Epsilon Archive for Student Projects

Abstract

To regularly remove woody vegetation along the roadside of forest roads is an important part of the road maintenance, since the vegetation binds moisture in the road side and, thus, the removal makes the road drying faster with results in improved bearing capacity. Vegetation removal also makes it easier to upgrade the road by material recycling from the ditch and, moreover, the visibility along the road is maintained.
The aim of the study was to evaluate what type of chain flail is the best and most cost-effective for removal of different kind of woody vegetation along forest roadsides.
Time studies were made on two chain flails when removing woody vegetation in three different classes; easy-, middle- and heavy shrub removal. The studied flails were one light and rather simple flail named Optimal M160 and a heavier and more advanced flail named Slagkraft H210. The removal was made according to Holmen Skogs’ specification and the quality of the cleaning was measured by objective belt inventory.
The productivity was higher with the heavy flail within all cleaning classes. The productivity of the heavy flail in the cleaning classes was; easy 16820 m2/h, middle 10498 m2/h and heavy 3669 m2/h and the corresponding numbers of the light flail was; easy 9439 m2/h, middle 6596 m2/h and heavy 2382 m2/h. According to the cost calculations the heavy flail had the lowest costs for all cleaning classes. However, calculated with the hourly wage that the entrepreneurs was paid during the time study the light flail were cheaper per m2 and per km cleaned road.
The heavy flail gave better quality of the performed work, since the stump height was lower and no residual trees remained after cleaning. The light flail was not adapted for heavy cleaning and left high stumps and residual trees at the heavier cleaning classes, even though some of the study units were recleaned to meet the specification.