Fuel Consumption of Forwarders in Lowland Forests of Pedunculate Oak

Abstract

background and Purpose: Fuel consumption in timber harvesting operations is significant for both economic and environmental reasons. In economic sense, one significant part of timber harvesting costs is reduced to fuel costs, and in environmental sense 80% to 95% of exhaust emissions and soot particles in forest machinery are in fact associated with fuel consumption. Materials and Methods: The research object was a 6-wheel Valmet 840.2 forwarder and research was conducted in Forest Administration Vinkovci (lowland part of Croatia) during seeding felling in a stand of pedunculate oak and narrow-leafed ash. For the purpose of measuring fuel consumption on the researched forwarder a differential flow device was installed together with FMS (Fleet Management System) which was used for data transfer. results: Fuel consumption is expressed in six different ways concerning: cycle, extraction distance of 100 m, time (hour), load mass (tons), gross load volume (m 3) and product of mass and transporting distance (tkm). Fuel consumption amounted to 0.56 l•tkm-1 during the extracting of logs and 0.78 l•tkm-1 during the extraction of energy wood. The results also show an increasing trend of fuel consumption expressed per ton of transported load with the increase of travelled distance during the extraction. Conclusions: Fuel consumption expressed in l•tkm-1 is the most accurate fuel consumption indicator because it allows a realistic comparison of different types of machines with different loads (t, m 3) at different extracting distances. The higher fuel consumption of an unloaded forwarder compared to a loaded forwarder can be explained with an increased wheel slip of an unloaded forwarder due to reduced traction between wheels and the soil both in the extraction of logs and energy wood.

Evaluation of an HSM 208F 14tone HVT-R2 Forwarder Prototype under Conditions of Steep-Terrain Low-Access Forests

“…This resulted in an estimated fuel consumption of 17.1 l/h, 1.25 l/m 3 and 1.47 l/t. The study of Pandur et al (2018) indicates, for similar conditions in terms of payload and log size, but for an extraction distance of 1.1 km, a fuel consumption of 15.6 l/h, 1.18 l/m 3 and 1.29 l/t reported for flat terrains. Similar figures were found by Danilovic et al (2015) in flat terrain, reaching as much as 1.4 l/m 3 .…”

“…Similar findings apply when comparing to other international studies. For instance, in the study by Tiernan et al (2004), clear felling was carried out on roughly half of the extraction distance and indicated a similar productivity, while Pandur et al (2018) found a productivity of approximately 18 m 3 /h on flat lands, but in their study the log size was higher and the extraction distance was less (about 1.1 km).…”

“…In fact, there are many studies that were developed in various conditions, showing the limits reached for empty and loaded turns in terms of speed. For empty turn, the reported speeds were in the range of 1.6-5 km/h, while for the loaded turn these were much lower, in the range of 2.2-3.7 km/h (Dinev et al 2015, Ghaffaryian et al 2007, Manner et al 2016, Pandur et al 2018, Stankić et al 2012, Williams et al 2016. From this point of view, both the cabin and the transmission system of the tested prototype worked synergistically and very well.…”

Modernization of Harvesting and Processing Head

“…Some feeding wheels are mounted on the griping elements (6), and some on the frame structure to ensure the trunk grip from three sides and feeding the processed tree trunks in the longitudinal direction. The mechanism requires several delimbing knives (7) with tilting axes (8) to grasp the tree trunk parallel the aforesaid longitudinal direction. The device comprises one fixed delimbing knife (9), ensuring branch removal on the side of the tree trunk adjacent to the delimbing head, and a chainsaw (10).…”

“…Many researchers are involved in searching for solutions to improve the structure of the working elements of harvesting machines [2-6] and modern machines working in close connection with them [7][8][9][10][11]. Based on the functional and technological analysis of harvester head, Budnik [12] and Demchuk [13] devise a development matrix, which contains all possible ways for its improvement.…”