EFFICIENCY OF VIMEK 610.2 FORWARDER AND ITS IMPACT ON SOIL IN FOREST THINNING

Effective haulage is one of the main requirements for cost-efficient logging services. The aim of the study is to estimate productivity of Vimek 610.2 forwarder in thinning and to determine soil compaction during haulage. Trials were conducted in Latvia, in 2 forest stands located in northern part of the country, in Engure municipality. The Vimek 610.2 Biocombi harwarder with additional bunk was used as a forwarder in the trials. It was equipped with Mowi P25 crane, tracks on rear axle and net chains on front axle to enhance performance on soils with low bearing capacity. Detailed time study was implemented for 56 forwarder loads. Working time was evaluated according to working cycle of forwarder crane (13 operations in total). Productivity of Vimek 610.2 forwarder and the prime cost of roundwood forwarding under optimal and extreme conditions is determined based on the time study results. According to the results productivity of forwarder Vimek 610.2 in trials with average hauling distance of 181 m, recalculated to productive time consumption spent to forward 1m3 of roundwood under optimal conditions is 6.03 min and under extreme conditions – 6.23 min. In soils with low bearing capacity Vimek 610.2 did not compacted soil, however formation of ruts were observed, and in areas with optimal soil bearing capacity soil compaction was detected at surface layers (down to 10 cm depth). Prime costs of forwarding with Vimek 610.2 under optimal conditions to 180 m distance is 2.46 € m-3, but under extreme conditions – 3.36 € m-3.