broj: 11-12/2002        pdf (28,5 MB)



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Znanstveno-stručno i staleško glasilo
Hrvatskoga šumarskoga društva
Journal of Forestry Society of Croatia
      Prvi puta izašao 1877. godine i neprekidno izlazi do današnjeg dana
   ISSN No.: 0373-1332              UDC 630* https://doi.org/10.31298/sl
upute autorima
WEB EDITION
ARHIVA ČASOPISA


HRČAK


 
ORIGINAL SCIENTIFIC PAPERS
     
Krpan, A. P. B., Poršinsky, T. UDK 630* 360 + 662 (001)
The Productivity of Timberjack 1070 Harvester in Scotch Pine thinning     pdf     HR     EN 551
Summary: This paper shows the research results of productivity and costs of mechanized felling and processing of wood by harvester Timberjack 1070 in the culture of conifers. The productivity of harvester was determined by time and work study method. Times of felling and processing wood by harvester were broken down into work components. Time consumptions of specific work components were measured by snap-back chronometry method with the record of the whole working day. The data on the size of felled trees and processed assortments were printed from the harvester computer. The collected data were processed by mathematical and statistical methods by use of a PC. The basic unit of analysis was the cut and processed tree.The analysis of work time consumptions of specific work components of felling and processing of wood by harvester showed no dependence between time consumption and size of felled trees. Putting into correlation the consumption of total harvester work time per tree with processed volume of assortment of each tree, the values were calculated of efficiency and productivity of harvester for each tree. The data were investigated by use of regression analysis and equalized by exponential curve with very strong correlation.
The well known effect of the law of piece volume can be easily seen through the dependence of productivity and unit costs of felling and processing of wood by harvester on breast height diameter of felled trees. In felling and processing trees of 10 cm BHD (0.03 m3/tree) the harvester productivity is 2.3 m3/h (EUR 30.24 per m3) and in felling trees of 30 cm BHD (0.63 m3/tree), the harvester productivity is 25.4 m3/h (EUR 2.74 per m3).
This paper also shows the comparison between productivity and unit costs of felling and processing of wood performed by chain saw and harvester depending on breast height diameter of the tree. The data related to machine rate have been taken from FBVA (Austria) database - the calculation of forest machines performance.
In felling and processing wood, the chain saw productivity is lower from 22 % (10 cm BHD) to 16 % (30 cm BHD) in relation to harvester productivity. Unit costs of felling and processing wood by chain saw are lower from 4.8 times (10 cm BHD) to 3.6 times (30 cm BHD) in relation to mechanized felling and processing performed by harvester.

Key words: cost per m3; cut-to-length harvesting method; harvester; productivity
Vučetić, M. UDK 630* 111 + 431 (001)
Weather Conditions and Comparison of the Forest Fire Season 2001 With the Long-term Mean Values     pdf     HR     EN 563
 
PRELIMINARY COMMUNICATION
     
Anić, I., Oršanić, M., Detelić, M. UDK 630* 429 + 231
The Revitalisation of Degraded Forest Ecosystem After the Dieback of Pedunculate Oak - a Case Study in the Kalje Forest     pdf     HR     EN 575
 
REVIEWS
     
Frković, A. UDK 630* 156
On Croatian Deer Antlers     pdf     HR     EN 589
Starčević, T., Dundović, J., Knepr, J. UDK 630* 156 + 180
Forest Ecosystems Under the Circumstances of Separated Managements of Forests and Hunting Areas     pdf     HR     EN 595
Majnarić, D. UDK 630* 156
Bear Management as a Task of State Forestry     pdf     HR     EN 601
Raguž, D., Grubešić, M., Starčević, T. UDK 630* 156 + 945
The Tradition of Educating Forestry Personnel for the Needs of Hunting Management in the Republic of Croatia     pdf     HR     EN 613
Vratarić, P., Tarnaj, I. UDK 630* 156 + 135
Hunting Management in State Forests as Key Factor in the Transfer of Red Deer (Cervus elaphus) and Wild Boar (Sus scrofa) Breeding Stock     pdf     HR     EN 617
 
PROFESSIONAL PAPERS
     
Križaj, D., Vodolšak, M. UDK 630* 156 + 931
Legal Provisions Regulating Game Loss and Damage from Game, and Protection Measures     pdf     HR     EN 623

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