A Comparison of tractor-trailer units and high-speed forwarders used in Alpine Forestry

The introduction of modern forwarders to Alpine forest operations must account for the traditional forwarding units used by local logging contractors. They generally use the same machine for extraction and intermediate off-road transportation on mountain trails, inaccessible to heavy road vehicles. Conventional forwarders are not designed for fast transportation on trail and cannot replace conventional tractor-trailer units. However, new high-speed forwarders could qualify for substitution. CNR set up a long-term follow-up study to determine the use pattern of three conventional tractor-trailer units and three high-speed forwarders. For this purpose, CNR installed commercial Global Positioning System/Global System for Mobile Communications data loggers for continuous real-time collection of the main work data, including position, status, speed and fuel consumption. The study showed that new forwarders could actually travel at a speed higher than 20 km h-1, and they performed both extraction and intermediate transportation. They were capable of independent relocation, which made them suitable for small-scale forestry. Both machine types were used intensively, but the annual usage of forwarders was almost twice as large as that of tractor-trailer units (i.e. 1301 vs. 717 hours per year). Furthermore, forwarders had a 27% higher hourly productivity and a 50% higher fuel consumption per hour, compared with tractor-trailer units.