Category :
Article
article id 5477,
category
Article
Martti Saarilahti.
(1992).
Skidding by sulky - a literature study.
Silva Fennica
vol.
26
no.
2
article id 5477.
https://doi.org/10.14214/sf.a15638
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Speed and load sizes presented in three study reports on sulky skidding were compared with estimates based on ergonomic models. Speed and load size estimates were closely correlated with the observed values, when a 400 W energy expenditure of the subject was used. This corresponds to less than half of his submaximal oxygen intake and matches well with the heart rate given in one of the time studies. It seems possible to develop methods for evaluating the work pace/production rate for sulky skidding in varying terrain conditions.
The PDF includes an abstract in Finnish.
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Saarilahti,
E-mail:
ms@mm.unknown
article id 4668,
category
Article
E. E. Stentzel.
(1957).
Forest work science and technics in the German Democratic Republic.
Silva Fennica
no.
90
article id 4668.
https://doi.org/10.14214/sf.a9114
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Forest work is physically hard. However, there are ways to make the work less damaging with right practices and utilization of machines. The article firstly presents the legal and silvicultural requirements for forest work. Then the ways to organize the work and machines used as well as the practical implications are discussed. Different work phases such as felling, skidding and transportation of timber are presented.
The PDG contains a summary in German.
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Stentzel,
E-mail:
es@mm.unknown
article id 4643,
category
Article
Paavo Yli-Vakkuri.
(1954).
Aikatutkimuksia metsäojitusten kivitöistä.
Silva Fennica
no.
84
article id 4643.
https://doi.org/10.14214/sf.a9105
English title:
Time studies on stone work done in forest drainage.
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When ditches are dug in forest drainage, smaller stones are removed by hand, but the larger ones require the use of explosives or stone lifting machinery. Use of explosives have been a more common method for the larger stones. Due to development of detonation methods, it has also been used for smaller stones than earlier.
The investigation was a time study comparing five different stone lifting machines. Time needed for different stages of the work was measured. The stages lasted approximately as long for all of the machines. However, the effectivity of the machines could not be determined, because the stones removed were not similar enough. Stone lifting machine Pekka appeared slightly more effective than the other four machines. It was also easy to assemble, disassemble and move.
The article includes a summary in German.
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Yli-Vakkuri,
E-mail:
py@mm.unknown
article id 4642,
category
Article
Einar Maliniemi.
(1954).
Tilastollinen tutkimus sahapuiden hakkuusta ja ajosta Perä-Pohjolassa.
Silva Fennica
no.
82
article id 4642.
https://doi.org/10.14214/sf.a9103
English title:
Statistical analysis on felling and haulage of sawlogs in Perä-Pohjola in Northern Finland.
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The wages of logging and haulage has been dependent on the decisions of foremen. The aim of this study was to provide better insight on how working conditions in a logging site affect productivity of the work. Six working sites operated by Forest Service, Veitsiluoto Oy and Kemi Oy in the communes of Salla, Muonio and Kolari in Lapland were studied. The forests in the area were mostly Scots pine (Pinus sylvestris L.).
The effect of average volume of the stems, the average daily haulage over distances of various lengths, density of the stand and shape of the stem on effectivity was calculated. The size of the team was of considerable importance to the felling and haulage result in the Northern Finland where the feller assists in loading of the logs. One of the aims of the study was to find out what size of team is most advantageous for each haulage distance. The results show the optimum distance of haulage for teams of different sizes.
The article includes a summary in English.
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Maliniemi,
E-mail:
em@mm.unknown
Category :
Article
article id 7454,
category
Article
English title:
Method of surveying forest labour.
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In Finland the general shortage of labour during the Second World War called attention to employment problems in forestry. After the war the scope widened to include sociological and human maters. The Finnish Rural Labour Force Study deals with the whole rural labour force, not only forest work. Due to the scale of the subject, pilot studies were started by the Institute of Forest Economics at the University of Helsinki and the Central Statistical Office and the Board of Agriculture in 1950. This article describes in detail the methods used in the pilot studies the and main survey.
The aim of the survey was to obtain a reliable picture of three subjects. 1) The labour input of the male rural population during the observation year, its distribution and the seasonal fluctuations in the structure of labour input. 2) The unemployment time of the rural population, the periods underemployment and its seasonal variation. 3) The number of male workers engaged for a shorter or longer period during the year in certain occupation. The paper discusses the different data sources and ways to collect the data either from enterprises or workers. One of the obstacles is the large number of enterprises in agriculture and forestry. Consequently, the total number of people employed in a particular industry, its distribution and the duration of the working season can be estimated only from a sample selected from the population.
