0695-B4
Ozgur TOPALAK 1 , Sadik Caglar 2 , H. Hulusi Acar 3
In practice wood harvesting is generally carried on under the effects of many variables and uncontrollable factors. In particular, for a woodland growing up on very mountainous and slope areas these variables and factors appear to be more complex, so it is much more difficult to plan and control the systematic works going on such lands.
When the characteristics of some processes used in wood harvesting are considered, the production activities are evaluated in two processes. The first one is "Cutting process" required for cutting down a standing tree and dividing it into logs. The second one is "Transportation Process" involved in moving the logs. After these two basic processes are completed it can be said that from a forest management point of view, wood harvesting has been achieved.
There are also two stages in the transportation of forest products. The first one is to transport the products from the place where it was originally cut down to the main storage area, better known as transportation of wood raw materials from forest compartment, the second one is to transport the products from the stacked or main storage areas to trading storage and factories.
This study on the effects of time and other active factors on the forest transportation of harvested wood raw materials from forest compartments by using different yarding systems (Koller K 300, URUS M III and Gantner USW) took place in Artvin district forests during the summer months. The results of these measurements were discussed. Relationship between the variables and the effects of the variables on working hours were statistically analysed. Regression equations related to the variables were mathematically set up for each work phases. At the end of the transportation of harvested wood materials from the compartments, mean productivity values for the skyline system were determined according to total activity and journey time.
The results of the variable factors affecting the working time sections of different winch skyline systems shown in this study can be used in Artvin district or areas showing the same characteristics. They can also be used for preparing annual production plans and skyline working programs and for monitoring and controlling the plans when applied in the practise.
Extraction is the process of moving trees or logs from the cutting site to a landing or roadside where they will be processed into logs or consolidated into larger loads for transport to processing facility or other final destination. Regardless of the type of logging system used, extraction is difficult, often hazardous operation that can inflict substantial damage on forest ecosystem (Dykstra, Heinrich, 1996).
Forest skylines can be settled between the distances 200-2000 m. and gives minimum harm to forest soil and transporting material. They are mobil or yarder strong transport machines. Forest skylines have different brands. They can make transportation in two directions and they are the machines which can be settled on the field by different combinations properties.
In Turkey, forest skylines came up such as Wyssen, Hinteregger and Baco long-distanced forest skylines after the recommends of FAO in 1960's. In following years, in turn in order the forest skyline's such as Koller K 300 and URUS M III and Gantner long distanced skylines are bought and have arrived todays (Acar, Topalak, 2000).
The forest skyline are being used especially at mountainously Artvin region in Turkey. Initially by the reason of unemployment, it had not demand but presently it has a large demand. Because, it decrease the hardness of work, workers immigration and it has the support of government forest management and being a modern transport vehicle.
While the wood materiel is being transported through the upon sides by the forest skyline that have not need of forest road, the wood material is being transported through the down hill by the long distanced Gantner forest skylines in present with these machines. Transportation and work organization can be done in every two direction as a result of combined workings.
By this study, the operations which have been done by Koller K 300, URUS M III and Gantner at Eastern Black Sea Region in last 10 years are researched and the results of them are evaluated.
In this study, the continuously time measuring technique is used. Obtained measurement of time consumption and observations were evaluated with SPSS Statistical Programme. The most effective work phases were determined for total activity time productivity.
Table 1. Forest enterprise, harvesting area, observed cable crane and tree species
Forest Enterprise |
Harvesting Area |
Yarder |
Tree species |
Ardanuç |
Suluhan |
Koller K 300 |
L, Cs, G |
Şavşat |
Tepebaşı |
URUS M III |
G, L |
Artvin |
Alabalık |
Gantner USW |
G, Kn, L |
Artvin |
Soçidibi |
Gantner USW |
L, G |
Cs: Pinus sylvestris, G: Abies nordmanniana, Kn: Fagus orientalis L: Picea orientalis |
These studies were completed at August-September 2000 in Artvin Region.
Measurement of time consumption and observations, which have tree different yarder, were obtained in different harvesting area. The number of the workers worked in these yarders change between 1 and 5. Transportation can be done in every two direction from uphill to downhill or from downhill to uphill.
Working phases were grouped aspect of human and machine for definition of the journey time. According to this was determined standard time for each yarders
Values of productivity were calculated for each yarder according to the total activity time and the journey time.
Statistical researches were done for determining the relation between the impressed factors which are accepted as independent variables and time consummations which are accepted as dependent variable and for calculating the time consumption by the help of independent variables.
Values of productivity Per hour belong to yarders were given according to the journey time (ST) which was determined with total activity time(yfa) and Refa standard programme (MPM - REFA, 1985).
