What is that bright blue armor wrapped around those skidder tires? They’re called Eco-Wheel Tracks, manufactured by the Swedish company Olofsfors, and they are marketed as helping to improve traction, reduce compaction and rutting, and last longer than traditional tire chains. But do they? Taylor Richmond, a Master’s student at SUNY-ESF, digs into these questions for the WAC Forestry Program.
Eco-Wheel Tracks fit onto skidder tires and their selling points include improved traction, reduced soil compaction and rutting, and longer lifespan in comparison to traditional tire chains. This article even suggests that these tracks may extend tire life. Depending on the tire size, a set of tracks covering all four tires runs between $14,000-19,000. They cost quite a bit more than chains, but with the potential benefits to water quality and the logger’s bottom line, it was a no-brainer that the WAC Forestry Program should get involved with testing the tracks out. Furthermore, no other studies have evaluated the environmental performance and usability of tracks on skidder tires in comparison to chains.
The Heiberg Forest crew’s Timberjack 360 skidder with a brand-new set of Eco-Wheel Tracks. The tracks are available for tire sizes 23.1 x 26, 24.5 x 32, 28L x 26, 30.5 x 32 and 35.5 x 32. Wheel tracks also need 4-5 inches of inside clearance to fit on the machine. There was just enough room between the back wheel flange and the cleats of the tracks on this machine.
This summer, I helped SUNY-ESF graduate student Taylor Richmond and Professor René Germain to complete two controlled field trials at the Heiberg Forest to quantify the effect of wheel cover type (bare tires, chains, and tracks) and increasing traffic (0 to 12 skidder passes) on soil compaction and rutting. Each trial consisted of 12 travel lanes, which represented four replications of the three wheel cover types. The skidder, a Timberjack 360 weighing approximately 10 tons, carried a 2.3-ton concrete block to simulate the weight of a load of logs without scarifying the ground surface.
With increasing levels of traffic, we measured soil mechanical resistance and collected soil samples for bulk density analysis, both of which are measures of soil compaction. We also measured the soil profile to capture changes in rut depth with increasing traffic. In total, each trial represented 144 skidder passes, 936 measurements of mechanical resistance, 192 soil cores for bulk density, and 48 wheel rut transects. With the help of the SUNY-ESF Forest Properties staff, including Ray Bartholomew (skidder operator), Norris Shute (welded our bulk density hammer back to life twice!), and Jill Rahn, we were able to complete the two trials over five days in early June 2020.
Before traffic and after 4, 8, and 12 skidder passes, Taylor Richmond collected soil cores for bulk density analysis from the left, center, and right wheel paths.
Before traffic and after 4, 8, and 12 skidder passes, René Germain used ground profile measurements to capture changes in rut depth. Soil moisture conditions were dry enough that there was little rutting for any of the wheel cover treatments.
This picture series shows the condition of the travel lanes after 12 skidder passes for bare tires (left), chains (middle), and tracks (right).
In addition to the tracks’ environmental performance, we learned about things like ease of installation. For example, the first attempt at putting on one of the tracks took over an hour, but subsequent wheels took about 15 minutes each. The Heiberg Forest crew was really cooking once they enlisted the help of a jack chain tightener tool to secure the tracks to the wheels.
The Eco-Wheel Tracks laid out in the driveway and ready for installation. These tracks come shipped on a pallet weighing 4600 lbs.
Ray (background) and Norris (foreground) used a jack chain tightener tool to move the tracks into position before the final link was secured.
For further background about usability, Taylor has also interviewed other loggers that have been using the tracks for a while now. One logger suggested that it is best to install the tracks with the wheels partially deflated. Then you can re-inflate the tires once the tracks are attached. This helps to ensure that the tracks are tightly secured, which keeps them from slipping on the tire during operation.
Overall, this research project serves as something of a Consumer Reports review of Eco-Wheel Tracks for loggers that may have been considering them for their own operations. If the tracks show evidence of helping to protect forest soils and/or increasing logger economic viability, WAC could consider a cost-share program to promote their use on logging jobs in the NYC Watershed.