Highlights• An important preoccupation in sustainable logging management is represented by the analysis of work time structure and productivity level in manual tree felling with a chainsaw.• Sound knowledge of the factors which influence work time allows better planning of harvesting operations so that deadlines could be met and damage to forest ecosystems be minimized. AbstractThe purpose of this research is to establish time consumption and productivity when using Husqvarna 365 chainsaw for resinous tree felling in mountainous regions. The research was conducted in the Romanian Southern Carpathians, in two mixed spruce (Picea abies (L.) H. Karst.) and fir (Abies alba Mill.) tree stands (S1 and S2). Only one team of workers, made up of a feller and an assistant, was used in the felling operation. This was divided into nine specific stages for which work times were measured. Work time structure used here includes WP -workplace time (PW -productive work time; SW -supportive work time, NT -non-work time) and NW -non-workplace time. The results indicated a productivity of 10.138 m 3 h -1 (4.55 tree h -1 ) in S1 and of 11.374 m 3 h -1 (4.33 tree h -1 ) in S2. Work time structure was WP 88.61% (PW 19.59%; SW 33.88%; NT 35.14%) and NW 11.39% in S1 and WP 83.77% (PW 17.66%; SW 30.73%; NT 35.38%) and NW 16.23% in S2. The results obtained showed that the power function best describes the relationship between productivity expressed by tree h -1 and breast height diameter (dbh) (R 2 = 0.89 in S1 and R 2 = 0.94 in S2). When productivity is expressed by m 3 h -1 the results obtained in the case of power, exponential and linear functions are comparable (R 2 = 0.65 to 0.67 in S1 and R 2 = 0.81 to 0.92 in S2). Productivity is also influenced by stump diameter and the distance between trees. Their influence on productivity was emphasized by linear regression equations.

This research established the time consumption, work time structure, and productivity for primary processing in felling areas of coniferous trees felled with a chainsaw. Delimbing and partial cross-cutting were taken into consideration. The research was conducted in a mixed spruce and fir tree stand situated in the Carpathian Mountains. The team of workers consisted of a chainsaw operator and assistant with over 10 years of experience. The results indicated a total time of 536.32 s•m −3 (1145.26 s•tree −1), work performance (including delays) of 6.716 m 3 •h −1 (3.14 tree•h −1), and work productivity (without delays) of 35.459 m 3 •h −1 (16.58 tree•h −1). The chainsaw productivity during tree cross-cutting was 82.29 cm 2 •s −1. Delimbing accounted for 96.18% of the real work time, while cross-cutting accounted for 3.82%. The time consumption for delimbing and cross-cutting, as well as the work productivity and performance in the primary processing of coniferous trees in the felling area, were influenced by the breast height diameter, stem length, and tree volume, while the chainsaw productivity was influenced by the diameter of the cross-cut sections. The relationships between the aforementioned dependent and independent variables were determined by simple and linear multiple regression equations.

In rural, isolated areas, sawmills are often equipped with one or more small-capacity hand-fed band saws. Even in this situation, the productivity of the band saw must be viewed through the factors that influence it, namely the characteristics of logs and the optimization of the stages and activities carried out. Therefore, time consumption, the structure of working time and the recovery rate in sawing logs into lumber provide important information for users. The structure of the sawing operation for a work team made up of an operator and an assistant was divided into six work stages. The sawing pattern used involves sawing the log up to approximately half of the diameter, then rolling the log with 180° and continuing the sawing, aiming to obtain lumber with a thickness of 40 and 50 mm from the central part of the log. The productivity was 2.45 m3·h−1, the recovery rate was 70.84% and the working time real-use coefficient was 0.37. Research has highlighted the positive correlation between working time and the middle diameter of the logs (R2 = 0.84). The feeding speed was also determined along with the quality of cuts, which was expressed by the thickness uniformity of the lumber and the presence of cutting teeth traces on the newly created surfaces.

Research Highlights: The felling of hung up trees is considered by literature in the field as an activity with a high injury risk. The low work productivity in the felling of hung up trees is wrongly cited by workers in order to justify various more or less safe work techniques. Background and objectives: The purpose of this paper was to determine work productivity in the felling of hung up trees when this activity has a well-defined structure with stages and specific activities that would allow workers to assess injury risk correctly. In addition, this paper aims to identify the moment when workers should give up the manual felling of hung up trees with a hand winch and start using specialized logging equipment. Materials and methods: The research was conducted in the Eastern Carpathians in a spruce (Picea abies (L.) H. Karst.) tree stand where clear cutting normally takes place. A single team of workers was used consisting of two chainsaw operators—a main one and a secondary one. This team had a high level of qualification and experience in the operations performed. For the felling of hung up trees, the technique based on rotating the tree around a pivot with a hand winch was used. Time was measured in seconds by using the continuous time study method. Results: The results indicated that work productivity decreases with the number of times the traction line needs to be repositioned. It decreases from 3.477 trees·h−1 (in trees where no repositioning is necessary) to 1.402 trees·h−1 (when the repositioning takes place twice). In trees that needed the repositioning of the traction line, safety rules were broken in the following ways: crossing over the tensioned cable of the traction line, the main chainsaw operator being positioned inside the triangle formed by the hung up trees and the anchorage points of the pulley and the hand winch as well as the operator being positioned very close to the hung up tree stem base while the latter is being tied. That is why, if the repositioning of the traction line is necessary, the question is—would it be better to give up the manual felling of hung up trees and start using specialized equipment? Conclusion: The felling of hung up trees must be regarded and understood, first and foremost, through the perspective of reducing injury risk and protecting workers. Thus, the work productivity of 3.477 trees·h−1 can be considered acceptable for trees that need no extra repositioning of the traction line or when the time consumed does not go over 17 min·tree−1.