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| ŠUMARSKI LIST 5-6/2004 str. 36 <-- 36 --> PDF |
Ž. Zečić, A. P. B. Krpan. T. Porsinsky, M. Šušnjar: DJELOTVORNOST TRAKTORA STEYR 8090 I 9078 ... Šumarski list br. 5-6. CXXV1II (2004). 245-254 SUMMARY: The paper shows research results of some exploitation features of the Steyr 8090 (53. kW) tractor with a one drum farmer winch Tajfun EGV 60 A and the Steyr 9087 (55. kW) tractor with a double drum prototype farmer winch Tajfun 2 x 60 kN, while skidding in mountainous hardwood stands. The one drum winch was remote controlled. Both tractors hauled wood simultaneously from a preparatory and final felling area. The stand for preparatory felling was 91 years old and the final felling stand was 100 years old. The slope on both work sites ranges from 0° to 40°, skidding was done downhill and winching was done uphill or mostly uphill. The tractors moved along skidding lines not entering the stand. The state of skidding lines during extraction is in younger felling areas moist and in older muddy. Technical wood is prepared using an cut-to-lenght method and stacked wood is prepared in the stand as long length. The average length of the assortments ranged from 2.0 to 6.5 m. The mean volume of extracted pieces ranged from 0.28 m3 to 0.36 m3. The effective time of the one drum winch tractor during preparatory felling (A) was 75.45 % and during final felling (B) 63.67 % of the total work time. The same tractor used 45.57 % i. e. 48.45 % of the total time for working in the felling area (loading), while the time used at the auxiliary storage (unloading) was shorter i.e. 19.06 % for preparatory felling and 27.89 % of effective time for final felling. The Steyr 8090 tractor with one drum remote control winch realised an average output of 9.64 m3/day in the preparatory felling stand and 11.32 m3/day in the final felling stand. The average skidding distances were 529 m (A) and 240 m (B), and the average distances of winching were 54. m (A) and 29 m (B). The Steyr 9087 tractor with double drum winch achieved in the preparatory felling stand (C) 76.71 % and in the final felling stand (D) 73.65 % of the effective time. The effective times for loading and unloading in both cases was equal to 1 : 0.52. In the preparatory felling stand the tractor achieved a output of 9.88 m3/day and in the final felling stand 13.75 m3/day. The average skidding distances were 649 m in the preparatory felling stand (C) and 313 m (D) in the final felling stand. The average winching distances were 48 m (C) and 49 m (D). The average speeds of both tractors along skidding lines were similar. The unloaded Steyr 8090 achieves an average speed of 4.31 km/h (A), and 3.99 km/h (B), and a loaded tractor achieves 4.17 km/h (A) and 3.88 km/h (B). The average speeds of the Steyr 9078 are also approximately 4 km/h. The average winching speed for both winches in all four cases was between 1.16 km/h (A) and a maximum of 1.57 km/h (D). The effect of the sloppiness of the terrain and the winch power was very evident. Key words: reproductive felling, farmer cables, Steyr tractors, productivity 254 |