T. Nordfjell
Swedish University of Agricultural Sciences
D. Athanassiadis
Forest Engineering Research Institute of Canada
B. Talbot
The Danish Forest and Landscape Research Institute
Abstract
Forwarder fuel consumption was studied by examining a total of 27 forwarders under field conditions. Three datasets, representing different data acquisition methods, were used. In a field study, time and fuel consumption by work-element of two 20-21 tonne forwarders in final felling were recorded. In a questionnaire survey, daily data concerning fuel consumption, productivity and average extraction distance was provided on 18 forwarders, divided between final felling and thinning. Finally, accounting data on fuel consumption for 11 forwarders were obtained.
In the field study, the fuel consumption varied between 8.3 to 15.7 l/PMH (productive machine hour) for different work elements. The total fuel consumption was 0.28-0.36 l/m3sub (solid under bark) at average extraction distances on 360-412 m for loads of sawlogs and 0.43-0.66 l/m3sub (458-514 m) for loads of pulpwood. 61-62% of that fuel was consumed during loading and driving during loading. The forwarders consumed 0.23-0.38 l/100 m driving and the difference was only 10% with and without load. In the questionnaire survey, the fuel consumption averaged 0.62 l/m3sub (sawlogs and pulpwood, 318 m average extraction distance) for final felling (16-20 tonne forwarders) and 0.92 l/m3sub (644 m) for thinning (11-14 tonnes). An exception was 2.5 tonne forwarders that consumed only 0.35-0.37 l/m3sub (120-180 m). 89% of the extracted volume in the accounting data was from thinnings and the fuel consumption was in average 0.67 l/m3sub (100-200 m) for 9 to11 tonne forwarders.
More difficult terrain conditions, the use of tracks and wheel-chains and one more assortment in the questionnaire survey are the most probable reasons for higher fuel consumption than in the field study. At long extraction distances it is especially important to utilize the maximum load capacity to benefit low fuel consumption on m3 basis.
