Preliminary communication
The Optimization of the Wood Harvesting System by Implementing Teamwork in Thinning Operations in the Grđevačka Bilogora Area
Željko Zečić
; Zavod za šumarske tehnike i tehnologije, Šumarski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Abstract
In wood harvesting, teamwork was for the fi rst time implemented in the area of the Bjelovar Forest Administration in 1979. The paper presents the research of the work of a team of workers recorded during the felling, processing, extraction, scaling and bunching of wood assortments in the spaced stand of deciduous mountain forests. Research was implemented in Grđevačka Bilogora in a team of eight workers (area of the Bjelovar Forest Administration). Felling and processing, tractor skidding, bunching and scaling of wood assortments, and piling of long-meter fi rewood by portable tractor crane on landing site were studied. The team worked in a spaced beech stand aged 62 years. Three fellers, three tractor drivers, one chainsaw operator-registerer and one crane operator form the team, working under the team leader. All team members were synchronically recorded throughout the working hours by using the retroactive method of chronometry. Based on the recorded total time and the eff ect realised, an analysis of time study according to operations and in total was conducted. The structure of eff ective time spent by every team member and of general times was defi ned, and additional time was shaped. Fellers spent 33.15 % (S1E), or rather 39.62 % (S2T) and 26.77 % (S3L) of eff ective out of total working time. Tractors spent 47.27 % (E), or rather 61.94 % (T) and 44.95 % (L) of eff ective out of total time. Chainsaw operator-registerer spent 19.88 %, while crane operator spent 29.64 % of eff ective out of total working time on bunching. The data relating to measured and calculated values have been processed by using mathematical and statistical methods of multiple linear regression. Mathematical models of the calculation of eff ective time were gained; based on this, added the additional time factor, the time norm and the daily performance of every team member were calculated. The time norm of the sub-team consisting of one feller and one tractor depends on the skidding distance. For the distance between 150 m and 650 m, the average time norm of the sub-team ranges between 41.73 min/m3 and 48.30 min/m3. Daily performance per team member may be realised in the amount of 15.88 m3/ day taken the distance ranging between 150 m and 9.88 m3/day, and the skidding distance equalling 650 m. The expense in the team ranges between 53.96 kn/m3 (150 m) and 86.73 kn/m3 (650 m) per product.
Keywords
teamwork; felling and processing; skidding; scaling; bunching; optimal team; productivity; expenses
Hrčak ID:
163201
URI
Publication date:
18.3.2016.
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