Concept evaluations of three novel forwarders for gentler forest operations. (August 2020)

• Record Type: Journal Article
• Authors: Gelin, Olle; Björheden, Rolf
• Is Part Of: Journal of terramechanics. Volume 90(2020)
• Page Start: 49
• Page End: 57
• Publication Date: 2020-08
• Subjects: Soft soil -- Machine-soil interaction -- Rubber track -- Operator comfort -- Forestry; Trafficability -- Periodicals; Praticabilité (Routes) -- Périodiques; Trafficability; Periodicals; 629.222
• DOI: 10.1016/j.jterra.2020.04.002
• Languages: English
• ISSNs: 0022-4898

Abstract

Highlights: Rubber tracks significantly reduce rut formation, compared to traditional bogie steel tracks. Decreased shearing with rubber tracks saves the reinforcing root layer and withstand rut formation. On normal forest ground, rubber tracks reduced the fuel consumption with 28% vs bogie tracks. The operator exposure to whole-body vibrations was significantly reduced through damped chassis. Abstract: In-terrain transport of wood from sensitive areas with soft soil has always been difficult to perform in without extensive rutting and soil distortion. To carry out logging in wintertime, on frozen ground, is increasingly difficult as prolonged, rainy fall seasons and milder winters have decreased the window of opportunity for such operations. This creates strong demands for forest machines that can master soft soils. Exposure to whole body vibrations is a serious problem for operators of forest machines, which is also related to the machine-ground interaction. Both the soil and operator benefit from damped chassis suspension. Vibrations and soil distortion indicate loss of tractive energy. Instead of moving the machine, energy is lost in deformation of the ground and tractive elements, adding to motion resistance and to machine vibrations. Three recent developments of concept machines with improved soil interaction properties, reducing soil impact and improving operator comfort are presented. Two rubber tracked forwarders and one wheeled pendulum arm machine with active damping have been constructed, tested and analyzed. Results from standardized rutting and vibration tests of the concept machines are presented. Notable improvements regarding soil impact and rutting, operator comfort and fuel consumption were found. Some remaining technical challenges are also discussed.