible to perform work operations throughout the year, continued employment, high work autonomy, independence in decision making, a possibility for workers to organise themselves and form work teams. The paper presents subjective perceptions and opinions of fifty operators of specialised machines with respect to their work load. Almost a half of the respondents worked over 50 hours per week. One third found their work conditions difficult. Work pace was recognised as particularly challenging to their well-being as merely 6% of respondents found it relatively low. Additionally, the selected elements of assessment of workstations under study in terms of energetic costs and noise load is discussed The maximum energy expenditure of a machine operator is related to operations performed outside a cab: tuning up, routine maintenance, and repairs. Energy expenditure related to work inside a cab did not exceed 14 kJ/min. Noise level in a low-noise cabin was lower than sixty dB(A). Use of machines to a large degree eliminates important health-adverse factors accompanying combined machine-driven and manual timber harvesting, however, it creates conditions favouring occurrence of new ailments and diseases, totally different from those which have been recorded so far in forestry.

3

Damages to the surface layer of soil during timber harvesting using the equipment aggregated with farm tractors

86%

Kulak D., Sowa J. M., Stanczykiewicz A., Szewczyk G.

Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria

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2012

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tom 11

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nr 2

In the study, impact of three devices aggregated with farm tractors on forest soil was compared – FRANSGARD 6000 GS cable winch and two processors – NIAB 5-15 and HYPRO 450. The basic difference between the above mentioned machines consists in the fact that the cable winch skids debranched tree stems while processors skid the whole trees, including their tree-tops. The percentage of soil injured in late pine stand thinning reached, respectively: 1.2%, 2.2% and 5.5%. The analysis of significance of differences in Ug indicators characterising the damages induced has shown that only the indicator computed for HYPRO processor is significantly higher than the others. However, as the simulation performed has confirmed, appropriate thickening of skidding routes enables to achieve a comparable level of damages for all the machines examined. Taking into account the impact on forest soil, application of processors aggregated with farm tractors can be recommended for thinning stands.

4

Planowana wielkosc pozyskiwania drewna na Bialorusi w 2006 r.

86%

W O.

Biuletyn Informacyjny Ośrodka Badawczo-Rozwojowego Przemysłu Płyt Drewnopochodnych w Czarnej Wodzie

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2006

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tom 46

|

nr 1-2

85

5

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Effect of kerf execution correctness during felling with internal combustion chain saw on direction of tree fall

86%

Wojcik K.

Annals of Warsaw University of Life Sciences - SGGW. Agriculture

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2014

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nr 64 Agric.Forest Eng.

6

Pozyskanie drewna w Niemczech

86%

W O.

Biuletyn Informacyjny Ośrodka Badawczo-Rozwojowego Przemysłu Płyt Drewnopochodnych w Czarnej Wodzie

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2009

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tom 49

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nr 3-4

174

7

Productivity of machine timber harvesting at the wind-damaged site

86%

Brzozko J., Szereszewiec B., Szereszewiec E.

Annals of Warsaw University of Life Sciences - SGGW. Agriculture

|

2009

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nr 54 Agric.Forest Eng.

41-49

8

Limitations and barriers to the development of forest firms providing timber harvesting and transport services in Poland

86%

Paschalis-Jakubowicz P.

Folia Forestalia Polonica. Series A . Forestry

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2007-2008

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tom 49-50

Compared with EU countries, Polish forestry features one of the highest proportions of forests under state ownership reaching nearly 80% of the country’s forested area. At the same time, all the operations related to timber harvest and transports are performed by private contractors. The private contractors have no development strategies. This is caused by a number of factors, such as economic, environmental and social, as well as lack of competition on the services market. Unit rates of 4.4 EUR/hour. to 4.9 EUR/hour for harvesting operations and 4.2 EUR/hour to 4.6 EUR/hour for timber skidding differ significantly from those in European Union states reaching for some operations 10–20% of the rates applied in Sweden or Germany. The low fees and the high costs of equipment purchase and use, as well as the difficulties in ensuring an adequately large and stable scope of work are the barrier in the development of service firms.

9

Effect of labour organisation on the level of energy expenditure and static loads of a worker in intermediate cutting

72%

Stempski W.

Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria

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2009

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tom 08

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nr 2

The aim of the performed experiments was to assess energy expenditure and static loads of the operator of a chain sawing machine harvesting timber in a pine stand intermediate cutting. The investigations included two technological variants. In variant I, all technological operations were carried out by one worker – operator of the chain saw, while in treatment II the operations were carried out by a team of three persons – two operators of chain sawing machines and a helper. The energy expenditure was determined on the basis of measurements of the ventilation of lungs, whereas the static load – using the OWAS method. The determined net unit energy expenditures of the chain saw operators in the experimental variants exceeded 20 kJ•min-1 and differed statistically significantly between one another. With regard to static loads, a greater proportion of positions negatively affecting the muscle-skeletal system of the operator were found in variant II.

10

Damage to trees and regeneration layer resulting from timber harvesting with the use of equipment aggregated with farm tractors in thinned pine stands

72%

Stanczykiewicz A., Sowa J. M., Kulak D., Leszczynski K., Szewczyk G.

Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria

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2012

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tom 11

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nr 2

The research was conducted in pine stands where selective early and late thinning was carried out with the use of NIAB 5-15 and HYPRO 450 debranching and cutting processors along with a FRANSGÅRD V-6000 GS cable winch aggregated with farm tractors. In case of cut-to-length system, timber harvesting was executed by means of processors and in case of tree-length system – by means of a cable winch. The harvested timber was forwarded to the depots in the second stage with the use of self-loading trailers or skidded with the use of a cable winch. Tree damage in case of processor technology oscillated at the level of 3.1-11.3%, and in case of a cable winch: 3.0-10.9%. The level of damage to the regeneration layer amounted to 4.1-27.1% for the areas where processors had been used. For the areas where timber was harvested by means of a cable winch, the level of tree damage was 5.2 -14.0% of trees growing under the main stand’s crown layer.

11

Accuracy of the timber estimates in selected mountain forest districts

72%

Poltorak-Kadziolka A.

Zeszyty Naukowe Akademii Rolniczej w Krakowie. Sesja Naukowa

|

2005

|

tom 91

457-461

12

The assessment of the level of energy expenditure of forest workers dislodging trees hang during early thinning

72%

Sowa J. M., Kulak D.

Zeszyty Naukowe Akademii Rolniczej w Krakowie. Sesja Naukowa

|

2005

|

tom 91

367-373

13

Emission of carbon monoxide during work with a power chain saw and a cable winch propelled by a chain saw engine

72%

Sowa J. M., Leszczynski K.

Zeszyty Naukowe Akademii Rolniczej w Krakowie. Sesja Naukowa

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2005

|

tom 91

375-381

14

Structure of the harvester's operation time utilization under conditions of Polish forests

72%

Nurek T.

Annals of Warsaw University of Life Sciences - SGGW. Agriculture

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2013

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nr 62 Agric.Forest Eng.

Achievement of beneficial economic results of timber harvesting with the use of harvesters is greatly determined by appropriate organization of their operation. It is important to find the solutions that could maximally reduce the share of working day phases that are unconnected with production. The carried out simulation calculations enabled to determine the working time structure under most favourable conditions, without preparation of bases and making passages to them and under conditions similar to the real ones. The experiments were executed for various number of tasks; therefore, the effect of passages between bases on working day structure was investigated also. The obtained results showed a very strong effect of mentioned factors working day utilization. In most favourable conditions and 100 tasks, about 50% of total time is taken by operating time that is directly devoted to execution of tasks, while in less favourable conditions and 600 tasks only 5% of time is spent on timber harvesting with the machine; the remaining part of time can be regarded as the lost time.

15

Energy expenditure in some silvicultural works

72%

Grzywinski W.

Electronic Journal of Polish Agricultural Universities. Series: Forestry

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2009

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tom 12

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nr 4

16

Basic parameters of timber harvesting processes in mountain beech stands in Komancza Forest Inspectorate

72%

Sadowski J., Moskalik T., Zastocki D.

Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria

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2012

|

tom 11

|

nr 4

The basic purpose of this study was to determine a working-day structure and work productivity rate during the process of timber harvesting in mountain conditions. The parameters were determined on the ground of data collected during field studies. The aforesaid working-day structure was defined on the ground of time study observations. The areas included in the survey were typically mountain stands, in which cutting was applied by means of a cutting method IVd. Work teams assigned approximately 50-70% of their work-shift time to technological operations, whose greatest part was taken by delimbing and slashing. A significant portion of the day was taken by preparation of a workstand (approx. 10%), as well as cutting and felling. This was caused primarily by the necessity of snow coat removal. Technological work productivity rates amounted to some 3 to 14 m3 per day per one worker. During the skidding process, a significant percentage of trees remaining along the skidding path was being injured. On the ground of the obtained results and their analyses, an attempt was made to evaluate and suggest possible changes in timber harvesting organization, in order to improve work productivity rates.

17

Worker's physical load when harvesting logs on clear cuts

72%

Stempski W.

Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria

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2008

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tom 07

|

nr 3

37-45

18

Analysis of timber harvesting process by means of the long-timber method in the technological variant with measurements of the length and diameter of logs by the chainsaw operator

72%

Stempski W.

Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria

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2012

|

tom 11

|

nr 1

Investigations were carried out in a pine stand 80 years of age, 24 cm average diameter of breast height and 22 m tall. Both long-timber and medium-length assortments 1.8 and 2.4 m long were harvested. The performed analyses comprised: mean duration times at individual activities during operating time, structure of the operation time, as well as labour consumption during this time. The impact of the length and diameter of the harvested long timber on the above-mentioned characteristics of the harvesting process was assessed. Measurements of operation times were taken with the assistance of a stopwatch using the method of continuous timekeeping. Times of the following operations were identified and measured: site preparation, felling, fastening of the self wind-up measuring tape, cutting logs into assortments, measurement, returning to the end of the handled bole, cutting into rollers, walking over to the next tree to be felled. The obtained results of the investigations revealed statistically significant differences of mean duration times and mean shares of some operations in groups of trees of differing length and diameters. In the structure of the operating time, the highest shares were recorded for roller cutting and measurements. It was found that the diameter of the handled long timber exerted the strongest influence on the labour consumption of the harvested timber.

19

Przelom w rosyjskiej gospodarce lesno-drzewnej

72%

W O.

Biuletyn Informacyjny Ośrodka Badawczo-Rozwojowego Przemysłu Płyt Drewnopochodnych w Czarnej Wodzie

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2007

|

tom 47

|

nr 3-4

211-212

20

Energy load of workers employed at timber harvesting

72%

Grzywinski W.

Electronic Journal of Polish Agricultural Universities. Series: Forestry

|

2004

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tom 07

|

nr 2

Ograniczanie wyników

Effectiveness of scots pine longwood timber cut-to-length (CTL) logging

Selected workload elements of the machine operators working in timber harvesting. Ergonomic point of view

Damages to the surface layer of soil during timber harvesting using the equipment aggregated with farm tractors

Planowana wielkosc pozyskiwania drewna na Bialorusi w 2006 r.

Effect of kerf execution correctness during felling with internal combustion chain saw on direction of tree fall

Pozyskanie drewna w Niemczech

Productivity of machine timber harvesting at the wind-damaged site

Limitations and barriers to the development of forest firms providing timber harvesting and transport services in Poland

Effect of labour organisation on the level of energy expenditure and static loads of a worker in intermediate cutting

Damage to trees and regeneration layer resulting from timber harvesting with the use of equipment aggregated with farm tractors in thinned pine stands

Accuracy of the timber estimates in selected mountain forest districts

The assessment of the level of energy expenditure of forest workers dislodging trees hang during early thinning

Emission of carbon monoxide during work with a power chain saw and a cable winch propelled by a chain saw engine

Structure of the harvester's operation time utilization under conditions of Polish forests

Energy expenditure in some silvicultural works

Basic parameters of timber harvesting processes in mountain beech stands in Komancza Forest Inspectorate

Worker's physical load when harvesting logs on clear cuts

Analysis of timber harvesting process by means of the long-timber method in the technological variant with measurements of the length and diameter of logs by the chainsaw operator

Przelom w rosyjskiej gospodarce lesno-drzewnej

Energy load of workers employed at timber harvesting