The article is devoted to the improvement of the quality of tree-trunks delimbing by means of time-effective bringing the delimbing knife into an operating position before its contact with the branches. The set goal was achieved by bringing the delimbing knife into the operational mode, parallel to the direction of the tree-trunk feed motion, following the load shift of the pusher beyond the cutting edge. This type of load emerges when the branches press upon the pusher. After the stress is fi nished both mechanisms return to their original position. The described method and the construction of the mechanism provides placement of the delimbing knife in the operational position, thus enhancing the delimbing quality.

Different variants of technological chain can be organized in logging process. Water or land types of transport can be used for transportation of timber. The use of timber landings where wood can be processed also increases the number of multiple variants of technological process. Performance of operations in various natural and production environment differs in productivity and material costs. Production efficiency depends on the choice of technology of logging operations in dynamic natural and production environment. The given research suggests the variant of the grapho-analytical model for solution of the set task. Detailed graphic models of transportation of wood from logging unit to consumer, loading /unloading and processing operations at the intermediate and lower timber landing are developed. They show possible options of technological chains of logging process. Mathematical dependences are shown on the basis of the problem of finding the maximum flow of minimum cost in the suggested dynamic network. They define the conditions for solution of the set problem.

Making managerial decisions when choosing a variant of the technological chain for logging is complicated by the variety of natural and climatic conditions. The climatic features of the periods affect the productivity of technological machines and the cost of implementation. This research suggests using network planning to determine the technological chain of timber land development. The purpose of the research is construction of multi-purpose network models for planning the technological chain of logging operations in various production conditions of forestry enterprises operation. These models are aimed at making it possible to conduct calculations to increase the efficiency of labour, materials, funds, equipment distribution with the maximum reduction in the cost of logged products. As a result of the analysis of possible options for technological chains, several network models for the implementation of logging technological processes have been built.

Background and Purpose: The article is devoted to the reduction of energy consumption necessary for delimbing. Materials and Methods: Branch delimbing method includes feeding the tree trunk through the ring formed by the delimbing knives and simultaneous reciprocator movement of the delimbing knives along the axis of the processed trunk. The distinctive feature of the construction is the presence of the beater unit comprising a pusher and a piston mounted inside a sealed housing. Results: As a result of the suggested construction the force of the beater impact of the delimbing knife is increased. Using this method, the branches are removed not only due to the force generated when the knives come in contact with branches pushed by feed rolls moving the trunk, but also due to extra beater stress affecting the delimbing knife. The use of the aforesaid method and the construction of the mechanism allows to reduce energy consumption necessary for the delimbing process. Conclusions: The design of harvesting and processing head proposed in this article can be used in the design and manufacture of logging machines and mechanisms. The technical solution may be an interesting advance of the delimbing process when processing trees, especially when cutting big branches or when cutting forces are temporarily higher than average force values.

The article offers the technique of choice of rational variants of placing the main skid roads in the forest compartment. This technique allows to reduce the cost of construction of loading points, skid roads and skidding of timber. The method is characterized by complex analysis of the process of logging from multiple disparate cutting areas within boundaries of the forest compartment with existing network of forest roads. The algorithmic graph theory is used in the calculations for solving this problem. The proposed method is recommended for low-volume logging companies who rent plots in limited operational forest areas.