Fuel and Time Consumption in Alpine Cable Yarder Operations

Abstract

A survey was conducted on 12 cable yarding operations in northern Italy, with the purpose of determining fuel consumption and time use. The observation unit was the individual operation, intended as all the activities needed to complete the harvesting of a sale (mean = 500 m3 of timber). All teams were equipped with a tower yarder, an excavator-based loader or processor and a truck or a tractor with trailer, if intermediate transportation to a larger roadside landing (two-staging) was required. The crew size was 3 or 4 operators. Time and fuel use were recorded separately for the following tasks: relocation; set up & dismantle; commuting; yarding; processing and/or loading; major delay events. Fuel consumption averaged 5.1 L m−3, of which 2.2 L m−3 was incurred by two-staging. In general, the yarder accounted for less than half the total fuel consumption of the operation: the processor was indeed the main consumer. Relocation had a very small incidence on time and fuel use. Set up and dismantle did not incur significant fuel consumption but occupied a meaningful share of total time (mean = 22%). Commuting also incurred unexpectedly large (and generally neglected) fuel and time use—with means at 13% and 7%, respectively. Technology developments aimed at reducing fuel consumption should target both main consumers: the yarder as well as the excavator-based processor. Significant benefits would also be achieved through improved planning and infrastructure development, aimed at minimizing the need for intermediate transportation (i.e. two-staging).

The Effect of Technological Progress on Yarder Productivity: An Example from the Bulgarian Mountains

“…While this study only focused on productive work time, set-up and dismantle times are also relevant components of cable operations and are expected to be faster for new, optimized machines [6]. Therefore, we compared the predictions obtained from [2] with those produced from a more recent work published in Austria for modern machines in the same class as the Mounty 4000 [7].…”

Logging Residue Assessment in Salvage Logging Areas

“…When the terrain gets steeper, cable yarding is the preferred system, viable also considering salvage logging conditions (Spinelli et al 2022), favouring a higher mechanization level and efficient processing of the full tree at roadside by using excavator-based processor head or by using a processor mounted on a cable tower yarder (Mologni et al 2016). In this case, the entire tree is extracted with the branches and the top, delimbed and cut by the processor head, thus accumulating most of the logging residues at the roadside, in the same area in which the trees are processed.…”