Rank distribution of wood removal from forest land

The article is devoted to the problem of modeling the speed of movement of timber trucks in various natural conditions of the Krasnoyarsk Territory. The results were obtained on the basis of multiple observations of the speed of timber trucks on various sections of forest roads. The results presented in the article are based on the selection and analysis of factors that can presumably have any effect on the speed of movement of timber trucks when hauling timber. The article presents the results of creating a multifactorial dependence for calculating the speed of timber transport. The analysis of the quality factor of each of the factors is carried out by the rank distribution of the obtained regularities and by compiling a rating of the conducted field experiments on the multivariate analysis of timber removal. The calculations and modeling were carried out in the CurveExpert-1.40 software environment and the Microsoft Office Excel software package in the RANK environment. Using the CurveExpert-1.40 software environment, the adequacy of the regularities of the rank distributions of the factors of timber removal from the forest area was assessed by the correlation coefficient. As a result, we obtained models of the total and private influence of factors from themselves (monar ratio) by ranks, which were placed before modeling for each factor in the direction of changing the level of their preference for factors from worse to better. When analyzing the quality factor of experiments, all analyzed factors received a correlation coefficient above 0,97, which corresponds to the level of adequacy of the «strongest factor relationship». This made it possible to add up the ranks of all 35 factors and, by the sum of the ranks, reveal the rating in the system of factors. The paper presents the mathematical dependences of rank distributions and graphs constructed from them. As a result of modeling, regression dependences were obtained and the quality factor of the values of the factors used by the authors in the course of production experiments was proved.

Mathematical substantiation of visual clarity indicators of curved segments of a forest automobile road

The paper discusses and analyzes the design parameters of timber transport roads. The possibility of improving the quality of design solutions is associated with taking into account the visual perception of roads, which is ensured by the correct combination of curvilinear sections of the plan and the longitudinal profile of the route of logging highways. A smooth change in the direction of the road in perspective (and in plan) ensures a gradual movement mode and, therefore, increases the efficiency of the timber road. The aim of the work is to consider the combination of curves in plan and profile and analyze their relationship.

Simulating Combined Self-Loading Truck and Semitrailer Truck Transport in the Wood Supply Chain

Forestry faces frequent and severe natural calamities causing high amounts of salvage wood. Especially under mountainous conditions, regional available self-loading truck capacity is often the main limiting factor causing transport capacity bottlenecks. Therefore, innovative logistics strategies are needed to ensure quick transport of high amounts of salvage wood. Consequently, a multi-echelon unimodal transport concept, where timber is synchronously transshipped at a truck terminal with four transshipment lots from self-loading trucks to semitrailers, was modeled by means of a discrete event simulation. The simulation model calculates key performance indicators such as transshipped volumes and costs and support estimations of optimal truck fleet configuration. The results provide cost-optimal truck fleet configurations in terms of the number of self-loading trucks, semitrailers and prime mover trucks for varying transshipment volumes, delivery time to terminal and legal truck payload scenarios. Applying the truck terminal concept considerably decreases the number of self-loading trucks needed to transport the same volume when compared to unimodal wood transport, which is most common under mountainous conditions in Europe. In the majority of delivery time to terminal and terminal transshipment volume scenarios, the number of self-loading trucks was reduced by more than 50%. Increasing the legal gross vehicle weight for timber transport from 44 t up to 50 t reduces the number of self-loading trucks needed by 20% to 38%, depending on the scenario setting. Additionally, less self-loading trucks arriving at the terminal also cuts queuing times and system efficiency increases as transport cost/t is reduced by 6% to 11% depending on the scenario setting. Expanding the truck terminal concept by adding storage capacity as well as varying the number of transshipping lots and also including costs for terminal construction and operations in the economic analyses are promising topics for future studies.

DESIGN FEATURES OF CABLE FORESTRY SYSTEMS ON SOFT PNEUMATIC SUPPORTS

The article presents the results of studies on an alternative type of forest transport based on cable systems equipped with soft pneumatic supports. The relevance of the research is dictated by the fact that currently logging processes are shifting from the most accessible forest areas to hard-to-reach mountain areas with characteristic signs of environmental dependence with the dense presence of water bodies such as rivers, lakes, swamps, which in its turn can also serve as transport corridors to move harvested wood. Based on theoretical and experimental studies, the authors have proposed a technology that allows efficiently and environmentally safe logging in the presence of various hydrological barriers, including swamps. The technological scheme of the use of rope complexes, the construction of a soft pneumatic support of an arch type, as well as a working experimental prototype of this timber transport system are presented. The results of calculations and examples of deformation isopoles are given, which make it possible to evaluate the loads arising in the design of an arch pneumatic support depending on the mass of the cargo held and the air pressure inside the support. LIRA software package was used to simulate the load process. The research results confirmed the possibility of using cable forest transport systems on soft pneumatic supports in the logging process

An approach to the optimal timber transport scheduling

An approach to the optimal timber transport scheduling is described in the paper. A description of this problem is given, a multi-criteria mathematical model is created. It is noted that the problem belongs to the class of General vehicle routing problems (GVRP) associated with the job-shop scheduling. A hybrid algorithm for solving this problem based on the decomposition method using the simplex method and the genetic algorithm is developed. Testing of the proposed approach using real data from wood harvesting enterprises showed its effectiveness. The algorithm was implemented in “Opti-Wood” decision support system for wood harvesting planning and management, developed by Opti-Soft company (Russia).