Journal of Forest Science (Feb 2012)
Evaluation of full tree skidding by HSM-904 skidder in patch cutting of aspen plantation in Northern Iran
Abstract
This paper presents research results of the performance of HSM-904 grapple skidder using a full tree harvesting method in a non-native aspen Populus deltoides plantation in even terrain conditions in Shafaroud, Northern Iran. Patch cutting as a silvicultural method was used in the plantation (2,000 ha). To evaluate the newly introduced machine to a ground skidding system in the aspen plantation and the possibility to increase the production rate, an empirical time study was conducted. The elements of the skidding work phase were identified and 58 cycles were recorded for the study. The models for effective time consumption, total productivity and work phase models are calculated. The average load per cycle was 2.2 m3, the average one-way skidding distance was 253 m. The average travel speed of unloaded skidder was 5.53 km.h-1 and the average speed of loaded skidder was lower than the speed of the unloaded one by 2.94 km.h-1. The average output in the study was 7.1 m3 per effective hour and the unit cost was 13.9 USD.m-3.
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