The technique of optimization of the provisions of attachment points of hydraulic cylinders lifting mechanism, which takes into account, the fact that using standard cylinders with certain minimum and maximum length and stroke, when the distance from the axis of rotation of the boom to the upper hinge cylinder also changes the distance from the axis of rotation of the boom to the lower hinge cylinder. The tests described and tech-nology unit carried out in the areas of protective forest plantations, showed results that match the original requirements, which indicates the effectiveness of the work.

Presented simulation mathematical model of the mechanism of rotation of the column manipulator with energy-saving hydraulic drive. The model takes into account three mechanical process: the rotational movement of the column arm around a vertical axis load sway relative attachment points on the boom arm and the piston motion of fluid accumulator. To describe the rotation of the column using the basic equation of dynamics of rotational motion. The load represented either as a mass point, when the dimen-sions are small and the proportionality, or a rod if the simulated moving manipulator logs or pipes.

Hydrokinetic diagram of the device for chokerless skidding is presented. Chokerless device for logging includes a frame, capture with two jaws and hydraulic cylinder of jaw gripping attached to the hinged system of tractor, linked via a double-hinged capture unit to one end of the bell crank, and between the second end of the bell crank and the frame there is pivotally mounted hydraulic cylinder for additional amortization of oscillations of grapple. The mathematical model of the process of logging trees is made. It includes a differential equation of whips pack and differential equation of motion of the accumulator piston.

New design of energy-efficient, high-speed compact band saw machine for small businesses of agriculture and forestry of forest-deficient steppe and steppe zones of Russia is proposed and justified, providing an increase in the quality and output of business sawn timber for cutting low-quality wood. From domestic and foreign counterparts’ machine differs by simplistic and reliable cutting unit, low power of technological process, capablity of providing high-speed cutting mode, lack of complex electronic circuits, complicating repair and increasing its value.

The analysis of the study of the dynamics of hydraulic drive of forest manipulators shows that work processes of column rotation mechanisms are accompanied by large dyna-mic loads that cause sudden changes of fluid pressure in the start-up and braking modes. The most effective are energy efficient hydro-pneumatic actuators of manipulator column that can recover energy during transient conditions and return some of the energy back into the system. A mathematical model of the operating modes was designed.