MECHANIZATION IN AGRICULTURE
Forests tractors are inseparable part of a forest economy. Forests tractors serve for logging of logs in forests. Current forests tractors are usually equipped by hydraulic arms, which allow to expand the utility of a tractor. A tractor with a hydraulic arm is able to handle with wood logs without a need additional forest machine, which helps to reduce costs. On the other hand, it is necessary to analyse tractors abilities, which has such an additional equipment. This article is focused on assessment of stability of a forest tractor, which is equipped by such a hydraulic arm. It is a newly designed forest tractor which smaller dimensions, which is intended to be used in conditions with requirements for lower contact pressure and better manoeuvrability. As the hydraulic arm changes the centre of gravity of an entire tractor, mainly with the load, safe operation of the tractor needs to know limit conditions of stability under the maximal load and in the given slope inclination.