Workload analysis in logging technology employing a processor aggregated with a farm tractor

Abstract

<p><em>Aim of study</em><em>: </em>The aim of this research was to analyze the workload of the operators while logging at the motor-manual level in coniferous stands undergoing two tending treatments (early and late thinning). The technologies under the investigation employed a power chainsaw, tractor equipped with a cable winch as well as delimbing and cross-cutting Hypro 450W processor.</p><p><em>Area of study, materials and methods:</em> The research areas were located in lowlands and in a mountain range of the Western Carpathians. In the analysis it was assumed that the heart rate at work, expressed in beats per minute, would be an indicator of the workload affecting the human organism. Based on the heart rate, three indicators were calculated: relative heart rate at work (%HRR), 50% level of heart rate reserve, ratio of working heart rate to resting heart rate.</p><p><em>Main results</em><em>: </em>The lowest average workload (typical for light work, %HRR&lt;20) was recorded for the processor operator in late thinning (%HRR=16), whereas, the highest one (indicating heavy work, %HRR=48.69&gt;40%) was for the chainsaw operator in early thinning, working with a processor. Cumulative distribution function of the workload at the work station of the skidder operator was characterized by bimodality – an occurrence of two extreme, high and low, workload values.</p><p><em>Research highlights:</em> The workload in early thinning was higher by about 7% than in late thinning at the work station of both, the processor operator as well as the chainsaw operator working with a processor.</p><p><strong>Keywords:</strong> logging; tractor processor; heart rate; workload; cardiovascular strain.</p><p> </p>