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Znanstveno-stručno i staleško glasilo
Hrvatskoga šumarskoga društva
Journal of Forestry Society of Croatia
      Prvi puta izašao 1877. godine i neprekidno izlazi do današnjeg dana
   ISSN No.: 0373-1332              UDC 630* https://doi.org/10.31298/sl
upute autorima
WEB EDITION
ARHIVA ČASOPISA


HRČAK


 
ORIGINAL SCIENTIFIC PAPERS
     
Pernar, N., Vukelić, J., Bakšić, D., Baričević, D. UDK 630* 114.4 + 188
An Insight Into Genesis and Properties of Soil in the Riparian Region of North-Eastern Baranja     pdf     HR     EN 223
Krpan, A. P. B., Poršinsky, T. UDK 630* 363
Efficiency of Mechanical Felling and Processing in Soft and Hardwood broadleaved stands – Part 2: Efficiency of harvesters in the culture of soft broadleaf trees     pdf     HR     EN 233
Zečić, Ž., Krpan, A. P. B., Poršinsky, T., Šušnjar, M. UDK 630* 375
Efficiency of tractors 8090 and 9078 in shelterwood fellings of stands in Požega mountains     pdf     HR     EN 245
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
Pilaš, I., Potočić, N. UDK 630* 561 + 116
Depedence of intraseasonal variations of tree stem diameter changes, electrical resistanee of cambial zone and groundwater in common oak stand (Q. robur L.)     pdf     HR     EN 255
Popijač, M., Seletković, I., Volner, M., Lovrenčić, I., Barišić, D., Kezić, N. UDK 630* 160 + 161
Dynamics of 137Cs and 40K Movement in Silver fir Trees on Sljeme Mountain     pdf     HR     EN 269
Posavec, S. UDK 630* 652
Specificy of Bussines Analyses Entities in Managing with Forest and Forest Land     pdf     HR     EN 279
Štorga, D. UDK 630* 582 + 525
Application of GIS in Stand Extraction According to Dendrometric Parameters     pdf     HR     EN 287

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