Skidder equipment is used by loggers and forestry departments primarily for the use of moving logs from one location to another. The two types are wheeled and tracked. Wheeled skidders feature an articulated chassis that can handle steep grades and unmanaged terrain that rigid trucks are unable to handle. Tracked skidders feature tracks rather than wheels, and are designed for extreme slopes that a wheeled skidder is unable to navigate. A bonus with tracked skidders is they are excellent to use to create roadways and landings that are often necessary for loggers. Creating a road or landing makes it easier to use wheeled skidders with the track skidders to haul more material at a time.
Skidders are equipped with a grapple, a cable drum, or both, to make loading easy. Grapples typically grabs stems for loading and cable drums feature a skid line to ease stems onto the skidder. Skidders with both will use the grapple to load the stems onto the cable drum and make loading a completely mechanical job.
Grapples are attached to the skidder by way of an arch or a boom. The arch lifts and assists in the positioning of the grapple to pick up a load of one or two logs. Single arches have a set of cylinders to control the position. When in use, the grapple will freely move in a vertical and horizontal arch with ease. Double arches have two arches that have their own independent cylinders for controlling the movement. While one is pinned to the skidder horizontally, the other can work vertically. It does provide more control over the grapple than a single arch. A swing boom looks similar to the arm on a backhoe. The boom allows the grapple to be positioned horizontally, vertically, and laterally. This is a useful tool when picking up logs that are next to the skidder and opens up many ways to dumping the load.