Izvorni znanstveni članak
https://doi.org/10.5552/crojfe.2023.1656
Productivity and Working Time Structure of Timber Forwarding in Flatland Thinned Pine Stand with the Use of Farm Tractors
Dariusz Kulak
orcid.org/0000-0001-7425-7990
; University of Agriculture in Krakow Faculty of Forestry Department of Forest Utilization Engineering and Forest Techniques al. 29 Listopada 46 31-425 Kraków POLAND
Grzegorz Szewczyk
; University of Agriculture in Krakow Faculty of Forestry Department of Forest Utilization Engineering and Forest Techniques al. 29 Listopada 46 31-425 Kraków POLAND
Arkadiusz Stańczykiewicz
orcid.org/0000-0003-0554-4499
; University of Agriculture in Krakow Faculty of Forestry Department of Forest Utilization Engineering and Forest Techniques al. 29 Listopada 46 31-425 Kraków POLAND
Sažetak
Farm tractors are very popular in Poland and other European countries. When coupled with
trailers equipped with a crane with a grapple, they are also used, especially in easily accessible,
flat terrain, for timber forwarding in the CTL (Cut-to-Length) method. A comparative analysis
of working time and productivity was performed on two forwarding units, consisting of a
farm tractor Ursus and a Farma trailer with the load capacity of 6 tons, as well as a farm
tractor Valtra Valmet and a Palms trailer with the capacity of 9 tons, which forwarded wood
in a mature pine stand. An analysis was done for 64 work cycles with an average load volume
of 2.1 m3 for the former unit, and 36 cycles with an average load volume of 7.9 m3 for the latter.
The working time structure of both units was similar. During work, tractor operators
spent most time, i.e. over 35%, loading the timber, then travelling with the load and unloading.
The lowest share in the work cycle, around 5%, belonged to travelling without a load and
forwarding. The average forwarding time for the Farma unit amounted to 33 minutes and was
about twice shorter than that for the Palms unit, amounting to 64 minutes. The distance
covered during loaded travel was the only factor that had a significant influence on the duration
of forwarding cycles. The coefficients of correlation between these variables were 0.56–0.76.
The net productivity obtained in the operating time of the Palms unit was 7.5 m3×PMH-1 and
was almost twice as high as that of the Farma unit, i.e. 3.8 m3×PMH-1. For both units multiple
regression models were developed, in which forwarding cycles productivity is calculated based
on the volume of the transported load and the distance of loaded travel.
Ključne riječi
late thinning; forest trailers, forwarding; work cycle time; productivity
Hrčak ID:
290873
URI
Datum izdavanja:
13.1.2023.
Posjeta: 757 *