Assessment of timber extraction distance and skid road network in steep karst terrain

This study aims to define a simple and effective method to calculate skidding distances on steep karst terrain, rich in ground obstacles (stoniness and rockiness) to support decision planning of secondary and primary forest infrastructure network for timber extraction in productive selective cut forests. Variations between geometrical extraction distances and actual distances were highlighted on the operational planning level (i.e., compartment level) through GIS-related calculation models, focusing on cable skidder timber extraction. Automation in defining geometrical and real extraction distances, as well as relative forest openness were achieved by geo-processing workflows in GIS environment. Due to variation of extraction correction factors at the compartment level from a minimum of 1.19 to a maximum of 5.05 in the same management unit, it can be concluded that planning harvesting operations (timber extraction) at operational level should not include the use of correction factors previously obtained for entire terrain (topographical) categories, sub-categories or even management units

Modelling of Downhill Timber Skidding: Bigger Load – Bigger Slope

Skidder mobility during timber extraction is defined by: 1) basic dimensional features of the vehicle, 2) ability to overcome obstacles during movement, 3) traction performance and 4) environmental soundness. Traction performance depends on the ground conditions (soil bearing capacity) and the total effect of all forces on the vehicle. In downhill skidding, the skidder is under great influence of parallel component of forces, adhesion weight and longitudinal terrain slope, which combined result in negative traction force, torque and thrust force. When the horizontal component of rope force is equal to zero i.e. the moment when the weight of the load and resistance to traction are in equilibrium, the slope angle α is a function of load mass distribution factor and skidding resistance factor. This is a »turning point« that can be defined as a critical slope because the load starts to push the vehicle downhill, which results in negative horizontal component of rope force. Depending on skidder Ecotrac 120V dimensional features, centre of gravity, load mass distribution factor, skidding resistance factor of previous research, five different loads were analyzed (1 to 5 tonnes) in order to define the critical slope angle for each of them. Critical slope for downhill skidding of 1 tonne timber is on longitudinal slope of –26%, for 2 tonne timber on –30%, 3 tonne timber on –34%, 4 timber on –38% and for 5 tonne timber on –43% of terrain longitudinal slope. Even though skidding bigger load increases vehicle mobility to even greater slope angles, the most important in downhill skidding, is to avoid blocking of the wheels, which will lead to a complete vehicle slippage and the driver must be constantly aware of that fact. The general recommendation should be that skidding small loads (1 to 3 tonnes) downhill is suitable for smaller longitudinal terrain slopes (up to maximum –34%), while the heavier the load, the further down the slope the skidder can go. The load of 5 tonnes »anchors« the skidder better and therefore it can go on terrain slopes up to –43%, during which less traction force is used (torque is used for braking) and skidder pulls the load by its own weight. It can be concluded that extending the operating range of skidder onto steeper slopes with heavier loads has the potential to decrease harvesting costs and increase productivity

Determination of Optimal Distribution and Transportation Network (Wood Transportation in Iran)

Today, transportation network optimization has become one of the significant aspects of supply chain planning, and even a slight rise in productivity can significantly reduce costs of distribution of wood in the transportation network. In the forest based industry, given that transportation is the main cost of raw wood supply, using transportation planning, distribution should be done in a way so as to minimize the overall wood displacement. Such planning must meet the needs of all demand centers and the distribution supplier points must be used to their full capacity. Accordingly, the present study strived to find an optimal solution for transportation and distribution of raw wood from the main supplier points to small and large centers of wood and paper industries in Iran. This optimization simultaneously focuses on several products and is at the macroeconomic level of the country wood market. To achieve this goal, linear programming – Transportation Simplex Algorithm was used. The results show a significant fall in transportation costs and a more organized wood distribution network than the current situation. This cost reduction can be attributed to decisions about the optimal distribution of wood types, determining transport routes, and opting for the right type of truck supplier based on load tonnage and distance. This plummet in transportation costs plunges the cost of wood and wood products, which will surge competition in the business and will be of interest to manufacturers, distributors, customers and stakeholders in general

Analysis of an existing forest road network

resources needed to plan these improvements, it is important to target these efforts based upon the available information. Previous research based on existing forest compartment and road network data produced the concept of a methodological study of forest accessibility. Six optimisation stages were defined. This paper deals with the first stage – Analysis of the existing primary forest road infrastructure network. This stage analyses the quantity and quality of the existing forest road network. The results of this analysis, obtained by use of Geographic Information System (GIS), help the forest manager to allocate efficiently the resources to specific forest areas. The results of the analysis are based on data that are easily obtained with GIS. The analysis model is sensitive to the situation on the ground and yet easily implemented. GIS measures of skidding distance, skidding costs and desirable accessibility are included in the model. Relative accessibility and forest road network efficiency are two important calculated results. The paper presents a detailed escription of each step of this work stage. The process is demonstrated on two mountainous Management Units within the Forestry Office Opatija, Forest Administration Buzet

Impact of traffic characteristics on forest roads due to forest managemen

Traffic load and transported quantity due to forest management were analysed on the forest roads in the forest district Dragatuš, SE Slovenia. On the basis of timber gravitating to particular sections, the traffic load and transported quantity were calculated for each of seven forest road sections. The cumulative traffic load is the highest on the section connected to the public road and the lowest on the section situated the furthest away from the public road. The cumulative transported quantity is the highest at the connection of the forest road to the public road and the lowest on the section situated the furthest away from the public road. Considering the distance from the public road, the technical elements and the level of maintenance of such forest road could be lower but the basic maintenance should be ensured (draining). Additional non-forestry uses of forest roads could change the described situation