Table 2. Working conditions belong to forest skyline, values of time and productivity (Caglar, 2002)
Conditions |
Koller K 300 |
URUS M III |
Gantner | |||
Alabalık |
Soçidibi | |||||
Distance of Establishment (m) |
350 |
650 |
1200 |
700 | ||
Number of Support |
- |
1 |
2 |
1 | ||
Terrain Slope (%) |
78 |
49 |
78 |
65 | ||
Main |
Height (m) |
18 |
25 |
35 |
15 | |
Slope (%) |
55 |
41 |
50 |
44 | ||
Transportation Distance |
Hanging (m) |
255 |
130 |
1090 |
635 | |
Onground (m) |
25 |
470 |
10 |
15 | ||
Direction of the lead |
Up to Hill |
Down to Hill | ||||
Kind of Tree (Log) |
L, G, Cs |
G, |
G, Kn L, |
G, | ||
Workers |
Worker, DS + US |
1 + 2 |
2 + 3 |
3 + 2 |
2 + 2 | |
Operatör + Worker |
1 + 0 |
1 + 1 |
1 + 1 |
1 + 1 | ||
Number of Piece (Number /shift) |
1,9 |
3,5 |
2,8 |
3,6 | ||
Number of Shift |
57 |
36 |
63 |
55 | ||
Total Activity Time, (yfa) |
1690 |
2764 |
2737 |
1326 | ||
Shift Time, (ST) |
1539 |
2463 |
2656 |
1274 | ||
Journey Time, (JT ) |
1208 |
1394 |
1442 |
815 | ||
Productivity |
m 3 /Shift |
1,274 |
1,767 |
1,842 |
1,563 | |
yfa (m 3 /hour) |
4,523 |
3,836 |
4,038 |
7,072 | ||
ST (m 3 /hour) |
4,967 |
4,268 |
4,161 |
7,361 | ||
DS: Down Station, US: Up Station., L: Picea, G: Abies, Cs: Pinus, Kn: Fagus |
The most influential work phases are impressing pulling of hook to logs and attaching of loads for Gantner and Koller K 300. The most influential work phase for URUS M III is transportation time.
Symbols in figure 1 are mentioned below :
Figure 1. Rates in total activity time for 1 m 3 (Caglar, 2002).
The treatments applied during wood extraction has materialized under the effects of multiple variables which can modify in current study area. It has been not true to calculate the time values relating to work pieces as average values and to accept them as standard time; because the forest operations have not realized as standard. The calculating of the time values and productivity values as appropriate to exchanging circumstances is necessary so that can be realistic the planning and payment.
Forest skylines had been required for Turkey forestry that have generally steep terrain. But, this machines are used only mountainously regions as Artvin.
Productivity of the forestry skylines used in Turkey are adequate when they work. But, annual productivity are low at these machines. Therefore the work planning had prepared before from the operations.
Generally, URUS M III mobile skylines which can be set up for longer distance. It were found stronger after comparing to Koller K 300.
It is a advantage that Gantner forest skyline can be set up long distances and it is required low road density. But, the setting time for these machines require longer time.
It was productivity and environmentally soun that using of Gantner long distance skyline for both study sites. To shorten total activity time and to prevent the harvesting damages, according to research, applying of skyline is very ideally. If the forest road had been constructed for the extraction of the logs, it would have been no economical, and very harmful for forest ecosystem.
Felling plan and felling direction must be determined during the extraction from compartment and work organization must be done firstly.
Before extraction from compartment by the skylines, the operations should finished on the bottom of tree-stump. The skyline must not be waited for this operations.
The products nearest to skyline should be transported firstly in the corridor. After that 20 m distance from skyline corridor both on the right and on the left should be transported.
The number of workers who do loading and unloading operations should be increased for productivity of the forest skyline. It should be used more choker for the productive of this machines.
Where the machine should be selected very well. The stocked logs on the side of forest road don't obstruct machine's work or should be transported unfortunately by trucks and are loaded by loader.
The staff problem of the skyline operators who used the expensive machines must be solved.
This operators should repaired the skylines winter and should be informed about the skylines when there isn't harvesting.
To shorten hooking time, in addition to normal chokers, it can be an automatic releasing chokers made by Feric in Canada (Lisland, 1998)
It should be chosen the machines can downhill and uphill transport during buying skylines.
It should be exposed the effective to sustainable forestry with increasing the ecological and economic investigations on skylines.
Acar,H.H., Topalak, O., 2000, Comparison of The Forest Skyline Systems for Harvesting in Turkey, XXI. IUFRO World Congress,7-12 August 2000, Poster Abstracts, Vol. 3, 101p.,Kuala Lumpur.
Çağlar. S., 2002, An İnvestigation of The Transport from Compartment with Cable Crane Aspect of Working Productivity in Artvin Region, Kafkas University, Master Thesis, 136p, Artvin.
Dykstra, P.,D., 1996. Heinrich, R. Model Code of Forest Harvesting Practice. FAO Publications. Rome, Italy.
Lisland, T., 1998. Use of Cable Systems On Soft Ground Norway. Proceedings of the Seminar On Environmentally Sound Forest Roads and wood Transport, Sinaia, Romania, 17-22 June 1996, FAO Publications. Rome, Italy.
MPM - REFA, 1985, İş Etüdü Yöntem Bilgisi, Milli Prodüktivite Merkezi Yayınları, 544, 74 s, Ankara.
1 Karadeniz Technical University, Faculty of Forestry, 61080, Trabzon-TURKEY, [email protected],
2 Karadeniz Technical University, Faculty of Forestry, 61080, Trabzon-TURKEY, [email protected],
3 Karadeniz Technical University, Faculty of Forestry, 61080, Trabzon-TURKEY, [email protected]