DIGITALNA ARHIVA ŠUMARSKOG LISTA
prilagođeno pretraživanje po punom tekstu



ŠUMARSKI LIST 11-12/2002 str. 15     <-- 15 -->        PDF

A. P. B. Krpan, T. Poriinsky: PROIZVODNOST HARVESTERA TIMBERJACK 1070 PRI PROREDI ... Šumarski lis! br. 11-12. CXXV1 (2002). 551-561
Meek , P., 2000: Effect of the commercial thinning in Croatian lowland forests. Master Thesis, Fore-
prescription on the performance of single-grip stry Faculty of Zagreb University, 1-140.
harvesters. For. Eng. Res. Inst. Can. (FERIC), Richardson , R., I. Makkonen , 1994: The perfor-
Pointe-Claire, Que. Advantage Vol. 1 No. 42, 1-2. mance of cut-to-length systems in eastern Cana-


Mellgren , P.O., 1980: Terrain Classification for Ca- da. For. Eng. Res. Inst. Can. (FERIC), Pointenadian
Forestry. Canadian Pulp and Paper Asso- Claire, Que. Tech. Rep. TR-109. 1-16.
ciation, 1-13. Sambo , S. M., 1999: Reduction of trail density in a


Peltola, A., K. Papunen, 2001: The mechanisation partial cut with a cut-to-length system. For. Eng.
of thinning in the Nordic countries. Proceedings Res. Inst. Can. (FERIC), Pointe-Claire, Que.
of International conference "Thinnings: A valua- Tech. Note TN-293. 1-12.
ble forest management tool", September Staff, K. A. G., N.A. Wiksten, 1984: Tree harvest9-
14, 2001, IUFRO Unit 3.09.00 & FERIC & in g Techniques. Martinus Nijhoff/DR W. Junk
Natural Resources Canada & Canadian Forest Publishers, Dodrechts/Boston/Lancaster, pp. 371.
Service, CD. Tufts, R. A., 1997: Productivity and cost of the Pons-


Poršinsky, T, 1996: Forwarder application to wood Se 15-series, cut-to-lenght harvesting system in
transportation in Croatia. Proceedings "Progres- southern pine plantations. Forest Products Jourses
in Forest Operations", Ljubljana, Slovenija, nal 47 (10): 39- 46.
133-141.


Poršinsky,T , 2000: Efficiency factors ofTimberjack
1210 at forwarding the main felling roundwood


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 mVtree) the harvester productivity is 2.3 mVh (EUR 30.24 per m3) and
in felling trees of 30 cm BHD (0.63 mVtree), the harvester productivity is 25.4 m3/h
(EUR 2.74 perm´).


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: cut-to-length harvesting method, harvester, productivity, cost per m3