Cable Skidders

Cable Skidder

Cable skidders are wheeled or tracked machines that use a winch and cable on the rear of the vehicle to gather and skid the logs to the landing (Conway 1976). The skidder operator drives to the woods, parks the machine, and climbs off to pull out the winch line to the load. Using chokers (nooses of chain or wire rope), the operator ties the load to the main winch line. In some cable skidding operations, a chokersetter is employed to pull out the winch line and connect the chokers. Multiple chokers can be attached to the winch line permitting scattered trees or logs to be pulled into a single load from one position. By using the winch, the tractor stays on stable ground while the cable is carried to the load. Cable skidders excel at extracting material from rough terrain, steep ground, or special areas such as riparian zones where traffic is excluded. An additional use of the winch is when the skidder loses traction during skidding. The operator can release the winch cable, drive through the difficult spot without the load, and then pull the load back up to the machine with the winch. When the skidder arrives at the landing with a load, the machine must stop and release the tension on the chokers. Either the operator or a person on the landing must manually unhook the chokers from the load.

Because cable skidders are more efficient than other skidders in scattered timber, they tend to be used with manual felling crews. They are also commonly employed in difficult terrain or where the soil is soft. LeDoux (2000) examined the effect of properly matching skidder size and capability to the treatment. The machines used were a 70 horsepower, 90 horsepower, and a 120 horsepower cable skidders. This study found that the smallest skidder broke even in stands that had an average d.b.h. of 6.6 inches. The medium-sized skidder broke even in stands averaging 8.5 inches d.b.h. And the largest broke even in stands averaging 9.1 inches d.b.h. By matching the optimal sized machine to the appropriate average d.b.h. of a stand, land managers can more economically treat small-diameter material in thinnings.