Time study and skidding capacity of the wheeled skidder Timberjack 450C in Caspian forests

Abstract

This study was carried out in a steep and difficult terrain. Trees were logged downhill to the landing by a wheeled skidder Timberjack 450C. Selection cutting was performed on a 66-hectare tract with an average slope of 30%. The elemental time study method was applied to develop the skidding time predicting model. In this study 43 working cycles were included. The skidding cycle time was mainly affected by skidding distance, winching distance and interaction between skidding distance and slope. The gross and net production rate was 20.51 and 22.93 m<sup>3</sup>/h, respectively. The unit cost considering the gross and net production rate was 6.31 and 6.22 USD/m<sup>3</sup>, respectively.

Replacement of steel cable with synthetic rope in mountain logging operations in Castanea sativa Mill. coppice stands

“…It is important to highlight that the percentage of time spent travelling is lower than in other studies (Behjou et al, 2008;Lotfalian et al, 2011) as the skidding was in fact only a pre-skidding, comprising extraction from stump to the roadside from where a second machine completed the extraction process to the final landing (a wheeled skidder or a forwarder depending on the slope). At the same time, consumption in hooking is longer than in other studies (Behjou et al, 2008;Barari et al, 2011) as we included winching in this work element because the steep terrain made it diff icult to separate the two activities.…”

“…The use of skidders for timber extraction is very common and there have been numerous studies of the productivity of these machines in Europe (Spinelli & Baldini, 1992;Sabo & Porsinsky, 2005;Marence & Kosir, 2008;, America (Kluender & Stokes, 1996;Wang et al, 2004;Spong & Wang, 2008;Becker et al, 2011) and Asia (Behjou et al, 2008;Barari et al, 2011;Lotfalian et al, 2011;Mousavi, 2012).…”

“…In stands where there are steep slopes and trees of large diameters, the skidder is often the most effective machine to use despite a high initial cost (Behjou et al, 2008). In contrast, other studies have suggested that although the adapted tractor has a lower pulling power, its low cost and smaller size are more appropriate for use in sites of particular environmental interest (Huyler & LeDoux, 1991;Spinelli & Baldini, 1992 Traditionally, steel cable has been used for all types of winching in timber harvesting owing to its strength, durability and longevity (Hartter et al, 2006).…”

Shape of skidder productivity function for ground based skidding system in Caspian forests

“…Times and operational variables were measured using a stopwatch and recorded on paper. 1,10 Time and motion studies for the skidding operations were conducted in 6 forest sites. The work cycle for each operation consisted certain elemental functions and factors ( Table 2).…”

“…Information on the productivity, cost and application of harvesting machines is a key component in the evaluation of management plans for the rehabilitation and utilization of Caspian forests. 1 Logging and transporting optimization are becoming key areas for improvement. Improving operational efficiency through better management is one way that the Iranian forest industry can enhance its competitive position.…”