The data of the survey is based on a systematic sample, collected by interviews, of the annual round of activity in 1950 of 44,667 men of 15-64 years of age living in Finnish rural communes. The interviews were made in connection with the 1950 census of Finland. The results of the survey are presented in the other articles of Acta Forestalia Fennica issue 63.
The PDF includes a comprehensive summary in English.
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Heikinheimo,
E-mail:
lh@mm.unknown
Category :
Research article
article id 165,
category
Research article
Yrjö Nuutinen,
Kari Väätäinen,
Antti Asikainen,
Robert Prinz,
Jaakko Heinonen.
(2010).
Operational efficiency and damage to sawlogs by feed rollers of the harvester head.
Silva Fennica
vol.
44
no.
1
article id 165.
https://doi.org/10.14214/sf.165
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In mechanical cutting, deep damage caused by feed rollers can reduce the yield of good quality timber for the sawmill and plywood industries. Additionally the feeding and energy efficiency of feed rollers are important for the profitability of harvester cutting. The objectives of this study were to compare the damages to sawlogs, as well as the time and fuel consumption of stem feeding with six different steel feed rollers during the processing of stems using a single grip harvester. This study tested two rollers with big spikes, two rollers with small spikes, one roller with studs in v-angle and one roller with adaptable steel plates in the ring of the roller. A highly detailed, and accurate processing and fuel consumption projection was recorded using the harvester’s automated data collector on a log and stem level. The roller adaptable plate averaged, for unbarked sawlogs, the lowest damages of 3.7 mm. While the damages of the roller with big spikes were the deepest with an average of 7.8 mm. For medium stems, volume of 0.35 m3, the range of differences between the maximum and minimum effective feeding time per roller was 6–19%, which would increase the effective time consumption of cutting by 1–3%. Corresponding differences in fuel consumption during total stem processing were in the range of 7–15%. According to this study it can be concluded that the traditional rollers with spikes were most effective in processing and fuel consumption, but at the same time they caused the deepest damages to the sawlogs. The roller type with adaptable steel plates was the most effective for small stems, additionally it also caused the least damage to the sawlogs.
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Nuutinen,
Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland
E-mail:
yrjo.nuutinen@metla.fi
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Väätäinen,
Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland
E-mail:
kv@nn.fi
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Asikainen,
Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland
E-mail:
aa@nn.fi
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Prinz,
Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland
E-mail:
rp@nn.fi
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Heinonen,
Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland
E-mail:
jh@nn.fi
article id 263,
category
Research article
Aksel Granhus,
Dag Fjeld.
(2008).
Time consumption of planting after partial harvests.
Silva Fennica
vol.
42
no.
1
article id 263.
https://doi.org/10.14214/sf.263
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Partial harvesting combined with underplanting may be a means to reduce the risk of regeneration failure when e.g. unfavourable microclimatic conditions or severe damage by bark-feeding insects may be expected after clear-cutting, and to maintain or establish certain stand structures or tree species mixture. In this study, we performed time studies of manual planting with and without prior site preparation (patch scarification, inverting) in partially harvested stands of Norway spruce (Picea abies (L.) Karst.). The harvest treatments included basal area removals of approx. 35, 45, and 55%, and a patch clear-cut treatment that was assumed to provide the same conditions for planting as conventional clear-cutting. Site preparation had a much larger influence on time consumption plant–1 (main time) than the harvest treatment. The lowest time consumption was found with inverting and the highest without site preparation. The time spent on walking between planting spots increased with decreasing harvest intensity, reflecting a lower density of planted seedlings in the partially harvested stands. A corresponding increase in main time per plant only occurred after site preparation, since the time spent on clearing the planting spot (removal of logging residue and humus) on untreated plots was higher at the higher harvest strengths. The variation in time consumption attributed to the six replicate stands was large and mainly due to the difference among stands planted by different workers.
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Granhus,
Norwegian University of Life Sciences, Dept. of Ecology and Natural Resource Management (INA), P.O.Box 5003, NO-1432 Ås, Norway
E-mail:
aksel.granhus@umb.no
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Fjeld,
Swedish University of Agricultural Sciences, Dept. of Forest Resource Management, SE-901 83 Umeå, Sweden
E-mail:
df@nn.se