Epsilon Archive for Student Projects

Abstract

This study was made for the Swedish forest company Sveaskog because the sawmills they delivered timber to had noticed a high frequency of bucking splits in their products. Coworker Jim Edström at Sveaskog also wanted to know if there was a big difference between different felling heads. The purpose with this study has been to find out the amount of bucking splits and if there is any felling head brand that did a bigger damage that the others.
The study was made in two steps, where the first part was a literary review to find out results and conclusions in earlier studies. The best measuring method to check bucking splits was the known “trissmetoden”. It gives an excellent amount of data and all the necessary information you need. The second step is to go out in the field and get the data. It was decided the best way was to follow behind the harvester and get samples from different harvester strokes. This way there was no interference in production and data was received from different drivers.
Totally 1680 logs were checked, half butt logs and half middle logs. The result showed that 3,8 % of the butt logs, and 6,8 % of the middle logs had bucking splits. The average length of the splits were 10,2 centimeters and the placement of the split was 6 centimeters from cambium towards the center.
The variation between the performances of different felling heads was poor, and the results were conflicting. The felling head with highest amount of bucking splits of butt logs had a quite good result at middle logs. And the felling head with high amount of bucking splits of middle logs was not that bad at butt logs.