Productivity and cost of farm tractor skidding

In this study, productivity rate and operation cost of farm tractor were evaluated in a mountainous natural forest. Data for the study came from a detailed time study in the Research and Educational Forest of Tarbiat Modares University (REFTMU) and was used to develop a multiple linear regression model to predict the skidding cycle time. The results showed that effective independent variables of skidding time were skidding distance and slope of skid trail (P = 0.01). Average productivity rate ranged from 2.43 to 2.60 m2.h-1. Total time and effective time, respectively. Total cost of the system was 10.24 USD.h-1 whereas 4.58% of the cost of skidding resulted from personal delay. The cost and productivity resulting from this study emphasized the importance for foresters to consider a farm tractor when designing skidding operations in young stands or prescribing a combination of two machines in mature stands.