Modeling Productivity and Costs of Mechanized Tree Length Skidding Operations

Abstract

Skidding operation constitute the entire process of moving felled trees from the stump site to the roadside landing. This operation normally bears substantial amount of the mill delivery costs. Thus, detailed information on productivity and cost is important for planning of cost-effective skidding operation. This study was conducted at Sao hill Forest plantation to quantify productivity and costs of tree length skidding operations. Continuous time study technique using snap-back method was used for time recording. Costs data were obtained from Mufindi Paper Mill logging department. Productivity and costs modeling, were performed using Microsoft excel. The analysis, showed that; the average productivity of the grapple skidder using tree length (TL) ranges between 398.423 m³/hr at a distance of 10 m and 49.862 m³/hr at a distance of 80 m. On the costs analysis, the unit skidding costs tends to increase with an increase of skidding distance (m) from 512.197 TZS/m³ at a distance of 10 m to 4,092.675 TZS/m³ at a distance of 80 m. Based on these findings it is recommended that variables distance and volume are the core factors to consider during planning to enhance efficient and costs effective skidding operation.