Browsing by Subject "energiapuuauto"

The use of forest chips has increased rapidly in the past 15 years and the usage must be increased even more in order to achieve the renewable energy usage goals. Forest chips are produced mainly from logging residues and stumps collected from clear cutting areas. One source is also small sized trees harvested from thinning areas. Increasing the use of forest chips could be possible, but the problem are the long transportation distances of the raw material. Most of the wood chip potential is located in Eastern and Central Finland and Kainuu, but the heat and power plants and demand are located by the sea. Transportation costs must be reduced to make usage possible. This was a pioneer study to develop working models for loading energy wood trucks. The aim of this study was to create systematic working models for loading logging residuals and stumps to bioenergy trucks to increase payload. The optimal load weight and its relation to transportation distance was also the point of interest. Twelve operators participated the study and the data was collected in Southern and Eastern Finland between April and September. The data set included 12 stump loads and 11 logging residual loads. The work researcher sat next to the driver, interviewed him about loading techniques and collected information about the loads. The loading events were also recorded by video camera for later performed time and observation studies. To compare the drivers the payloads were weighted. Drivers’ loadings where observed and analyzed with the payload weights and the loading times and as a result four different working models were developed. For stump material two different working models were described by the size of the stump: for small sized stump and normal sized stump. The working model for normal sized stumps was divided into two working models to achieve a large payload and an average payload with minimal loading time. For logging residues only one working model was necessary to describe. Working models consisted of systematic ways of work and different types of compressing methods and tricks. The average loading time towards one ton for stumps was 2.7 minutes and for logging residuals 2.2 minutes. Aiming for large payload is not always the most cost-efficient choice. The operator should consider the transportation distance as well as loading time along with the payload. The longer the driving distance the larger the payload should be. With shorter distances it is optimal to use less time for the loading even tough large payloads will not be achieved and use the spared time for driving of extra loads.