Current issue: 54(2)
Under compilation: 54(3)
The 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 m3 h–1 (4.55 tree h–1) in S1 and of 11.374 m3 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) (R2 = 0.89 in S1 and R2 = 0.94 in S2). When productivity is expressed by m3 h–1 the results obtained in the case of power, exponential and linear functions are comparable (R2 = 0.65 to 0.67 in S1 and R2 = 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.
The origins of time study has been in the need to streamline industrial work. One of the differences between industrial and forest work is that in forest work the working conditions are subject to continuous changes. The work is also strenuous, and physical strength may come into its own in addition to skill. For these reasons, the product of a worker per time unit varies in forest work much more than in industrial work.
In industrial time studies, determination of working tempo is, besides measurement of working time, vital when calculating the normal work performance. In the Northern Countries, it has been concluded that it is impossible to determine the working tempo of a forest worker. A so-called comparative time study in which a study is made of the work performances of the same workers at different jobs and in different conditions so that the measured working times are directly comparative. Also, the requirements made for the extension of time study material are considerably greater than in Central European time studies. It is believed that the workers subjected to time studies must be observed for at least a week in each kind of work studied if the results are to be considered reliable.
The Silva Fennica issue 61 was published in honour of professor Eino Saari‘s 60th birthday.
The PDF includes a summary in English.