Original scientific paper
Fuel consumption as an indicator of skidder productivity
Branimir Jovanović
Abstract
This paper presents the results of simultaneous research of fuel consumption and time consumption of a skidder during three types of wood skidding (long roundwood skidding, long roundwood skidding along with stackwood forwarding, stackwood forwarding), aimed at analysing the advantages of fuel consumption as an indicator of productivity. In doing so, the time of wood skidding was divided into the following components or groups of work components: unloaded travel, loaded travel, total travel, gathering travel, cable pulling out, load hooking, load winching, load adjusting, felling site work, load unhooking, load bunching, landing work, and felling site and landing work. Based on simultaneous measurement of time consumption and fuel consumption of the above components of wood skidding, linear regression analysis was used for observing time consumption dependences of individual components of wood skidding and fuel consumption of the skidder depending on: distances of unloaded travel and loaded travel, gathering travel, cable pulling out, load winching and volume of an average piece in the load. Regression analyses show greater dependence of fuel and time consumption of individual components of wood skidding on distances than on the volume of an average piece in the load. The volume of an average piece in the load is significant for the following components: load hooking and unhooking, and load modelling. The comparison of determination coefficients of work components, in which time consumption and fuel consumption were analysed, show in all three types of wood skidding that the correlations between time consumption and fuel consumption in regression equations are the strongest in case of long roundwood skidding, less strong in long roundwood skidding performed together with stackwood forwarding, and they almost disappear in stackwood forwarding. For the purpose of searching for reliable indicators that would give an answer to the key question of this paper, regression analysis was carried out and determination coefficients were established of the dependence of fuel consumption on times of individual components (groups) of wood skidding. The analyses indicate that there are strong correlations between the above values in case of comparison of all the three types of wood skidding, as well as in case of a higher number of work components. However, analyses showed hat time consumption was a more reliable indicator of skidding efficiency than fuel consumption. Along with insufficient sensibility of devices for measuring fuel consumption, the deficiency of fuel consumption as the indicator of efficiency was especially observed in case of a loaded skidder downward travel, as well as during operations depending on the volume of an average piece in the load.
Keywords
skidder; timber extraction; work time; fuel consumption
Hrčak ID:
10032
URI
Publication date:
28.12.2006.
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