sustainable forest management in caspian forests of iran requires cost-benefit analysis in order to maintain the quality of timber stands during logging operations. this study was done with the aim of cost and gross revenue computations from current logging (net present value) in three adjacent compartments in district 2 of shafroud watershed. motion and time studies were carried out during fel...

This study examined the influence of turn radius on velocity and energy profiles when skidding and step turning during more and less effective downhill turns while cross-country skiing. Thirteen elite female cross-country skiers performed single turns with a 9- or 12-m radius using the skidding technique and a 12- or 15-m radius with step turning. Mechanical parameters were monitored using a re...

the optimum road spacing has been studied by many researches. it is an important step of forest road network planning. the goals of this study are determining the optimum road spacing in kheiroudkenar forest of nowshahr in northern iran and study of effect of kind of skidder on skidding cost and road spacing. continues time study method was used to determine the production rate of taf and timbe...

skid resistance and road condition are common indices of road safety; therefore providing adequate skidding resistance will reduce the incidence of road accidents. the surface macrotexture has a large effect on the characteristics of road surface skidding, which is the focus of this research. during the study, the mean texture depth of the road surface was measured, in order to determine the co...

Abstract The term “over-skidding” indicates that the cage rotational speed ratio exceeds theoretical value as ball purely rolls on raceway. Different from skidding phenomenon occurs in low-load and high-speed bearing, over-skidding usually large-size angular contact bearings, it is still difficult to suppress under high load conditions. main forms of damage raceway by are spinning gyro slip. To...

The operating hourly cost of the machine is a suitable factor to analyze the cost fluctuation certain machinery in a changing environment and to find of economically feasible work concepts for the studied machine system. This paper, which is based on studies carried out in northern forests of IR-Iran, analyzed and compared costs of four skidding and excavation machines used in timber harvesting...

Beech (Fagus spp.) is one of the most common tree species in Europe and Western Asia. The implementation sustainable forest Operations (SFOs) beech forests therefore crucial terms management. This review summarises state art concerning time-motion studies carried out forests, defining work productivity related costs different harvesting systems applied these stands. main focus recent years on f...

Abstract Intensive forestry operations may cause soil compaction, plastic disturbances and rutting, which are responsible for undesirable effects on soils, vegetation water bodies. Despite the numerous studies aimed to identify main factors affecting damages, it still remains unclear whether wood extraction methods driving direction (uphill or downhill) affect impacts of forest machines. This r...